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Additions to the NASA Aeronautics and Space Database as of 09/14/2009
20090030896 NASA Glenn Research Center, Cleveland, OH, United States
Coupled Thermo-Electro-Magneto-Elastic Response of Smart Stiffened Panels
Bednarcyk, Brett A.; Yarrington, Phillip W.; July 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NCC3-878WBS 645846.02.07.03.03.02
Report No.(s): NASA/CR-2009-215269; E-16540; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090030896
This report documents the procedures developed for incorporating smart laminate and panel analysis capabilities within the HyperSizer aerospace structural sizing software package. HyperSizer analyzes stiffened panels composed of arbitrary composite laminates through stiffener homogenization, or "smearing " techniques. The result is an effective constitutive equation for the stiffened panel that is suitable for use in a full vehicle-scale finite element analysis via MSC/NASTRAN. The existing thermo-elastic capabilities of HyperSizer have herein been extended to include coupled thermo-electro-magneto-elastic analysis capabilities. This represents a significant step toward realization of design tools capable of guiding the development of the next generation of smart aerospace structures. Verification results are presented that compare the developed smart HyperSizer capability with an ABAQUS piezoelectric finite element solution for a facesheet-flange combination. These results show good agreement between HyperSizer and ABAQUS, but highlight a limitation of the HyperSizer formulation in that constant electric field components are assumed.
Author
SMART STRUCTURES; PIEZOELECTRICITY; LAMINATES; APPLICATIONS PROGRAMS (COMPUTERS); HOMOGENIZING
20090030897 NASA Langley Research Center, Hampton, VA, United States
Engine Concept Study for an Advanced Single-Aisle Transport
Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael; Thurman, Douglas R.; August 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.07.13.04
Report No.(s): NASA/TM-2009-215784; L-19712; LF-9138; No Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090030897
The desire for higher engine efficiency has resulted in the evolution of aircraft gas turbine engines from turbojets, to low bypass ratio, first generation turbofans, to today's high bypass ratio turbofans. Although increased bypass ratio has clear benefits in terms of propulsion system metrics such as specific fuel consumption, these benefits may not translate into aircraft system level benefits due to integration penalties. In this study, the design trade space for advanced turbofan engines applied to a single aisle transport (737/A320 class aircraft) is explored. The benefits of increased bypass ratio and associated enabling technologies such as geared fan drive are found to depend on the primary metrics of interest. For example, bypass ratios at which mission fuel consumption is minimized may not require geared fan technology. However, geared fan drive does enable higher bypass ratio designs which result in lower noise. The results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.
Author
AIRCRAFT DESIGN; GAS TURBINE ENGINES; TURBOJET ENGINES; NOISE REDUCTION; ENGINE DESIGN
Additions to the NASA Aeronautics and Space Database as of 09/15/2009
20090030985 NASA Johnson Space Center, Houston, TX, United States
NASA Papilledema Summit Case Presentation #2
Gibson, C. Robert; Duncan, James; July 27, 2009; In English; NASA Papilledema Summit, 27-28 Jul. 2009, Houston, TX, United States; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18653; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090030985
This slide presentation reviews the case of an astronaut who developed Papilledema and Disc Edema after return from the International Space Station (ISS). Included in the presentation is relevant information about the astronaut, the medical history, information about the pre-flight eye exam, a summary of the medical experiences on-board the ISS, and the report on returning to Earth. The ocular findings 5 days after return are described, and the diagnostic studies are reviewed. Views of the fundus (preflight) and 5 days upon return are shown. The MRI is also shown, and the Humphrey 30-2 SITA results are reviewed. Further views of the Fundus from 18, 80, and 225 days following return to earth, and further Humphrey 30-2 SITA results 41 days after return are reviewed. Views of the optic nerve head from 32 days prior to launch, through 225 days following return are shown. Discussion about the causes, pathology, features and the clinical assessment is given. Finally information about the Frisen Grading Scale in respect to grading Papilledema is reviewed.
CASI
EDEMA; EYE (ANATOMY); PATHOLOGY; OPHTHALMOLOGY; EYE DISEASES; CASE HISTORIES; CLINICAL MEDICINE; PHYSIOLOGICAL EFFECTS
20090030986 NASA Langley Research Center, Hampton, VA, United States
Aircraft Flight Envelope Determination using Upset Detection and Physical Modeling Methods
Keller, Jeffrey D.; McKillip, Robert M. Jr.; Kim, Singwan; August 10, 2009; In English; AIAA Guidance, Navigation, and Control Conference, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNX09CE91P; NNL07AA63PWBS 736466.11.01.07.43.17.01
Report No.(s): LF99-9220; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090030986
The development of flight control systems to enhance aircraft safety during periods of vehicle impairment or degraded operations has been the focus of extensive work in recent years. Conditions adversely affecting aircraft flight operations and safety may result from a number of causes, including environmental disturbances, degraded flight operations, and aerodynamic upsets. To enhance the effectiveness of adaptive and envelope limiting controls systems, it is desirable to examine methods for identifying the occurrence of anomalous conditions and for assessing the impact of these conditions on the aircraft operational limits. This paper describes initial work performed toward this end, examining the use of fault detection methods applied to the aircraft for aerodynamic performance degradation identification and model-based methods for envelope prediction. Results are presented in which a model-based fault detection filter is applied to the identification of aircraft control surface and stall departure failures/upsets. This application is supported by a distributed loading aerodynamics formulation for the flight dynamics system reference model. Extensions for estimating the flight envelope due to generalized aerodynamic performance degradation are also described.
Author
ADAPTIVE CONTROL; AIRCRAFT CONTROL; FLIGHT CONTROL; DEGRADATION; CONTROL SYSTEMS DESIGN; AERODYNAMIC CHARACTERISTICS
Additions to the NASA Aeronautics and Space Database as of 09/16/2009
20090031730 Dartmouth Coll., Hanover, NH, United States
Spontaneous Radio Frequency Emissions from Natural Aurora Chapter 4
LaBelle, J.; Characterising the Ionosphere; January 2009; pp. 4-1 - 4-2; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG04WC27G; NNG05GM37G; NNG04WC44G; NSF ATM-0243595; NSF ANT-0442369; NSF ANT-0341050
Copyright; Avail.: CASI: A03, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document
At high latitudes, suitably sensitive radio experiments tuned below 5 MHz detect up to three types of spontaneous radio emissions from the Earth s ionosphere. In recent years, ground-based and rocket-borne experiments have provided strong evidence for theoretical explanations of the generation mechanism of some of these emissions, but others remain unexplained. Achieving a thorough understanding of these ionospheric emissions, accessible to ground-based experiments, will not only bring a deeper understanding of Earth s radio environment and the interactions between waves and particles in the ionosphere but also shed light on similar spontaneous emissions occurring elsewhere in Earth s environment as well as other planetary and stellar atmospheres.
Author
EARTH IONOSPHERE; RADIO FREQUENCIES; STELLAR ATMOSPHERES; ROCKET-BORNE INSTRUMENTS; AURORAS
Additions to the NASA Aeronautics and Space Database as of 09/17/2009
20090031767 NASA Johnson Space Center, Houston, TX, United States; Triakis, Redmond, WA, United States
Automation for System Safety Analysis
Malin, Jane T.; Fleming, Land; Throop, David; Thronesbery, Carroll; Flores, Joshua; Bennett, Ted; Wennberg, Paul; [2009]; In English; NASA OSMA SARP Software Assurance Symposium, 22-23 Sep. 2009, Fairmont, WV, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 724297.50.56.05
Report No.(s): JSC-CN-18753; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031767
This presentation describes work to integrate a set of tools to support early model-based analysis of failures and hazards due to system-software interactions. The tools perform and assist analysts in the following tasks: 1) extract model parts from text for architecture and safety/hazard models; 2) combine the parts with library information to develop the models for visualization and analysis; 3) perform graph analysis and simulation to identify and evaluate possible paths from hazard sources to vulnerable entities and functions, in nominal and anomalous system-software configurations and scenarios; and 4) identify resulting candidate scenarios for software integration testing. There has been significant technical progress in model extraction from Orion program text sources, architecture model derivation (components and connections) and documentation of extraction sources. Models have been derived from Internal Interface Requirements Documents (IIRDs) and FMEA documents. Linguistic text processing is used to extract model parts and relationships, and the Aerospace Ontology also aids automated model development from the extracted information. Visualizations of these models assist analysts in requirements overview and in checking consistency and completeness.
Author
AUTOMATIC CONTROL; SAFETY FACTORS; SYSTEMS ENGINEERING; PROGRAM VERIFICATION (COMPUTERS); FAILURE ANALYSIS; DATA PROCESSING; SAFETY; FAILURE MODES
20090031769 NASA Johnson Space Center, Houston, TX, United States
Unified Communications for Space Inventory Management
Gifford, Kevin K.; Fink, Patrick W.; Barton, Richard; Ngo, Phong H.; [2009]; In English; AIAA Space 2009 Conference and Exposition, 14-17 Sep. 2009, Pasadena, CA, United States; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18761; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031769
To help assure mission success for long-duration exploration activities, NASA is actively pursuing wireless technologies that promote situational awareness and autonomy. Wireless technologies are typically extensible, offer freedom from wire tethers, readily support redundancy, offer potential for decreased wire weight, and can represent dissimilar implementation for increased reliability. In addition, wireless technologies can enable additional situational awareness that otherwise would be infeasible. For example, addition of wired sensors, the need for which might not have been apparent at the outset of a program, night be extremely costly due in part to the necessary routing of cables through the vehicle. RFID, or radio frequency identification, is a wireless technology with the potential for significant savings and increased reliability and safety in space operations. Perhaps the most obvious savings relate to the application of inventory management. A fully automated inventory management system is highly desirable for long-term sustaining operations in space environments. This assertion is evidenced by inventory activities on the International Space Station, which represents the most extensive inventory tracking experience base in the history of space operations. In the short tern, handheld RFID readers offer substantial savings owing to reduced crew time for inventory audits. Over the long term, a combination of improved RFID technology and operational concepts modified to fully utilize the technology should result in space based inventory management that is highly reliable and requires very little crew time. In addition to inventory management, RFID is likely to find space applications in real-time location and tracking systems. These could vary from coarse-resolution RFID portals to the high resolution afforded by ultra-wideband (UWB) RFID. Longer range RFID technologies that leverage passive surface acoustic wave (SAW) devices are being investigated to track assets on a lunar or planetary surface.
Author
INVENTORY MANAGEMENT; TECHNOLOGY UTILIZATION; WIRELESS COMMUNICATION; AUTONOMY; RADIO FREQUENCIES; INTERNATIONAL SPACE STATION
20090031777 National Academy of Sciences - National Research Council, Washington, DC, United States
Ensuring the Climate Record from the NPOESS and GOES-R Spacecraft: Elements of a Strategy to Recover Measurement Capabilities Lost in Program Restructuring
[2008]; In English
Contract(s)/Grant(s): NNH06CE15B; DG133R07SE1940
Report No.(s): PB2009-100247; Copyright; Avail.: CASI: A09, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031777
http://www.nap.edu/catalog/12254.html
In June 2007, the National Research Council (NRC) held a 3-day workshop, Options to Ensure the Climate Record from the NPOESS and GOES-R Spacecraft, in Washington, D.C., to discuss options to recover measurement capabilities, especially those related to climate research, that were lost following a congressionally mandated review completed in June 2006 (Nunn-McCurdy certification) of the NPOESS program and the September 2006 cancellation of the HES sensor on GOES-R. Some 100 scientists and engineers from academia, government, and industry attended the workshop, which gave participants a chance to consider and comment on a mitigation plan developed by NASA-NOAA as well as to explore options that were not included in the NASA-NOAA study. An NRC report on the workshop proceedings was released in prepublication form in September 2007. By design, that report did not present findings or recommendations.
Author
CLIMATE; GOES SATELLITES; POLAR ORBITS; NASA PROGRAMS
20090031802 NASA Johnson Space Center, Houston, TX, United States
Photometric Studies of GEO Debris
Seitzer, Patrick; Cowardin, Heather M.; Barker, Edwin; Abercromby, Kira J.; Foreman, Gary; Horstman, Matt; [2009]; In English; 10th Annual AMOS Conference, 1 - 4 Sep. 2009, Maui, HI, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNJ05HI05CC036-HY00-0100 -ODO
Report No.(s): JSC-CN-18803; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031802
The photometric signature of a debris object can be useful in determining what the physical characteristics of a piece of debris are. We report on optical observations in multiple filters of debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the SMARTS (Small and Medium Aperture Research Telescope System) 0.9-m at CTIO for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 th magnitude that are discovered in the MODEST survey. At this magnitude the distribution of observed angular rates changes significantly from that of brighter objects. There are two objectives: 1. Estimate the orbital distribution of objects selected on the basis of two observational criteria: brightness (magnitude) and angular rates. 2. Obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. What is the faint debris likely to be? In this paper we report on the photometric results. For a sample of 50 objects, more than 90 calibrated sequences of R-B-V-I-R magnitudes have been obtained with the CTIO 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could be that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus the B-R color is a true measure of the surface of the debris piece facing the telescopes for that observation. Any change in color reflects a real change in the debris surface.
Author
GEOSYNCHRONOUS ORBITS; PHOTOMETRY; SPACE DEBRIS; OBSERVATORIES; TELESCOPES
Additions to the NASA Aeronautics and Space Database as of 09/18/2009
20090031829 NASA Dryden Flight Research Center, Edwards, CA, United States
Student Opportunities with NASA
Bird, John J.; Waggoner, Erin R.; July 27, 2009; In English; EAA AireVenture Oshkosh 2009, 27 Jul. - 2 Aug. 2009, Oshkosh, WI, United States; Original contains color illustrations
Report No.(s): DFRC-1043; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031829
The presentation is intended to interest the next generation in joining the NASA workforce and to inspire them to pursue careers in science and technology and with NASA.
Derived from text
EDUCATION; AEROSPACE SCIENCES; TECHNOLOGY UTILIZATION; NASA PROGRAMS
Additions to the NASA Aeronautics and Space Database as of 09/22/2009
20090031882 NASA Johnson Space Center, Houston, TX, United States
The Human in Space: Lesson from ISS
Sams, Clarence F.; August 23, 209; In English; 6th International Space Life Sciences Working Group, 23-25 Aug. 2009, Sonanna, CA, United States; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18779; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090031882
This viewgraph presentation reviews the lessons learned from manned space flight on the International Space Station. The contents include: 1) Overview of space flight effects on crewmembers; 2) General overview of immune system; 3) How does space flight alter immune system? 4) What factors associated with space flight inteact with crewmember immune function and impact health risks? 5) What is the current understanding of space flight effects on the immune system? and 6) Why should NASA be interested in immunology? Why is it significant?
CASI
GENERAL OVERVIEWS; INTERNATIONAL SPACE STATION; LESSONS LEARNED; MANNED SPACE FLIGHT; IMMUNOLOGY
Additions to the NASA Aeronautics and Space Database as of 09/23/2009
20090032005 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Brazed Joints Design and Allowables: Discuss Margins of Safety in Critical Brazed Structures
FLom, Yury; April 26, 2009; In English; IBSC 2009, 26 Apr. 2009, Orlando, FL, United States; Original contains color and black and white illustrations
No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032005
This slide presentation tutorial discusses margins of safety in critical brazed structures. It reviews: (1) the present situation (2) definition of strength (3) margins of safety (4) design allowables (5) mechanical testing (6) failure criteria (7) design flowchart (8) braze gap (9) residual stresses and (10) delayed failures. This presentation addresses the strength of the brazed joints, the methods of mechanical testing, and our ability to evaluate the margins of safety of the brazed joints as it applies to the design of critical and expensive brazed assemblies.
Derived from text
BRAZING; SAFETY; STRUCTURAL FAILURE; METAL BONDING
20090032015 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Use of Fuzzycones for Sun-Only Attitude Determination: THEMIS Becomes ARTEMIS
Hashmall, Joseph A.; Felikson, Denis; Sedlak, Joseph E.; September 28, 2009; In English; 21st International Symposium on Space Flight Dynamics, 28 Sep. - 2 Oct. 2009, Toulouse, France; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG04DA01C
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032015
In order for two THEMIS probes to successfully transition to ARTEMIS it will be necessary to determine attitudes with moderate accuracy using Sun sensor data only. To accomplish this requirement, an implementation of the Fuzzycones maximum likelihood algorithm was developed. The effect of different measurement uncertainty models on Fuzzycones attitude accuracy was investigated and a bin-transition technique was introduced to improve attitude accuracy using data with uniform error distributions. The algorithm was tested with THEMIS data and in simulations. The analysis results show that the attitude requirements can be met using Fuzzycones and data containing two bin-transitions.
Author
ALGORITHMS; MAXIMUM LIKELIHOOD ESTIMATES; SUN; MISSION PLANNING; ATTITUDE (INCLINATION); ORBITAL MANEUVERS; SPACECRAFT GUIDANCE
20090032016 NASA Goddard Space Flight Center, Greenbelt, MD, United States
A Single Conjunction Risk Assessment Metric: the F-Value
Frigm, Ryan Clayton; Newman, Lauri K.; August 09, 2009; In English; 2009 AAS/AIAA Astrodynamics Specialist Conference, 9-13 Aug. 2009, Pittsburgh, PA, United States; Original contains black and white illustrations
Contract(s)/Grant(s): NNG04DA01C
Report No.(s): AAS-09-373; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032016
The Conjunction Assessment Team at NASA Goddard Space Flight Center provides conjunction risk assessment for many NASA robotic missions. These risk assessments are based on several figures of merit, such as miss distance, probability of collision, and orbit determination solution quality. However, these individual metrics do not singly capture the overall risk associated with a conjunction, making it difficult for someone without this complete understanding to take action, such as an avoidance maneuver. The goal of this analysis is to introduce a single risk index metric that can easily convey the level of risk without all of the technical details. The proposed index is called the conjunction "F-value." This paper presents the concept of the F-value and the tuning of the metric for use in routine Conjunction Assessment operations.
Author
ORBIT DETERMINATION; RISK ASSESSMENT; SPACE NAVIGATION; SPACECRAFT CONTROL; PREDICTIONS; SPACECRAFT TRAJECTORIES
20090032018 NASA Goddard Space Flight Center, Greenbelt, MD, United States
RXTE Monitoring of the Anomalous X-ray Pulsar 1E 1048.1-5937: Long-Term Variability and the 2007 March Event
Dib, Rim; Kaspi, Victoria M.; Gavriil, Foris P.; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNG06EO90ARgpin 228738-08
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032018
After three years of no unusual activity, Anomalous X-ray Pulsar 1E 1048.1-5937 reactivated in 2007 March. We report on the detection of a large glitch (deltav/v = 1.63(2) x 10(exp -5)) on 2007 March 26 (MJD 54185.9), contemporaneous with the onset of a pulsed-flux flare, the third flare observed from this source in 10 years of monitoring with the Rossi X-ray Timing Explorer. Additionally, we report on a detailed study of the evolution of the timing properties, the pulsed flux, and the pulse profile of this source as measured by RXTE from 1996 July to 2008 January. In our timing study, we attempted phase coherent timing of all available observations. We show that in 2001, a timing anomaly of uncertain nature occurred near the rise of the first pulsed flux flare; we show that a likely glitch (deltav/v = 2.91(9) x 10(exp -6)) occurred in 2002, near the rise of the second flare, and we present a detailed description of the variations in the spin-down. In our pulsed flux study, we compare the decays of the three flares and discuss changes in the hardness ratio. In our pulse profile study, we show that the profile exhibited large variations near the peak of the first two flares, and several small short-term profile variations during the most recent flare. Finally, we report on the discovery of a small burst 27 days after the peak of the last flare, the fourth burst discovered from this source. We discuss the relationships between the observed properties in the framework of the magnetar model.
Author
PULSARS; X RAY TIMING EXPLORER; X RAYS; STELLAR MODELS; ANOMALIES
20090032023 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Earth Science Missions Engineering Challenges
Marius, Julio L.; August 08, 2009; In English; XVI Congreso Internacional de Ingenier?a El?ctrica, Electr?nica y Sistemas - INTERCON 2009, 8 - 14 Aug. 2009, Arequipa, Peru; Original contains black and white illustrations
No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032023
This presentation gives a general overlook of the engineering efforts that are necessary to meet science mission requirement especially for Earth Science missions. It provides brief overlook of NASA's current missions and future Earth Science missions and the engineering challenges to meet some of the specific science objectives. It also provides, if time permits, a brief summary of two significant weather and climate phenomena in the Southern Hemisphere: El Nino and La Nina, as well as the Ozone depletion over Antarctica that will be of interest to IEEE intercom 2009 conference audience.
Author
OZONE DEPLETION; EARTH SCIENCES; EL NINO; CLIMATE
20090032024 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Evidence for an Intermediate Mass Black Hole in NGC 5408 X-1
Strohmayer, Tod E.; Mushotzky, Richard F.; [2009]; In English; Original contains black and white illustrations
No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032024
We report the discovery with XMM-Newton of correlated spectral and timing behavior in the ultraluminous X-ray source (ULX) NGC 5408 X-1. An approx. 100 ksec pointing with XMM/Newton obtained in January, 2008 reveals a strong 10 mHz QPO in the > 1 keV flux, as well as flat-topped, band limited noise breaking to a power law. The energy spectrum is again dominated by two components, a 0.16 keV thermal disk and a power-law with an index of approx. 2.5. These new measurements, combined with results from our previous January 2006 pointing in which we first detected QPOs, show for the first time in a ULX a pattern of spectral and temporal correlations strongly analogous to that seen in Galactic black hole sources, but at much higher X-ray luminosity and longer characteristic time-scales. We find that the QPO frequency is proportional to the inferred disk flux, while the QPO and broad-band noise amplitude (root mean squared, rms) are inversely proportional to the disk flux. Assuming that QPO frequency scales inversely with black hole mass at a given power-law spectral index we derive mass estimates using the observed QPO frequency - spectral index relations from five stellar-mass black hole systems with dynamical mass constraints. The results from all sources are consistent with a mass range for NGC 5408 X-1 from 1000 - 9000 Stellar mass. We argue that these are conservative limits, and a more likely range is from 2000 - 5000 Stellar mass. Moreover, the recent relation from Gierlinski et al. that relates black hole mass to the strength of variability at high frequencies (above the break in the power spectrum), and the variability plane results of McHardy et al. and Koerding et al., are also suggestive of such a. high mass for NGC 5408 X-1. Importantly, none of the above estimates appears consistent with a black hole mass less than approx. 1000 Stellar mass for NGC 5408 X-1. We argue that these new findings strongly support the conclusion that NGC 5408 X-1 harbors an intermediate mass black hole.
Author
BLACK HOLES (ASTRONOMY); ENERGY SPECTRA; HIGH FREQUENCIES; MEAN SQUARE VALUES; SPECTRAL CORRELATION; STELLAR MASS; X RAY SOURCES; POWER SPECTRA
20090032026 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Chandra Detection of a Parsec Scale Wind in the Broad Line Radio Galaxy 3C 382
Reeves, J. N.; Sambruna, R. M.; Braito, V.; Eracleous, Michael; [2009]; In English; Original contains color illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032026
We present unambiguous evidence for a parsec scale wind in the Broad-Line Radio Galaxy (BLRG) 3C 382, the first radio-loud AGN whereby an outflow has been measured with X-ray grating spectroscopy. A 118 ks Chandra grating (HETG) observation of 3C 382 has revealed the presence of several high ionization absorption lines in the soft X-ray band, from Fe, Ne, Mg and Si. The absorption lines are blue-shifted with respect to the systemic velocity of 3C 382 by -840+/-60 km/s and are resolved by Chandra with a velocity width of sigma = 340+/-70 km/s. The outflow appears to originate from a single zone of gas of column density N(sub H) = 1.3 x 10(exp 21)/sq cm and ionization parameter log(E/erg/cm/s) = 2.45. From the above measurements we calculate that the outflow is observed on parsec scales, within the likely range from 10-1000 pc, i.e., consistent with an origin in the Narrow Line Region. Finally we also discuss the possibility of a much faster (0.1c) outflow component, based on a blue-shifted iron K(alpha) emission line in the Suzaku observation of 3C 382, which could have an origin in an accretion disk wind.
Author
RADIO GALAXIES; X RAY SPECTROSCOPY; IONIZATION; GAS DENSITY; ACCRETION DISKS
20090032027 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Heavy Ion Microbeam- and Broadbeam-Induced Transients in SiGe HBTs
Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Ferlet-Cavrois, Veronique; Baggio, Jacques; Duhamel, Olivier; Moen, Kurt A.; Phillips, Stanley D.; Diestelhorst, Ryan M.; Cressler, John D.; Sutton, Akil K.; Raman, Ashok; Turowski, Marek; Dodd, Paul E.; Alles, Michael L.; Schrimpf, Ronald D.; Marshall, Paul W.; LaBel, Kenneth A.; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): DE-AC04-94AL85000
Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032027
SiGe HBT heavy ion-induced current transients are measured using Sandia National Laboratories microbeam and high- and low-energy broadbeam sources at the Grand Accelerateur National d'Ions Lourds and the University of Jyvaskyla. The data were captured using a custom broadband IC package and real-time digital phosphor oscilloscopes with at least 16 GHz of analog bandwidth. These data provide detailed insight into the effects of ion strike location, range, and LET.
Author
BIPOLAR TRANSISTORS; HETEROJUNCTION DEVICES; BROADBAND; ION CURRENTS; MICROBEAMS; BANDWIDTH
20090032028 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Dynamics and Predictability of Hurricane Humberto (2007) Revealed from Ensemble Analysis and Forecasting
Sippel, Jason A.; Zhang, Fuqing; March 10, 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): N000140410471; N000140910526; ATM-0840651
Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032028
This study uses short-range ensemble forecasts initialized with an Ensemble-Kalman filter to study the dynamics and predictability of Hurricane Humberto, which made landfall along the Texas coast in 2007. Statistical correlation is used to determine why some ensemble members strengthen the incipient low into a hurricane and others do not. It is found that deep moisture and high convective available potential energy (CAPE) are two of the most important factors for the genesis of Humberto. Variations in CAPE result in as much difference (ensemble spread) in the final hurricane intensity as do variations in deep moisture. CAPE differences here are related to the interaction between the cyclone and a nearby front, which tends to stabilize the lower troposphere in the vicinity of the circulation center. This subsequently weakens convection and slows genesis. Eventually the wind-induced surface heat exchange mechanism and differences in landfall time result in even larger ensemble spread. 1
Author
KALMAN FILTERS; HURRICANES; FORECASTING; CYCLONES; CONVECTION; POTENTIAL ENERGY; TROPOSPHERE
20090032029 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Evaluation of TRMM Ground-Validation Radar-Rain Errors Using Rain Gauge Measurements
Wang, Jianxin; Wolff, David B.; April 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): NNG07EJ50C
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032029
Ground-validation (GV) radar-rain products are often utilized for validation of the Tropical Rainfall Measuring Mission (TRMM) spaced-based rain estimates, and hence, quantitative evaluation of the GV radar-rain product error characteristics is vital. This study uses quality-controlled gauge data to compare with TRMM GV radar rain rates in an effort to provide such error characteristics. The results show that significant differences of concurrent radar-gauge rain rates exist at various time scales ranging from 5 min to 1 day, despite lower overall long-term bias. However, the differences between the radar area-averaged rain rates and gauge point rain rates cannot be explained as due to radar error only. The error variance separation method is adapted to partition the variance of radar-gauge differences into the gauge area-point error variance and radar rain estimation error variance. The results provide relatively reliable quantitative uncertainty evaluation of TRMM GV radar rain estimates at various times scales, and are helpful to better understand the differences between measured radar and gauge rain rates. It is envisaged that this study will contribute to better utilization of GV radar rain products to validate versatile spaced-based rain estimates from TRMM, as well as the proposed Global Precipitation Measurement, and other satellites.
Author
PRECIPITATION (METEOROLOGY); TRMM SATELLITE; ERROR ANALYSIS; VARIANCE (STATISTICS); MEASURING INSTRUMENTS; METEOROLOGICAL RADAR; RAIN GAGES; PRECIPITATION MEASUREMENT
20090032030 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Diagnosing the Ice Crystal Enhancement Factor in the Tropics
Zeng, Xiping; Tao, Wei-Kuo; Matsui, Toshihisa; Xie, Shaocheng; Lang, Stephen; Zhang, Minghua; Starr, David O'C; Li, Xiaowen; Simpson, Joanne; June 09, 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): DE-AI02-04ER63755; DE-AI02-09ER64753; DE-AC52-07NA27344
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032030
Recent modeling studies have revealed that ice crystal number concentration is one of the dominant factors in the effect of clouds on radiation. Since the ice crystal enhancement factor and ice nuclei concentration determine the concentration, they are both important in quantifying the contribution of increased ice nuclei to global warming. In this study, long-term cloud-resolving model (CRM) simulations are compared with field observations to estimate the ice crystal enhancement factor in tropical and midlatitudinal clouds, respectively. It is found that the factor in tropical clouds is ~10 3-104 times larger than that of mid-latitudinal ones, which makes physical sense because entrainment and detrainment in the Tropics are much stronger than in middle latitudes. The effect of entrainment/detrainment on the enhancement factor, especially in tropical clouds, suggests that cloud microphysical parameterizations should be coupled with subgrid turbulence parameterizations within CRMs to obtain a more accurate depiction of cloud-radiative forcing.
Author
ATMOSPHERIC MODELS; CLOUDS (METEOROLOGY); GLOBAL WARMING; RADIATION EFFECTS; RADIATIVE FORCING; CLOUD PHYSICS
20090032031 NASA Goddard Space Flight Center, Greenbelt, MD, United States
WRF Simulations of the 20-22 January 2007 Snow Events over Eastern Canada: Comparison with In-Situ and Satellite Observations
Shi, J. J.; Tao, W.-K.; Matsui, T.; Cifelli, R.; Huo, A.; Lang, S.; Tokay, A.; Peters-Lidard, C.; Jackson, G.; Rutledge, S.; Petersen, W.; [2009]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032031
One of the grand challenges of the Global Precipitation Measurement (GPM) mission is to improve cold season precipitation measurements in middle and high latitudes through the use of high-frequency passive microwave radiometry. For this, the Weather Research and Forecasting (WRF) model with the Goddard microphysics scheme is coupled with a satellite data simulation unit (WRF-SDSU) that has been developed to facilitate over-land snowfall retrieval algorithms by providing a virtual cloud library and microwave brightness temperature (Tb) measurements consistent with the GPM Microwave Imager (GMI). This study tested the Goddard cloud microphysics scheme in WRF for two snowstorm events, a lake effect and a synoptic event, that occurred between 20 and 22 January 2007 over the Canadian CloudSAT/CALIPSO Validation Project (C3VP) site in Ontario, Canada. The 24h-accumulated snowfall predicted by the WRF model with the Goddard microphysics was comparable to the observed accumulated snowfall by the ground-based radar for both events. The model correctly predicted the onset and ending of both snow events at the CARE site. WRF simulations capture the basic cloud properties as seen by the ground-based radar and satellite (i.e., CloudSAT, AMSU-B) observations as well as the observed cloud streak organization in the lake event. This latter result reveals that WRF was able to capture the cloud macro-structure reasonably well.
Author
CLOUD PHYSICS; PRECIPITATION MEASUREMENT; MICROWAVE RADIOMETERS; TEMPERATURE MEASUREMENT; SNOWSTORMS; DATA SIMULATION; FORECASTING
20090032034 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Improving the Global Precipitation Record: GPCP Version 2.1
Huffman, George J.; Adler, Robert F.; Bolvin, David t.; Gu, Guojun; [2009]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032034
The GPCP has developed Version 2.1 of its long-term (1979-present) global Satellite-Gauge (SG) data sets to take advantage of the improved GPCC gauge analysis, which is one key input. As well, the OPI estimates used in the pre-SSM/I era have been rescaled to 20 years of the SSM/I-era SG. The monthly, pentad, and daily GPCP products have been entirely reprocessed, continuing to enforce consistency of the submonthly estimates to the monthly. Version 2.1 is close to Version 2, with the global ocean, land, and total values about 0%, 6%, and 2% higher, respectively. The revised long-term global precipitation rate is 2.68 mm/d. The corresponding tropical (25 N-S) increases are 0%, 7%, and 3%. Long-term linear changes in the data tend to be smaller in Version 2.1, but the statistics are sensitive to the threshold for land/ocean separation and use of the pre-SSM/I part of the record.
Author
PRECIPITATION (METEOROLOGY); MEASURING INSTRUMENTS; LAND USE; OCEANS; ESTIMATES
20090032035 NASA Langley Research Center, Hampton, VA, United States
Automation of a Versatile Crane (the LSMS) for Lunar Outpost Construction, Maintenance and Inspection
Doggett, William R.; Roithmayr, Carlos M.; Dorsey, John T.; Jones, Thomas C.; Shen, Haijun; Seywald, Hans; King, Bruce D.; Mikulas, Martin M., Jr.; April 06, 2009; In English; AIAA Infotech@Aerospace Conference and Exhibit, 6-9 Apr. 2009, Seattle, WA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 431731.04.02.04
Report No.(s): LF99-8299; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032035
Devices for lifting, translating and precisely placing payloads are critical for efficient Earth-based construction operations. Both recent and past studies have demonstrated that devices with similar functionality will be needed to support lunar outpost operations. Although several designs have been developed for Earth based applications, these devices lack unique design characteristics necessary for transport to and use on the harsh lunar surface. These design characteristics include: a) lightweight components, b) compact packaging for launch, c) automated deployment, d) simple in-field reconfiguration and repair, and e) support for tele-operated or automated operations. Also, because the cost to transport mass to the lunar surface is very high, the number of devices that can be dedicated to surface operations will be limited. Thus, in contrast to Earth-based construction, where many single-purpose devices dominate a construction site, a lunar outpost will require a limited number of versatile devices that provide operational benefit from initial construction through sustained operations. The first generation test-bed of a new high performance device, the Lunar Surface Manipulation System (LSMS) has been designed, built and field tested. The LSMS has many unique features resulting in a mass efficient solution to payload handling on the lunar surface. Typically, the LSMS device mass is estimated at approximately 3% of the mass of the heaviest payload lifted at the tip, or 1.8 % of the mass of the heaviest mass lifted at the elbow or mid-span of the boom for a high performance variant incorporating advanced structural components. Initial operational capabilities of the LSMS were successfully demonstrated during field tests at Moses Lake, Washington using a tele-operated approach. Joint angle sensors have been developed for the LSMS to improve operator situational awareness. These same sensors provide the necessary information to support fully automated operations, greatly expanding the operational versatility of the LSMS. This paper develops the equations describing the forward and inverse relation between LSMS joint angles and Cartesian coordinates of the LSMS tip. These equations allow a variety of schemes to be used to maneuver the LSMS to optimize the maneuver. One such scheme will be described in detail that eliminates undesirable swinging of the payload at the conclusion of a maneuver, even when the payload is suspended from a passive rigid link. The swinging is undesirable when performing precision maneuvers, such as aligning an object for mating or positioning a camera. Use of the equations described here enables automated control of the LSMS greatly improving its operational versatility.
Author
CRANES; LUNAR SURFACE; CONSTRUCTION; STRUCTURAL DESIGN; DESIGN ANALYSIS; TEST STANDS; DEPLOYMENT; FIELD TESTS
20090032036 NASA Langley Research Center, Hampton, VA, United States
Further Investigations of Gravity Modeling on Surface-Interacting Vehicle Simulations
Madden, Michael M.; August 10, 2009; In English; 2009 AIAA Modeling and Simulation Technology Conference, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 160961.01.02.01
Report No.(s): AIAA Paper 2009-5007; LF99-8357; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032036
A vehicle simulation is "surface-interacting" if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. The dynamics of surface-interacting simulations are influenced by the modeling of gravity. Gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. Both components are functions of position relative to the world s center and that position for a given set of geodetic coordinates (latitude, longitude, and altitude) depends on the world model (world shape and dynamics). Thus, gravity fidelity depends on the fidelities of the gravitation model and the world model and on the interaction of the gravitation and world model. A surface-interacting simulation cannot treat the gravitation separately from the world model. This paper examines the actual performance of different pairs of world and gravitation models (or direct gravity models) on the travel of a subsonic civil transport in level flight under various starting conditions.
Author
SURFACE VEHICLES; GEODETIC COORDINATES; CENTRIFUGAL FORCE; GRAVITATION; SIMULATION
20090032037 NASA Langley Research Center, Hampton, VA, United States
Predictor-Based Model Reference Adaptive Control
Lavretsky, Eugene; Gadient, Ross; Gregory, Irene M.; August 10, 2009; In English; AIAA Guidance, Navigation, and Control Conference (GNC) 2009, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color illustrations
Contract(s)/Grant(s): NNL06AA04BWBS 736422
Report No.(s): LF99-8365; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032037
This paper is devoted to robust, Predictor-based Model Reference Adaptive Control (PMRAC) design. The proposed adaptive system is compared with the now-classical Model Reference Adaptive Control (MRAC) architecture. Simulation examples are presented. Numerical evidence indicates that the proposed PMRAC tracking architecture has better than MRAC transient characteristics. In this paper, we presented a state-predictor based direct adaptive tracking design methodology for multi-input dynamical systems, with partially known dynamics. Efficiency of the design was demonstrated using short period dynamics of an aircraft. Formal proof of the reported PMRAC benefits constitute future research and will be reported elsewhere.
Author
MODEL REFERENCE ADAPTIVE CONTROL; DYNAMICAL SYSTEMS; PROVING
20090032038 NASA Langley Research Center, Hampton, VA, United States
Explosion/Blast Dynamics for Constellation Launch Vehicles Assessment
Baer, Mel; Crawford, Dave; Hickox, Charles; Kipp, Marlin; Hertel, Gene; Morgan, Hal; Ratzel, Arthur; Cragg, Clinton H.; August 2009; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 869021.06.07.02.99
Report No.(s): NASA/TM-2009-215786; NESC-RP-08-43/07-029-E; L-19734; LF99-9287; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032038
An assessment methodology is developed to guide quantitative predictions of adverse physical environments and the subsequent effects on the Ares-1 crew launch vehicle associated with the loss of containment of cryogenic liquid propellants from the upper stage during ascent. Development of the methodology is led by a team at Sandia National Laboratories (SNL) with guidance and support from a number of National Aeronautics and Space Administration (NASA) personnel. The methodology is based on the current Ares-1 design and feasible accident scenarios. These scenarios address containment failure from debris impact or structural response to pressure or blast loading from an external source. Once containment is breached, the envisioned assessment methodology includes predictions for the sequence of physical processes stemming from cryogenic tank failure. The investigative techniques, analysis paths, and numerical simulations that comprise the proposed methodology are summarized and appropriate simulation software is identified in this report.
Author
ARES 1 LAUNCH VEHICLE; CRYOGENIC ROCKET PROPELLANTS; COMPUTERIZED SIMULATION; CONTAINMENT; SPACECREWS; LIQUID ROCKET PROPELLANTS; EXPLOSIONS; DEBRIS; CRYOGENICS
20090032041 NASA Johnson Space Center, Houston, TX, United States
Preserving the Near-Earth Space Environment with Green Engineering and Operations
Johnson, Nicholas L.; September 30, 2009; In English; NASA Green Engineering Masters Forum, 30 Sep. - 1 Oct. 2009, San Francisco, CA, United States; Original contains color illustrations
Report No.(s): JSC-CN-18722; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032041
Green engineering and operations are essential to preserving the near-Earth space environment for future generations. The U.S. and the international aerospace community have been proactive in addressing the threat of the increasing orbital debris population and the risks to people and property from reentering debris. NASA has led this activity first by devoting resources to thoroughly understand the technical issues and then by developing effective and acceptable policies and guidelines. NASA also worked closely with the international community to ensure that the US aerospace industry was not placed at an economic disadvantage. In the long term, the removal of large orbital debris will be essential to the sustainability of space operations.
Derived from text
AEROSPACE ENVIRONMENTS; SPACE DEBRIS; EARTH ORBITS; COMMUNICATION SATELLITES; NASA SPACE PROGRAMS
20090032043 NASA Langley Research Center, Hampton, VA, United States
A Future State for NASA Laboratories - Working in the 21st Century
Kegelman, Jerome T.; Harris, Charles E.; Antcliff, Richard R.; Bushnell, Dennis M.; Dwoyer, Douglas L.; July 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 478076.07.15.05
Report No.(s): NASA/TM-2009-215780; LF99-9167; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032043
The name "21 st Century Laboratory" is an emerging concept of how NASA (and the world) will conduct research in the very near future. Our approach is to carefully plan for significant technological changes in products, organization, and society. The NASA mission can be the beneficiary of these changes, provided the Agency prepares for the role of 21st Century laboratories in research and technology development and its deployment in this new age. It has been clear for some time now that the technology revolutions, technology "mega-trends" that we are in the midst of now, all have a common element centered around advanced computational modeling of small scale physics. Whether it is nano technology, bio technology or advanced computational technology, all of these megatrends are converging on science at the very small scale where it is profoundly important to consider the quantum effects at play with physics at that scale. Whether it is the bio-technology creation of "nanites" designed to mimic our immune system or the creation of nanoscale infotechnology devices, allowing an order of magnitude increase in computational capability, all involve quantum physics that serves as the heart of these revolutionary changes.
Author
RESEARCH AND DEVELOPMENT; TECHNOLOGICAL FORECASTING; LABORATORIES
20090032044 NASA Goddard Space Flight Center, Greenbelt, MD, United States
A Contribution by Ice Nuclei to Global Warming
Zeng, Xiping; Tao, Wei-Kuo; Zhang, Minghua; Hou, Arthur Y.; Xie, Shaocheng; Lang, Stephen; Li, Xiaowen; Starr, David O.; Li, Xiaofan; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): W-7405-Eng-48; DE-A102-04ER63755
Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032044
Ice nuclei (IN) significantly affect clouds via supercooled droplets, that in turn modulate atmospheric radiation and thus climate change. Since the IN effect is relatively strong in stratiform clouds but weak in convective ones, the overall effect depends on the ratio of stratiform to convective cloud amount. In this paper, 10 years of TRMM (Tropical Rainfall Measuring Mission) satellite data are analyzed to confirm that stratiform precipitation fraction increases with increasing latitude, which implies that the IN effect is stronger at higher latitudes. To quantitatively evaluate the IN effect versus latitude, large-scale forcing data from ten field campaigns are used to drive a CRM (cloud-resolving model) to generate longterm cloud simulations. As revealed in the simulations, the increase in the net downward radiative flux at the TOA (top of the atmosphere) from doubling the current IN concentrations is larger at higher latitude, which is attributed to the meridional tendency in the stratiform precipitation fraction. Surface warming from doubling the IN concentrations, based on the radiative balance of the globe, is compared with that from anthropogenic COZ . It is found that the former effect is stronger than the latter in middle and high latitudes but not in the Tropics. With regard to the impact of IN on global warming, there are two factors to consider: the radiative effect from increasing the IN concentration and the increase in IN concentration itself. The former relies on cloud ensembles and thus varies mainly with latitude. In contrast, the latter relies on IN sources (e.g., the land surface distribution) and thus varies not only with latitude but also longitude. Global desertification and industrialization provide clues on the geographic variation of the increase in IN concentration since pre-industrial times. Thus, their effect on global warming can be inferred and then be compared with observations. A general match in geographic and seasonal variations between the inferred and observed warming suggests that IN may have contributed positively to global warming over the past decades, especially in middle and high latitudes.
Author
GLOBAL WARMING; ICE NUCLEI; CLOUDS (METEOROLOGY); CLIMATE CHANGE; ATMOSPHERIC MODELS; EARTH SURFACE; CONVECTION
Additions to the NASA Aeronautics and Space Database as of 09/24/2009
20090032049 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Progressive Band Selection
Fisher, Kevin; Chang, Chein-I; August 02, 2009; In English; SPIE Optics and Photonics, 2 - 6 Aug. 2009, San Diego, CA, United States; Original contains black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032049
Progressive band selection (PBS) reduces spectral redundancy without significant loss of information, thereby reducing hyperspectral image data volume and processing time. Used onboard a spacecraft, it can also reduce image downlink time. PBS prioritizes an image's spectral bands according to priority scores that measure their significance to a specific application. Then it uses one of three methods to select an appropriate number of the most useful bands. Key challenges for PBS include selecting an appropriate criterion to generate band priority scores, and determining how many bands should be retained in the reduced image. The image's Virtual Dimensionality (VD), once computed, is a reasonable estimate of the latter. We describe the major design details of PBS and test PBS in a land classification experiment.
Author
IMAGE PROCESSING; SPECTRAL BANDS; PRIORITIES; DATA REDUCTION; DOWNLINKING; CLASSIFICATIONS
20090032050 NASA Goddard Space Flight Center, Greenbelt, MD, United States
It's Not a Big Sky After All: Justification for a Close Approach Prediction and Risk Assessment Process
Newman, Lauri Kraft; Frigm, Ryan; McKinley, David; August 09, 2009; In English; 2009 AAS/AIAA Astrodynamics Specialist Conference, 9 - 13 Aug. 2009, Pittsburgh, PA, United States; Original contains color and black and white illustrations
Report No.(s): AAS 09-369; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032050
There is often skepticism about the need for Conjunction Assessment from mission operators that invest in the "big sky theory", which states that the likelihood of a collision is so small that it can be neglected. On 10 February 2009, the collision between Iridium 3; and Cosmos 2251 provided an indication that this theory is invalid and that a CA process should be considered for all missions. This paper presents statistics of the effect of the Iridium/Cosmos collision on NASA's Earth Science Constellation as well as results of analyses which characterize the debris environment for NASA's robotic missions.
Author
SPACE DEBRIS; EARTH SCIENCES; RISK ASSESSMENT; SPACE MISSIONS; IRIDIUM; UNMANNED SPACECRAFT
20090032051 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Radiative Forcing and Temperature Response to Changes in Urban Albedos and Associated CO2 Offsets
Menon, Surabi; Akbari, Hashem; Mahanama, Sarith; Sednev, Igor; Levinson, Ronnen; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): DE-AC02-05CH11231
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032051
The two main forcings that can counteract to some extent the positive forcings from greenhouse gases from pre-industrial times to present-day are the aerosol and related aerosol-cloud forcings, and the radiative response to changes in surface albedo. Here, we quantify the change in radiative forcing and surface temperature that may be obtained by increasing the albedos of roofs and pavements in urban areas in temperate and tropical regions of the globe. Using the catchment land surface model (the land model coupled to the GEOS-5 Atmospheric General Circulation Model), we quantify the response of the total outgoing (outgoing shortwave+longwave) radiation to urban albedo changes. Globally, the total outgoing radiation increased by 0.5 W/square m and temperature decreased by -0.008 K for an average 0.003 increase in albedo. For the U.S. the total outgoing total radiation increased by 2.3 W/square meter, and temperature decreased by approximately 0.03 K for an average 0.01 increase in albedo. These values are for the boreal summer (Tune-July-August). Based on these forcings, the expected emitted CO2 offset for a plausible 0.25 and 0.15 increase in albedos of roofs and pavements, respectively, for all global urban areas, was found to be approximately 57 Gt CO2 . A more meaningful evaluation of the impacts of urban albedo increases on climate and the expected CO2 offsets would require simulations which better characterizes urban surfaces and represents the full annual cycle.
Author
CARBON DIOXIDE; CITIES; GREENHOUSE EFFECT; RADIATIVE FORCING; SURFACE PROPERTIES; EARTH ALBEDO; ATMOSPHERIC RADIATION
20090032052 NASA Johnson Space Center, Houston, TX, United States
Projectile Density Effects on Shield Performance
Christiansen, Eric L.; Lear, Dana; Lyons, Frankel; Davis, Alan; [2009]; In English; 11th Hypervelocity Impact Symposium, 11 - 15 Apr. 2010, Freiburg, Germany; Original contains color illustrations
Report No.(s): JSC-CN-18674; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032052
In the past, the orbital debris environment was modeled as consisting entirely of aluminum particles. As a consequence, most of the impact test database on spacecraft micro-meteoroid and orbital debris (MMOD) shields, and the resulting ballistic limit equations used to predict shielding performance, has been based on using aluminum projectiles. Recently, data has been collected from returned spacecraft materials and other sources that indicate higher and lower density components of orbital debris also exist. New orbital debris environment models such as ORDEM2008 provide predictions of the fraction of orbital debris in various density bins (high = 7.9 g/cu cm, medium = 2.8 g/cu cm, and low = 0.9-1.1 g/cu cm). This paper describes impact tests to assess the effects of projectile density on the performance capabilities of typical MMOD shields. Updates to shield ballistic limit equations are provided based on results of tests and analysis.
Author
PROJECTILES; SPACE DEBRIS; IMPACT TESTS; METAL PARTICLES; MICROMETEOROIDS; PERFORMANCE PREDICTION
20090032054 NASA Goddard Space Flight Center, Greenbelt, MD, United States
JWST Near-Infrared Detectors: Latest Test Results
Smith, Erin C.; Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Chiao, Meng; Clemons, Brian L.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Greenhouse, Matthew A.; Henegar, Greg; Hill, Robert J.; Johnson, Thomas; Lavaque, Dodolfo J.; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Cheryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Schnurr, Richard; Smith, Miles; Waczynski, Augustyn; August 02, 2009; In English; SPIE Optics + Photonics, 2-6 Aug. 2009, San Diego, CA, United States; Original contains black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032054
The James Webb Space Telescope, an infrared-optimized space telescope being developed by NASA for launch in 2013, will utilize cutting-edge detector technology in its investigation of fundamental questions in astrophysics. JWST's near infrared spectrograph, NIRSpec utilizes two 2048 x 2048 HdCdTe arrays with Sidecar ASIC readout electronics developed by Teledyne to provide spectral coverage from 0.6 microns to 5 microns. We present recent test and calibration results for the NIRSpec flight arrays as well as data processing routines for noise reduction and cosmic ray rejection.
Author
JAMES WEBB SPACE TELESCOPE; NEAR INFRARED RADIATION; SPACEBORNE TELESCOPES; APPLICATION SPECIFIC INTEGRATED CIRCUITS; ASTROPHYSICS
20090032057 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The NASA NEESPI Data Portal: Products, Information, and Services
Shen, Suhung; Leptoukh, Gregory; Loboda, Tatiana; Csiszar, Ivan; Romanov, Peter; Gerasimov, Irina; December 15, 2008; In English; American Geophysical Union 2008 Fall Meeting, 15-19 Dec. 2008, San Francisco, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): NNG06EB68C
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032057
Studies have indicated that land cover and use changes in Northern Eurasia influence global climate system. However, the procedures are not fully understood and it is challenging to understand the interactions between the land changes in this region and the global climate. Having integrated data collections form multiple disciplines are important for studies of climate and environmental changes. Remote sensed and model data are particularly important die to sparse in situ measurements in many Eurasia regions especially in Siberia. The NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) NEESPI data portal has generated infrastructure to provide satellite remote sensing and numerical model data for atmospheric, land surface, and cryosphere. Data searching, subsetting, and downloading functions are available. ONe useful tool is the Web-based online data analysis and visualization system, Giovanni (Goddard Interactive Online Visualization ANd aNalysis Infrastructure), which allows scientists to assess easily the state and dynamics of terrestrial ecosystems in Northern Eurasia and their interactions with global climate system. Recently, we have created a metadata database prototype to expand the NASA NEESPI data portal for providing a venue for NEESPI scientists fo find the desired data easily and leveraging data sharing within NEESPI projects. The database provides product level information. The desired data can be found through navigation and free text search and narrowed down by filtering with a number of constraints. In addition, we have developed a Web Map Service (WMS) prototype to allow access data and images from difference data resources.
Author
EARTH SCIENCES; ECOSYSTEMS; INFORMATION SYSTEMS; METADATA; REMOTE SENSING; CLIMATOLOGY
20090032058 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Thermal and Electrical Conductivity Measurements of CDA 510 Phosphor Bronze
Tuttle, James E.; Canavan, Edgar; DiPirro, Michael; [2009]; In English; Original contains black and white illustrations
No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032058
Many cryogenic systems use electrical cables containing phosphor bronze wire. While phosphor bronze's electrical and thermal conductivity values have been published, there is significant variation among different phosphor bronze formulations. The James Webb Space Telescope (JWST) will use several phosphor bronze wire harnesses containing a specific formulation (CDA 510, annealed temper). The heat conducted into the JWST instrument stage is dominated by these harnesses, and approximately half of the harness conductance is due to the phosphor bronze wires. Since the JWST radiators are expected to just keep the instruments at their operating temperature with limited cooling margin, it is important to know the thermal conductivity of the actual alloy being used. We describe an experiment which measured the electrical and thermal conductivity of this material between 4 and 295 Kelvin.
Author
PHOSPHORS; BRONZES; ELECTRICAL RESISTIVITY; CRYOGENICS; THERMAL CONDUCTIVITY; WIRE; JAMES WEBB SPACE TELESCOPE
20090032059 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Vertical Cloud Climatology During TC4 Derived from High-Altitude Aircraft Merged Lidar and Radar Profiles
Hlavka, Dennis; Tian, Lin; Hart, William; Li, Lihua; McGill, Matthew; Heymsfield, Gerald; [2009]; In English; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032059
Aircraft lidar works by shooting laser pulses toward the earth and recording the return time and intensity of any of the light returning to the aircraft after scattering off atmospheric particles and/or the Earth s surface. The scattered light signatures can be analyzed to tell the exact location of cloud and aerosol layers and, with the aid of a few optical assumptions, can be analyzed to retrieve estimates of optical properties such as atmospheric transparency. Radar works in a similar fashion except it sends pulses toward earth at a much larger wavelength than lidar. Radar records the return time and intensity of cloud or rain reflection returning to the aircraft. Lidar can measure scatter from optically thin cirrus and aerosol layers whose particles are too small for the radar to detect. Radar can provide reflection profiles through thick cloud layers of larger particles that lidar cannot penetrate. Only after merging the two instrument products can accurate measurements of the locations of all layers in the full atmospheric column be achieved. Accurate knowledge of the vertical distribution of clouds is important information for understanding the Earth/atmosphere radiative balance and for improving weather/climate forecast models. This paper describes one such merged data set developed from the Tropical Composition, Cloud and Climate Coupling (TC4) experiment based in Costa Rica in July-August 2007 using the nadir viewing Cloud Physics Lidar (CPL) and the Cloud Radar System (CRS) on board the NASA ER-2 aircraft. Statistics were developed concerning cloud probability through the atmospheric column and frequency of the number of cloud layers. These statistics were calculated for the full study area, four sub-regions, and over land compared to over ocean across all available flights. The results are valid for the TC4 experiment only, as preferred cloud patterns took priority during mission planning. The TC4 Study Area was a very cloudy region, with cloudy profiles occurring 94 percent of the time during the ER-2 flights. One to three cloud layers were common, with the average calculated at 2.03 layers per profile. The upper troposphere had a cloud frequency generally over 30%, reaching 42 percent near 13 km during the study. There were regional differences. The Caribbean was much clearer than the Pacific regions. Land had a much higher frequency of high clouds than ocean areas. One region just south and west of Panama had a high probability of clouds below 15 km altitude with the frequency never dropping below 25% and reaching a maximum of 60% at 11-13 km altitude. These cloud statistics will help characterize the cloud volume for TC4 scientists as they try to understand the complexities of the tropical atmosphere.
Author
CLIMATE MODELS; CLOUD PHYSICS; CLIMATOLOGY; OPTICAL RADAR; HIGH ALTITUDE; LUMINOUS INTENSITY; PULSED LASERS; VERTICAL DISTRIBUTION; CLOUD COVER; RAIN
Additions to the NASA Aeronautics and Space Database as of 09/25/2009
20090032070 NASA, Washington, DC, United States
NASA Tech Briefs, September 2009
September 2009; In English; Original contains color illustrations
Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032070
opics covered include: Filtering Water by Use of Ultrasonically Vibrated Nanotubes; Computer Code for Nanostructure Simulation; Functionalizing CNTs for Making Epoxy/CNT Composites; Improvements in Production of Single-Walled Carbon Nanotubes; Progress Toward Sequestering Carbon Nanotubes in PmPV; Two-Stage Variable Sample-Rate Conversion System; Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas; Board Saver for Use with Developmental FPGAs; Circuit for Driving Piezoelectric Transducers; Digital Synchronizer without Metastability; Compact, Low-Overhead, MIL-STD-1553B Controller; Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM; Differential InP HEMT MMIC Amplifiers Embedded in Waveguides; Improved Aerogel Vacuum Thermal Insulation; Fluoroester Co-Solvents for Low-Temperature Li+ Cells; Using Volcanic Ash to Remove Dissolved Uranium and Lead; High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell; Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays; Micro-Horn Arrays for Ultrasonic Impedance Matching; Improved Controller for a Three-Axis Piezoelectric Stage; Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water; Micro-Organ Devices; Nonlinear Thermal Compensators for WGM Resonators; Dynamic Self-Locking of an OEO Containing a VCSEL; Internal Water Vapor Photoacoustic Calibration; Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings; Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays; Improved Scanners for Microscopic Hyperspectral Imaging; Rate-Compatible LDPC Codes with Linear Minimum Distance; PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model; Integrated Planning for Telepresence With Time Delays; Minimizing Input-to-Output Latency in Virtual Environment; Battery Cell Voltage Sensing and Balancing Using Addressable Transformers; Gaussian and Lognormal Models of Hurricane Gust Factors; Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft; Integrated Modeling of Spacecraft Touch-and-Go Sampling; Spacecraft Station-Keeping Trajectory and Mission Design Tools; Efficient Model-Based Diagnosis Engine; and DSN Simulator.
Author
AEROGELS; ANTENNA ARRAYS; CARBON NANOTUBES; COMPUTER PROGRAMS; DYNAMIC CONTROL; ELECTROLYTIC CELLS; HEAT EXCHANGERS; IMAGING TECHNIQUES; INTEGRATED CIRCUITS; NANOSTRUCTURE (CHARACTERISTICS); MAN MACHINE SYSTEMS; MICROWAVE CIRCUITS; SPACECRAFT CONTROL; WATER VAPOR
20090032071 California Inst. of Tech., Pasadena, CA, United States
Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM
Gray, Andrew; Lee, Dennis; Hoy, Scott; Fisher, Dave; Fong, Wai; Ghuman, Parminder; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English
Report No.(s): NPO-40809; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032071
http://www.techbriefs.com/component/content/article/5614
There has been some additional development of parts reported in "Multi-Modulator for Bandwidth-Efficient Communication" (NPO-40807), NASA Tech Briefs, Vol. 32, No. 6 (June 2009), page 34. The focus was on 1) The generation of M-order quadrature amplitude modulation (M-QAM) and octonary-phase-shift-keying, trellis-coded modulation (8PSK TCM), 2) The use of square-root raised-cosine pulse-shaping filters, 3) A parallel-processing architecture that enables low-speed [complementary metal oxide/semiconductor (CMOS)] circuitry to perform the coding, modulation, and pulse-shaping computations at a high rate; and 4) Implementation of the architecture in a CMOS field-programmable gate array.
Author
PARALLEL PROCESSING (COMPUTERS); FIELD-PROGRAMMABLE GATE ARRAYS; PHASE SHIFT KEYING; MODULATORS; CIRCUITS; QUADRATURE AMPLITUDE MODULATION
20090032072 Vista Photonics, Inc., United States
Internal Water Vapor Photoacoustic Calibration
Pilgrim, Jeffrey S.; NASA Tech Briefs, September 2009; September 2009; pp. 2; In English
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032072
http://www.techbriefs.com/component/content/article/5649
Water vapor absorption is ubiquitous in the infrared wavelength range where photoacoustic trace gas detectors operate. This technique allows for discontinuous wavelength tuning by temperature-jumping a laser diode from one range to another within a time span suitable for photoacoustic calibration. The use of an internal calibration eliminates the need for external calibrated reference gases. Commercial applications include an improvement of photoacoustic spectrometers in all fields of use.
Author
WATER VAPOR; TRACE CONTAMINANTS; INFRARED SPECTRA; SEMICONDUCTOR LASERS; GAS DETECTORS; ATMOSPHERIC COMPOSITION; TRACE ELEMENTS
20090032073 NASA Kennedy Space Center, Cocoa Beach, FL, United States
MAGIC: Model and Graphic Information Converter
Herbert, W. C.; NASA Tech Briefs, September 2009; September 2009; pp. 56-5; In English
Report No.(s): KSC-13201; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032073
http://www.techbriefs.com/component/content/article/5709
MAGIC is a software tool capable of converting highly detailed 3D models from an open, standard format, VRML 2.0/97, into the proprietary DTS file format used by the Torque Game Engine from GarageGames. MAGIC is used to convert 3D simulations from authoritative sources into the data needed to run the simulations in NASA's Distributed Observer Network. The Distributed Observer Network (DON) is a simulation presentation tool built by NASA to facilitate the simulation sharing requirements of the Data Presentation and Visualization effort within the Constellation Program. DON is built on top of the Torque Game Engine (TGE) and has chosen TGE's Dynamix Three Space (DTS) file format to represent 3D objects within simulations.
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SIMULATION; THREE DIMENSIONAL MODELS; COMPUTER PROGRAMS; COMPUTER GRAPHICS; DATA CONVERSION ROUTINES
20090032074 NASA Goddard Space Flight Center, Greenbelt, MD, United States
GlastCam: A Telemetry-Driven Spacecraft Visualization Tool
Stoneking, Eric T.; Tsai, Dean; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): GSC-15572-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032074
http://www.techbriefs.com/component/content/article/5699
Developed for the GLAST project, which is now the Fermi Gamma-ray Space Telescope, GlastCam software ingests telemetry from the Integrated Test and Operations System (ITOS) and generates four graphical displays of geometric properties in real time, allowing visual assessment of the attitude, configuration, position, and various cross-checks. Four windows are displayed: a "cam" window shows a 3D view of the satellite; a second window shows the standard position plot of the satellite on a Mercator map of the Earth; a third window displays star tracker fields of view, showing which stars are visible from the spacecraft in order to verify star tracking; and the fourth window depicts
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TELEMETRY; FERMI GAMMA-RAY SPACE TELESCOPE; APPLICATIONS PROGRAMS (COMPUTERS); IN-FLIGHT MONITORING
20090032075 T3 Scientific, LLC, Blaine, MN, United States
Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water
Tsai, Chung-Yi; Alexander, Jerry; NASA Tech Briefs, September 2009; September 2009; pp. 2; In English
Report No.(s): MSC-24264-1/6-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032075
A nanoporous membrane is used for the pervaporation process in which potable water is maintained, at atmospheric pressure, on the feed side of the membrane. The water enters the non-pervaporation (NPV) membrane device where it is separated into two streams -- retentate water and permeated water. The permeated pure water is removed by applying low vapor pressure on the permeate side to create water vapor before condensation. This permeated water vapor is subsequently condensed by coming in contact with the cool surface of a heat exchanger with heat being recovered through transfer to the feed water stream.
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MEMBRANES; POTABLE WATER; WATER VAPOR; HEAT EXCHANGERS; LIFE SUPPORT SYSTEMS; WATER TREATMENT
20090032076 NASA Johnson Space Center, Houston, TX, United States
FPGA Boot Loader and Scrubber
Wade, Randall S.; Jones, Bailey; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): MSC-24124-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032076
http://www.techbriefs.com/component/content/article/5670
A computer program loads configuration code into a Xilinx field-programmable gate array (FPGA), reads back and verifies that code, reloads the code if an error is detected, and monitors the performance of the FPGA for errors in the presence of radiation. The program consists mainly of a set of VHDL files (wherein "VHDL" signifies "VHSIC Hardware Description Language" and "VHSIC" signifies "very-high-speed integrated circuit").
CASI
COMPUTER PROGRAMS; FIELD-PROGRAMMABLE GATE ARRAYS; HARDWARE DESCRIPTION LANGUAGES; VHSIC (CIRCUITS)
20090032077 Geospatial Research Innovation Design, Corpus Christi, TX, United States
Geospatial Authentication
Lyle, Stacey D.; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): SSC-00282; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032077
http://www.techbriefs.com/component/content/article/5170
A software package that has been designed to allow authentication for determining if the rover(s) is/are within a set of boundaries or a specific area to access critical geospatial information by using GPS signal structures as a means to authenticate mobile devices into a network wirelessly and in real-time. The advantage lies in that the system only allows those with designated geospatial boundaries or areas into the server.
Author
APPLICATIONS PROGRAMS (COMPUTERS); ROVING VEHICLES; POSITION INDICATORS; POSITION (LOCATION)
20090032078 California Inst. of Tech., Pasadena, CA, United States
XVD Image Display Program
Deen, Robert G.; Andres, Paul M.; Mortensen, Helen B.; Parizher, Vadim; McAuley, Myche; Bartholomew, Paul; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): NPO-46412; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032078
http://www.techbriefs.com/component/content/article/5697
The XVD [X-Windows VICAR (video image communication and retrieval) Display] computer program offers an interactive display of VICAR and PDS (planetary data systems) images. It is designed to efficiently display multiple-GB images and runs on Solaris, Linux, or Mac OS X systems using X-Windows.
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COMPUTER PROGRAMS; VIDEO COMMUNICATION; IMAGES
20090032079 California Inst. of Tech., Pasadena, CA, United States
Efficient Model-Based Diagnosis Engine
Fijany, Amir; Vatan, Farrokh; Barrett, Anthony; James, Mark; Mackey, Ryan; Williams, Colin; NASA Tech Briefs, September 2009; September 2009; pp. 36-3; In English
Report No.(s): NPO-40544; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032079
http://www.techbriefs.com/component/content/article/5669
An efficient diagnosis engine - a combination of mathematical models and algorithms - has been developed for identifying faulty components in a possibly complex engineering system. This model-based diagnosis engine embodies a twofold approach to reducing, relative to prior model-based diagnosis engines, the amount of computation needed to perform a thorough, accurate diagnosis. The first part of the approach involves a reconstruction of the general diagnostic engine to reduce the complexity of the mathematical-model calculations and of the software needed to perform them. The second part of the approach involves algorithms for computing a minimal diagnosis (the term "minimal diagnosis" is defined below). A somewhat lengthy background discussion is prerequisite to a meaningful summary of the innovative aspects of the present efficient model-based diagnosis engine. In model-based diagnosis, the function of each component and the relationships among all the components of the engineering system to be diagnosed are represented as a logical system denoted the system description (SD). Hence, the expected normal behavior of the engineering system is the set of logical consequences of the SD. Faulty components lead to inconsistencies between the observed behaviors of the system and the SD (see figure). Diagnosis - the task of finding faulty components - is reduced to finding those components, the abnormalities of which could explain all the inconsistencies. The solution of the diagnosis problem should be a minimal diagnosis, which is a minimal set of faulty components. A minimal diagnosis stands in contradistinction to the trivial solution, in which all components are deemed to be faulty, and which, therefore, always explains all inconsistencies.
Author
MATHEMATICAL MODELS; ALGORITHMS; COMPLEX SYSTEMS; DIAGNOSIS; COMPUTATION
20090032080 California Inst. of Tech., Pasadena, CA, United States
Mars Science Laboratory Workstation Test Set
Henriquez, David A.; Canham, Timothy K.; Chang, Johnny T.; Villaume, Nathaniel; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45690; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032080
http://www.techbriefs.com/component/content/article/5698
The Mars Science Laboratory developed the Workstation TestSet (WSTS) is a computer program that enables flight software development on virtual MSL avionics. The WSTS is the non-real-time flight avionics simulator that is designed to be completely software-based and run on a workstation class Linux PC.
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AVIONICS; COMPUTER PROGRAMS; SIMULATION
20090032081 NASA Johnson Space Center, Houston, TX, United States
Micro-Organ Devices
Gonda, Steven R.; Leslie, Julia; Chang, Robert C.; Starly, Binil; Sun, Wei; Culbertson, Christopher; Holtorf, Heidi; NASA Tech Briefs, September 2009; September 2009; pp. 21-2; In English; Original contains color illustrations
Report No.(s): MSC-23988-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032081
Micro-organ devices (MODs) are an emerging reproducible, are amenable to automated impose and fluids). In simplest terms, a MOD is a microfluidic and assemblies of cells, all designed to mimic a vivo microenvironment by vivo composition of the extracellular interest, to micro-organ wells microscopic shapes and compositions of which corresponding
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MICROSTRUCTURE; MICROFLUIDIC DEVICES; SIMULATION; CELLS (BIOLOGY)
20090032082 NASA Johnson Space Center, Houston, TX, United States
Battery Cell Voltage Sensing and Balancing Using Addressable Transformers
Davies, Francis; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): MSC-24466-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032082
http://www.techbriefs.com/component/content/article/5659
A document discusses the use of saturating transformers in a matrix arrangement to address individual cells in a high voltage battery. This arrangement is able to monitor and charge individual cells while limiting the complexity of circuitry in the battery. The arrangement has inherent galvanic isolation, low cell leakage currents, and allows a single bad cell in a battery of several hundred cells to be easily spotted.
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ELECTRIC BATTERIES; ELECTROLYTIC CELLS; HIGH VOLTAGES; TRANSFORMERS; DETECTION; BALANCING
20090032083 NASA Johnson Space Center, Houston, TX, United States
Proton Upset Monte Carlo Simulation
O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): MSC-24274-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032083
http://www.techbriefs.com/component/content/article/5672
The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.
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MICROELECTRONICS; MONTE CARLO METHOD; PROTONS; RADIATION DAMAGE; SATELLITE-BORNE INSTRUMENTS; COMPUTERIZED SIMULATION
20090032084 California Inst. of Tech., Pasadena, CA, United States
Cliffbot Maestro
Norris, Jeffrey S.; Powell, Mark W.; Fox, Jason M.; Crockett, Thomas M.; Joswig, Joseph C.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English; Original contains color and black and white illustrations
Report No.(s): NPO-46433; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032084
http://www.techbriefs.com/component/content/article/5678
Cliffbot Maestro permits teleoperation of remote rovers for field testing in extreme environments. The application user interface provides two sets of tools for operations: stereo image browsing and command generation.
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ROVING VEHICLES; TELEOPERATORS; REMOTE CONTROL; TELEROBOTICS
20090032085 NASA Glenn Research Center, Cleveland, OH, United States
Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings
Edlridge, Jeffrey I.; Martin, Richard E.; NASA Tech Briefs, September 2009; September 2009; pp. 25-2; In English; Original contains color illustrations
Report No.(s): LEW-17950-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032085
An apparatus for mid-infrared reflectance imaging has been developed as means of inspecting for subsurface damage in thermal-barrier coatings (TBCs). The apparatus is designed, more specifically, for imaging the progression of buried delamination cracks in plasma-sprayed yttria-stabilized zirconia coatings on turbine-engine components. Progression of TBC delamination occurs by the formation of buried cracks that grow and then link together to produce eventual TBC spallation. The mid-infrared reflectance imaging system described here makes it possible to see delamination progression that is invisible to the unaided eye, and therefore give sufficiently advanced warning before delamination progression adversely affects engine performance and safety. The apparatus (see figure) includes a commercial mid-infrared camera that contains a liquid-nitrogen-cooled focal plane indium antimonide photodetector array, and imaging is restricted by a narrow bandpass centered at wavelength of 4 microns. This narrow wavelength range centered at 4 microns was chosen because (1) it enables avoidance of interfering absorptions by atmospheric OH and CO2 at 3 and 4.25 microns, respectively; and (2) the coating material exhibits maximum transparency in this wavelength range. Delamination contrast is produced in the midinfrared reflectance images because the introduction of cracks into the TBC creates an internal TBC/air-gap interface with a high diffuse reflectivity of 0.81, resulting in substantially higher reflectance of mid-infrared radiation in regions that contain buried delamination cracks. The camera is positioned a short distance (.12 cm) from the specimen. The mid-infrared illumination is generated by a 50-watt silicon carbide source positioned to the side of the mid-infrared camera, and the illumination is collimated and reflected onto the specimen by a 6.35-cm-diameter off-axis paraboloidal mirror. Because the collected images are of a steady-state reflected intensity (in contrast to the transient thermal response observed in infrared thermography), collection times can be lengthened to whatever extent needed to achieve desired signal-to-noise ratios. Each image is digitized, and the resulting data are processed in several steps to obtain a true mid-infrared reflectance image. The raw image includes thermal radiation emitted by the specimen in addition to the desired reflected radiation. The thermal-radiation contribution is eliminated by subtracting the image obtained with the illumination off from the image obtained with the illumination on. A flat-field correction is then made to remove the effects of non-uniformities in the illumination level and pixel-to-pixel variations in sensitivity. This correction is performed by normalizing to an image of a standard object that has a known reflectance at a wavelength of 4 microns. After correction, each pixel value is proportional to the reflectance (at a wavelength of 4-microns) at the corresponding location on the specimen. Mid-infrared reflectance imaging of thermally cycled for performed imaging was able to progression Reproducible values associated that intermediate reflectance to failure.
Author
THERMAL CONTROL COATINGS; YTTRIA-STABILIZED ZIRCONIA; INFRARED RADIATION; REFLECTED WAVES; IMAGING TECHNIQUES; DIFFUSE RADIATION; CARBON DIOXIDE CONCENTRATION; DELAMINATING; THERMAL RADIATION
20090032086 NASA Johnson Space Center, Houston, TX, United States
Oxygen Generation System Laptop Bus Controller Flight Software
Rowe, Chad; Panter, Donna; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): MSC-24316-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032086
http://www.techbriefs.com/component/content/article/5676
The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.
Author
BUS CONDUCTORS; FLIGHT CONTROL; SOFTWARE ENGINEERING; CONTROLLERS; FIRMWARE; OXYGEN
20090032087 California Inst. of Tech., Pasadena, CA, United States
Rate-Compatible LDPC Codes with Linear Minimum Distance
Divsalar, Dariush; Jones, Christopher; Dolinar, Samuel; NASA Tech Briefs, September 2009; September 2009; pp. 2; In English; Original contains color illustrations
Report No.(s): NPO-43949; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032087
http://www.techbriefs.com/component/content/article/5650
A recently developed method of constructing protograph-based low-density parity-check (LDPC) codes provides for low iterative decoding thresholds and minimum distances proportional to block sizes, and can be used for various code rates. A code constructed by this method can have either fixed input block size or fixed output block size and, in either case, provides rate compatibility. The method comprises two submethods: one for fixed input block size and one for fixed output block size. The first mentioned submethod is useful for applications in which there are requirements for rate-compatible codes that have fixed input block sizes. These are codes in which only the numbers of parity bits are allowed to vary. The fixed-output-blocksize submethod is useful for applications in which framing constraints are imposed on the physical layers of affected communication systems. An example of such a system is one that conforms to one of many new wireless-communication standards that involve the use of orthogonal frequency-division modulation
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DECODING; PARITY; ERROR DETECTION CODES; WIRELESS COMMUNICATION
20090032088 NASA Kennedy Space Center, Cocoa Beach, FL, United States
PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model
Calluzzi, Michael; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): KSC-13185; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032088
http://www.techbriefs.com/component/content/article/5656
PrimeSupplier, a supplier cross-program and element-impact simulation model, with supplier solvency indicator (SSI), has been developed so that the shuttle program can see early indicators of supplier and product line stability, while identifying the various elements and/or programs that have a particular supplier or product designed into the system. The model calculates two categories of benchmarks to determine the SSI, with one category focusing on agency programmatic data and the other focusing on a supplier's financial liquidity. PrimeSupplier was developed to help NASA smoothly transition design, manufacturing, and repair operations from the Shuttle program to the Constellation program, without disruption in the industrial supply base.
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SUPPLYING; RESOURCES; PROCUREMENT MANAGEMENT; COMPUTERIZED SIMULATION
20090032089 California Inst. of Tech., Pasadena, CA, United States
Integrated Planning for Telepresence With Time Delays
Johnston, Mark; Rabe, Kenneth; NASA Tech Briefs, September 2009; September 2009; pp. 30-3; In English
Report No.(s): NPO-43520; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032089
http://www.techbriefs.com/component/content/article/5658
A conceptual "intelligent assistant" and an artificial-intelligence computer program that implements the intelligent assistant have been developed to improve control exerted by a human supervisor over a robot that is so distant that communication between the human and the robot involves significant signal-propagation delays. The goal of the effort is not only to help the human supervisor monitor and control the state of the robot, but also to improve the efficiency of the robot by allowing the supervisor to "work ahead". The intelligent assistant is an integrated combination of an artificial-intelligence planner and a monitor of states of both the human supervisor and the remote robot. The novelty of the system lies in the way it uses the planner to reason about the states at both ends of the time delay. The purpose served by the assistant is to provide advice to the human supervisor about current and future activities, derived from a sequence of high-level goals to be achieved.
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ARTIFICIAL INTELLIGENCE; COMPUTER PROGRAMS; MAN MACHINE SYSTEMS; TELEOPERATORS; TELEROBOTICS; TASK PLANNING (ROBOTICS)
20090032090 California Inst. of Tech., Pasadena, CA, United States
Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas
Paal, Leslie; Mukai, Ryan; Vilntrotter, Victor; Cornish, Timothy; Lee, Dennis; NASA Tech Briefs, September 2009; September 2009; pp. 9-1; In English; Original contains color illustrations
Report No.(s): NPO-44611; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032090
http://www.techbriefs.com/component/content/article/5620
A method of estimating phase drifts of microwave signals distributed to, and transmitted by, antennas in an array involves the use of the signals themselves as phase references. The method was conceived as part of the solution of the problem of maintaining precise phase calibration required for proper operation of an array of Deep Space Network (DSN) antennas on Earth used for communicating with distant spacecraft at frequencies between 7 and 8 GHz. The method could also be applied to purely terrestrial phased-array radar and other radio antenna array systems. In the DSN application, the electrical lengths (effective signal-propagation path lengths) of the various branches of the system for distributing the transmitted signals to the antennas are not precisely known, and they vary with time. The variations are attributable mostly to thermal expansion and contraction of fiber-optic and electrical signal cables and to a variety of causes associated with aging of signal-handling components. The variations are large enough to introduce large phase drifts at the signal frequency. It is necessary to measure and correct for these phase drifts in order to maintain phase calibration of the antennas. A prior method of measuring phase drifts involves the use of reference-frequency signals separate from the transmitted signals. A major impediment to accurate measurement of phase drifts over time by the prior method is the fact that although DSN reference-frequency sources separate from the transmitting signal sources are stable and accurate enough for most DSN purposes, they are not stable enough for use in maintaining phase calibrations, as required, to within a few degrees over times as long as days or possibly even weeks. By eliminating reliance on the reference-frequency subsystem, the present method overcomes this impediment. In a DSN array to which the present method applies (see figure), the microwave signals to be transmitted are generated by exciters in a signal-processing center, then distributed to the antennas via optical fibers. At each antenna, the signals are used to drive a microwave power-amplifier train, the output of which is coupled to the antenna for transmission. A small fraction of the power-amplifier-train output is sent back to the signal-processing center along another optical fiber that is part of the same fiber-optic cable used to distribute the transmitted signal to the antenna. In the signal-processing center, the signal thus returned from each antenna is detected and its phase is compared with the phase of the signal sampled directly from the corresponding exciter. It is known, from other measurements, that the signal-propagation path length from the power-amplifier-train output port to the phase center of each antenna is sufficiently stable and, hence, that sampling the signal at the power-amplifier-train output port suffices for the purpose of characterizing the phase drift of the transmitted signal at the phase center of the antenna
Author
ANTENNA ARRAYS; UPLINKING; ESTIMATING; SIGNAL ANALYSIS; FREQUENCY MEASUREMENT; PHASED ARRAYS; CALIBRATING; FIBER OPTICS; THERMAL EXPANSION; POWER AMPLIFIERS; TRANSMISSION
20090032091 NASA Goddard Space Flight Center, Greenbelt, MD, United States
TurboTech Technical Evaluation Automated System
Tiffany, Dorothy J.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): GSC-15554-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032091
http://www.techbriefs.com/component/content/article/5688
TurboTech software is a Web-based process that simplifies and semiautomates technical evaluation of NASA proposals for Contracting Officer's Technical Representatives (COTRs). At the time of this reporting, there have been no set standards or systems for training new COTRs in technical evaluations. This new process provides boilerplate text in response to interview style questions. This text is collected into a Microsoft Word document that can then be further edited to conform to specific cases. By providing technical language and a structured format, TurboTech allows the COTRs to concentrate more on the actual evaluation, and less on deciding what language would be most appropriate. Since the actual word choice is one of the more time-consuming parts of a COTRs job, this process should allow for an increase in quantity of proposals evaluated. TurboTech is applicable to composing technical evaluations of contractor proposals, task and delivery orders, change order modifications, requests for proposals, new work modifications, task assignments, as well as any changes to existing contracts.
Author
AUTOMATIC CONTROL; COMPUTER PROGRAMS; SYSTEMS ENGINEERING; EVALUATION
20090032092 NASA Johnson Space Center, Houston, TX, United States
Using Volcanic Ash to Remove Dissolved Uranium and Lead
McKay, David S.; Cuero, Raul G.; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English
Report No.(s): MSC-23545-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032092
http://www.techbriefs.com/component/content/article/5630
Experiments have shown that significant fractions of uranium, lead, and possibly other toxic and/or radioactive substances can be removed from an aqueous solution by simply exposing the solution, at ambient temperature, to a treatment medium that includes weathered volcanic ash from Pu'u Nene, which is a cinder cone on the Island of Hawaii. Heretofore, this specific volcanic ash has been used for an entirely different purpose: simulating the spectral properties of Martian soil. The treatment medium can consist of the volcanic ash alone or in combination with chitosan, which is a natural polymer that can be produced from seafood waste or easily extracted from fungi, some bacteria, and some algae. The medium is harmless to plants and animals and, because of the abundance and natural origin of its ingredient( s), is inexpensive. The medium can be used in a variety of ways and settings: it can be incorporated into water-filtration systems; placed in contact or mixed with water-containing solids (e.g., soils and sludges); immersed in bodies of water (e.g., reservoirs, lakes, rivers, or wells); or placed in and around nuclear power plants, mines, and farm fields.
Author
ASHES; URANIUM; VOLCANOES; LEAD (METAL); CONES (VOLCANOES); DISSOLVING
20090032093 California Inst. of Tech., Pasadena, CA, United States
Board Saver for Use with Developmental FPGAs
Berkun, Andrew; NASA Tech Briefs, September 2009; September 2009; pp. 10-1; In English; Original contains color illustrations
Report No.(s): NPO-44745; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032093
http://www.techbriefs.com/component/content/article/5616
A device denoted a board saver has been developed as a means of reducing wear and tear of a printed-circuit board onto which an antifuse field programmable gate array (FPGA) is to be eventually soldered permanently after a number of design iterations. The need for the board saver or a similar device arises because (1) antifuse-FPGA design iterations are common and (2) repeated soldering and unsoldering of FPGAs on the printed-circuit board to accommodate design iterations can wear out the printed-circuit board. The board saver is basically a solderable/unsolderable FPGA receptacle that is installed temporarily on the printed-circuit board. The board saver is, more specifically, a smaller, square-ring-shaped, printed-circuit board (see figure) that contains half via holes one for each contact pad along its periphery. As initially fabricated, the board saver is a wider ring containing full via holes, but then it is milled along its outer edges, cutting the via holes in half and laterally exposing their interiors. The board saver is positioned in registration with the designated FPGA footprint and each via hole is soldered to the outer portion of the corresponding FPGA contact pad on the first-mentioned printed-circuit board. The via-hole/contact joints can be inspected visually and can be easily unsoldered later. The square hole in the middle of the board saver is sized to accommodate the FPGA, and the thickness of the board saver is the same as that of the FPGA. Hence, when a non-final FPGA is placed in the square hole, the combination of the non-final FPGA and the board saver occupy no more area and thickness than would a final FPGA soldered directly into its designated position on the first-mentioned circuit board. The contact leads of a non-final FPGA are not bent and are soldered, at the top of the board saver, to the corresponding via holes. A non-final FPGA can readily be unsoldered from the board saver and replaced by another one. Once the final FPGA design has been determined, the board saver can be unsoldered from the contact pads on the first-mentioned printed-circuit board and replaced by the final FPGA.
Author
FIELD-PROGRAMMABLE GATE ARRAYS; CIRCUIT BOARDS; PRINTED CIRCUITS; SOLDERING; FABRICATION
20090032094 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Perl Modules for Constructing Iterators
Tilmes, Curt; NASA Tech Briefs, September 2009; September 2009; pp. 47-4; In English
Report No.(s): GSC-15560-1/1-1/2-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032094
http://www.techbriefs.com/component/content/article/5690
The Iterator Perl Module provides a general-purpose framework for constructing iterator objects within Perl, and a standard API for interacting with those objects. Iterators are an object-oriented design pattern where a description of a series of values is used in a constructor. Subsequent queries can request values in that series. These Perl modules build on the standard Iterator framework and provide iterators for some other types of values. Iterator::DateTime constructs iterators from DateTime objects or Date::Parse descriptions and ICal/RFC 2445 style re-currence descriptions. It supports a variety of input parameters, including a start to the sequence, an end to the sequence, an Ical/RFC 2445 recurrence describing the frequency of the values in the series, and a format description that can refine the presentation manner of the DateTime. Iterator::String constructs iterators from string representations. This module is useful in contexts where the API consists of supplying a string and getting back an iterator where the specific iteration desired is opaque to the caller. It is of particular value to the Iterator::Hash module which provides nested iterations. Iterator::Hash constructs iterators from Perl hashes that can include multiple iterators. The constructed iterators will return all the permutations of the iterations of the hash by nested iteration of embedded iterators. A hash simply includes a set of keys mapped to values. It is a very common data structure used throughout Perl programming. The Iterator:: Hash module allows a hash to include strings defining iterators (parsed and dispatched with Iterator::String) that are used to construct an overall series of hash values.
Author
ITERATION; MODULES; DATA STRUCTURES; APPLICATION PROGRAMMING INTERFACE
20090032095 California Inst. of Tech., Pasadena, CA, United States
Fluoroester Co-Solvents for Low-Temperature Li+ Cells
Smart, Marshall; Bugga, Ratnakumar; Prakash, G. K. Surya; Smith, Kiah; Bhalla, Pooja; NASA Tech Briefs, September 2009; September 2009; pp. 15-1; In English; Original contains color illustrations
Report No.(s): NPO-44626; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032095
http://www.techbriefs.com/component/content/article/5628
Electrolytes comprising LiPF6 dissolved in alkyl carbonate/fluoroester mixtures have been found to afford improved low-temperature performance and greater high-temperature resilience in rechargeable lithium-ion electrochemical cells. These and other electrolytes comprising lithium salts dissolved mixtures of esters have been studied in continuing research directed toward extending the lower limit of operating temperatures of such cells. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles. The purpose of the present focus on high-temperature resilience in addition to low-temperature performance is to address issues posed by the flammability of the esters and, at temperatures near the upper end (about 55 C) of their intended operating temperature range, by their high chemical reactivity. As used here, high-temperature resilience signifies, loosely, a desired combination of low flammability of an electrolyte mixture and the ability of a cell that contains the mixture to sustain a relatively small loss of reversible charge/discharge capacity during storage in the fully charged condition at high temperature. The selection of fluoroesters for study as candidate electrolyte solvent components to increase high-temperature resilience was prompted in part by the observation that like other halogenated compounds, fluoroesters have low flammability. The fluoroesters investigated in this study include trifluoroethyl butyrate (TFEB), ethyl trifluoroacetate (ETFA), trifluoroethyl acetate (TFEA), and methyl pentafluoropropionate (MPFP). Solvent mixtures were prepared by mixing these fluoroesters with two other esters: ethylene carbonate (EC) and ethyl methyl carbonate (EMC).
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LITHIUM; METAL IONS; SOLVENTS; LOW TEMPERATURE; ELECTROCHEMICAL CELLS; ESTERS; FLUORIDES
20090032096 Lockheed Martin Corp., Houston, TX, United States
Digital Synchronizer without Metastability
Simle, Robert M.; Cavazos, Jose A.; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English
Report No.(s): MSC-23220-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032096
http://www.techbriefs.com/component/content/article/5617
A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop. The proposed design calls for (1) use of a clock frequency greater than the frequency of the asynchronous signal, (2) use of flip-flop asynchronous preset or clear signals for the asynchronous input, (3) use of a clock asynchronous recovery delay with pulse width discriminator, and (4) tying the data inputs to constant logic levels to obtain (5) two half-rate synchronous partial signals - one for the falling and one for the rising edge. Inasmuch as the flip-flop data inputs would be permanently tied to constant logic levels, setup and hold times would not be violated. The half-rate partial signals would be recombined to construct a signal that would replicate the original asynchronous signal at its original rate but would be synchronous with the clock signal.
Author
DIGITAL ELECTRONICS; SYNCHRONIZERS; METASTABLE STATE; LOGIC CIRCUITS; CLOCKS; PULSE DURATION
20090032097 California Inst. of Tech., Pasadena, CA, United States
Micro-Horn Arrays for Ultrasonic Impedance Matching
Rao, Shanti; Palmer, Dean; NASA Tech Briefs, September 2009; September 2009; pp. 19-2; In English; Original contains color illustrations
Report No.(s): NPO-43907; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032097
http://www.techbriefs.com/component/content/article/5634
Thin-layered structures containing arrays of micromachined horns, denoted solid micro-horn arrays (SMIHAs), have been conceived as improved means of matching acoustic impedances between ultrasonic transducers and the media with which the transducers are required to exchange acoustic energy. Typically, ultrasonic transducers (e.g., those used in medical imaging) are piezoelectric or similar devices, which produce small displacements at large stresses. However, larger displacements at smaller stresses are required in the target media (e.g., human tissues) with which acoustic energy is to be exchanged. Heretofore, efficiencies in transmission of acoustic energy between ultrasonic transducers and target media have been severely limited because substantial mismatches of acoustic impedances have remained, even when coupling material layers have been interposed between the transducers and the target media. In contrast, SMIHAs can, in principle, be designed to effect more nearly complete acoustic impedance matching, leading to power transmission efficiencies of 90 percent or even greater. The SMIHA concept is based on extension, into the higher-frequency/ lower-wavelength ultrasonic range, of the use of horns to match acoustic impedances in the audible and lower-frequency ultrasonic ranges. In matching acoustic impedance in transmission from a higher-impedance acoustic source (e.g., a piezoelectric transducer) and a lowerimpedance target medium (e.g., air or human tissue), a horn acts as a mechanical amplifier. The shape and size of the horn can be optimized for matching acoustic impedance in a specified frequency range. A typical SMIHA would consist of a base plate, a face plate, and an array of horns that would constitute pillars that connect the two plates (see figure). In use, the base plate would be connected to an ultrasonic transducer and the face plate would be placed in contact with the target medium. As at lower frequencies, the sizes and shapes of the pillars could be tailored for impedance matching in a specified ultrasonic frequency range. In a design that would be simplest to implement by micromachining, the horns would have constant cross-sectional areas as shown in the upper part of the figure. In this case, the dimensions of the horns could be chosen on the basis of a Mason equivalent-circuit model (a simplified model, well-known in the piezoelectric-transducer art, in which the electrical and mechanical dynamics, including electromechanical couplings, are expressed as electrical circuit elements that can include inductors, capacitors, and lumped-parameter complex impedances.) In a more complex, more nearly optimum design, the cross-sectional area of each horn would be either stepped or made to vary as a continuous function of through-the thickness position, as shown in the lower part of the figure.
Author
ELECTROMECHANICS; IMPEDANCE MATCHING; MICROMACHINING; ULTRASONIC WAVE TRANSDUCERS; HORNS; ARRAYS
20090032098 California Inst. of Tech., Pasadena, CA, United States
Mission Operations and Navigation Toolkit Environment
Sunseri, Richard F.; Wu, Hsi-Cheng; Hanna, Robert A.; Mossey, Michael P.; Duncan, Courtney B.; Evans, Scott E.; Evans, James R.; Drain, Theodore R.; Guevara, Michelle M.; Martin Mur, Tomas J.; Attiyah, Ahlam A.; NASA Tech Briefs, September 2009; September 2009; pp. 53-5; In English
Report No.(s): NPO-46083; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032098
MONTE (Mission Operations and Navigation Toolkit Environment) Release 7.3 is an extensible software system designed to support trajectory and navigation analysis/design for space missions. MONTE is intended to replace the current navigation and trajectory analysis software systems, which, at the time of this reporting, are used by JPL's Navigation and Mission Design section. The software provides an integrated, simplified, and flexible system that can be easily maintained to serve the needs of future missions in need of navigation services.
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MISSION PLANNING; TRAJECTORY ANALYSIS; COMPUTER PROGRAMS; SPACECRAFT TRAJECTORIES; TRAJECTORY PLANNING
20090032099 NASA Stennis Space Center, Stennis Space Center, MS, United States
Improved Scanners for Microscopic Hyperspectral Imaging
Mao, Chengye; NASA Tech Briefs, September 2009; September 2009; pp. 27-2; In English; Original contains color illustrations
Report No.(s): SCC-00280-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032099
Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version, the window would be a slit, the CCD would contain a one-dimensional array of pixels, and the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion. The image built up by scanning in this case would be an ordinary (non-spectral) image. In another version, the optics of which are depicted in the lower part of the figure, the spatial window would be a slit, the CCD would contain a two-dimensional array of pixels, the slit image would be refocused onto the CCD by a relay-lens pair consisting of a collimating and a focusing lens, and a prism-gratingprism optical spectrometer would be placed between the collimating and focusing lenses. Consequently, the image on the CCD would be spatially resolved along the slit axis and spectrally resolved along the axis perpendicular to the slit. As in the first-mentioned version, the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion.
Author
IMAGE PROCESSING; SCANNERS; MICROSCOPY; SERVOMOTORS; LENSES; CCD CAMERAS
20090032100 California Inst. of Tech., Pasadena, CA, United States
Using Thermal Radiation in Detection of Negative Obstacles
Rankin, Arturo L.; Matthies, Larry H.; NASA Tech Briefs, September 2009; September 2009; pp. 38-3; In English; Original contains color and black and white illustrations
Report No.(s): NPO-40368; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032100
http://www.techbriefs.com/component/content/article/5673
A method of automated detection of negative obstacles (potholes, ditches, and the like) ahead of ground vehicles at night involves processing of imagery from thermal-infrared cameras aimed at the terrain ahead of the vehicles. The method is being developed as part of an overall obstacle-avoidance scheme for autonomous and semi-autonomous offroad robotic vehicles. The method could also be applied to help human drivers of cars and trucks avoid negative obstacles -- a development that may entail only modest additional cost inasmuch as some commercially available passenger cars are already equipped with infrared cameras as aids for nighttime operation.
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DETECTION; INFRARED RADIATION; OBSTACLE AVOIDANCE; THERMAL RADIATION; UNMANNED GROUND VEHICLES
20090032101 California Inst. of Tech., Pasadena, CA, United States
Estimating Thruster Impulses From IMU and Doppler Data
Lisano, Michael E.; Kruizinga, Gerhard L.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): NPO-45825; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032101
http://www.techbriefs.com/component/content/article/5677
A computer program implements a thrust impulse measurement (TIM) filter, which processes data on changes in velocity and attitude of a spacecraft to estimate the small impulsive forces and torques exerted by the thrusters of the spacecraft reaction control system (RCS). The velocity-change data are obtained from line-of-sight-velocity data from Doppler measurements made from the Earth. The attitude-change data are the telemetered from an inertial measurement unit (IMU) aboard the spacecraft. The TIM filter estimates the threeaxis thrust vector for each RCS thruster, thereby enabling reduction of cumulative navigation error attributable to inaccurate prediction of thrust vectors. The filter has been augmented with a simple mathematical model to compensate for large temperature fluctuations in the spacecraft thruster catalyst bed in order to estimate thrust more accurately at deadbanding cold-firing levels. Also, rigorous consider-covariance estimation is applied in the TIM to account for the expected uncertainty in the moment of inertia and the location of the center of gravity of the spacecraft. The TIM filter was built with, and depends upon, a sigma-point consider-filter algorithm implemented in a Python-language computer program.
Author
MATHEMATICAL MODELS; MOMENTS OF INERTIA; INERTIAL PLATFORMS; THRUST; ESTIMATING; DOPPLER RADAR
20090032102 Eltron Research, Inc., Boulder, CO, United States
Progress Toward Sequestering Carbon Nanotubes in PmPV
Bley, Richard A.; NASA Tech Briefs, September 2009; September 2009; pp. ; In English
Report No.(s): MSC-23733-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032102
http://www.techbriefs.com/component/content/article/5612
Sequestration of single-walled carbon nanotubes (SWNTs) in molecules of poly(m-phenylenevinylene-co-2,5-diocty-loxy-p-phenylenevinyl ene) [PmPV] is a candidate means of promoting dissolution of single-walled carbon nanotubes (SWNTs) into epoxies for making strong, lightweight epoxy-matrix/carbon-fiber composite materials. Bare SWNTs cannot be incorporated because they are not soluble in epoxies. In the present approach, one exploits the tendency of PmPV molecules to wrap themselves around SWNTs without chemically bonding to them.
Derived from text
CARBON NANOTUBES; MATRIX MATERIALS; EPOXY MATRIX COMPOSITES
20090032103 California Inst. of Tech., Pasadena, CA, United States
Two-Stage Variable Sample-Rate Conversion System
Tkacenko, Andre; NASA Tech Briefs, September 2009; September 2009; pp. ; In English; Original contains color illustrations
Report No.(s): NPO-44539; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032103
http://www.techbriefs.com/component/content/article/5618
A two-stage variable sample-rate conversion has been proposed system utilizes a variety of data rates. be used as analog-todigital receiver to sample an intermediatefrequency fixed input rate and loops rates that are generally lower This Two-Stage System would be capable of converting from an input sample rate to a desired lower that could be variable and not necessarily a rational fraction of the input rate.
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PULSE COMMUNICATION; SIGNAL PROCESSING; VARIABILITY
20090032104 NASA Marshall Space Flight Center, Huntsville, AL, United States
Prediction of Launch Vehicle Ignition Overpressure and Liftoff Acoustics
Casiano, Matthew; NASA Tech Briefs, September 2009; September 2009; pp. 44-4; In English
Report No.(s): MFS-32579-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032104
http://www.techbriefs.com/component/content/article/5686
The LAIOP (Launch Vehicle Ignition Overpressure and Liftoff Acoustic Environments) program predicts the external pressure environment generated during liftoff for a large variety of rocket types. These environments include ignition overpressure, produced by the rapid acceleration of exhaust gases during rocket-engine start transient, and launch acoustics, produced by turbulence in the rocket plume. The ignition overpressure predictions are time-based, and the launch acoustic predictions are frequency-based. Additionally, the software can predict ignition overpressure mitigation, using water-spray injection into the rocket exhaust stream, for a limited number of configurations. The framework developed for these predictions is extensive, though some options require additional relevant data and development time. Once these options are enabled, the already extensively capable code will be further enhanced. The rockets, or launch vehicles, can either be elliptically or cylindrically shaped, and up to eight strap-on structures (boosters or tanks) are allowed. Up to four engines are allowed for the core launch vehicle, which can be of two different types. Also, two different sizes of strap-on structures can be used, and two different types of booster engines are allowed. Both tabular and graphical presentations of the predicted environments at the selected locations can be reviewed by the user. The output includes summaries of rocket-engine operation, ignition overpressure time histories, and one-third octave sound pressure spectra of the predicted launch acoustics. Also, documentation is available to the user to help him or her understand the various aspects of the graphical user interface and the required input parameters.
Author
ACOUSTICS; LAUNCH VEHICLES; OVERPRESSURE; SOUND PRESSURE; ROCKET EXHAUST; EXHAUST GASES; BOOSTER ROCKET ENGINES
20090032105 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, United States
Spacecraft Station-Keeping Trajectory and Mission Design Tools
Chung, Min-Kun J.; NASA Tech Briefs, September 2009; September 2009; pp. 35-3; In English
Report No.(s): NPO-44452; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032105
http://www.techbriefs.com/component/content/article/5665
Two tools were developed for designing station-keeping trajectories and estimating delta-v requirements for designing missions to a small body such as a comet or asteroid. This innovation uses NPOPT, a non-sparse, general-purpose sequential quadratic programming (SQP) optimizer and the Two-Level Differential Corrector (T-LDC) in LTool (Libration point mission design Tool) to design three kinds of station-keeping scripts: vertical hovering, horizontal hovering, and orbiting. The T-LDC is used to differentially correct several trajectory legs that join hovering points. In a vertical hovering, the maximum and minimum range points must be connected smoothly while maintaining the spacecrafts range from a small body, all within the law of gravity and the solar radiation pressure. The same is true for a horizontal hover. A PatchPoint is an LTool class that denotes a space-time event with some extra information for differential correction, including a set of constraints to be satisfied by T-LDC. Given a set of PatchPoints, each with its own constraint, the T-LDC differentially corrects the entire trajectory by connecting each trajectory leg joined by PatchPoints while satisfying all specified constraints at the same time. Vertical and horizontal hover both are needed to minimize delta-v spent for station keeping. A Python I/F to NPOPT has been written to be used from an LTool script. In vertical hovering, the spacecraft stays along the line joining the Sun and a small body. An instantaneous delta-v toward the anti- Sun direction is applied at the closest approach to the small body for station keeping. For example, the spacecraft hovers between the minimum range (2 km) point and the maximum range (2.5 km) point from the asteroid 1989ML. Horizontal hovering buys more time for a spacecraft to recover if, for any reason, a planned thrust fails, by returning almost to the initial position after some time later via a near elliptical orbit around the small body. The mapping or staging orbit may be similarly generated using T-LDC with a set of constraints. Some delta-v tables are generated for several different asteroid masses.
Author
STATIONKEEPING; MISSION PLANNING; COMETS; ASTEROIDS; ELLIPTICAL ORBITS; SPACECRAFT TRAJECTORIES
20090032106 SouthWest Nano Technologies, Inc., Norman, OK, United States
Improvements in Production of Single-Walled Carbon Nanotubes
Balzano, Leandro; Resasco, Daniel E.; NASA Tech Briefs, September 2009; September 2009; pp. 6-; In English
Report No.(s): MSC-23706-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032106
http://www.techbriefs.com/component/content/article/5611
A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to modification for conversion from batch to continuous production.
Author
CARBON NANOTUBES; FLUIDIZED BED PROCESSORS; CARBON MONOXIDE; COMPOSITE MATERIALS; MATRIX MATERIALS; CERAMICS; COMPUTATIONAL FLUID DYNAMICS
20090032107 Zyvex Corp., Richardson, TX, United States
Functionalizing CNTs for Making Epoxy/CNT Composites
Chen, Jian; Rajagopal, Ramasubramaniam; NASA Tech Briefs, September 2009; September 2009; pp. ; In English
Report No.(s): MSC-23719-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032107
http://www.techbriefs.com/component/content/article/5613
Functionalization of carbon nanotubes (CNTs) with linear molecular side chains of polyphenylene ether (PPE) has been shown to be effective in solubilizing the CNTs in the solvent components of solutions that are cast to make epoxy/CNT composite films. (In the absence of solubilization, the CNTs tend to clump together instead of becoming dispersed in solution as needed to impart, to the films, the desired CNT properties of electrical conductivity and mechanical strength.) Because the PPE functionalizes the CNTs in a noncovalent manner, the functionalization does not damage the CNTs. The functionalization can also be exploited to improve the interactions between CNTs and epoxy matrices to enhance the properties of the resulting composite films. In addition to the CNTs, solvent, epoxy resin, epoxy hardener, and PPE, a properly formulated solution also includes a small amount of polycarbonate, which serves to fill voids that, if allowed to remain, would degrade the performance of the film. To form the film, the solution is drop-cast or spin-cast, then the solvent is allowed to evaporate.
Author
CARBON NANOTUBES; ELECTRICAL RESISTIVITY; EPOXY MATRIX COMPOSITES; EPOXY RESINS; MATRIX MATERIALS; POLYCARBONATES; MOLECULAR CHAINS
20090032108 California Inst. of Tech., Pasadena, CA, United States
Robot Vision Library
Howard, Andrew B.; Ansar, Adnan I.; Litwin, Todd E.; Goldberg, Steven B.; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-46532; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032108
http://www.techbriefs.com/component/content/article/5691
The JPL Robot Vision Library (JPLV) provides real-time robot vision algorithms for developers who are not vision specialists. The package includes algorithms for stereo ranging, visual odometry and unsurveyed camera calibration, and has unique support for very wideangle lenses
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COMPUTER VISION; ROBOTS; ALGORITHMS; COMPUTER PROGRAMS; SOFTWARE REUSE; IMAGE PROCESSING
20090032109 California Inst. of Tech., Pasadena, CA, United States
Improved Controller for a Three-Axis Piezoelectric Stage
Rao, Shanti; Palmer, Dean; NASA Tech Briefs, September 2009; September 2009; pp. 2; In English; Original contains color illustrations
Report No.(s): NPO-44806; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032109
http://www.techbriefs.com/component/content/article/5635
An improved closed-loop controller has been built for a three-axis piezoelectric positioning stage. The stage can be any of a number of commercially available or custom-made units that are used for precise three-axis positioning of optics in astronomical instruments and could be used for precise positioning in diverse fields of endeavor that include adaptive optics, fabrication of semiconductors, and nanotechnology.
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CONTROLLERS; FEEDBACK CONTROL; PIEZOELECTRICITY; POSITIONING; CONTROL SYSTEMS DESIGN
20090032110 California Inst. of Tech., Pasadena, CA, United States
Data Management Applications for the Service Preparation Subsystem
Luong, Ivy P.; Chang, George W.; Bui, Tung; Allen, Christopher; Malhotra, Shantanu; Chen, Fannie C.; Bui, Bach X.; Gutheinz, Sandy C.; Kim, Rachel Y.; Zendejas, Silvino C.; Yu, Dan; Kim, Richard M.; Sadaqathulla, Syed; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45021; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032110
http://www.techbriefs.com/component/content/article/5713
These software applications provide intuitive User Interfaces (UIs) with a consistent look and feel for interaction with, and control of, the Service Preparation Subsystem (SPS). The elements of the UIs described here are the File Manager, Mission Manager, and Log Monitor applications. All UIs provide access to add/delete/update data entities in a complex database schema without requiring technical expertise on the part of the end users. These applications allow for safe, validated, catalogued input of data. Also, the software has been designed in multiple, coherent layers to promote ease of code maintenance and reuse in addition to reducing testing and accelerating maturity.
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HUMAN-COMPUTER INTERFACE; DATA SYSTEMS; DATA BASES; SOFTWARE ENGINEERING
20090032111 NASA Ames Research Center, Moffett Field, CA, United States
Minimizing Input-to-Output Latency in Virtual Environment
Adelstein, Bernard D.; Ellis, Stephen R.; Hill, Michael I.; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): ARC-15102-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032111
http://www.techbriefs.com/component/content/article/5655
A method and apparatus were developed (time delay) in discrete- real-time display in response to such systems is required within and between sensors,
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COMPUTER TECHNIQUES; REAL TIME OPERATION; TIME LAG; ON-LINE SYSTEMS
20090032112 I/NET, Inc., Kalamazoo, MI, United States
Complex Event Recognition Architecture
Fitzgerald, William A.; Firby, R. James; NASA Tech Briefs, September 2009; September 2009; pp. 46-4; In English
Report No.(s): MSC-23637-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032112
http://www.techbriefs.com/component/content/article/5684
Complex Event Recognition Architecture (CERA) is the name of a computational architecture, and software that implements the architecture, for recognizing complex event patterns that may be spread across multiple streams of input data. One of the main components of CERA is an intuitive event pattern language that simplifies what would otherwise be the complex, difficult tasks of creating logical descriptions of combinations of temporal events and defining rules for combining information from different sources over time. In this language, recognition patterns are defined in simple, declarative statements that combine point events from given input streams with those from other streams, using conjunction, disjunction, and negation. Patterns can be built on one another recursively to describe very rich, temporally extended combinations of events. Thereafter, a run-time matching algorithm in CERA efficiently matches these patterns against input data and signals when patterns are recognized. CERA can be used to monitor complex systems and to signal operators or initiate corrective actions when anomalous conditions are recognized. CERA can be run as a stand-alone monitoring system, or it can be integrated into a larger system to automatically trigger responses to changing environments or problematic situations.
Author
ARCHITECTURE (COMPUTERS); COMPLEX SYSTEMS; LANGUAGE PROGRAMMING; PATTERN RECOGNITION
20090032113 NASA Johnson Space Center, Houston, TX, United States
Monitoring and Controlling an Underwater Robotic Arm
Haas, John; Todd, Brian Keith; Woodcock, Larry; Robinson, Fred M.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): MSC-24165-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032113
http://www.techbriefs.com/component/content/article/5679
The SSRMS Module 1 software is part of a system for monitoring an adaptive, closed-loop control of the motions of a robotic arm in NASA s Neutral Buoyancy Laboratory, where buoyancy in a pool of water is used to simulate the weightlessness of outer space. This software is so named because the robot arm is a replica of the Space Shuttle Remote Manipulator System (SSRMS). This software is distributed, running on remote joint processors (RJPs), each of which is mounted in a hydraulic actuator comprising the joint of the robotic arm and communicating with a poolside processor denoted the Direct Control Rack (DCR). Each RJP executes the feedback joint-motion control algorithm for its joint and communicates with the DCR. The DCR receives joint-angular-velocity commands either locally from an operator or remotely from computers that simulate the flight like SSRMS and perform coordinated motion calculations based on hand-controller inputs. The received commands are checked for validity before they are transmitted to the RJPs. The DCR software generates a display of the statuses of the RJPs for the DCR operator and can shut down the hydraulic pump when excessive joint-angle error or failure of a RJP is detected.
Author
ADAPTIVE CONTROL; FEEDBACK CONTROL; ROBOT ARMS; REMOTE MANIPULATOR SYSTEM; BUOYANCY; WEIGHTLESSNESS
20090032114 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Port-O-Sim Object Simulation Application
Lanzi, Raymond J.; NASA Tech Briefs, September 2009; September 2009; pp. 41-4; In English
Report No.(s): GSC-15571-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032114
http://www.techbriefs.com/component/content/article/5668
Port-O-Sim is a software application that supports engineering modeling and simulation of launch-range systems and subsystems, as well as the vehicles that operate on them. It is flexible, distributed, object-oriented, and realtime. A scripting language is used to configure an array of simulation objects and link them together. The script is contained in a text file, but executed and controlled using a graphical user interface. A set of modules is defined, each with input variables, output variables, and settings. These engineering models can be either linked to each other or run as standalone. The settings can be modified during execution. Since 2001, this application has been used for pre-mission failure mode training for many Range Safety Scenarios. It contains range asset link analysis, develops look-angle data, supports sky-screen site selection, drives GPS (Global Positioning System) and IMU (Inertial Measurement Unit) simulators, and can support conceptual design efforts for multiple flight programs with its capacity for rapid six-degrees-of-freedom model development. Due to the assembly of various object types into one application, the application is applicable across a wide variety of launch range problem domains.
Author
OBJECT-ORIENTED PROGRAMMING; GLOBAL POSITIONING SYSTEM; SIMULATORS; DEGREES OF FREEDOM; GRAPHICAL USER INTERFACE; MODULES
20090032115 NASA Johnson Space Center, Houston, TX, United States
Digital Camera Control for Faster Inspection
Brown, Katharine; Siekierski, James D.; Mangieri, Mark L.; Dekome, Kent; Cobarruvias, John; Piplani, Perry J.; Busa, Joel; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): MSC-24319-1/168-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032115
http://www.techbriefs.com/component/content/article/5680
Digital Camera Control Software (DCCS) is a computer program for controlling a boom and a boom-mounted camera used to inspect the external surface of a space shuttle in orbit around the Earth. Running in a laptop computer in the space-shuttle crew cabin, DCCS commands integrated displays and controls. By means of a simple one-button command, a crewmember can view low- resolution images to quickly spot problem areas and can then cause a rapid transition to high- resolution images. The crewmember can command that camera settings apply to a specific small area of interest within the field of view of the camera so as to maximize image quality within that area. DCCS also provides critical high-resolution images to a ground screening team, which analyzes the images to assess damage (if any); in so doing, DCCS enables the team to clear initially suspect areas more quickly than would otherwise be possible and further saves time by minimizing the probability of re-imaging of areas already inspected. On the basis of experience with a previous version (2.0) of the software, the present version (3.0) incorporates a number of advanced imaging features that optimize crewmember capability and efficiency.
Author
DIGITAL CAMERAS; IMAGING TECHNIQUES; COMPUTER PROGRAMS; DISPLAY DEVICES; IMAGE RESOLUTION; INSPECTION
20090032116 California Inst. of Tech., Pasadena, CA, United States
Integrated Modeling of Spacecraft Touch-and-Go Sampling
Quadrelli, Marco; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): NPO-44371; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032116
http://www.techbriefs.com/component/content/article/5666
An integrated modeling tool has been developed to include multi-body dynamics, orbital dynamics, and touch-and-go dynamics for spacecraft covering three types of end-effectors: a sticky pad, a brush-wheel sampler, and a pellet gun. Several multi-body models of a free-flying spacecraft with a multi-link manipulator driving these end-effectors have been tested with typical contact conditions arising when the manipulator arm is to sample the surface of an asteroidal body. The test data have been infused directly into the dynamics formulation including such information as the mass collected as a function of end-effector longitudinal speed for the brush-wheel and sticky-pad samplers, and the mass collected as a function of projectile speed for the pellet gun sampler. These data represent the realistic behavior of the end effector while in contact with a surface, and represent a low-order model of more complex contact conditions that otherwise would have to be simulated. Numerical results demonstrate the adequacy of these multibody models for spacecraft and manipulator- arm control design. The work contributes to the development of a touch-and-go testbed for small body exploration, denoted as the GREX Testbed (GN&C for Rendezvous-based EXploration). The GREX testbed addresses the key issues involved in landing on an asteroidal body or comet; namely, a complex, low-gravity field; partially known terrain properties; possible comet outgassing; dust ejection; and navigating to a safe and scientifically desirable zone.
Author
ORBITAL MANEUVERS; END EFFECTORS; MANIPULATORS; PELLETS; SPACECRAFT MODELS; SAMPLERS; HYPERVELOCITY GUNS
20090032117 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Analog Input Data Acquisition Software
Arens, Ellen; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): KSC-13203; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032117
http://www.techbriefs.com/component/content/article/5706
DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.
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ANALOG DATA; DATA ACQUISITION; DATA PROCESSING
20090032118 California Inst. of Tech., Pasadena, CA, United States
Relay Sequence Generation Software
Gladden, Roy E.; Khanampompan, Teerapat; NASA Tech Briefs, September 2009; September 2009; pp. 52-5; In English
Report No.(s): NPO-46512; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032118
http://www.techbriefs.com/component/content/article/5692
Due to thermal and electromagnetic interactivity between the UHF (ultrahigh frequency) radio onboard the Mars Reconnaissance Orbiter (MRO), which performs relay sessions with the Martian landers, and the remainder of the MRO payloads, it is required to integrate and de-conflict relay sessions with the MRO science plan. The MRO relay SASF/PTF (spacecraft activity sequence file/ payload target file) generation software facilitates this process by generating a PTF that is needed to integrate the periods of time during which MRO supports relay activities with the rest of the MRO science plans. The software also generates the needed command products that initiate the relay sessions, some features of which are provided by the lander team, some are managed by MRO internally, and some being derived.
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DATA TRANSMISSION; SATELLITE TRANSMISSION; RADIO RELAY SYSTEMS; DATA LINKS; INTERPLANETARY COMMUNICATION
20090032119 United Space Alliance, Cape Canaveral, FL, United States
Group Capability Model
Olejarski, Michael; Appleton, Amy; Deltorchio, Stephen; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): KSC-13187; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032119
http://www.techbriefs.com/component/content/article/5695
The Group Capability Model (GCM) is a software tool that allows an organization, from first line management to senior executive, to monitor and track the health (capability) of various groups in performing their contractual obligations. GCM calculates a Group Capability Index (GCI) by comparing actual head counts, certifications, and/or skills within a group. The model can also be used to simulate the effects of employee usage, training, and attrition on the GCI. A universal tool and common method was required due to the high risk of losing skills necessary to complete the Space Shuttle Program and meet the needs of the Constellation Program. During this transition from one space vehicle to another, the uncertainty among the critical skilled workforce is high and attrition has the potential to be unmanageable. GCM allows managers to establish requirements for their group in the form of head counts, certification requirements, or skills requirements. GCM then calculates a Group Capability Index (GCI), where a score of 1 indicates that the group is at the appropriate level; anything less than 1 indicates a potential for improvement. This shows the health of a group, both currently and over time. GCM accepts as input head count, certification needs, critical needs, competency needs, and competency critical needs. In addition, team members are categorized by years of experience, percentage of contribution, ex-members and their skills, availability, function, and in-work requirements. Outputs are several reports, including actual vs. required head count, actual vs. required certificates, CGI change over time (by month), and more. The program stores historical data for summary and historical reporting, which is done via an Excel spreadsheet that is color-coded to show health statistics at a glance. GCM has provided the Shuttle Ground Processing team with a quantifiable, repeatable approach to assessing and managing the skills in their organization. They now have a common frame of reference across NASA/contractor lines to communicate and mitigate any critical skills concerns.
Author
SOFTWARE DEVELOPMENT TOOLS; ORGANIZATIONS; HUMAN PERFORMANCE; GROUP DYNAMICS
20090032120 California Inst. of Tech., Pasadena, CA, United States
Dynamic Hurricane Data Analysis Tool
Knosp, Brian W.; Li, Peggy; Vu, Quoc A.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): NPO-46417; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032120
http://www.techbriefs.com/component/content/article/5694
A dynamic hurricane data analysis tool allows users of the JPL Tropical Cyclone Information System (TCIS) to analyze data over a Web medium. The TCIS software is described in the previous article, Tropical Cyclone Information System (TCIS) (NPO-45748). This tool interfaces with the TCIS database to pull in data from several different atmospheric and oceanic data sets, both observed by instruments. Users can use this information to generate histograms, maps, and profile plots for specific storms. The tool also displays statistical values for the user-selected parameter for the mean, standard deviation, median, minimum, and maximum values. There is little wait time, allowing for fast data plots over date and spatial ranges. Users may also zoom-in for a closer look at a particular spatial range. This is version 1 of the software. Researchers will use the data and tools on the TCIS to understand hurricane processes, improve hurricane forecast models and identify what types of measurements the next generation of instruments will need to collect.
Author
HURRICANES; DATA PROCESSING; TROPICAL STORMS; CYCLONES; INFORMATION SYSTEMS
20090032121 NASA Johnson Space Center, Houston, TX, United States
Tracking Debris Shed by a Space-Shuttle Launch Vehicle
Stuart, Phillip C.; Rogers, Stuart E.; NASA Tech Briefs, September 2009; September 2009; pp. 40-4; In English
Report No.(s): MSC-23945-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032121
http://www.techbriefs.com/component/content/article/5675
The DEBRIS software predicts the trajectories of debris particles shed by a space-shuttle launch vehicle during ascent, to aid in assessing potential harm to the space-shuttle orbiter and crew. The user specifies the location of release and other initial conditions for a debris particle. DEBRIS tracks the particle within an overset grid system by means of a computational fluid dynamics (CFD) simulation of the local flow field and a ballistic simulation that takes account of the mass of the particle and its aerodynamic properties in the flow field. The computed particle trajectory is stored in a file to be post-processed by other software for viewing and analyzing the trajectory. DEBRIS supplants a prior debris tracking code that took .15 minutes to calculate a single particle trajectory: DEBRIS can calculate 1,000 trajectories in .20 seconds on a desktop computer. Other improvements over the prior code include adaptive time-stepping to ensure accuracy, forcing at least one step per grid cell to ensure resolution of all CFD-resolved flow features, ability to simulate rebound of debris from surfaces, extensive error checking, a builtin suite of test cases, and dynamic allocation of memory.
Author
COMPUTATIONAL FLUID DYNAMICS; SPACE SHUTTLES; DEBRIS; LAUNCH VEHICLES; COMPUTER PROGRAMS
20090032122 California Inst. of Tech., Pasadena, CA, United States
Planning Flight Paths of Autonomous Aerobots
Kulczycki, Eric; Elfes, Alberto; Sharma, Shivanjli; NASA Tech Briefs, September 2009; September 2009; pp. 39-4; In English; Original contains color illustrations
Report No.(s): NPO-44395; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032122
http://www.techbriefs.com/component/content/article/5674
Algorithms for planning flight paths of autonomous aerobots (robotic blimps) to be deployed in scientific exploration of remote planets are undergoing development. These algorithms are also adaptable to terrestrial applications involving robotic submarines as well as aerobots and other autonomous aircraft used to acquire scientific data or to perform surveying or monitoring functions.
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AUTONOMY; FLIGHT PATHS; ROBOTICS; UNMANNED AIRCRAFT SYSTEMS; AIRCRAFT MANEUVERS
20090032123 NASA Kennedy Space Center, Cocoa Beach, FL, United States
Gaussian and Lognormal Models of Hurricane Gust Factors
Merceret, Frank; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): KSC-13347; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032123
http://www.techbriefs.com/component/content/article/5660
A document describes a tool that predicts the likelihood of land-falling tropical storms and hurricanes exceeding specified peak speeds, given the mean wind speed at various heights of up to 500 feet (150 meters) above ground level. Empirical models to calculate mean and standard deviation of the gust factor as a function of height and mean wind speed were developed in Excel based on data from previous hurricanes. Separate models were developed for Gaussian and offset lognormal distributions for the gust factor. Rather than forecasting a single, specific peak wind speed, this tool provides a probability of exceeding a specified value. This probability is provided as a function of height, allowing it to be applied at a height appropriate for tall structures. The user inputs the mean wind speed, height, and operational threshold. The tool produces the probability from each model that the given threshold will be exceeded. This application does have its limits. They were tested only in tropical storm conditions associated with the periphery of hurricanes. Winds of similar speed produced by non-tropical system may have different turbulence dynamics and stability, which may change those winds statistical characteristics. These models were developed along the Central Florida seacoast, and their results may not accurately extrapolate to inland areas, or even to coastal sites that are different from those used to build the models. Although this tool cannot be generalized for use in different environments, its methodology could be applied to those locations to develop a similar tool tuned to local conditions.
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NORMAL DENSITY FUNCTIONS; MATHEMATICAL MODELS; HURRICANES; GUSTS; TROPICAL STORMS
20090032124 NASA Glenn Research Center, Cleveland, OH, United States
Interactive, Automated Management of Icing Data
Levinson, Laurie H.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English; Original contains color illustrations
Report No.(s): LEW-18343-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032124
http://www.techbriefs.com/component/content/article/5685
IceVal DatAssistant is software (see figure) that provides an automated, interactive solution for the management of data from research on aircraft icing. This software consists primarily of (1) a relational database component used to store ice shape and airfoil coordinates and associated data on operational and environmental test conditions and (2) a graphically oriented database access utility, used to upload, download, process, and/or display data selected by the user. The relational database component consists of a Microsoft Access 2003 database file with nine tables containing data of different types. Included in the database are the data for all publicly releasable ice tracings with complete and verifiable test conditions from experiments conducted to date in the Glenn Research Center Icing Research Tunnel. Ice shapes from computational simulations with the correspond ing conditions performed utilizing the latest version of the LEWICE ice shape prediction code are likewise included, and are linked to the equivalent experimental runs. The database access component includes ten Microsoft Visual Basic 6.0 (VB) form modules and three VB support modules. Together, these modules enable uploading, downloading, processing, and display of all data contained in the database. This component also affords the capability to perform various database maintenance functions for example, compacting the database or creating a new, fully initialized but empty database file.
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AUTOMATIC CONTROL; ICE FORMATION; COMPUTER SYSTEMS DESIGN; DATA PROCESSING
20090032125 California Inst. of Tech., Pasadena, CA, United States
Extensible Infrastructure for Browsing and Searching Abstracted Spacecraft Data
Wallick, Michael N.; Crockett, Thomas M.; Joswig, Joseph C.; Torres, Recaredo J.; Norris, Jeffrey S.; Fox, Jason M.; Powell, Mark W.; Mittman, David S.; Abramyan, Lucy; Shams, Khawaja S.; Vaughn, Michael B.; Pyrzak, Guy; Ludowise, Melissa; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-46397; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032125
http://www.techbriefs.com/component/content/article/5703
A computer program has been developed to provide a common interface for all space mission data, and allows different types of data to be displayed in the same context. This software provides an infrastructure for representing any type of mission data.
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COMPUTER PROGRAMS; HUMAN-COMPUTER INTERFACE; DATA BASES; DATA INTEGRATION; DATA RETRIEVAL
20090032126 California Inst. of Tech., Pasadena, CA, United States
XML Translator for Interface Descriptions
Boroson, Elizabeth R.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): NPO-46447; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032126
http://www.techbriefs.com/component/content/article/5696
A computer program defines an XML schema for specifying the interface to a generic FPGA from the perspective of software that will interact with the device. This XML interface description is then translated into header files for C, Verilog, and VHDL. User interface definition input is checked via both the provided XML schema and the translator module to ensure consistency and accuracy. Currently, programming used on both sides of an interface is inconsistent. This makes it hard to find and fix errors. By using a common schema, both sides are forced to use the same structure by using the same framework and toolset. This makes for easy identification of problems, which leads to the ability to formulate a solution. The toolset contains constants that allow a programmer to use each register, and to access each field in the register. Once programming is complete, the translator is run as part of the make process, which ensures that whenever an interface is changed, all of the code that uses the header files describing it is recompiled.
Author
COMPUTER PROGRAMS; DOCUMENT MARKUP LANGUAGES; HARDWARE DESCRIPTION LANGUAGES; OPERATING SYSTEMS (COMPUTERS); FIELD-PROGRAMMABLE GATE ARRAYS
20090032127 California Inst. of Tech., Pasadena, CA, United States
Framework for ReSTful Web Services in OSGi
Shams, Khawaja S.; Norris, Jeffrey S.; Powell, Mark W.; Crockett, Thomas M.; Mittman, David S.; Fox, Jason M.; Joswig, Joseph C.; Wallick, Michael N.; Torres, Recaredo J.; Rabe, Kenneth; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45848; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032127
http://www.techbriefs.com/component/content/article/5712
Ensemble ReST is a software system that eases the development, deployment, and maintenance of server-side application programs to perform functions that would otherwise be performed by client software. Ensemble ReST takes advantage of the proven disciplines of ReST (Representational State Transfer. ReST leverages the standardized HTTP protocol to enable developers to offer services to a diverse variety of clients: from shell scripts to sophisticated Java application suites
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APPLICATIONS PROGRAMS (COMPUTERS); SOFTWARE ENGINEERING; SOFTWARE DEVELOPMENT TOOLS; PROGRAMMING ENVIRONMENTS
20090032128 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Alert Notification System Router
Gurganus, Joseph; Carey, Everett; Antonucci, Robert; Hitchener, Peter; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): GSC-15592-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032128
http://www.techbriefs.com/component/content/article/5708
The Alert Notification System Router (ANSR) software provides satellite operators with notifications of key events through pagers, cell phones, and e-mail. Written in Java, this application is specifically designed to meet the mission-critical standards for mission operations while operating on a variety of hardware environments. ANSR is a software component that runs inside the Mission Operations Center (MOC). It connects to the mission's message bus using the GMSEC [Goddard Space Flight Center (GSFC) Mission Services Evolution Center (GMSEC)] standard. Other components, such as automation and monitoring components, can use ANSR to send directives to notify users or groups. The ANSR system, in addition to notifying users, can check for message acknowledgements from a user and escalate the notification to another user if there is no acknowledgement. When a firewall prevents ANSR from accessing the Internet directly, proxies can be run on the other side of the wall. These proxies can be configured to access the Internet, notify users, and poll for their responses. Multiple ANSRs can be run in parallel, providing a seamless failover capability in the event that one ANSR system becomes incapacitated.
Author
WARNING SYSTEMS; CONNECTORS; FIREWALLS (COMPUTERS); COMPUTER SYSTEMS PROGRAMS; COMPUTER COMPONENTS
20090032129 California Inst. of Tech., Pasadena, CA, United States
Lossless Compression of Classification-Map Data
Hua, Xie; Klimesh, Matthew; NASA Tech Briefs, September 2009; September 2009; pp. 55-5; In English; Original contains color illustrations
Report No.(s): NPO-45103; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032129
http://www.techbriefs.com/component/content/article/5704
A lossless image-data-compression algorithm intended specifically for application to classification-map data is based on prediction, context modeling, and entropy coding. The algorithm was formulated, in consideration of the differences between classification maps and ordinary images of natural scenes, so as to be capable of compressing classification- map data more effectively than do general-purpose image-data-compression algorithms. Classification maps are typically generated from remote-sensing images acquired by instruments aboard aircraft (see figure) and spacecraft. A classification map is a synthetic image that summarizes information derived from one or more original remote-sensing image(s) of a scene. The value assigned to each pixel in such a map is the index of a class that represents some type of content deduced from the original image data for example, a type of vegetation, a mineral, or a body of water at the corresponding location in the scene. When classification maps are generated onboard the aircraft or spacecraft, it is desirable to compress the classification-map data in order to reduce the volume of data that must be transmitted to a ground station.
Author
CLASSIFICATIONS; IMAGE PROCESSING; REMOTE SENSING; MAPPING; DATA ACQUISITION; LOSSLESS MATERIALS; DATA COMPRESSION
20090032130 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft
Stoneking, Eric T.; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): GSC-15737-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032130
http://www.techbriefs.com/component/content/article/5667
Agora software is a simulation of spacecraft attitude and orbit dynamics. It supports spacecraft models composed of multiple rigid bodies or flexible structural models. Agora simulates multiple spacecraft simultaneously, supporting rendezvous, proximity operations, and precision formation flying studies. The Agora environment includes ephemerides for all planets and major moons in the solar system, supporting design studies for deep space as well as geocentric missions. The environment also contains standard models for gravity, atmospheric density, and magnetic fields. Disturbance force and torque models include aerodynamic, gravity-gradient, solar radiation pressure, and third-body gravitation. In addition to the dynamic and environmental models, Agora supports geometrical visualization through an OpenGL interface. Prototype models are provided for common sensors, actuators, and control laws. A clean interface accommodates linking in actual flight code in place of the prototype control laws. The same simulation may be used for rapid feasibility studies, and then used for flight software validation as the design matures. Agora is open-source and portable across computing platforms, making it customizable and extensible. It is written to support the entire GNC (guidance, navigation, and control) design cycle, from rapid prototyping and design analysis, to high-fidelity flight code verification. As a top-down design, Agora is intended to accommodate a large range of missions, anywhere in the solar system. Both two-body and three-body flight regimes are supported, as well as seamless transition between them. Multiple spacecraft may be simultaneously simulated, enabling simulation of rendezvous scenarios, as well as formation flying. Built-in reference frames and orbit perturbation dynamics provide accurate modeling of precision formation control.
Author
SIMULATION; SPACECRAFT CONTROL; SPACECRAFT MODELS; SYSTEMS ENGINEERING; SPACECRAFT TRAJECTORIES; ATTITUDE CONTROL
20090032131 NASA Johnson Space Center, Houston, TX, United States
Improved Aerogel Vacuum Thermal Insulation
Ruemmele, Warren P.; Bue, Grant C.; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English; Original contains color illustrations
Report No.(s): MSC-24351-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032131
http://www.techbriefs.com/component/content/article/5629
An improved design concept for aerogel vacuum thermal-insulation panels calls for multiple layers of aerogel sandwiched between layers of aluminized Mylar (or equivalent) poly(ethylene terephthalate), as depicted in the figure. This concept is applicable to both the rigid (brick) form and the flexible (blanket) form of aerogel vacuum thermal-insulation panels. Heretofore, the fabrication of a typical aerogel vacuum insulating panel has involved encapsulation of a single layer of aerogel in poly(ethylene terephthalate) and pumping of gases out of the aerogel-filled volume. A multilayer panel according to the improved design concept is fabricated in basically the same way: Multiple alternating layers of aerogel and aluminized poly(ethylene terephthalate) are assembled, then encapsulated in an outer layer of poly(ethylene terephthalate), and then the volume containing the multilayer structure is evacuated as in the single-layer case. The multilayer concept makes it possible to reduce effective thermal conductivity of a panel below that of a comparable single-layer panel, without adding weight or incurring other performance penalties. Implementation of the multilayer concept is simple and relatively inexpensive, involving only a few additional fabrication steps to assemble the multiple layers prior to evacuation. For a panel of the blanket type, the multilayer concept, affords the additional advantage of reduced stiffness.
Author
AEROGELS; FABRICATION; THERMAL CONDUCTIVITY; THERMAL INSULATION; MULTILAYER INSULATION
20090032132 California Inst. of Tech., Pasadena, CA, United States
Video-Game-Like Engine for Depicting Spacecraft Trajectories
Upchurch, Paul R.; NASA Tech Briefs, September 2009; September 2009; pp. 54-5; In English
Report No.(s): NPO-45274; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032132
http://www.techbriefs.com/component/content/article/5705
GoView is a video-game-like software engine, written in the C and C++ computing languages, that enables real-time, three-dimensional (3D)-appearing visual representation of spacecraft and trajectories (1) from any perspective; (2) at any spatial scale from spacecraft to Solar-system dimensions; (3) in user-selectable time scales; (4) in the past, present, and/or future; (5) with varying speeds; and (6) forward or backward in time. GoView constructs an interactive 3D world by use of spacecraft-mission data from pre-existing engineering software tools. GoView can also be used to produce distributable application programs for depicting NASA orbital missions on personal computers running the Windows XP, Mac OsX, and Linux operating systems. GoView enables seamless rendering of Cartesian coordinate spaces with programmable graphics hardware, whereas prior programs for depicting spacecraft trajectories variously require non-Cartesian coordinates and/or are not compatible with programmable hardware. GoView incorporates an algorithm for nonlinear interpolation between arbitrary reference frames, whereas the prior programs are restricted to special classes of inertial and non-inertial reference frames. Finally, whereas the prior programs present complex user interfaces requiring hours of training, the GoView interface provides guidance, enabling use without any training.
Author
VIDEO COMMUNICATION; SPACECRAFT TRAJECTORIES; SOFTWARE DEVELOPMENT TOOLS; NASA PROGRAMS
20090032133 California Inst. of Tech., Pasadena, CA, United States
Lossless Compression of Data into Fixed-Length Packets
Kiely, Aaron B.; Klimesh, Matthew A.; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45942; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032133
http://www.techbriefs.com/component/content/article/5704
A computer program effects lossless compression of data samples from a one-dimensional source into fixed-length data packets. The software makes use of adaptive prediction: it exploits the data structure in such a way as to increase the efficiency of compression beyond that otherwise achievable. Adaptive linear filtering is used to predict each sample value based on past sample values. The difference between predicted and actual sample values is encoded using a Golomb code.
Derived from text
COMPUTER PROGRAMS; DATA COMPRESSION; PACKETS (COMMUNICATION); DATA SAMPLING
20090032134 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Compact, Low-Overhead, MIL-STD-1553B Controller
Katz, Richard; Barto, Rod; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English
Report No.(s): GSC-15491-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032134
http://www.techbriefs.com/component/content/article/5624
A compact and flexible controller has been developed to provide MIL-STD- 1553B Remote Terminal (RT) communications and supporting and related functions with minimal demand on the resources of the system in which the controller is to be installed. (MIL-STD-1553B is a military standard that encompasses a method of communication and electrical-interface requirements for digital electronic subsystems connected to a data bus. MIL-STD-1553B is commonly used in defense and space applications.) Many other MIL-STD-1553B RT controllers are complicated, and to enable them to function, it is necessary to provide software and to use such ancillary separate hardware devices as microprocessors and dual-port memories. The present controller functions without need for software and any ancillary hardware. In addition, it contains a flexible system interface and extensive support hardware while including on-chip error-checking and diagnostic support circuitry. This controller is implemented within part of a modern field-programmable gate array.
Author
FIELD-PROGRAMMABLE GATE ARRAYS; CONTROLLERS; DIGITAL DATA; CHANNELS (DATA TRANSMISSION); COMPUTER PROGRAMS; CIRCUITS
20090032135 NASA Ames Research Center, Moffett Field, CA, United States
Computing Bounds on Resource Levels for Flexible Plans
Muscvettola, Nicola; Rijsman, David; NASA Tech Briefs, September 2009; September 2009; pp. 50-5; In English; Original contains color illustrations
Report No.(s): ARC-14948-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032135
http://www.techbriefs.com/component/content/article/5701
A new algorithm efficiently computes the tightest exact bound on the levels of resources induced by a flexible activity plan (see figure). Tightness of bounds is extremely important for computations involved in planning because tight bounds can save potentially exponential amounts of search (through early backtracking and detection of solutions), relative to looser bounds. The bound computed by the new algorithm, denoted the resource-level envelope, constitutes the measure of maximum and minimum consumption of resources at any time for all fixed-time schedules in the flexible plan. At each time, the envelope guarantees that there are two fixed-time instantiations one that produces the minimum level and one that produces the maximum level. Therefore, the resource-level envelope is the tightest possible resource-level bound for a flexible plan because any tighter bound would exclude the contribution of at least one fixed-time schedule. If the resource- level envelope can be computed efficiently, one could substitute looser bounds that are currently used in the inner cores of constraint-posting scheduling algorithms, with the potential for great improvements in performance. What is needed to reduce the cost of computation is an algorithm, the measure of complexity of which is no greater than a low-degree polynomial in N (where N is the number of activities). The new algorithm satisfies this need. In this algorithm, the computation of resource-level envelopes is based on a novel combination of (1) the theory of shortest paths in the temporal-constraint network for the flexible plan and (2) the theory of maximum flows for a flow network derived from the temporal and resource constraints. The measure of asymptotic complexity of the algorithm is O(N O(maxflow(N)), where O(x) denotes an amount of computing time or a number of arithmetic operations proportional to a number of the order of x and O(maxflow(N)) is the measure of complexity (and thus of cost) of a maximumflow algorithm applied to an auxiliary flow network of 2N nodes. The algorithm is believed to be efficient in practice; experimental analysis shows the practical cost of maxflow to be as low as O(N1.5). The algorithm could be enhanced following at least two approaches. In the first approach, incremental subalgorithms for the computation of the envelope could be developed. By use of temporal scanning of the events in the temporal network, it may be possible to significantly reduce the size of the networks on which it is necessary to run the maximum-flow subalgorithm, thereby significantly reducing the time required for envelope calculation. In the second approach, the practical effectiveness of resource envelopes in the inner loops of search algorithms could be tested for multi-capacity resource scheduling. This testing would include inner-loop backtracking and termination tests and variable and value-ordering heuristics that exploit the properties of resource envelopes more directly.
Author
HEURISTIC METHODS; COMPUTATION; ALGORITHMS; LOOPS; POLYNOMIALS; SCHEDULES
20090032136 California Inst. of Tech., Pasadena, CA, United States
MSLICE Science Activity Planner for the Mars Science Laboratory Mission
Powell, Mark W.; Shams, Khawaja S.; Wallick, Michael N.; Norris, Jeffrey S.; Joswig, Joseph C.; Crockett, Thomas M.; Fox, Jason M.; Torres, Recaredo J.; Kurien, James A.; McCurdy, Michael P.; Pyrzak, Guy; Aghevli, Arash; Bachmann, Andrew G.; NASA Tech Briefs, September 2009; September 2009; pp. 51-5; In English
Report No.(s): NPO-45908; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032136
http://www.techbriefs.com/component/content/article/5707
MSLICE (Mars Science Laboratory InterfaCE) is the tool used by scientists and engineers on the Mars Science Laboratory rover mission to visualize the data returned by the rover and collaboratively plan its activities. It enables users to efficiently and effectively search all mission data to find applicable products (e.g., images, targets, activity plans, sequences, etc.), view and plan the traverse of the rover in HiRISE (High Resolution Imaging Science Experiment) images, visualize data acquired by the rover, and develop, model, and validate the activities the rover will perform. MSLICE enables users to securely contribute to the mission s activity planning process from their home institutions using off-the-shelf laptop computers. This software has made use of several plug-ins (software components) developed for previous missions [e.g., Mars Exploration Rover (MER), Phoenix Mars Lander (PHX)] and other technology tasks. It has a simple, intuitive, and powerful search capability. For any given mission, there is a huge amount of data and associated metadata that is generated. To help users sort through this information, MSLICE s search interface is provided in a similar fashion as major Internet search engines. With regard to the HiRISE visualization of the rover s traverse, this view is a map of the mission that allows scientists to easily gauge where the rover has been and where it is likely to go. The map also provides the ability to correct or adjust the known position of the rover through the overlaying of images acquired from the rover on top of the HiRISE image. A user can then correct the rover s position by collocating the visible features in the overlays with the same features in the underlying HiRISE image. MSLICE users can also rapidly search all mission data for images that contain a point specified by the user in another image or panoramic mosaic. MSLICE allows the creation of targets, which provides a way for scientists to collaboratively name features on the surface of Mars. These targets can also be used to convey instrument-pointing information to the activity plan. The software allows users to develop a plan of what they would like the rover to accomplish for a given time period. When developing the plan, the user can input constraints between activities or groups of activities. MSLICE will enforce said constraints and ensure that all mission flight rules are satisfied.
Author
MARS EXPLORATION; MARS MISSIONS; IMAGING TECHNIQUES; PHOENIX MARS LANDER; ROVING VEHICLES; MISSION PLANNING; MARS SURFACE; HIGH RESOLUTION; INFORMATION RETRIEVAL
20090032137 California Inst. of Tech., Pasadena, CA, United States
Circuit for Driving Piezoelectric Transducers
Randall, David P.; Chapsky, Jacob; NASA Tech Briefs, September 2009; September 2009; pp. 11-1; In English; Original contains color illustrations
Report No.(s): NPO-45529; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032137
http://www.techbriefs.com/component/content/article/5615
The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the piezoelectric transducer. This positive AC feedback, in combination with the slow feedback to the voltage-variable resistors, causes the overall loop gain to be just large enough to keep the oscillator running. The positive feedback loop includes two 16-channel multiplexers, which are not shown in the figure. One multiplexer is used to select the desired piezoelectric transducer. The other multiplexer, which is provided for use in the event that there are significant differences among the damping times of the 16 piezoelectric transducers, facilitates changing the value of one of the resistors in the positive-feedback loop to accommodate the damping time of the selected transducer.
Author
CIRCUITS; PIEZOELECTRIC TRANSDUCERS; OSCILLATORS; VIBRATION; MECHANICAL DRIVES; ALTERNATING CURRENT; FEEDBACK CONTROL; RESONANT FREQUENCIES; POSITIVE FEEDBACK
20090032138 NASA Johnson Space Center, Houston, TX, United States
Filtering Water by Use of Ultrasonically Vibrated Nanotubes
Gavalas, Lillian Susan; NASA Tech Briefs, September 2009; September 2009; pp. ; In English; Original contains color illustrations
Report No.(s): MSC-24180-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032138
http://www.techbriefs.com/component/content/article/5609
Devices that could be characterized as acoustically driven molecular sieves have been proposed for filtering water to remove all biological contaminants and all molecules larger than water molecules. Originally intended for purifying wastewater for reuse aboard spacecraft, these devices could also be attractive for use on Earth in numerous settings in which there are requirements to obtain potable, medical-grade, or otherwise pure water from contaminated water supplies. These devices could also serve as efficient means of removing some or all water from chemical products . for example, they might be useful as adjuncts or substitutes for stills in the removal of water from alcohols and alcoholic beverages. These devices may be constructed using various materials, such as ceramics, metallics, or polymers, depending on end-use requirements. A representative device of this type (see figure) would include a polymeric disk, about 1 mm in diameter and between 1 and 40 microns thick, within which would be embedded single-wall carbon nanotubes aligned along the thickness axis. The polymeric disk would be part of a unitary polymeric ring assembly. An acoustic transducer in the form of a piezoelectric-film-and-electrode subassembly - typically 9 microns thick and made of poly(vinylidene fluoride) coated with copper 150 nm thick -. would be affixed to the outside of the outer polymeric ring by means of an electrically nonconductive epoxy. The nanotubes would be chosen to have diameters between about 8 and about 13.5 A because water molecules could fit into the nanotubes, but larger molecules could not. Water to be purified would be placed in contact with one face (typically, the upper face) of the filter disk. The surface tension of water is low enough that water molecules should enter and travel along the nanotubes, and computational simulations of molecular dynamics and experimental measurements have shown that the water molecules inside the nanotubes in this size range can be expected to become aligned into helical columns that exhibit properties of both hexagonal ice crystals and liquid water
Author
CARBON NANOTUBES; SOUND TRANSDUCERS; ELECTROACOUSTIC TRANSDUCERS; INTERFACIAL TENSION; PIEZOELECTRICITY; WASTE WATER; FILTRATION
20090032139 North Carolina Central Univ., Durham, NC, United States
Computer Code for Nanostructure Simulation
Filikhin, Igor; Vlahovic, Branislav; NASA Tech Briefs, September 2009; September 2009; pp. ; In English
Report No.(s): LEW-18414-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032139
http://www.techbriefs.com/component/content/article/5610
Due to their small size, nanostructures can have stress and thermal gradients that are larger than any macroscopic analogue. These gradients can lead to specific regions that are susceptible to failure via processes such as plastic deformation by dislocation emission, chemical debonding, and interfacial alloying. A program has been developed that rigorously simulates and predicts optoelectronic properties of nanostructures of virtually any geometrical complexity and material composition. It can be used in simulations of energy level structure, wave functions, density of states of spatially configured phonon-coupled electrons, excitons in quantum dots, quantum rings, quantum ring complexes, and more. The code can be used to calculate stress distributions and thermal transport properties for a variety of nanostructures and interfaces, transport and scattering at nanoscale interfaces and surfaces under various stress states, and alloy compositional gradients. The code allows users to perform modeling of charge transport processes through quantum-dot (QD) arrays as functions of inter-dot distance, array order versus disorder, QD orientation, shape, size, and chemical composition for applications in photovoltaics and physical properties of QD-based biochemical sensors. The code can be used to study the hot exciton formation/relation dynamics in arrays of QDs of different shapes and sizes at different temperatures. It also can be used to understand the relation among the deposition parameters and inherent stresses, strain deformation, heat flow, and failure of nanostructures.
Author
NANOSTRUCTURES (DEVICES); COMPUTER PROGRAMS; TEMPERATURE GRADIENTS; PHOTOVOLTAIC CONVERSION; ENERGY LEVELS; DEBONDING (MATERIALS); CHARGE TRANSFER; HEAT TRANSMISSION
20090032140 California Inst. of Tech., Pasadena, CA, United States
Telemetry-Enhancing Scripts
Maimone, Mark W.; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45700; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032140
http://www.techbriefs.com/component/content/article/5700
Scripts Providing a Cool Kit of Telemetry Enhancing Tools (SPACKLE) is a set of software tools that fill gaps in capabilities of other software used in processing downlinked data in the Mars Exploration Rovers (MER) flight and test-bed operations. SPACKLE tools have helped to accelerate the automatic processing and interpretation of MER mission data, enabling non-experts to understand and/or use MER query and data product command simulation software tools more effectively. SPACKLE has greatly accelerated some operations and provides new capabilities. The tools of SPACKLE are written, variously, in Perl or the C or C++ language. They perform a variety of search and shortcut functions that include the following: Generating text-only, Event Report-annotated, and Web-enhanced views of command sequences; Labeling integer enumerations with their symbolic meanings in text messages and engineering channels; Systematic detecting of corruption within data products; Generating text-only displays of data-product catalogs including downlink status; Validating and labeling of commands related to data products; Performing of convenient searches of detailed engineering data spanning multiple Martian solar days; Generating tables of initial conditions pertaining to engineering, health, and accountability data; Simplified construction and simulation of command sequences; and Fast time format conversions and sorting.
Author
C (PROGRAMMING LANGUAGE); C++ (PROGRAMMING LANGUAGE); TELEMETRY; DATA SIMULATION; MARS EXPLORATION; ROVING VEHICLES; DISPLAY DEVICES
20090032141 California Inst. of Tech., Pasadena, CA, United States
Policy-Based Management Natural Language Parser
James, Mark; NASA Tech Briefs, September 2009; September 2009; pp. 5; In English
Report No.(s): NPO-45816; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032141
http://www.techbriefs.com/component/content/article/5711
The Policy-Based Management Natural Language Parser (PBEM) is a rules-based approach to enterprise management that can be used to automate certain management tasks. This parser simplifies the management of a given endeavor by establishing policies to deal with situations that are likely to occur. Policies are operating rules that can be referred to as a means of maintaining order, security, consistency, or other ways of successfully furthering a goal or mission. PBEM provides a way of managing configuration of network elements, applications, and processes via a set of high-level rules or business policies rather than managing individual elements, thus switching the control to a higher level. This software allows unique management rules (or commands) to be specified and applied to a cross-section of the Global Information Grid (GIG). This software embodies a parser that is capable of recognizing and understanding conversational English. Because all possible dialect variants cannot be anticipated, a unique capability was developed that parses passed on conversation intent rather than the exact way the words are used. This software can increase productivity by enabling a user to converse with the system in conversational English to define network policies. PBEM can be used in both manned and unmanned science-gathering programs. Because policy statements can be domain-independent, this software can be applied equally to a wide variety of applications.
Author
POLICIES; NATURAL LANGUAGE (COMPUTERS); PARSING ALGORITHMS; PRODUCTIVITY; WORDS (LANGUAGE)
20090032142 California Inst. of Tech., Pasadena, CA, United States
DSN Simulator
Fijany, Amir; Vatan, Farrokh; Barrett, Anthony; James, Mark; Mackey, Ryan; Williams, Colin; NASA Tech Briefs, September 2009; September 2009; pp. 3; In English
Report No.(s): NPO-45513; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032142
http://www.techbriefs.com/component/content/article/5671
The DSN Simulator (wherein DSN signifies NASA's Deep Space Network) is an updated version of the software described in DSN Array Simulator (NPO-44506), Software Tech Briefs (Special supplement to NASA Tech Briefs), Vol. 32, No. 9 (September 2008), page 26. To recapitulate: This software is used for computational modeling of proposed DSN facilities comprising arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and data volumes), and statistical distributions thereof as functions of time. The prior version of the software could model only one DSN facility at a time and included hard-coded, unconfigurable metrics. The present updated version is capable of modeling the entire DSN and provides for configurable metrics, making it possible to perform loading analyses for alternative future DSN architectures and mission-set scenarios. The present version also features an improved user interface and interfaces for exchange of data with other DSN software and with a DSN mission model database.
Author
DEEP SPACE NETWORK; SIMULATORS; ANTENNA ARRAYS; MICROWAVE EQUIPMENT; STATISTICAL DISTRIBUTIONS; RECEIVERS; TRANSMISSION; COMPUTER PROGRAMS
20090032143 California Inst. of Tech., Pasadena, CA, United States
Dynamic Self-Locking of an OEO Containing a VCSEL
Strekalov, Dmitry; Matsko, Andrey; Yu, Nan; Savchenkov, Anatoliy; Maleki, Lute; NASA Tech Briefs, September 2009; September 2009; pp. 24-2; In English; Original contains color illustrations
Report No.(s): NPO-43751; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032143
http://www.techbriefs.com/component/content/article/5637
A method of dynamic self-locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface-emitting laser (VCSEL) that is an active element in the frequency-control loop of an optoelectronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency (EIT) resonance. This scheme can be considered an alternative to the one described in Optical Injection Locking of a VCSEL in an OEO (NPO-43454), NASA Tech Briefs, Vol. 33, No. 7 (July 2009), page 33. Both schemes are expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. To recapitulate from the cited prior article: In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. This concludes the background information. From the perspective that led to the conception of the optical injection-locking scheme described in the cited prior article, the variation of the VCSEL wavelength with the microwave power circulating in the frequency-control loop is regarded as a disadvantage and optical injection locking is a solution of the problem of stabilizing the wavelength in the presence of uncontrolled fluctuations in the microwave power. The present scheme for dynamic self-locking emerges from a different perspective, in which the dependence of VCSEL wavelength on microwave power is regarded as an advantageous phenomenon that can be exploited as a means of controlling the wavelength. The figure schematically depicts an atomic-clock OEO of the type in question, wherein (1) the light from the VCSEL is used to excite an EIT resonance in selected atoms in a gas cell (e.g., 87Rb atoms in a low-pressure mixture of Ar and Ne) and (2) the power supplied to the VCSEL is modulated by a microwave signal that includes components at beat frequencies among the VCSEL wavelength and modulation sidebands. As the VCSEL wavelength changes, it moves closer to or farther from a nearby absorption spectral line, and the optical power transmitted through the cell (and thus the loop gain) changes accordingly. A change in the loop gain causes a change in the microwave power and, thus, in the VCSEL wavelength. It is possible to choose a set of design and operational parameters (most importantly, the electronic part of the loop gain) such that the OEO stabilizes itself in the sense that an increase in circulating microwave power causes the VCSEL wavelength to change in a direction that results in an increase in optical absorption and thus a decrease in circulating microwave power. Typically, such an appropriate choice of operational parameters involves setting the nominal VCSEL wavelength to a point on the shorter-wavelength wing of an absorption spectral line.
Author
ATOMIC CLOCKS; DESIGN ANALYSIS; MICROWAVE FREQUENCIES; ELECTROMAGNETIC ABSORPTION; FREQUENCY CONTROL; INJECTION LOCKING; MICROWAVES; LINE SPECTRA
20090032144 California Inst. of Tech., Pasadena, CA, United States
Nonlinear Thermal Compensators for WGM Resonators
Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute; Yu, Nan; Iltchenko, Vladimir; NASA Tech Briefs, September 2009; September 2009; pp. 23-2; In English; Original contains color illustrations
Report No.(s): NPO-44567; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032144
http://www.techbriefs.com/component/content/article/5644
In an alternative version of a proposed bimaterial thermal compensator for a whispering-gallery-mode (WGM) optical resonator, a mechanical element having nonlinear stiffness would be added to enable stabilization of a desired resonance frequency at a suitable fixed working temperature. The previous version was described in "Bimaterial Thermal Compensators for WGM Resonators." Both versions are intended to serve as inexpensive means of preventing (to first order) or reducing temperature-related changes in resonance frequencies.
Derived from text
COMPENSATORS; NONLINEARITY; OPTICAL RESONATORS; WHISPERING GALLERY MODES; THERMAL STABILITY
20090032145 Nightsky Systems, Raleigh, NC, United States
Reaction Wheel Disturbance Model Extraction Software - RWDMES
Blaurock, Carl; NASA Tech Briefs, September 2009; September 2009; pp. 42-4; In English
Report No.(s): GSC15401-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032145
http://www.techbriefs.com/component/content/article/5681
The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral densities); converting PSDs to order analysis data; extracting harmonics; initializing and simultaneously tuning a harmonic model and a wheel structural model; initializing and tuning a broadband model; and verifying the harmonic/broadband/structural model against the measurement data. Functional operation is through a MATLAB GUI that loads test data, performs the various analyses, plots evaluation data for assessment and refinement of analysis parameters, and exports the data to documentation or downstream analysis code. The harmonic models are defined as specified functions of frequency, typically speed-squared. The reaction wheel structural model is realized as mass, damping, and stiffness matrices (typically from a finite element analysis package) with the addition of a gyroscopic forcing matrix. The broadband noise model is realized as a set of speed-dependent filters. The tuning of the combined model is performed using nonlinear least squares techniques. RWDMES is implemented as a MATLAB toolbox comprising the Fit Manager for performing the model extraction, Data Manager for managing input data and output models, the Gyro Manager for modifying wheel structural models, and the Harmonic Editor for evaluating and tuning harmonic models. This software was validated using data from Goodrich E wheels, and from GSFC Lunar Reconnaissance Orbiter (LRO) wheels. The validation testing proved that RWDMES has the capability to extract accurate disturbance models from flight reaction wheels with minimal user effort.
Author
REACTION WHEELS; EXTRACTION; PERFORMANCE PREDICTION; ENVIRONMENT MODELS; POINTING CONTROL SYSTEMS; GRAPHICAL USER INTERFACE
20090032146 California Inst. of Tech., Pasadena, CA, United States
Differential InP HEMT MMIC Amplifiers Embedded in Waveguides
Kangaslahti, Pekka; Schlecht, Erich; Samoska, Lorene; NASA Tech Briefs, September 2009; September 2009; pp. 13-1; In English
Report No.(s): NPO-42857; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032146
http://www.techbriefs.com/component/content/article/5623
Monolithic microwave integrated-circuit (MMIC) amplifiers of a type now being developed for operation at frequencies of hundreds of gigahertz contain InP high-electron-mobility transistors (HEMTs) in a differential configuration. The differential configuration makes it possible to obtain gains greater than those of amplifiers having the single-ended configuration. To reduce losses associated with packaging, the MMIC chips are designed integrally with, and embedded in, waveguide packages, with the additional benefit that the packages are compact enough to fit into phased transmitting and/or receiving antenna arrays. Differential configurations (which are inherently balanced) have been used to extend the upper limits of operating frequencies of complementary metal oxide/semiconductor (CMOS) amplifiers to the microwave range but, until now, have not been applied in millimeter- wave amplifier circuits. Baluns have traditionally been used to transform from single-ended to balanced configurations, but baluns tend to be lossy. Instead of baluns, finlines are used to effect this transformation in the present line of development. Finlines have been used extensively to drive millimeter- wave mixers in balanced configurations. In the present extension of the finline balancing concept, finline transitions are integrated onto the affected MMICs (see figure). The differential configuration creates a virtual ground within each pair of InP HEMT gate fingers, eliminating the need for inductive vias to ground. Elimination of these vias greatly reduces parasitic components of current and the associated losses within an amplifier, thereby enabling more nearly complete utilization of the full performance of each transistor. The differential configuration offers the additional benefit of multiplying (relative to the single-ended configuration) the input and output impedances of each transistor by a factor of four, so that it is possible to use large transistors that would otherwise have prohibitively low impedances. Yet another advantage afforded by the virtual ground of the differential configuration is elimination of the need for a ground plane and, hence, elimination of the need for back-side metallization of the MMIC chip. In turn, elimination of the back-side metallization simplifies fabrication, reduces parasitic capacitances, and enables mounting of the MMIC in the electric-field plane ("E-plane") of a waveguide. E-plane mounting is consistent with (and essential for the utility of) the finline configuration, in which transmission lines lie on a dielectric sheet in the middle of a broad side of the waveguide. E-plane mounting offers a combination of low loss and ease of assembly because no millimeter-wave wire bonds or transition substrates are required. Moreover, because there is no ground plane behind the MMIC, the impedance for the detrimental even (single-ended) mode is high, suppressing coupling to that mode. Still another advantage of E-plane mounting is that the fundamental waveguide mode is inherently differential, eliminating the need for a balun to excite the differential mode.
Author
HIGH ELECTRON MOBILITY TRANSISTORS; ANTENNA ARRAYS; EMBEDDING; TRANSMISSION LINES; MICROWAVE CIRCUITS; MICROWAVE AMPLIFIERS; ELECTRON MOBILITY; DIFFERENTIAL AMPLIFIERS
20090032147 California Inst. of Tech., Pasadena, CA, United States
Tropical Cyclone Information System
Li, P. Peggy; Knosp, Brian W.; Vu, Quoc A.; Yi, Chao; Hristova-Veleva, Svetla M.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English; Original contains color illustrations
Report No.(s): NPO-45748; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032147
http://www.techbriefs.com/component/content/article/5693
The JPL Tropical Cyclone Infor ma tion System (TCIS) is a Web portal (http://tropicalcyclone.jpl.nasa.gov) that provides researchers with an extensive set of observed hurricane parameters together with large-scale and convection resolving model outputs. It provides a comprehensive set of high-resolution satellite (see figure), airborne, and in-situ observations in both image and data formats. Large-scale datasets depict the surrounding environmental parameters such as SST (Sea Surface Temperature) and aerosol loading. Model outputs and analysis tools are provided to evaluate model performance and compare observations from different platforms. The system pertains to the thermodynamic and microphysical structure of the storm, the air-sea interaction processes, and the larger-scale environment as depicted by ocean heat content and the aerosol loading of the environment. Currently, the TCIS is populated with satellite observations of all tropical cyclones observed globally during 2005. There is a plan to extend the database both forward in time till present as well as backward to 1998. The portal is powered by a MySQL database and an Apache/Tomcat Web server on a Linux system. The interactive graphic user interface is provided by Google Map.
Author
CYCLONES; INFORMATION SYSTEMS; TROPICAL STORMS; HURRICANES; SATELLITE OBSERVATION
20090032148 California Inst. of Tech., Pasadena, CA, United States
High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell
Narayan, Sri; Haines, Brennan; Blosiu, Julian; Marzwell, Neville; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English; Original contains color illustrations
Report No.(s): NPO-45777; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032148
http://www.techbriefs.com/component/content/article/5632
A new cell designed to mimic the photosynthetic processes of plants to convert carbon dioxide into carbonaceous products and oxygen at high efficiency, has an improved configuration using a polymer membrane electrolyte and an alkaline medium. This increases efficiency of the artificial photosynthetic process, achieves high conversion rates, permits the use of inexpensive catalysts, and widens the range of products generated by this type of process. The alkaline membrane electrolyte allows for the continuous generation of sodium formate without the need for any additional separation system. The electrolyte type, pH, electrocatalyst type, and cell voltage were found to have a strong effect on the efficiency of conversion of carbon dioxide to formate. Indium electrodes were found to have higher conversion efficiency compared to lead. Bicarbonate electrolyte offers higher conversion efficiency and higher rates than water solutions saturated with carbon dioxide. pH values between 8 and 9 lead to the maximum values of efficiency. The operating cell voltage of 2.5 V, or higher, ensures conversion of the carbon dioxide to formate, although the hydrogen evolution reaction begins to compete strongly with the formate production reaction at higher cell voltages. Formate is produced at indium and lead electrodes at a conversion efficiency of 48 mg of CO2/kilojoule of energy input. This efficiency is about eight times that of natural photosynthesis in green plants. The electrochemical method of artificial photosynthesis is a promising approach for the conversion, separation and sequestration of carbon dioxide for confined environments as in space habitats, and also for carbon dioxide management in the terrestrial context. The heart of the reactor is a membrane cell fabricated from an alkaline polymer electrolyte membrane and catalyst- coated electrodes. This cell is assembled and held in compression in gold-plated hardware. The cathode side of the cell is supplied with carbon dioxide-saturated water or bicarbonate solution. The anode side of the cell is supplied with sodium hydroxide solution. The solutions are circulated past the electrodes in the electrochemical cell using pumps. A regulated power supply provides the electrical energy required for the reactions. Photovoltaic cells can be used to better mimic the photosynthetic reaction. The current flowing through the electrochemical cell, and the cell voltage, are monitored during experimentation. The products of the electrochemical reduction of carbon dioxide are allowed to accumulate in the cathode reservoir. Samples of the cathode solution are withdrawn for product analysis. Oxygen is generated on the anode side and is allowed to vent out of the reservoir.
Author
ALKALINE BATTERIES; CELL ANODES; FABRICATION; OXYGEN; PHOTOSYNTHESIS
20090032149 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays
Jhabvala, Murzy; Franz, David E.; Ewin, Audrey J.; Jhabvala, Christine; Babu, Sachi; Snodgrass, Stephen; Costen, Nicholas; Zincke, Christian; NASA Tech Briefs, September 2009; September 2009; pp. 1; In English
Report No.(s): GSC- 15665-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032149
http://www.techbriefs.com/component/content/article/5633
The silicon substrate carrier was created so that a large-area array (in this case 62,000+ elements of a microshutter array) and a variety of discrete passive and active devices could be mounted on a single board, similar to a printed circuit board. However, the density and number of interconnects far exceeds the capabilities of printed circuit board technology. To overcome this hurdle, a method was developed to fabricate this carrier out of silicon and implement silicon integrated circuit (IC) technology. This method achieves a large number of high-density metal interconnects; a 100-percent yield over a 6-in. (approximately equal to 15-cm) diameter wafer (one unit per wafer); a rigid, thermally compatible structure (all components and operating conditions) to cryogenic temperatures; re-workability and component replaceability, if required; and the ability to precisely cut large-area holes through the substrate. A method that would employ indium bump technology along with wafer-scale integration onto a silicon carrier was also developed. By establishing a silicon-based version of a printed circuit board, the objectives could be met with one solution. The silicon substrate would be 2 mm thick to survive the environmental loads of a launch. More than 2,300 metal traces and over 1,500 individual wire bonds are required. To mate the microshutter array to the silicon substrate, more than 10,000 indium bumps are required. A window was cut in the substrate to allow the light signal to pass through the substrate and reach the microshutter array. The substrate was also the receptacle for multiple unpackaged IC die wire-bonded directly to the substrate (thus conserving space over conventionally packaged die). Unique features of this technology include the implementation of a 2-mmthick silicon wafer to withstand extreme mechanical loads (from a rocket launch); integrated polysilicon resistor heaters directly on the substrate; the precise formation of an open aperture (approximately equal to 3x3cm) without any crack propagation; implementation of IR transmission blocking techniques; and compatibility with indium bump bonding. Although designed for the microshutter arrays for the NIRSpec instrument on the James Webb Space Telescope, these substrates can be linked to microshutter applications in the photomask generation and stepper equipment used to make ICs and microelectromechanical system (MEMS) devices.
Author
FABRICATION; WAFERS; SUBSTRATES; DETECTORS; SILICON; TECHNOLOGIES; INTEGRATED CIRCUITS; POLYCRYSTALS
20090032150 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays
Jhabvala, Murzy; Li, Mary; Moseley, Harvey; Franz, Dave; Yun, Zheng; Kutyrev, Alexander; NASA Tech Briefs, September 2009; September 2009; pp. 26-2; In English
Report No.(s): GSC- 15609-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032150
Three device improvements have been developed that dramatically enhance the contrast ratio of microshutters. The goal of a microshutter is to allow as much light through as possible when the shutters are in the open configuration, and preventing any light from passing through when they are in the closed position. The ratio of the transmitted light that is blocked is defined here as the contrast ratio. Three major components contribute to the improved performance of these microshutters: 1. The precise implementation of light shields, which protect the gap around the shutters so no light can leak through. It has been ascertained that without the light shield there would be a gap on the order of 1 percent of the shutter area, limiting the contrast to a maximum of 100. 2. The precise coating of the interior wall of each microshutter was improved with an insulator and metal using an angle deposition technique. The coating prevents any infrared light that finds an entrance on the surface of the microshutter cell from being emitted from a sidewall. Since silicon is in effect transparent to any light with a wavelength longer than .1 micrometer, these coatings are essential to blocking any stray signals when the shutters are closed. 3. A thin film of molybdenum nitride (MoN) was integrated onto the surface of the microshutter blade. This film provides the majority of light blockage over the microshutter and also ensures that the shutter can be operated over a wide temperature range by maintaining its flatness. These improvements were motivated by the requirements dictated by the James Webb Space Telescope NIRSpec instrument. The science goals of the NIRSpec require observing some of the very faintest objects in a given field of view that also may contain some very bright objects. To observe the faint objects, the light from the bright objects - which could be thousands of times brighter - must be completely blocked. If a closed microshutter is even slightly transmissive, a very bright object will still transmit a small signal, which can be larger than a signal from a very faint object transmitted through an open shutter. Since this situation can completely corrupt the results, it was necessary that the closed shutters be able to attenuate light by at least a factor of 2,000. There currently exist four flight-quality microshutter arrays that have been fully or are currently undergoing testing and the results support that the three improvements described above have successfully led to contrast levels greater than 50,000 in over 99 percent of the microshutters at an operating temperature of 35 K. Applications for these high-contrast microshutters are in the photomask generation and stepper equipment used to make integrated circuits and microelectromechanical (MEMS) devices. Since microshutters are a reconfigurable optical element, their versatility in these industries provides an improvement over printed masks and fixed projection alignment systems.
Author
MICROELECTROMECHANICAL SYSTEMS; INFRARED RADIATION; INTEGRATED CIRCUITS; FABRICATION; MOLYBDENUM; NITRIDES
20090032151 California Inst. of Tech., Pasadena, CA, United States
Conical-Domain Model for Estimating GPS Ionospheric Delays
Sparks, Lawrence; Komjathy, Attila; Mannucci, Anthony; NASA Tech Briefs, September 2009; September 2009; pp. 43-4; In English; Original contains color illustrations
Report No.(s): NPO-40930; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032151
http://www.techbriefs.com/component/content/article/5683
The conical-domain model is a computational model, now undergoing development, for estimating ionospheric delays of Global Positioning System (GPS) signals. Relative to the standard ionospheric delay model described below, the conical-domain model offers improved accuracy. In the absence of selective availability, the ionosphere is the largest source of error for single-frequency users of GPS. Because ionospheric signal delays contribute to errors in GPS position and time measurements, satellite-based augmentation systems (SBASs) have been designed to estimate these delays and broadcast corrections. Several national and international SBASs are currently in various stages of development to enhance the integrity and accuracy of GPS measurements for airline navigation. In the Wide Area Augmentation System (WAAS) of the United States, slant ionospheric delay errors and confidence bounds are derived from estimates of vertical ionospheric delay modeled on a grid at regularly spaced intervals of latitude and longitude. The estimate of vertical delay at each ionospheric grid point (IGP) is calculated from a planar fit of neighboring slant delay measurements, projected to vertical using a standard, thin-shell model of the ionosphere. Interpolation on the WAAS grid enables estimation of the vertical delay at the ionospheric pierce point (IPP) corresponding to any arbitrary measurement of a user. (The IPP of a given user s measurement is the point where the GPS signal ray path intersects a reference ionospheric height.) The product of the interpolated value and the user s thin-shell obliquity factor provides an estimate of the user s ionospheric slant delay. Two types of error that restrict the accuracy of the thin-shell model are absent in the conical domain model: (1) error due to the implicit assumption that the electron density is independent of the azimuthal angle at the IPP and (2) error arising from the slant-to-vertical conversion. At low latitudes or at mid-latitudes under disturbed conditions, the accuracy of SBAS systems based upon the thin-shell model suffers due to the presence of complex ionospheric structure, high delay values, and large electron density gradients. Interpolation on the vertical delay grid serves as an additional source of delay error. The conical-domain model permits direct computation of the user s slant delay estimate without the intervening use of a vertical delay grid. The key is to restrict each fit of GPS measurements to a spatial domain encompassing signals from only one satellite. The conical domain model is so named because each fit involves a group of GPS receivers that all receive signals from the same GPS satellite (see figure); the receiver and satellite positions define a cone, the satellite position being the vertex. A user within a given cone evaluates the delay to the satellite directly, using (1) the IPP coordinates of the line of sight to the satellite and (2) broadcast fit parameters associated with the cone. The conical-domain model partly resembles the thin-shell model in that both models reduce an inherently four-dimensional problem to two dimensions. However, unlike the thin-shell model, the conical domain model does not involve any potentially erroneous simplifying assumptions about the structure of the ionosphere. In the conical domain model, the initially four-dimensional problem becomes truly two-dimensional in the sense that once a satellite location has been specified, any signal path emanating from a satellite can be identified by only two coordinates; for example, the IPP coordinates. As a consequence, a user s slant-delay estimate converges to the correct value in the limit that the receivers converge to the user s location (or, equivalently, in the limit that the measurement IPPs converge to the user s IPP).
Author
GLOBAL POSITIONING SYSTEM; ATMOSPHERIC MODELS; EARTH IONOSPHERE; ELECTRON DENSITY (CONCENTRATION); COMPUTATIONAL GRIDS; LINE OF SIGHT; TIME MEASUREMENT
20090032152 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Evolvable Neural Software System
Curtis, Steven A.; NASA Tech Briefs, September 2009; September 2009; pp. 4; In English
Report No.(s): GSC-14657-1; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032152
http://www.techbriefs.com/component/content/article/5682
The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.
Author
NEURAL NETS; COMPUTER PROGRAMS; HEURISTIC METHODS; GENETIC CODE
20090032153 California Inst. of Tech., Pasadena, CA, United States
LDPC-PPM Coding Scheme for Optical Communication
Barsoum, Maged; Moision, Bruce; Divsalar, Dariush; Fitz, Michael; NASA Tech Briefs, September 2009; September 2009; pp. 45-4; In English; Original contains color illustrations
Report No.(s): NPO-44408; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032153
http://www.techbriefs.com/component/content/article/5687
In a proposed coding-and-modulation/demodulation-and-decoding scheme for a free-space optical communication system, an error-correcting code of the low-density parity-check (LDPC) type would be concatenated with a modulation code that consists of a mapping of bits to pulse-position-modulation (PPM) symbols. Hence, the scheme is denoted LDPC-PPM. This scheme could be considered a competitor of a related prior scheme in which an outer convolutional error-correcting code is concatenated with an interleaving operation, a bit-accumulation operation, and a PPM inner code. Both the prior and present schemes can be characterized as serially concatenated pulse-position modulation (SCPPM) coding schemes. Figure 1 represents a free-space optical communication system based on either the present LDPC-PPM scheme or the prior SCPPM scheme. At the transmitting terminal, the original data (u) are processed by an encoder into blocks of bits (a), and the encoded data are mapped to PPM of an optical signal (c). For the purpose of design and analysis, the optical channel in which the PPM signal propagates is modeled as a Poisson point process. At the receiving terminal, the arriving optical signal (y) is demodulated to obtain an estimate (a^) of the coded data, which is then processed by a decoder to obtain an estimate (u^) of the original data.
Derived from text
FREE-SPACE OPTICAL COMMUNICATION; PARITY; LOW DENSITY FLOW; COMPUTERIZED SIMULATION; ALGORITHMS; PULSE POSITION MODULATION
Additions to the NASA Aeronautics and Space Database as of 09/28/2009
20090032235 NASA Langley Research Center, Hampton, VA, United States
Experimental Performance of a Genetic Algorithm for Airborne Strategic Conflict Resolution
Karr, David A.; Vivona, Robert A.; Roscoe, David A.; DePascale, Stephen M.; Consiglio, Maria; August 10, 2009; In English; AIAA Guidance, Navigation, and Control Conference (GNC) 2009, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 411931.02.51.07.01
Report No.(s): LF99-8342; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032235
The Autonomous Operations Planner, a research prototype flight-deck decision support tool to enable airborne self-separation, uses a pattern-based genetic algorithm to resolve predicted conflicts between the ownship and traffic aircraft. Conflicts are resolved by modifying the active route within the ownship s flight management system according to a predefined set of maneuver pattern templates. The performance of this pattern-based genetic algorithm was evaluated in the context of batch-mode Monte Carlo simulations running over 3600 flight hours of autonomous aircraft in en-route airspace under conditions ranging from typical current traffic densities to several times that level. Encountering over 8900 conflicts during two simulation experiments, the genetic algorithm was able to resolve all but three conflicts, while maintaining a required time of arrival constraint for most aircraft. Actual elapsed running time for the algorithm was consistent with conflict resolution in real time. The paper presents details of the genetic algorithm s design, along with mathematical models of the algorithm s performance and observations regarding the effectiveness of using complimentary maneuver patterns when multiple resolutions by the same aircraft were required.
Author
FLIGHT MANAGEMENT SYSTEMS; REAL TIME OPERATION; GENETIC ALGORITHMS; AUTONOMY; OPERATIONS RESEARCH; AIRSPACE; MONTE CARLO METHOD
20090032241 International Trade Bridge, Inc., Beavercreek, OH, United States
Precision Cleaning of Oxygen Systems and Components
McLaughlin, Russell; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNH06CC40C
Copyright; Avail.: CASI: C01, CD-ROM: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032241
Currently, NASA uses Dichloropentafluoropropane (HCFC-225), a Class II ozone depleting substance (ODs), to clean contaminated oxygen systems. Starting in 20 15, the Montreal Protocols and Clean Air Act prohibit the production and importation of all hydrochlorofluorocarbons (HCFC), except for limited use in refrigeration applications. Thus, a new non-ozone depleting solvent needs to be developed for use in cleaning. Optimally, such a solvent should also be environmentally benign or green to avoid needing to replace the new solvent with yet another solvent in the future due to other environmental concerns. Work for the first year consisted of two parts. The first part was developing a method of testing the cleaning efficiency of potential solvents. Stainless steel coupons were contaminated with a known weight of various contaminants and contaminant combinations and then immersed in solvent for ten minutes. The coupons were then removed and dried in an oven until all solvent had evaporated. Once dry, the coupons were weighed and the mass of the non-volatile residue (NVR) left on the coupon was determined. The cleaning efficiency of the solvents is reported as percent cleaning, with 100% cleaning being zero NVR left on the test coupon. The second half of the first goal was to use the develop method to perform baseline testing on current solvents. The second part of the work was to begin exploring alternative cleaning solvents. A variety of hydrofluorocarbons (HFCs) were tested. Preliminary testing was also performed with ionic liquids and aqueous surfactant solutions. Once potential solvents were identified, an analysis of the performance and environmental characteristics of each was to be conducted. Four contaminants were specified for use in testing. These are Mil-Spec-H-5606 (5606), a hydraulic fluid, Mil-H-83282B (83282), another hydraulic fluid, diethylhexyl sebacate (Sebacate), and WD-40. The structures of these contaminants are all similar, with long aliphatic hydrocarbon chains of lengths between fifteen and fifty. Contaminants were tested both individually and in combination. All combinations were done with equal weights of the constituent contaminants.
Author
CLEANING; CONTAMINANTS; OXYGEN SUPPLY EQUIPMENT; SOLVENTS; STAINLESS STEELS; AIR QUALITY; PRECISION
20090032243 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Thermal Infrared Spectroscopy of Saturn and Titan from Cassini
Jennings, Donald E.; Brasunas, J. C.; Carlson, R. C.; Flasar, F. M.; Kunde, V. G.; Mamoutkine, A. A.; Nixon, A.; Pearl, J. C.; Romani, P. N.; Simon-Miller, A. A.; Bjoraker, G. L.; April 26, 2009; In English; OSA Fourier Transform Spectroscopy (FTS) Technical Conference, 26 Apr. - 1 May 2009, Vancouver, BC, Canada; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032243
The Cassini spacecraft completed its nominal mission at Saturn in 2008 and began its extended mission. Cassini carries the Composite Infrared Spectrometer (CIRS); a Fourier transform spectrometer that measures the composition, thermal structure and dynamics of the atmospheres of Saturn and Titan, and also the temperatures of other moons and the rings.
Author
CASSINI MISSION; INFRARED SPECTROSCOPY; TITAN; SATURN RINGS; PLANETARY TEMPERATURE
20090032244 NASA Johnson Space Center, Houston, TX, United States
Going South: Analysis of an Historic Project Engineering Failure
Scott, John H.; September 14, 2009; In English; AIAA Space 2009, 14-17 Sep. 2009, Reston, VA, United States; Original contains color illustrations
Report No.(s): JSC-CN-18782; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032244
NASA's successful conduct of the Apollo Program greatly enhanced the prestige of the United States and remains broadly accepted as America's gift to all Mankind. NASA's accomplishments continue to amaze the world. With the Vision for Space Exploration (VSE) Americans once again tasked NASA to carry out a project that is expected to provide inspiration and economic stimulus to the United States and to the world. In preparation NASA has thoroughly examined space program precedents. There is, however, another precedent which has not been examined in this context but whose scope and environment in many ways parallel the VSE. This project was initiated by a team that had, ten years before, successfully completed an effort that, at a cost of $173 billion (in 2008 dollars), had pushed the envelope of technology, brought economic growth, established their country as the world leader in engineering, and been broadly accepted as that country's gift to all Mankind. The new project was again inspired by popular desire to enhance national prestige and make yet another major contribution to Humanity. This effort was predicted to require eight years and $156 billion (2008 dollars). However, after nine years and expenditures of 96% beyond the baseline, the project collapsed amid bankruptcy, political scandal, and criminal prosecution. This paper applies current project management metrics, such as earned value analysis, to review the strategic decisions in this historic failure and describe its ultimate collapse. Key mistakes are identified, and lessons are drawn which may prove useful in guiding the VSE.
Author
ENGINEERING; APOLLO PROJECT; PROJECT MANAGEMENT; ECONOMICS; FAILURE ANALYSIS
20090032245 NASA Johnson Space Center, Houston, TX, United States
Identification of Trends into Dose Calculations for Astronauts through Performing Sensitivity Analysis on Calculational Models Used by the Radiation Health Office
Adams, Thomas; VanBaalen, Mary; [2009]; In English
Report No.(s): JSC-CN-18787; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032245
The Radiation Health Office (RHO) determines each astronaut s cancer risk by using models to associate the amount of radiation dose that astronauts receive from spaceflight missions. The baryon transport codes (BRYNTRN), high charge (Z) and energy transport codes (HZETRN), and computer risk models are used to determine the effective dose received by astronauts in Low Earth orbit (LEO). This code uses an approximation of the Boltzman transport formula. The purpose of the project is to run this code for various International Space Station (ISS) flight parameters in order to gain a better understanding of how this code responds to different scenarios. The project will determine how variations in one set of parameters such as, the point of the solar cycle and altitude can affect the radiation exposure of astronauts during ISS missions. This project will benefit NASA by improving mission dosimetry.
Author
RADIATION DOSAGE; ASTRONAUTS; CANCER; SENSITIVITY ANALYSIS; DOSIMETERS
20090032246 NASA Johnson Space Center, Houston, TX, United States
Human-System Integration Scorecard Update to VB.Net
Sanders, Blaze D.; [2009]; In English; Original contains color illustrations
Report No.(s): JSC-CN-18792; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032246
The purpose of this project was to create Human-System Integration (HSI) scorecard software, which could be utilized to validate that human factors have been considered early in hardware/system specifications and design. The HSI scorecard is partially based upon the revised Human Rating Requirements (HRR) intended for NASA's Constellation program. This software scorecard will allow for quick appraisal of HSI factors, by using visual aids to highlight low and rapidly changing scores. This project consisted of creating a user-friendly Visual Basic program that could be easily distributed and updated, to and by fellow colleagues. Updating the Microsoft Word version of the HSI scorecard to a computer application will allow for the addition of useful features, improved easy of use, and decreased completion time for user. One significant addition is the ability to create Microsoft Excel graphs automatically from scorecard data, to allow for clear presentation of problematic areas. The purpose of this paper is to describe the rational and benefits of creating the HSI scorecard software, the problems and goals of project, and future work that could be done.
Author
SYSTEMS INTEGRATION; COMPUTER PROGRAMS; COMPUTER PROGRAMMING; HUMAN FACTORS ENGINEERING; OPTIMIZATION
20090032257 NASA, Washington, DC, United States
Top Level Summary of Technologies
Craig, Douglas, A.; June 22, 2009; In English
Report No.(s): HQ-Ref-09-S-1945; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032257
This document is a chart that reviews the technology of various NASA projects. Included in the chart is the title, a brief description of the technology, the funding status, a statement of the benefits, the date required, how the element connects to the Constellation project architecture, and how critical the technology is to the Constellation project.
CASI
TECHNOLOGY UTILIZATION; NASA PROGRAMS; RESEARCH AND DEVELOPMENT; TECHNOLOGIES; CONSTELLATION PROGRAM
Additions to the NASA Aeronautics and Space Database as of 09/29/2009
20090032601 NASA Langley Research Center, Hampton, VA, United States
L(sub 1) Adaptive Control Design for NASA AirSTAR Flight Test Vehicle
Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira; Zou, Xiaotian; August 06, 2009; In English; AIAA Guidance, Navigation, and Control Conference (GNC) 2009, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 736466
Report No.(s): LF99-8378; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032601
In this paper we present a new L(sub 1) adaptive control architecture that directly compensates for matched as well as unmatched system uncertainty. To evaluate the L(sub 1) adaptive controller, we take advantage of the flexible research environment with rapid prototyping and testing of control laws in the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. We apply the L(sub 1) adaptive control laws to the subscale turbine powered Generic Transport Model. The presented results are from a full nonlinear simulation of the Generic Transport Model and some preliminary pilot evaluations of the L(sub 1) adaptive control law.
Author
ADAPTIVE CONTROL; FLIGHT TEST VEHICLES; TRANSPORT AIRCRAFT; RAPID PROTOTYPING; CONTROL THEORY; POWERED MODELS
20090032603 NASA Goddard Space Flight Center, Greenbelt, MD, United States
GSFC Heliophysics Science Division 2008 Science Highlights
Gilbert, Holly R.; Strong, Keith T.; Saba, Julia L. R.; Firestone, Elaine R.; March 2009; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TM-2009-214178; Copyright; Avail.: CASI: A09, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032603
This report is intended to record and communicate to our colleagues, stakeholders, and the public at large about heliophysics scientific and flight program achievements and milestones for 2008, for which NASA Goddard Space Flight Center's Heliophysics Science Division (HSD) made important contributions. HSD comprises approximately 261 scientists, technologists, and administrative personnel dedicated to the goal of advancing our knowledge and understanding of the Sun and the wide variety of domains that its variability influences. Our activities include Lead science investigations involving flight hardware, theory, and data analysis and modeling that will answer the strategic questions posed in the Heliophysics Roadmap; Lead the development of new solar and space physics mission concepts and support their implementation as Project Scientists; Provide access to measurements from the Heliophysics Great Observatory through our Science Information Systems, and Communicate science results to the public and inspire the next generation of scientists and explorers.
Author
ATMOSPHERIC PHYSICS; SOLAR PHYSICS; CORONAS; TOPOGRAPHY; MISSION PLANNING
20090032634 NASA Johnson Space Center, Houston, TX, United States
The Legacy of the Space Shuttle Program: Scientific and Engineering Accomplishments
Torrez, Jonathan; [2009]; In English
Report No.(s): JSC-CN-18797; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032634
The goal of this project was to assist in the creation of the appendix for the book being written about the Space Shuttle that is titled The Legacy of the Space Shuttle Program: Scientific and Engineering Accomplishments. The specific responsibility of the intern was the creation of the human health and performance (life sciences) and space biology sections of the appendix. This included examining and finalizing the list of flights with life sciences and space biology experiments flown aboard them, researching the experiments performed, synopsizing each experiment into two sentences, and placing the synopses into an appendix template. Overall, approximately 70 flights had their experiments synopsized and a good method for researching and construction of the template was established this summer.
Author
HUMAN PERFORMANCE; LIFE SCIENCES; EXOBIOLOGY; SPACE SHUTTLES; HEALTH
20090032639 NASA Langley Research Center, Hampton, VA, United States
Fiber Optic Thermographic Detection of Flaws in Composites
Wu, Meng-Chou; Winfree, William P.; July 26, 2009; In English; QNDE 2009: Quantitative Nondestructive Evaluation Conference, 26-31 Jul. 2009, Kingston, RI, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 645846.02.07.07.02
Report No.(s): LF99-8710; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032639
Optical fibers with multiple Bragg gratings bonded to surfaces of structures were used for thermographic detection of subsurface defects in structures. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The obtained data were analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with the simulation results.
Author
NONDESTRUCTIVE TESTS; OPTICAL FIBERS; THERMOGRAPHY; BRAGG GRATINGS; DELAMINATING; TEMPERATURE SENSORS; BONDED JOINTS; FIBER OPTICS
20090032640 NASA Langley Research Center, Hampton, VA, United States
Heat Transfer Modeling and Validation for Optically Thick Alumina Fibrous Insulation
Daryabeigi, Kamran; August 29, 2009; In English; 30th International Thermal Conductivity Conference, 29 Aug. - 2 Sep. 2009, Pittsburgh, PA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.07.02.03.01
Report No.(s): LF99-8972; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032640
Combined radiation/conduction heat transfer through unbonded alumina fibrous insulation was modeled using the diffusion approximation for modeling the radiation component of heat transfer in the optically thick insulation. The validity of the heat transfer model was investigated by comparison to previously reported experimental effective thermal conductivity data over the insulation density range of 24 to 96 kg/cu m, with a pressure range of 0.001 to 750 torr (0.1 to 101.3 x 10(exp 3) Pa), and test sample hot side temperature range of 530 to 1360 K. The model was further validated by comparison to thermal conductivity measurements using the transient step heating technique on an insulation sample at a density of 144 kg/cu m over a pressure range of 0.001 to 760 torr, and temperature range of 290 to 1090 K.
Author
CONDUCTIVE HEAT TRANSFER; INSULATION; THERMAL CONDUCTIVITY; TRANSIENT HEATING; ALUMINUM OXIDES; RADIATIVE HEAT TRANSFER
20090032644 NASA Johnson Space Center, Houston, TX, United States
Serial Network Flow Monitor
Robinson, Julie A.; Tate-Brown, Judy M.; [2009]; In English; Original contains color illustrations
Report No.(s): JSC-CN-17962; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032644
Using a commercial software CD and minimal up-mass, SNFM monitors the Payload local area network (LAN) to analyze and troubleshoot LAN data traffic. Validating LAN traffic models may allow for faster and more reliable computer networks to sustain systems and science on future space missions. Research Summary: This experiment studies the function of the computer network onboard the ISS. On-orbit packet statistics are captured and used to validate ground based medium rate data link models and enhance the way that the local area network (LAN) is monitored. This information will allow monitoring and improvement in the data transfer capabilities of on-orbit computer networks. The Serial Network Flow Monitor (SNFM) experiment attempts to characterize the network equivalent of traffic jams on board ISS. The SNFM team is able to specifically target historical problem areas including the SAMS (Space Acceleration Measurement System) communication issues, data transmissions from the ISS to the ground teams, and multiple users on the network at the same time. By looking at how various users interact with each other on the network, conflicts can be identified and work can begin on solutions. SNFM is comprised of a commercial off the shelf software package that monitors packet traffic through the payload Ethernet LANs (local area networks) on board ISS.
Author
APPLICATIONS PROGRAMS (COMPUTERS); DATA LINKS; DATA TRANSMISSION; COMPUTER NETWORKS; COMMERCIAL OFF-THE-SHELF PRODUCTS; LOCAL AREA NETWORKS
20090032649 NASA Marshall Space Flight Center, Huntsville, AL, United States
Characterization of a Plasmoid in the Afterglow of a Supersonic Flowing Microwave Discharge
Drake, D. J.; Miller, S.; Nikolic, M.; Popovic, S.; Vuskovic, L.; July 12, 2009; In English; 29th International Conference on Phenomena in Ionized Gases (ICPIG), 12-17 Jul. 2009, Cancun, Mexico; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNX07AQ44H
Report No.(s): M09-0474; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032649
We performed a detailed characterization a plasmoid in the afterglow region of an Ar supersonic microwave cavity discharge. The supersonic flow was generated using a convergent-divergent nozzle upstream of the discharge region. A cylindrical cavity was used to sustain a discharge in the pressure range of 100-600 Pa. Optical emission spectroscopy was used to observe populations of excited and ionic species in the plasmoid region. Plasmoid formation in the supersonic flowing afterglow located downstream from the primary microwave cavity discharge was characterized by measuring the radial and axial distributions of Argon excited states and Argon ions. More experiments are being carried out on the plasmoid to understand the discharge parameters within the region, i.e. rotational temperature, vibrational temperature, electron density, and how the electrodynamic and aerodynamic effects combine to form this plasmoid.
Author
PLASMAS (PHYSICS); SUPERSONIC FLOW; ARGON; AFTERGLOWS; MICROWAVES; ELECTRON DENSITY (CONCENTRATION); OPTICAL EMISSION SPECTROSCOPY; CAVITIES; IONS
20090032652 NASA Johnson Space Center, Houston, TX, United States
Controls on Highly Siderophile Element Concentrations in Martian Basalt: Sulfide Saturation and Under-Saturation
Righter, Kevin; July 13, 2009; In English; 72nd Annual Meeting of the Meteoritical Society (Met Soc 2009), 13 - 18 Jul. 2009, Nancy, France
Report No.(s): JSC-CN-18345; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032652
Highly siderophile elements (HSE; Re, Au and the platinum group elements) in shergottites exhibit a wide range from very high, similar to the terrestrial mantle, to very low, similar to sulfide saturated mid ocean ridge basalt (e.g., [1]). This large range has been difficult to explain without good constraints on sulfide saturation or under-saturation [2]. A new model for prediction of sulfide saturation places new constraints on this problem [3]. Shergottite data: For primitive shergottites, pressure and temperature estimates are between 1.2-1.5 GPa, and 1350-1470 C [4]. The range of oxygen fugacities is from FMQ-2 to IW, where the amount of Fe2O3 is low and thus does not have a significant effect on the S saturation values. Finally, the bulk compositions of shergottites have been reported in many recent studies (e.g., [5]). All of this information will be used to test whether shergottites are sulfide saturated [3]. Modeling values and results: The database for HSE partition coefficients has been growing with many new data for silicates and oxides [6-8] to complement a large sulfide database [9- 11]. Combining these data with simple batch melting models allows HSE contents of mantle melts to be estimated for sulfide-bearing vs. sulfide-free mantle. Combining such models with fractional crystallization modeling (e.g., [12]) allows HSE contents of more evolved liquids to be modeled. Most primitive shergottites have high HSE contents (and low S contents) that can be explained by sulfide under-saturated melting of the mantle. An exception is Dhofar 019 which has high S contents and very low HSE contents suggesting sulfide saturation. Most evolved basaltic shergottites have lower S contents than saturation, and intermediate HSE contents that can be explained by olivine, pyroxene, and chromite fractionation. An exception is EET A79001 lithology B, which has very low HSE contents and S contents higher than sulfide saturation values . evidence for sulfide saturation during late fractional crystallization. These results show that shergottite HSE contents are controlled by silicates, oxides, and sulfides. In addition, the mantle producing the most primitive shergottites did not contain near chondritic relative ratios of the HSEs like the terrestrial mantle, and did not experience a late chondritic veneer.
Author
BASALT; SHERGOTTITES; MARS (PLANET); SULFIDES; PLATINUM; CRYSTALLIZATION; CHONDRITES
20090032661 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Atmospheric Aerosol Properties and Climate Impacts
Chin, Mian; Kahn, Ralph A.; Remer, Lorraine A.; Yu, Hongbin; Rind, David; Feingold, Graham; Quinn, Patricia K.; Schwartz, Stephen E.; Streets, David G.; DeCola, Phillip; Halthore, Rangasayi; January 2009; In English; Original contains color and black and white illustrations
Report No.(s): NASA/SP-2009-568; Copyright; Avail.: CASI: A07, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032661
This report critically reviews current knowledge about global distributions and properties of atmospheric aerosols, as they relate to aerosol impacts on climate. It assesses possible next steps aimed at substantially reducing uncertainties in aerosol radiative forcing estimates. Current measurement techniques and modeling approaches are summarized, providing context. As a part of the Synthesis and Assessment Product in the Climate Change Science Program, this assessment builds upon recent related assessments, including the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4, 2007) and other Climate Change Science Program reports. The objectives of this report are (1) to promote a consensus about the knowledge base for climate change decision support, and (2) to provide a synthesis and integration of the current knowledge of the climate-relevant impacts of anthropogenic aerosols for policy makers, policy analysts, and general public, both within and outside the U.S government and worldwide.
Derived from text
AEROSOLS; CLIMATE; CLIMATE CHANGE; ATMOSPHERIC EFFECTS; CLIMATOLOGY; EARTH ATMOSPHERE
Additions to the NASA Aeronautics and Space Database as of 09/30/2009
20090032801 NASA Johnson Space Center, Houston, TX, United States
Sea-Level Flight Demonstration and Altitude Characterization of a LO2/LCH4 Based Accent Propulsion Lander
Collins, Jacob; Hurlbert, Eric; Romig, Kris; Melcher, John; Hobson, Aaron; Eaton, Phil; [2009]; In English; 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2 - 5 Aug. 2009, Denver, CO, United States; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18506; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032801
A 1,500 lbf thrust-class liquid oxygen (LO2)/Liquid Methane (LCH4) rocket engine was developed and tested at both sea-level and simulated altitude conditions. The engine was fabricated by Armadillo Aerospace (AA) in collaboration with NASA Johnson Space Center. Sea level testing was conducted at Armadillo Aerospace facilities at Caddo Mills, TX. Sea-level tests were conducted using both a static horizontal test bed and a vertical take-off and landing (VTOL) test bed capable of lift-off and hover-flight in low atmosphere conditions. The vertical test bed configuration is capable of throttling the engine valves to enable liftoff and hover-flight. Simulated altitude vacuum testing was conducted at NASA Johnson Space Center White Sands Test Facility (WSTF), which is capable of providing altitude simulation greater than 120,000 ft equivalent. The engine tests demonstrated ignition using two different methods, a gas-torch and a pyrotechnic igniter. Both gas torch and pyrotechnic ignition were demonstrated at both sea-level and vacuum conditions. The rocket engine was designed to be configured with three different nozzle configurations, including a dual-bell nozzle geometry. Dual-bell nozzle tests were conducted at WSTF and engine performance data was achieved at both ambient pressure and simulated altitude conditions. Dual-bell nozzle performance data was achieved over a range of altitude conditions from 90,000 ft to 50,000 ft altitude. Thrust and propellant mass flow rates were measured in the tests for specific impulse (Isp) and C* calculations.
Author
LIQUID OXYGEN; LIQUEFIED GASES; METHANE; ROCKET ENGINES; SEA LEVEL; ALTITUDE SIMULATION; VERTICAL TAKEOFF AIRCRAFT; VERTICAL LANDING
20090032825 NASA Langley Research Center, Hampton, VA, United States
Application of CFE/POST2 for Simulation of Launch Vehicle Stage Separation
Pamadim Bandu N.; Tartabini, Paul V.; Toniolo, Matthew D.; Roithmayr, Carlos M.; Karlgaard, Christopher D.; Samareh, Jamshid A.; August 10, 2009; In English; AIAA Atmospheric Flight Mechanics Conference, 10-13 Aug. 2009, Chicago, Il, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 736466.11.01.07.54.01.01
Report No.(s): LF99-9267; AIAA Paper 2009-5842; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032825
The constraint force equation (CFE) methodology provides a framework for modeling constraint forces and moments acting at joints that connect multiple vehicles. With implementation in Program to Optimize Simulated Trajectories II (POST 2), the CFE provides a capability to simulate end-to-end trajectories of launch vehicles, including stage separation. In this paper, the CFE/POST2 methodology is applied to the Shuttle-SRB separation problem as a test and validation case. The CFE/POST2 results are compared with STS-1 flight test data.
Author
LAUNCH VEHICLES; SIMULATION; STAGE SEPARATION; TRAJECTORIES; SPACE SHUTTLE ORBITERS
20090032918 NASA Marshall Space Flight Center, Huntsville, AL, United States
The Hurricane Imaging Radiometer (HIRAD): Instrument Status and Performance Predictions
Ruf, Christopher; Bailey, M. C.; Gross, Steven; Hood, Robbie; James, Mark; Johnson, James; Jones, Linwood; Miller, Timothy; Uhlhorn, Eric; July 13, 2009; In English; IGARSS 2009 International Geoscience and Remote Sensing Symposium, 13-17 Jul. 2009, Capetown, South Africa
Report No.(s): IGARSS Paper No. 2914; M09-0284; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032918
The Hurricane Imaging Radiometer (HIRAD) is an innovative radiometer which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR) [Uhlhorn and Black, 2004]. The HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology [Ruf et al., 1988]. This sensor operates over 4-7 GHz, where the required tropical cyclone remote sensing physics has been validated by both SFMR and WindSat radiometer [Bettenhausen et al., 2006; Brown et al., 2006]. HIRAD incorporates a new and unique array antenna design along with several technologies successfully demonstrated by the Lightweight Rain Radiometer instrument [Ruf et al., 2002; Ruf and Principe, 2003]. HIRAD will be a compact, lightweight, low-power instrument with no moving parts that will produce wide-swath imagery of ocean winds and rain in hurricane conditions. Accurate observations of surface ocean vector winds (OVW) with high spatial and temporal resolution are required for understanding and predicting tropical cyclones. The Hurricane Imaging Radiometer (HIRAD) is an innovative architecture which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR), which is a proven remote sensing technique for observing tropical cyclone (TC) ocean surface wind speeds and rain rates. The proposed HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology combined with a a unique array antenna design. The overarching design concept of HIRAD is to combine the multi-frequency C-band observing strategy of the SFMR with STAR technology to produce a wide-swath imager. Single frequency STAR technology The Hurricane Imaging Radiometer (HIRAD) is an innovative radiometer which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR) [Uhlhorn and Black, 2004]. The HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology [Ruf et al., 1988]. This sensor operates over 4-7 GHz, where the required tropical cyclone remote sensing physics has been validated by both SFMR and WindSat radiometer [Bettenhausen et al., 2006; Brown et al., 2006]. HIRAD incorporates a new and unique array antenna design along with several technologies successfully demonstrated by the Lightweight Rain Radiometer instrument [Ruf et al., 2002; Ruf and Principe, 2003]. HIRAD will be a compact, lightweight, low-power instrument with no moving parts that will produce wide-swath imagery of ocean winds and rain in hurricane conditions. Accurate observations of surface ocean vector winds (OVW) with high spatial and temporal resolution are required for understanding and predicting tropical cyclones. The Hurricane Imaging Radiometer (HIRAD) is an innovative architecture which offers new and unique remotely sensed observations of both extreme oceanic wind events and strong precipitation. It is based on the airborne Stepped Frequency Microwave Radiometer (SFMR), which is a proven remote sensing technique for observing tropical cyclone (TC) ocean surface wind speeds and rain rates. The proposed HIRAD instrument advances beyond the current nadir viewing SFMR to an equivalent wide-swath SFMR imager using passive microwave synthetic thinned aperture radiometer (STAR) technology combined with a a unique array antenna design. The overarching design concept of HIRAD is to combine the multi-frequency C-banbserving strategy of the SFMR with STAR technology to produce a wide-swath imager. Single frequency STAR technology
Author
HURRICANES; MICROWAVE RADIOMETERS; IMAGING TECHNIQUES; SPATIAL RESOLUTION; TEMPORAL RESOLUTION; WIND (METEOROLOGY); AIRBORNE EQUIPMENT; ANTENNA ARRAYS; MARINE METEOROLOGY; REMOTE SENSING
20090032975 Gray Research, Inc., United States
Creating a Lunar EVA Work Envelope
Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David; July 12, 2009; ISSN 0148-7191; In English; 39th International Conference on Environmental Systems, 12 - 16 Jul. 2009, Savannah, GA, United States; Original contains color and black and white illustrations
Report No.(s): 09ICES-0029; M09-0134; M09-0373; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090032975
A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.
Author
EXTRAVEHICULAR ACTIVITY; EXTRAVEHICULAR MOBILITY UNITS; WEIGHTLESSNESS; TASKS; ROVING VEHICLES; MICROGRAVITY
20090033063 National Space Science and Technology Center, Huntsville, AL, United States
Simulation of Relativistic Shocks and Associated Radiation from Turbulent Magnetic Fields
Nishikawa, K.; Niemiec, J.; Medvedev, M.; Zhang, B.; Hardee, P.; Mizuno, Y.; Nordlund, A.; Frederiksen, J.; Sol, H.; Pohl, M.; Oka, M.; Hartmann, D. H.; Fishman, J. F.; June 29, 2009; In English; 4th International Conference on Numerical Modeling of Space Plasma Flows (ASTRONUM 2009), 29 Jun. - 3 Jul. 2009, Chamonix, France; Original contains color and black and white illustrations
Report No.(s): M09-0458; M09-0459; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033063
Plasma instabilities (e.g., Buneman, Weibel and other two-stream instabilities) excited in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a new 3-D relativistic particle-in-cell code, we have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating into an unmagnetized electron-positron plasma. The simulation has been performed using a long simulation system in order to study the nonlinear stages of the Weibel instability, the particle acceleration mechanism, and the shock structure. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic (HD) like shock structure. In the leading shock, electron density increases by a factor of <_ 3.5 in the simulation frame. Strong electromagnetic fields are generated in the trailing shock and provide an emission site. We discuss the possible implication of our simulation results within the AGN and GRB context. We have calculated the time evolution of the spectrum from two electrons propagating in a uniform parallel magnetic field to verify the technique. The same technique will be used to calculate radiation from accelerated electrons (positrons) in turbulent magnetic fields generated by Weibel instability.
Author
PARTICLE ACCELERATION; RELATIVISTIC PARTICLES; WEIBEL INSTABILITY; ELECTRON DENSITY (CONCENTRATION); ELECTRON-POSITRON PLASMAS; MAGNETOHYDRODYNAMIC STABILITY; POSITRONS
Additions to the NASA Aeronautics and Space Database as of 10/01/2009
20090033079 Alabama Univ., Huntsville, AL, United States
Performance of "Waterless Concrete"
Toutanji, H. A.; Grugel, R. N.; June 29, 2009; In English; Concrete Solutions 2009, 3rd International Conference on Concrete Repair, 29 Jun. - 2 Jul. 2009, Venice, Italy; Original contains black and white illustrations
Contract(s)/Grant(s): NNM05AA22A
Report No.(s): M09-0491; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033079
Waterless concrete consists of molten elementary sulfur and aggregate. The aggregates in a lunar environment will be lunar rocks and soil. Sulfur is present on the Moon in Troilite soil (FeS) and, by oxidation of the soil, iron and sulfur can be produced. Sulfur concrete specimens were cycled between liquid nitrogen (approx.]91 C) and room temperature (^21 C) to simulate exposure to a lunar environment. Cycled and control specimens were subsequently tested in compression at room temperatures (^21 C) and ^-101 C. Test results showed that due to temperature cycling, the compressive strength of cycled specimens was 20% of those non-cycled. This reduction in strength can be attributed to the large differences in thermal coefficients of expansion of the materials constituting the concrete which promoted cracking. Similar sulfur concrete mixtures were strengthened with short and long glass fibres. The lunar regolith simulant was melted in a 25 cc Pt- Rh crucible in a Sybron Thermoline high temperature MoSi2 furnace at melting temperatures of 1450 to 1600 C for times of 30 min to i hour. Glass fibres and small rods were pulled from the melt. The glass fibres were used to reinforce sulfur concrete plated to improve the flexural strength of the sulfur concrete. Beams strengthened with glass fibres showed to exhibit an increase in the flexural strength by as much as 45%.
Author
CONCRETES; FLEXURAL STRENGTH; SULFUR; AGGREGATES; COMPRESSIVE STRENGTH; LUNAR ROCKS; HEAT TRANSFER COEFFICIENTS
20090033091 Alabama Univ., Huntsville, AL, United States
Preliminary Development and Evaluation of Lightning Jump Algorithms for the Real-Time Detection of Severe Weather
Schultz, Christopher J.; Petersen, Walter A.; Carey, Lawrence D.; July 28, 2009; In English; Southern Thunder Workshop, 28 - 30 Jul. 2009, Cocoa Beach, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NA07AANEG0284; NA08NWS4680034
Report No.(s): M09-0500; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033091
Previous studies have demonstrated that rapid increases in total lightning activity (intracloud + cloud-to-ground) are often observed tens of minutes in advance of the occurrence of severe weather at the ground. These rapid increases in lightning activity have been termed "lightning jumps." Herein, we document a positive correlation between lightning jumps and the manifestation of severe weather in thunderstorms occurring across the Tennessee Valley and Washington D.C. A total of 107 thunderstorms were examined in this study, with 69 of the 107 thunderstorms falling into the category of non-severe, and 38 into the category of severe. From the dataset of 69 isolated non-severe thunderstorms, an average peak 1 minute flash rate of 10 flashes/min was determined. A variety of severe thunderstorm types were examined for this study including an MCS, MCV, tornadic outer rainbands of tropical remnants, supercells, and pulse severe thunderstorms. Of the 107 thunderstorms, 85 thunderstorms (47 non-severe, 38 severe) from the Tennessee Valley and Washington D.C tested 6 lightning jump algorithm configurations (Gatlin, Gatlin 45, 2(sigma), 3(sigma), Threshold 10, and Threshold 8). Performance metrics for each algorithm were then calculated, yielding encouraging results from the limited sample of 85 thunderstorms. The 2(sigma) lightning jump algorithm had a high probability of detection (POD; 87%), a modest false alarm rate (FAR; 33%), and a solid Heidke Skill Score (HSS; 0.75). A second and more simplistic lightning jump algorithm named the Threshold 8 lightning jump algorithm also shows promise, with a POD of 81% and a FAR of 41%. Average lead times to severe weather occurrence for these two algorithms were 23 minutes and 20 minutes, respectively. The overall goal of this study is to advance the development of an operationally-applicable jump algorithm that can be used with either total lightning observations made from the ground, or in the near future from space using the GOES-R Geostationary Lightning Mapper.
Author
CLOUD-TO-GROUND DISCHARGES; THUNDERSTORMS; REAL TIME OPERATION; LIGHTNING; FRONTS (METEOROLOGY); RAIN; TROPICAL REGIONS; WEATHER FORECASTING; TORNADOES
20090033092 NASA Marshall Space Flight Center, Huntsville, AL, United States
A Real-Time Microwave Camera at 24 GHz (K-Band}
Ghasr, M. T.; Baumgartner, M. A.; Clark, D.; Kharkovsky, S.; Abou-Khousa, M.; Zoughi, R.; July 26, 2009; In English; Quantitative Nondestructive Evaluation Conference (QNDE2009), 26-31 Jul. 2009, RI, United States; Original contains color illustrations
Contract(s)/Grant(s): NNX09AF81G
Report No.(s): M09-054; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033092
The objective is to design and build a real-time microwave imaging system (i.e., camera) Microwave imaging offers tremendous potential in many applications: a) Inspection of low-loss composites, radomes, etc.; b) Detection and evaluation of corrosion under paint; c) Security, contraband detection. Raster scanning is slow and requires bulky mechanical systems. A real-time and portable imaging system can be extremely useful for rapid nondestructive testing of large structures.
Author
MICROWAVE IMAGERY; CAMERAS; RASTER SCANNING; NONDESTRUCTIVE TESTS; INSPECTION; IMAGING TECHNIQUES
20090033093 NASA Marshall Space Flight Center, Huntsville, AL, United States
NanoSail-D: A Solar Sail Demonstration Mission
Johnson, Les; Whorton, Mark; Heaton, Andy; Pinson, robin; Laue, Greg; Adams, Charles; August 13, 2009; In English; 6th IAA Symposium on Realistic Near-Term Advanced Scientific Space Missions, 6-9 Jul. 2009, Aosta, Italy; Original contains color illustrations
Report No.(s): M09-0505; M09-0506; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033093
During the past decade, within the United States, NASA Marshall Space Flight Center (MSFC) was heavily engaged in the development of revolutionary new technologies for in-space propulsion. One of the major in-space propulsion technologies developed was a solar sail propulsion system. Solar sail propulsion uses the solar radiation pressure exerted by the momentum transfer of reflected photons to generate a net force on a spacecraft. To date, solar sail propulsion systems have been designed for large spacecraft in the tens to hundreds of kilograms mass range. Recently, however, MSFC has been investigating the application of solar sails for small satellite propulsion. Likewise, NASA Ames Research Center (ARC) has been developing small spacecraft missions that have a need for amass-efficient means of satisfying deorbit requirements. Hence, a synergistic collaboration was established between these two NASA field Centers with the objective of conducting a flight demonstration of solar sail technologies for small satellites. The NanoSail-D mission flew onboard the ill-fated Falcon Rocket launched August 2, 2008, and, due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare is ready for flight and a suitable launch arrangement is being actively pursued. Both the original sailcraft and the flight spare are hereafter referred to as NanoSail-D. The sailcraft consists of a sail subsystem stowed in a three-element CubeSat. Shortly after deployment of the NanoSail-D, the solar sail will deploy and mission operations will commence. This demonstration flight has two primary technical objectives: (1) to successfully stow and deploy the sail and (2) to demonstrate deorbit functionality. Given a near-term opportunity for launch on Falcon, the project was given the challenge of delivering the flight hardware in 6 mo, which required a significant constraint on flight system functionality. As a consequence, passive attitude stabilization of the spacecraft will be achieved using permanent magnets to detumble and orient the body with the magnetic field lines and then rely on atmospheric drag to passively stabilize the sailcraft in an essentially maximum drag attitude. This paper will present an introduction to solar sail propulsion systems and an overview of the NanoSail-D spacecraft.
Author
ATTITUDE CONTROL; LARGE SPACE STRUCTURES; SOLAR SAILS; PROPULSION SYSTEM CONFIGURATIONS; ATTITUDE STABILITY; RADIATION PRESSURE; PROPULSION SYSTEM PERFORMANCE; FLIGHT TESTS; SOLAR RADIATION
20090033094 NASA Marshall Space Flight Center, Huntsville, AL, United States
Systematics in the Electron Spectrum Measured by ATIC
Panov, A. D.; Zatsepin, V. I.; Sokolskaya, N. V.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Chang, J.; Christl, M.; Guzik, T. G.; Isbert, J.; Kim, K. C.; Kouznetsov, E. N.; Panasyuk, M. I.; Postnikov, E. B.; Seo, E.S.; Watts, J.; Wefel, J. P.; Wu, J.; July 07, 2009; In English; 31st International Cosmic Ray Conference, 7-15 Jul. 2009, Lodz, Poland; Original contains black and white illustrations
Report No.(s): M09-0516; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033094
An analysis of different parameters to separate electrons from protons in the ATIC experiment has been performed. Five separate discriminants were studied by different Monte Carlo programs, leading to a variety of results. Application to the ATIC data indicates the range of variation possible in the interpretation of the data. The results of this analysis, when compared with the published results [5], show good agreement in the most interesting region of energy (from 90 GeV to 600 GeV). The measured electron spectrum is compared with the recent data reported by Fermi/LAT, and there is no major disagreement between ATIC s results and Fermi/LAT. Finally, possible systematics-free, short energy scale features of the ATIC electron spectrum are mentioned. Keywords: ATIC, electron spectrum, fine structure
Author
FINE STRUCTURE; ENERGY SPECTRA; FREE ENERGY; ELECTRON SPECTROSCOPY
20090033095 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Energetic Trans-Iron Cosmic-ray Experiment (ENTICE)
Binns, W. R.; Adams. J. H.; Barghouty, A. F.; Christian, E. R.; Cummings, A. C.; Hams, T.; Israel, M. H.; Labrador, A. W.; Leske, R. A.; Link, J. T.; Mewwaldt, R. A.; Mitchell, J. W.; De Nolfo, G. A.; Sasaki, M.; Stone, E. C.; Waddington, C. J.; Wiedenbeck, M. E.; July 07, 2009; In English; 31st International Cosmic Ray Conference, 7-5 Jul. 2009, Lodz, Poland; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNM08AA10A
Report No.(s): M09-0518; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033095
The ENTICE experiment is one of two instruments that comprise the "Orbiting Astrophysical Spectrometer in Space (OASIS)", which is presently undergoing a NASA "Astrophysics Strategic Mission Concept Study". ENTICE is designed to make high precision measurements of the abundances of individual elements from neon through the actinides and, in addition, will search for possible superheavy nuclei in the galactic cosmic rays. The ENTICE instrument utilizes silicon detectors, aerogel and acrylic Cherenkov counters, and a scintillating optical fiber hodoscope to measure the charge and energy of these ultra-heavy nuclei for energies greater than 0.5 GeV/nucleon. It is a large instrument consisting of four modules with a total effective geometrical factor of approx.20 sq m sr. Measurements made in space for a period of three years with ENTICE will enable us to determine if cosmic rays include a component of recently synthesized transuranic elements (Pu-94 and Cm-96), to measure the age of that component, and to test the model of the OB association origin of galactic cosmic rays. Additionally, these observations will enable us to study how diffusive shock acceleration of cosmic rays operates differently on interstellar grains and gas. Keywords: cosmic rays Galaxy:abundances
Author
INTERSTELLAR MATTER; NUCLEONS; ASTROPHYSICS; GALACTIC COSMIC RAYS; MISSION PLANNING; OPTICAL FIBERS; HEAVY NUCLEI; COSMIC RAYS
20090033096 Purple Mountain Observatory, Nanjing, China
Determining the Detection Efficiency and Background Level of ATIC Electron Observation from Flight Data
Chang, J.; Wu, J.; Guzik, T. G.; Wefel, J. P.; Isbert, J.; Adams, J. H., Jr.; Christl, M.; Watts, J.; Ahn, H. S.; Kim, K. C.; Seo, E. S.; Wu, J.; Bashindzhagyan, G. L.; Kouznetsov, E. N.; Panasyuk, M. I.; Sokolskaya, N. V.; Panov, A. D.; Zatsepin, V. I.; July 07, 2009; In English; 31st International Cosmic Ray Conference, 7 - 15 Jul. 2009, Lodz, Poland; Original contains black and white illustrations
Report No.(s): M09-0517; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033096
Observations of Cosmic-ray electrons are difficult due to the large flux of cosmic ray hadrons. The event selection efficiency and background levels can be estimated from flight data for the ATIC instrument. This reduces the dependence upon Monte Carlo simulations, which show differences between different codes, thereby reducing the systematic errors resulting from analyses that only use simulations. This paper discusses some of the methods used in the ATIC analysis to determine the detection efficiency and background level for the flight data.
Author
GAMMA RAYS; ESTIMATING; HIGH ENERGY ELECTRONS; SYSTEMATIC ERRORS; ELECTRONS; COSMIC RAYS
20090033097 NASA Marshall Space Flight Center, Huntsville, AL, United States
Status of the Regenerative ECLSS Water Recovery System
Carter, Donald Layne; July 12, 2009; In English; International Conference on Environmental Systems, 12 - 16 Jul. 2009, Savannah, GA, United States; Original contains color and black and white illustrations
Report No.(s): M09-0530; 2009-01-2352; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033097
NASA has completed the delivery of the regenerative Water Recovery System (WRS) for the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the final effort to deliver the hardware to the Kennedy Space Center for launch on STS-126, the on-orbit status as of April 2009, and describes some of the technical challenges encountered and lessons learned over the past year.
Author
WATER RECLAMATION; INTERNATIONAL SPACE STATION; LIFE SUPPORT SYSTEMS; SPACECRAFT LAUNCHING
20090033100 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Problems Encountered During the Recertification of the GLORY Solar Array Dual Axis Gimbal Drive Actuators
Saltzman, Marc; Schepis, Jospeh P.; Bruckner, Michael J.; September 23, 2009; In English; 13th European Space Mechanisms and Tribology Symposium/European Space Agency, 23-25 Sep. 2009, Vienna, Austria; Original contains color and black and white illustrations
Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033100
The Glory observatory is the current incarnation of the Vegetation Canopy Lidar (VCL) mission spacecraft bus. The VCL spacecraft bus, having been cancelled for programmatic reasons in 2000, was nearly integrated when it was put into storage for possible future use. The Glory mission was a suitable candidate for using this spacecraft and in 2006 an effort to recertify the two axis solar array gimbal drive after its extended storage was begun. What was expected to be a simple performance validation of the two dual axis gimbal stepper motors became a serious test, diagnosis and repair task once questions arose on the flight worthiness of the hardware. A significant test program logic flow was developed which identified decisions that could be made based on the results of individual recertification tests. Without disassembling the bi-axial gimbals, beginning with stepper motor threshold voltage measurements and relating these to powered drive torque measurements, both performed at the spacecraft integrator s facility, a confusing picture of the health of the actuators came to light. Tests at the gimbal assembly level and tests of the disassembled actuators were performed by the manufacturer to validate our results and torque discrepancies were noted. Further disassembly to the component level of the actuator revealed the source of the torque loss.
Author
CANOPIES (VEGETATION); GLORY MISSION SATELLITE; BUS CONDUCTORS; OPTICAL RADAR; SOLAR ARRAYS; THRESHOLD VOLTAGE; ACTUATORS
20090033101 NASA Goddard Space Flight Center, Greenbelt, MD, United States
Insights into the Galactic Cosmic-ray Source from the TIGER Experiment
Link, Jason T.; Barbier, L. M.; Binns, W. R.; Christian, E. R.; Cummings, J. R.; Geier, S.; Israel, M. H.; Lodders, K.; Mewaldt,R. A.; Mitchell, J. W.; deNolfo, G. A.; Rauch, B. F.; Schindler, S. M.; Scott, L. M.; Streitmatter, R. E.; Stone, E. C.; Waddington, C. J.; Wiedenbeck, M. E.; July 07, 2009; In English; 31st International Cosmic Ray Conference/International Union of Pure and Applied Physics (IUPAP), 7-15 Jul. 2009, Lodz, Poland; Original contains black and white illustrations
Contract(s)/Grant(s): NNG06EO90A; NNG05WC04G; NNG05WC21G; NSF AST-0807356
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033101
We report results from 50 days of data accumulated in two Antarctic flights of the Trans-Iron Galactic Element Recorder (TIGER). With a detector system composed of scintillators, Cherenkov detectors, and scintillating optical fibers, TIGER has a geometrical acceptance of 1.7 sq m sr and a charge resolution of 0.23 cu at Iron. TIGER has obtained abundance measurements of some of the rare galactic cosmic rays heavier than iron, including Zn, Ga, Ge, Se, and Sr, as well as the more abundant lighter elements (down to Si). The heavy elements have long been recognized as important probes of the nature of the galactic cosmic-ray source and accelerator. After accounting for fragmentation of cosmic-ray nuclei as they propagate through the Galaxy and the atmosphere above the detector system, the TIGER source abundances are consistent with a source that is a mixture of about 20% ejecta from massive stars and 80% interstellar medium with solar system composition. This result supports a model of cosmic-ray origin in OB associations previously inferred from ACE-CRIS data of more abundant lighter elements. These TIGER data also support a cosmic-ray acceleration model in which elements present in interstellar grains are accelerated preferentially compared with those found in interstellar gas.
Author
COSMIC RAYS; COSMIC DUST; INTERSTELLAR MATTER; STAR CLUSTERS; O STARS; MASSIVE STARS; INTERSTELLAR GAS; GALACTIC COSMIC RAYS; FRAGMENTATION
20090033102 NASA Langley Research Center, Hampton, VA, United States
Aerodynamic Interference Due to MSL Reaction Control System
Dyakonov, Artem A.; Schoenenberger, Mark; Scallion, William I.; VanNorman, John W.; Novak, Luke A.; Tang, Chun Y.; January 05, 2009; In English; 47th AIAA Aerospace Sciences Meeting and Exhibit, 5-8 Jan. 2009, Orlando, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 857464.02.07.08
Report No.(s): LF99-7145; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033102
An investigation of effectiveness of the reaction control system (RCS) of Mars Science Laboratory (MSL) entry capsule during atmospheric flight has been conducted. The reason for the investigation is that MSL is designed to fly a lifting actively guided entry with hypersonic bank maneuvers, therefore an understanding of RCS effectiveness is required. In the course of the study several jet configurations were evaluated using Langley Aerothermal Upwind Relaxation Algorithm (LAURA) code, Data Parallel Line Relaxation (DPLR) code, Fully Unstructured 3D (FUN3D) code and an Overset Grid Flowsolver (OVERFLOW) code. Computations indicated that some of the proposed configurations might induce aero-RCS interactions, sufficient to impede and even overwhelm the intended control torques. It was found that the maximum potential for aero-RCS interference exists around peak dynamic pressure along the trajectory. Present analysis largely relies on computational methods. Ground testing, flight data and computational analyses are required to fully understand the problem. At the time of this writing some experimental work spanning range of Mach number 2.5 through 4.5 has been completed and used to establish preliminary levels of confidence for computations. As a result of the present work a final RCS configuration has been designed such as to minimize aero-interference effects and it is a design baseline for MSL entry capsule.
Author
AERODYNAMIC INTERFERENCE; COMPUTATIONAL GRIDS; SYSTEM EFFECTIVENESS; ANALYSIS (MATHEMATICS); DATA REDUCTION; FLIGHT TESTS; DYNAMIC PRESSURE
20090033104 NASA Marshall Space Flight Center, Huntsville, AL, United States
Observation and Interpretation of Energetic Neutral Hydrogen Atoms from the December 5, 2006 Solar Flare
Barghouty, A. F.; Mewaldt, R. A.; Leske, R. A.; Shih, A. Y.; Stone, E. C.; Cohen, C. M. S.; Cummings, A. C.; Labrador, A. W.; vonRosenvinge, T. T.; Wiedenbeck, M. E.; July 07, 2009; In English; 31st International Cosmic Ray Conference, 7-15 Jul. 2009, Lodz, Poland
Contract(s)/Grant(s): NAS5-03131; SA2715-26309
Report No.(s): M09-0557; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033104
We discuss observations of energetic neutral hydrogen atoms (ENAs) from a solar flare/coronal mass ejection event reported by Mewaldt et al. (2009). The observations were made during the 5 December 2006 X9 solar flare, located at E79, by the Low Energy Telescopes (LETs) on STEREO A and B. Prior to the arrival of the main solar energetic particle (SEP) event at Earth, both LETs observed a sudden burst of 1.6 to 15 MeV particles arriving from the Sun. The derived solar emission profile, arrival directions, and energy spectrum all show that the <5 MeV particles were due to energetic neutral hydrogen atoms produced by either flare or shock-accelerated protons. RHESSI measurements of the 2.2-MeV gamma-ray line provide an estimate of the number of interacting flare-accelerated protons in this event, which leads to an improved estimate of ENA production by flare-accelerated protons. CME-driven shock acceleration is also considered. Taking into account ENA losses, we conclude that the observed ENAs must have been produced in the high corona at heliocentric distances .2 solar radii.
Author
SOLAR FLARES; GAMMA RAYS; SOLAR CORPUSCULAR RADIATION; CORONAL MASS EJECTION; ENERGETIC PARTICLES; EMISSION SPECTRA; ENERGY SPECTRA; HYDROGEN ATOMS
20090033105 NASA Langley Research Center, Hampton, VA, United States
NO PLIF Study of Hypersonic Transition Over a Discrete Hemispherical Roughness Element
Danehy, Paul M.; Bathel, Brett F.; Ivey, Christopher; Inman, Jennifer A.; Jones, Stephen B.; January 05, 2009; In English; 47th AIAA Aerospace Sciences Meeting and Exhibit, 5-8 Jan. 2009, Orlando, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 599489.02.07.07.06.03
Report No.(s): LF99-7115; AIAA Paper 2009-0394; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033105
Nitric oxide (NO) planar laser-induced fluorescence (PLIF) has been use to investigate the hypersonic flow over a flat plate with and without a 2-mm (0.08-in) radius hemispherical trip. In the absence of the trip, for all angles of attack and two different Reynolds numbers, the flow was observed to be laminar and mostly steady. Boundary layer thicknesses based on the observed PLIF intensity were measured and compared with a CFD computation, showing agreement. The PLIF boundary layer thickness remained constant while the NO flowrate was varied by a factor of 3, indicating non-perturbative seeding of NO. With the hemispherical trip in place, the flow was observed to be laminar but unsteady at the shallowest angle of attack and lowest Reynolds number and appeared vigorously turbulent at the steepest angle of attack and highest Reynolds number. Laminar corkscrew-shaped vortices oriented in the streamwise direction were frequently observed to transition the flow to more turbulent structures.
Author
TRANSITION FLOW; TURBULENT FLOW; LASER INDUCED FLUORESCENCE; BOUNDARY LAYER THICKNESS; SURFACE ROUGHNESS; REYNOLDS NUMBER; HYPERSONIC FLOW; FLOW VELOCITY; COMPUTATIONAL FLUID DYNAMICS; ANGLE OF ATTACK; NITRIC OXIDE
20090033111 NASA Goddard Space Flight Center, Greenbelt, MD, United States
An Intelligent Archive Testbed Incorporating Data Mining
Ramapriyan, H.; Isaac, D.; Yang, W.; Bonnlander, B.; Danks, D.; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NCC5-645
Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033111
Many significant advances have occurred during the last two decades in remote sensing instrumentation, computation, storage, and communication technology. A series of Earth observing satellites have been launched by U.S. and international agencies and have been operating and collecting global data on a regular basis. These advances have created a data rich environment for scientific research and applications. NASA s Earth Observing System (EOS) Data and Information System (EOSDIS) has been operational since August 1994 with support for pre-EOS data. Currently, EOSDIS supports all the EOS missions including Terra (1999), Aqua (2002), ICESat (2002) and Aura (2004). EOSDIS has been effectively capturing, processing and archiving several terabytes of standard data products each day. It has also been distributing these data products at a rate of several terabytes per day to a diverse and globally distributed user community (Ramapriyan et al. 2009). There are other NASA-sponsored data system activities including measurement-based systems such as the Ocean Data Processing System and the Precipitation Processing system, and several projects under the Research, Education and Applications Solutions Network (REASoN), Making Earth Science Data Records for Use in Research Environments (MEaSUREs), and the Advancing Collaborative Connections for Earth-Sun System Science (ACCESS) programs. Together, these activities provide a rich set of resources constituting a value chain for users to obtain data at various levels ranging from raw radiances to interdisciplinary model outputs. The result has been a significant leap in our understanding of the Earth systems that all humans depend on for their enjoyment, livelihood, and survival. The trend in the community today is towards many distributed sets of providers of data and services. Despite this, visions for the future include users being able to locate, fuse and utilize data with location transparency and high degree of interoperability, and being able to convert data to information and usable knowledge in an efficient, convenient manner, aided significantly by automation (Ramapriyan et al. 2004; NASA 2005). We can look upon the distributed provider environment with capabilities to convert data to information and to knowledge as an Intelligent Archive in the Context of a Knowledge Building system (IA-KBS). Some of the key capabilities of an IA-KBS are: Virtual Product Generation, Significant Event Detection, Automated Data Quality Assessment, Large-Scale Data Mining, Dynamic Feedback Loop, and Data Discovery and Efficient Requesting (Ramapriyan et al. 2004).
Author
DATA MINING; EARTH OBSERVING SYSTEM (EOS); EARTH SCIENCES; EOS DATA AND INFORMATION SYSTEM; REMOTE SENSING
20090033112 California Space Education and Workforce Inst., Inc., Santa Maria, CA, United States
Human-rating Automated and Robotic Systems - (How HAL Can Work Safely with Astronauts)
Baroff, Lynn; Dischinger, Charlie; Fitts, David; July 12, 2009; In English; 39th International Conference on Environmental Systems, 12 - 16 Jul. 2009, Savannah, GA, United States; Original contains color illustrations
Report No.(s): M09-0567; 09ICES-0011; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033112
Long duration human space missions, as planned in the Vision for Space Exploration, will not be possible without applying unprecedented levels of automation to support the human endeavors. The automated and robotic systems must carry the load of routine housekeeping for the new generation of explorers, as well as assist their exploration science and engineering work with new precision. Fortunately, the state of automated and robotic systems is sophisticated and sturdy enough to do this work - but the systems themselves have never been human-rated as all other NASA physical systems used in human space flight have. Our intent in this paper is to provide perspective on requirements and architecture for the interfaces and interactions between human beings and the astonishing array of automated systems; and the approach we believe necessary to create human-rated systems and implement them in the space program. We will explain our proposed standard structure for automation and robotic systems, and the process by which we will develop and implement that standard as an addition to NASA s Human Rating requirements. Our work here is based on real experience with both human system and robotic system designs; for surface operations as well as for in-flight monitoring and control; and on the necessities we have discovered for human-systems integration in NASA's Constellation program. We hope this will be an invitation to dialog and to consideration of a new issue facing new generations of explorers and their outfitters.
Author
ROBOTICS; HUMAN BEINGS; SYSTEMS INTEGRATION; SPACE MISSIONS; RATINGS; IN-FLIGHT MONITORING; AUTOMATIC CONTROL
20090033114 NASA Johnson Space Center, Houston, TX, United States
STS-114 Engine Cut-off Sensor Anomaly Technical Consultation Report
Wilson, Timmy R.; Kichak, Robert A.; Ungar, Eugene K.; Cherney, Robert; Rickman, Steve L.; April 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 869021.06.07.02.99
Report No.(s): NASA/TM-2009-215567; NESC-RP-05-125/05-045-E; L-19639; LF99-8395; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033114
The NESC consultation team participated in real-time troubleshooting of the Main Propulsion System (MPS) Engine Cutoff (ECO) sensor system failures during STS-114 launch countdown. The team assisted with External Tank (ET) thermal and ECO Point Sensor Box (PSB) circuit analyses, and made real-time inputs to the Space Shuttle Program (SSP) problem resolution teams. Several long-term recommendations resulted. One recommendation was to conduct cryogenic tests of the ECO sensors to validate, or disprove, the theory that variations in circuit impedance due to cryogenic effects on swaged connections within the sensor were the root cause of STS-114 failures.
Author
ENGINE FAILURE; SPACE TRANSPORTATION SYSTEM; LAUNCHING; CRYOGENICS; EXTERNAL TANKS; MAINTENANCE; NETWORK ANALYSIS; SYSTEM FAILURES
20090033115 NASA Langley Research Center, Hampton, VA, United States
On the Effects of Surface Roughness on Boundary Layer Transition
Choudhari, Meelan M.; Li, Fei; Chang, Chau-Lyan; Edwards, Jack; May 18, 2009; In English; IISc Centenary International Conference and Exhibition on Aerospace Engineering (ICEAE2009), 18 - 22 May 2009, Bangalore, India; Original contains color and black and white illustrations
Contract(s)/Grant(s): FA9550-0701-0191
Report No.(s): LF99-8476; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033115
Surface roughness can influence laminar-turbulent transition in many different ways. This paper outlines selected analyses performed at the NASA Langley Research Center, ranging in speed from subsonic to hypersonic Mach numbers and highlighting the beneficial as well as adverse roles of the surface roughness in technological applications. The first theme pertains to boundary-layer tripping on the forebody of a hypersonic airbreathing configuration via a spanwise periodic array of trip elements, with the goal of understanding the physical mechanisms underlying roughness-induced transition in a high-speed boundary layer. The effect of an isolated, finite amplitude roughness element on a supersonic boundary layer is considered next. The other set of flow configurations examined herein corresponds to roughness based laminar flow control in subsonic and supersonic swept wing boundary layers. A common theme to all of the above configurations is the need to apply higher fidelity, physics based techniques to develop reliable predictions of roughness effects on laminar-turbulent transition.
Author
BOUNDARY LAYER CONTROL; FINITE ELEMENT METHOD; HYPERSONIC SPEED; LAMINAR BOUNDARY LAYER; SURFACE ROUGHNESS; SURFACE ROUGHNESS EFFECTS; TURBULENT BOUNDARY LAYER; SWEPT WINGS; FOREBODIES
20090033116 NASA Langley Research Center, Hampton, VA, United States
Possible Deficiencies in Predicting Transonic Aerodynamics on the X-43A
Labbe, Steven G.; Gilbert, Michael G.; Kehoe, Michael W.; April 2009; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 869021.05.07.04.04
Report No.(s): NASA/TM-2009-215711; NESC-RP-04-02/03-002-E; L-19650; LF99-8657; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033116
The initial X-43A flight test, June 2, 2001, resulted in a mishap and loss of the vehicle. A mishap investigation board (MIB) report and findings, including the established root cause, were publicly released on July, 23, 2003. The X-43A Flight 1 Hyper-X Launch Vehicle (HXLV) failed because the vehicle control system design was deficient for the trajectory flown due to inaccurate analytical models (Pegasus heritage and HXLV specific), which overestimated the (control) system margin ? X-43A Mishap Investigation Report, Vol. I. ? included as Reference 1. Several specific errors were noted, 1) HXLV aerodynamics ? failure to model changes to wing, fin and rudder airfoil shapes due to addition of thermal protection system (TPS); 2) Fin actuation system (FAS) modeling ? under prediction of the control surface hinge moments and FAS compliance; and 3) Parametric uncertainties ? insufficient variation in the aerodynamic, FAS and control system models. In response to the MIB findings, the X-43A program has been working RTF through an approved Corrective Action Plan (CAP) over the last two years.
Author
LAUNCH VEHICLES; FLIGHT TESTS; FAILURE; ERRORS; CONTROL SYSTEMS DESIGN; MATHEMATICAL MODELS
20090033117 NASA Marshall Space Flight Center, Huntsville, AL, United States
The Next Generation Advanced Video Guidance Sensor: Flight Heritage and Current Development
Howard, Richard T.; Bryan, Thomas C.; February 24, 2009; In English; Space, Propulsion & Energy Sciences International Forum: SPESIF-2009, 24 - 26 Feb. 2009, Huntsville, AL, United States; Original contains color and black and white illustrations
Report No.(s): M09-0273; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033117
The Next Generation Advanced Video Guidance Sensor (NGAVGS) is the latest in a line of sensors that have flown four times in the last 10 years. The NGAVGS has been under development for the last two years as a long-range proximity operations and docking sensor for use in an Automated Rendezvous and Docking (AR&D) system. The first autonomous rendezvous and docking in the history of the U.S. Space Program was successfully accomplished by Orbital Express, using the Advanced Video Guidance Sensor (AVGS) as the primary docking sensor. That flight proved that the United States now has a mature and flight proven sensor technology for supporting Crew Exploration Vehicles (CEV) and Commercial Orbital Transport Systems (COTS) Automated Rendezvous and Docking (AR&D). NASA video sensors have worked well in the past: the AVGS used on the Demonstration of Autonomous Rendezvous Technology (DART) mission operated successfully in "spot mode" out to 2 km, and the first generation rendezvous and docking sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on Space Shuttle flights in 1997 and 1998. This paper presents the flight heritage and results of the sensor technology, some hardware trades for the current sensor, and discusses the needs of future vehicles that may rendezvous and dock with the International Space Station (ISS) and other Constellation vehicles. It also discusses approaches for upgrading AVGS to address parts obsolescence, and concepts for minimizing the sensor footprint, weight, and power requirements. In addition, the testing of the various NGAVGS development units will be discussed along with the use of the NGAVGS as a proximity operations and docking sensor.
Author
GUIDANCE SENSORS; AUTONOMOUS DOCKING; SPACE TRANSPORTATION SYSTEM FLIGHTS; ORBITAL RENDEZVOUS; SPACECRAFT DOCKING; AUTONOMY
20090033119 NASA Marshall Space Flight Center, Huntsville, AL, United States
Reefing of Quarter Spherical Ribbon Parachutes Used in the Ares I First Stage Deceleration System
Schmidt, Jason R.; McFadden, Peter G.; May 04, 2009; In English; AIAA 20th Aerodynamic Decelerator Systems Technology Conference and Seminar, 4 May 2009, Seattle, WA, United States; Original contains color illustrations
Contract(s)/Grant(s): NNM07AA75C
Report No.(s): M09-0428; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033119
This paper introduces the parachutes that have been drop tested in support of the Ares I first stage deceleration system development. The results of the tests show that the reefing ratios for these quarter spherical ribbon parachutes provide the same reefed drag area as historical conical ribbon parachutes. Two sources are investigated for properly normalizing the parachutes relative to their suspension line length, and one is found to be superior.
Author
PARACHUTES; RIBBON PARACHUTES; SYSTEMS ENGINEERING; DECELERATION; ARES 1 FIRST STAGE
20090033123 Mississippi State Univ., MS, United States
Effects of Core-Shell Rubber (CSR) Nanoparticles on the Cryogenic Fracture Toughness of CSR Modified Epoxy
Wang, Jun; Magee, Daniel; Schneider, Judy; Cannon, Seth; February 15, 2009; In English; TMS 2009 Annual Meeting and Exhibition, 15 - 19 Feb. 2009, San Francisco, CA, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): DMR-0619773; DMR-0216703
Report No.(s): M09-0310; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033123
This study investigated the effects of core-shell rubber (CSR) nanoparticles on the mechanical properties and fracture toughness of an epoxy resin at ambient and liquid nitrogen (LN2) temperatures. Varying amounts of Kane Ace(Registered TradeMark) MX130 and Kane Ace(Registered TradeMark) MX960 toughening agent were added to a commercially available EPON 862/Epikure W epoxy resin. Elastic modulus was calculated using quasi-static tensile data. Fracture toughness was evaluated by the resulting breaking energy measured in Charpy impact tests conducted on an instrumented drop tower. The size and distribution of the CSR nanoparticles were characterized using Transmission Electron Microscopy (TEM) and Small Angle X-ray Scattering (SAXS). Scanning Electron Microscopy (SEM) was used to study the fracture surface morphology. The addition of the CSR nanoparticles increased the breaking energy with negligible change in elastic modulus and ultimate tensile stress (UTS). At ambient temperature the breaking energy increased with increasing additions of the CSR nanoparticles up to 13.8wt%, while at LN2 temperatures, it reached a plateau at much lower CSR concentration.
Author
EPOXY RESINS; FRACTURE STRENGTH; RUBBER; NANOPARTICLES; TENSILE STRESS; TRANSMISSION ELECTRON MICROSCOPY
20090033131 Alabama Univ., Huntsville, AL, United States
Developing an Enhanced Lightning Jump Algorithm for Operational Use
Schultz, Christopher J.; Petersen, Walter A.; Carey, Lawrence D.; July 28, 2009; In English; Southern Thunder Workshop, 28 - 30 Jul. 2009, Cocoa Beach, FL, United States; Original contains color and black and white illustrations
Report No.(s): M09-0618; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033131
Overall Goals: 1. Build on the lightning jump framework set through previous studies. 2. Understand what typically occurs in nonsevere convection with respect to increases in lightning. 3. Ultimately develop a lightning jump algorithm for use on the Geostationary Lightning Mapper (GLM). 4 Lightning jump algorithm configurations were developed (2(sigma), 3(sigma), Threshold 10 and Threshold 8). 5 algorithms were tested on a population of 47 nonsevere and 38 severe thunderstorms. Results indicate that the 2(sigma) algorithm performed best over the entire thunderstorm sample set with a POD of 87%, a far of 35%, a CSI of 59% and a HSS of 75%.
Author
ALGORITHMS; LIGHTNING; CONVECTION
20090033134 Jacobs Engineering Group, Inc., Houston, TX, United States
The Duration of Chemical Weathering of Gusev Crater's Wishstone-Watchtower Sequence
Sutter, Brad; Ming, D. W.; Golden, D. C.; June 1, 2009; In English; Workshop on Modeling Hydrous Environments, 1 - 3 Jun. 2009, Houston, TX, United States; Original contains color illustrations
Contract(s)/Grant(s): C037-AS00-0100-MARS
Report No.(s): JSC-CN-18423; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033134
Mineralogical abundance of primary minerals versus secondary minerals, chemical mixing relationships, and elemental ratios have been used to assess the degree of aqueous alteration at Gusev Crater and Meridiani Planum. However, limited work has used Ti-normalized mass-balance analysis chemical data to quantify gains and losses of elements from altered materials as well as estimate the duration of aqueous alteration on Mars. The Ti-normalized mass-balance approach accounts for volumetric changes associated with geochemical alteration. If volumetric changes are not considered, observed geochemical trends based on un-normalized data have the potential to be misleading. Assessing gains and losses from altered materials can indicate the geochemistry of fluids involved in the alteration. Furthermore, elemental losses can be combined with dissolution rates to estimate the duration of chemical weathering. Knowledge of the duration of aqueous alteration will provide insight into the climate history of Mars as well as indicate the potential for microbial habitability. The Wishstone-Watchtower materials in Gusev Crater are suitable candidates for Ti-normalized mass-balance analysis because mixing relationships of these two materials indicate that Watchtower materials may be derived from Wishstone-like materials. The objectives of this work are to (1) employ Ti-normalized mass-balance to assess gains and losses from the Wishstone-Watchtower sequence and (2) to combine losses with laboratory dissolution rates to estimate alteration times of the Watchtower material.
Author
MARS CRATERS; GEOCHEMISTRY; MINERALOGY; MICROORGANISMS; MARS SURFACE; WEATHERING; MIXING RATIOS; CLIMATE
20090033138 NASA Ames Research Center, Moffett Field, CA, United States
The Thermal Electrical Conductivity Probe (TECP) for Phoenix
Zent, Aaron P.; Hecht, Michael H.; Cobos, Doug R.; Campbell, Gaylon S.; Campbell, Colin S.; Cardell, Greg; Foote, Marc C.; Wood, Stephen E.; Mehta, Manish; [2009]; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 439654.02.01.03
Report No.(s): ARC-E-DAA-TN264; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033138
The Thermal and Electrical Conductivity Probe (TECP) is a component of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) payload on the Phoenix Lander. TECP will measure the temperature, thermal conductivity and volumetric heat capacity of the regolith. It will also detect and quantify the population of mobile H2O molecules in the regolith, if any, throughout the polar summer, by measuring the electrical conductivity of the regolith, as well as the dielectric permittivity. In the vapor phase, TECP is capable of measuring the atmospheric H2O vapor abundance, as well as augment the wind velocity measurements from the meteorology instrumentation. TECP is mounted near the end of the 2.3 m Robotic Arm, and can be placed either in the regolith material or held aloft in the atmosphere. This paper describes the development and calibration of the TECP. In addition, substantial characterization of the instrument has been conducted to identify behavioral characteristics that might affect landed surface operations. The greatest potential issue identified in characterization tests is the extraordinary sensitivity of the TECP to placement. Small gaps alter the contact between the TECP and regolith, complicating data interpretation. Testing with the Phoenix Robotic Arm identified mitigation techniques that will be implemented during flight. A flight model of the instrument was also field tested in the Antarctic Dry Valleys during the 2007-2008 International Polar year. 2
Author
THERMAL CONDUCTIVITY; ELECTROCHEMISTRY; ELECTRICAL RESISTIVITY; PAYLOADS; VELOCITY MEASUREMENT; SPECIFIC HEAT; PERMITTIVITY; FLIGHT INSTRUMENTS; CALIBRATING
20090033140 Triumph Aerospace Systems, Newport News, VA, United States
Technology Transfer Challenges: A Case Study of User-Centered Design in NASA's Systems Engineering Culture
Quick, Jason; July 12, 2009; In English; 39th International Conference on Environmental Systems, 12-16 Jul. 2009, Savannah, GA, United States; Original contains color illustrations
Contract(s)/Grant(s): NNM05ABSOC
Report No.(s): M09-0131; M09-0349; 09ICES-0317; M09-581; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033140
The Upper Stage (US) section of the National Aeronautics and Space Administration's (NASA) Ares I rocket will require internal access platforms for maintenance tasks performed by humans inside the vehicle. Tasks will occur during expensive critical path operations at Kennedy Space Center (KSC) including vehicle stacking and launch preparation activities. Platforms must be translated through a small human access hatch, installed in an enclosed worksite environment, support the weight of ground operators and be removed before flight - and their design must minimize additional vehicle mass at attachment points. This paper describes the application of a user-centered conceptual design process and the unique challenges encountered within NASA's systems engineering culture focused on requirements and "heritage hardware". The NASA design team at Marshall Space Flight Center (MSFC) initiated the user-centered design process by studying heritage internal access kits and proposing new design concepts during brainstorming sessions. Simultaneously, they partnered with the Technology Transfer/Innovative Partnerships Program to research inflatable structures and dynamic scaffolding solutions that could enable ground operator access. While this creative, technology-oriented exploration was encouraged by upper management, some design stakeholders consistently opposed ideas utilizing novel, untested equipment. Subsequent collaboration with an engineering consulting firm improved the technical credibility of several options, however, there was continued resistance from team members focused on meeting system requirements with pre-certified hardware. After a six-month idea-generating phase, an intensive six-week effort produced viable design concepts that justified additional vehicle mass while optimizing the human factors of platform installation and use. Although these selected final concepts closely resemble heritage internal access platforms, challenges from the application of the user-centered process provided valuable lessons for improving future collaborative conceptual design efforts.
Author
SYSTEMS ENGINEERING; HUMAN FACTORS ENGINEERING; NASA PROGRAMS; TECHNOLOGY TRANSFER; ARES 1 UPPER STAGE
20090033142 NASA Langley Research Center, Hampton, VA, United States
Tensile Properties and Microstructure of Inconel 718 Fabricated with Electron Beam Freeform Fabrication (EBF(sup 3))
Bird, R. Keith; Hibberd, Joshua; September 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 561581.02.08.07.15.03
Report No.(s): NASA/TM-2009-215929; L-19731; LF99-9226; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033142
Electron beam freeform fabrication (EBF3) direct metal deposition processing was used to fabricate two Inconel 718 single-bead-width wall builds and one multiple-bead-width block build. Specimens were machined to evaluate microstructure and room temperature tensile properties. The tensile strength and yield strength of the as-deposited material from the wall and block builds were greater than those for conventional Inconel 718 castings but were less than those for conventional cold-rolled sheet. Ductility levels for the EBF3 material were similar to those for conventionally-processed sheet and castings. An unexpected result was that the modulus of the EBF3-deposited Inconel 718 was significantly lower than that of the conventional material. This low modulus may be associated with a preferred crystallographic orientation resultant from the deposition and rapid solidification process. A heat treatment with a high solution treatment temperature resulted in a recrystallized microstructure and an increased modulus. However, the modulus was not increased to the level that is expected for Inconel 718.
Author
INCONEL (TRADEMARK); ELECTRON BEAMS; FABRICATION; DEPOSITION; METALLIZING; RAPID QUENCHING (METALLURGY); HEAT TREATMENT; TENSILE STRENGTH; HEAT OF SOLUTION
20090033144 Blackhawk Management Corp., Houston, TX, United States
Improving the Estimates of International Space Station (ISS) Induced K-Factor Failure Rates for On-Orbit Replacement Unit (ORU) Supportability Analyses
Anderson, Leif F.; Harrington, Sean P.; Omeke, Ojei, II; Schwaab, Douglas G.; September 14, 2009; In English; AIAA SPACE 2009 Conference and Exposition, 14-17 Sep. 2009, Pasadena, CA, United States; Original contains color illustrations
Contract(s)/Grant(s): NAS5-10000
Report No.(s): JSC-CN-18626; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033144
This is a case study on revised estimates of induced failure for International Space Station (ISS) on-orbit replacement units (ORUs). We devise a heuristic to leverage operational experience data by aggregating ORU, associated function (vehicle sub -system), and vehicle effective' k-factors using actual failure experience. With this input, we determine a significant failure threshold and minimize the difference between the actual and predicted failure rates. We conclude with a discussion on both qualitative and quantitative improvements the heuristic methods and potential benefits to ISS supportability engineering analysis.
Author
FAILURE; INTERNATIONAL SPACE STATION; HEURISTIC METHODS; ESTIMATES; SYSTEMS ENGINEERING; FAILURE MODES; ANALOG DATA
Additions to the NASA Aeronautics and Space Database as of 10/02/2009
20090033478 NASA Johnson Space Center, Houston, TX, United States
Cratering Equations for Zinc Orthotitanate Coated Aluminum
Hyde, James; Christiansen, Eric; Liou, Jer-Chyi; Ryan, Shannon; [2009]; In English; 11th Hypervelocity Impact Symposium: Hypervelocity Phenomenology Studies, 11-14 Apr. 2010, Freiburg, Germany; Original contains color illustrations
Report No.(s): JSC-CN-18615; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033478
The final STS-125 servicing mission (SM4) to the Hubble Space Telescope (HST) in May of 2009 saw the return of the 2nd Wide Field Planetary Camera (WFPC2) aboard the shuttle Discovery. This hardware had been in service on HST since it was installed during the SM1 mission in December of 1993 yielding one of the longest low Earth orbit exposure times (15.4 years) of any returned space hardware. The WFPC2 is equipped with a 0.8 x 2.2 m radiator for thermal control of the camera electronics (Figure 1). The space facing surface of the 4.1 mm thick aluminum radiator is coated with Z93 zinc orthotitanate thermal control paint with a nominal thickness of 0.1 0.2 mm. Post flight inspections of the radiator panel revealed hundreds of micrometeoroid/orbital debris (MMOD) impact craters ranging in size from less than 300 to nearly 1000 microns in diameter. The Z93 paint exhibited large spall areas around the larger impact sites (Figure 2) and the craters observed in the 6061-T651 aluminum had a different shape than those observed in uncoated aluminum. Typical hypervelocity impact craters in aluminum have raised lips around the impact site. The craters in the HST radiator panel had suppressed crater lips, and in some cases multiple craters were present instead of a single individual crater. Humes and Kinard observed similar behavior after the WFPC1 post flight inspection and assumed the Z93 coating was acting like a bumper in a Whipple shield. Similar paint behavior (spall) was also observed by Bland2 during post flight inspection of the International Space Station (ISS) S-Band Antenna Structural Assembly (SASA) in 2008. The SASA, with similar Z93 coated aluminum, was inspected after nearly 4 years of exposure on the ISS. The multi-crater phenomena could be a function of the density, composition, or impact obliquity angle of the impacting particle. For instance, a micrometeoroid particle consisting of loosely bound grains of material could be responsible for creating the multiple craters. Samples were obtained from the HST largest craters for examination by electron microscope equipped with x-ray spectrometers to determine impactor source (micrometeoroid or orbital debris). In an attempt to estimate the MMOD particle diameters that produced these craters, this paper will present equations for spall diameter, crater depth and crater diameter in Z93 coated aluminum. The equations will be based on hypervelocity impact tests of Z93 painted aluminum at the NASA White Sands Test Facility. Equations inputs for velocities beyond the testable regime are expected from hydrocode simulations of Z93 coated aluminum using CTH and ANSYS AUTODYN.
Author
CRATERING; ZINC; COATINGS; ALUMINUM; HUBBLE SPACE TELESCOPE; SUPERHIGH FREQUENCIES; IMPACT TESTS; SPACE DEBRIS; HYPERVELOCITY IMPACT
Additions to the NASA Aeronautics and Space Database as of 10/05/2009
20090033637 NASA Dryden Flight Research Center, Edwards, CA, United States
UAV Research, Operations, and Flight Test at the NASA Dryden Flight Research Center
Cosentino, Gary B.; August 26, 2009; In English; UCSD Seminar, 26 Aug. 2009, San Diego, CA, United States; Original contains color illustrations
Report No.(s): DFRC-1055; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033637
This slide presentation reviews some of the projects that have extended NASA Dryden's capabilities in designing, testing, and using Unmanned Aerial Vehicles (UAV's). Some of the UAV's have been for Science and experimental applications, some have been for flight research and demonstration purposes, and some have been small UAV's for other customers.
CASI
FLIGHT TESTS; AIRCRAFT DESIGN; PILOTLESS AIRCRAFT; UNMANNED AIRCRAFT SYSTEMS; RESEARCH AIRCRAFT
20090033640 NASA Marshall Space Flight Center, Huntsville, AL, United States
Characterizing the Effect of Shock on Isotopic Ages 2 Mg-Suite Troctolite Major Elements
Edmunson, Jennifer; Cohen, Barbara; July 13, 2009; In English; 72nd Annual Meeting of the Meteoritical Society, 13-18 Jul. 2009, Nancy, France
Report No.(s): M09-0460; M09-0553; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033640
Two troctolites from the lunar magnesium suite (Mg-suite), 76335 and 76535, have Sm-147-ND-143 and Rb-87- Sr-87 ages that do not indicate the same age for their respective sample. In the case of 76335, the Sm-147-ND-143 age is 4278 +/- 60 Ma, but the Rb-87-Sr-87 data does not reveal an isochron]. For 76535, the Sm-147-ND-143 age is significantly younger (4260 +/- 60 Ma) than the Rb-87- Sr-87 age (4570 +/- 70 Ma, Lambda = 1.402x10(exp -11)). This study was designed to discover why the Sm-147-ND-143 and Rb-87-Sr-87 ages did not match for each individual sample.
Derived from text
ISOTOPES; GEOCHRONOLOGY; ISOTOPE RATIOS; METEORITIC COMPOSITION
20090033641 NASA Stennis Space Center, Stennis Space Center, MS, United States
A3 Subscale Rocket Hot Fire Testing
Saunders, G. P.; Yen, J.; August 03, 2009; In English; 45th AIAA JPC, 3-5 Aug. 2009, Denver, CO, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NNS04AB67T
Report No.(s): SSTI-8080-0034; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033641
This paper gives a description of the methodology and results of J2-X Subscale Simulator (JSS) hot fire testing supporting the A3 Subscale Diffuser Test (SDT) project at the E3 test facility at Stennis Space Center, MS (SSC). The A3 subscale diffuser is a geometrically accurate scale model of the A3 altitude simulating rocket test facility. This paper focuses on the methods used to operate the facility and obtain the data to support the aerodynamic verification of the A3 rocket diffuser design and experimental data quantifying the heat flux throughout the facility. The JSS was operated at both 80% and 100% power levels and at gimbal angle from 0 to 7 degrees to verify the simulated altitude produced by the rocket-rocket diffuser combination. This was done with various secondary GN purge loads to quantify the pumping performance of the rocket diffuser. Also, special tests were conducted to obtain detailed heat flux measurements in the rocket diffuser at various gimbal angles and in the facility elbow where the flow turns from vertical to horizontal upstream of the 2nd stage steam ejector.
Author
ROCKET TEST FACILITIES; ALTITUDE TESTS; SIMULATION; LOADS (FORCES); EJECTORS; PURGING; SCALE MODELS
20090033643 NASA Ames Research Center, Moffett Field, CA, United States
Analysis of Sting Balance Calibration Data Using Optimized Regression Models
Ulbrich, Norbert; Bader, Jon B.; August 02, 2009; In English; 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 2-5 Aug. 2009, Denver, CO, United States; Original contains color illustrations
Contract(s)/Grant(s): NNA04BA85C
Report No.(s): ARC-E-DAA-TN259; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033643
Calibration data of a wind tunnel sting balance was processed using a search algorithm that identifies an optimized regression model for the data analysis. The selected sting balance had two moment gages that were mounted forward and aft of the balance moment center. The difference and the sum of the two gage outputs were fitted in the least squares sense using the normal force and the pitching moment at the balance moment center as independent variables. The regression model search algorithm predicted that the difference of the gage outputs should be modeled using the intercept and the normal force. The sum of the two gage outputs, on the other hand, should be modeled using the intercept, the pitching moment, and the square of the pitching moment. Equations of the deflection of a cantilever beam are used to show that the search algorithm s two recommended math models can also be obtained after performing a rigorous theoretical analysis of the deflection of the sting balance under load. The analysis of the sting balance calibration data set is a rare example of a situation when regression models of balance calibration data can directly be derived from first principles of physics and engineering. In addition, it is interesting to see that the search algorithm recommended the same regression models for the data analysis using only a set of statistical quality metrics.
Author
CALIBRATING; REGRESSION ANALYSIS; WIND TUNNEL APPARATUS; MEASURING INSTRUMENTS; CANTILEVER BEAMS; DEFLECTION; PITCHING MOMENTS; MATHEMATICAL MODELS; LOADS (FORCES)
Additions to the NASA Aeronautics and Space Database as of 10/06/2009
20090033663 NASA Langley Research Center, Hampton, VA, United States
NASA Aerosciences Perspective on Proposed De-Scope of Ares I-X Development Flight Instrumentation
Schuster, David M.; August 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 869021.01.07.01.01
Report No.(s): NASA/TM-2009-215909; NESC-RP-08-19/08-00454; L-19744; LF99-9312; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033663
This position paper is written as a result of a number of emails and a presentation that have recently been circulated concerning the potential reduction of Development Flight Instrumentation (DFI) to be included on the Ares I-X flight test vehicle. A reduction in instrumentation has been proposed presumably to reduce project costs and relieve project schedule pressures. This proposal has generated a significant amount of discussion on both sides of the issue, primarily from those within the project. The intention here is to provide a perspective on this issue from outside the mainline project.
Author
AEROSPACE SCIENCES; FLIGHT TEST VEHICLES; FLIGHT INSTRUMENTS
20090033665 NASA Johnson Space Center, Houston, TX, United States
Ares I-X Vibroacoustic Environments
Larsen, Curtis E.; Schuster, David M.; Kaufman, Daniel S.; August 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 869021.03.07.01.05
Report No.(s): NASA/TM-2009-215910; NESC-RP-08-70/08-00456; L-19745; LF99-9313; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033665
This paper provides a summary of the NASA Engineering and Safety Center (NESC) team recommendations and observations following participation with the Ares I-X Vibroacoustic (VA) Environments Panel in meetings at the Kennedy Space Center (KSC) and the Marshall Space Flight Center (MSFC) in March and April 2008, respectively.
Author
VIBRATIONAL STRESS; ACOUSTICS; FLIGHT TESTS; SYSTEMS ENGINEERING; CONFIGURATION MANAGEMENT
20090033666 NASA Langley Research Center, Hampton, VA, United States
Review of the Constellation Level II Safety, Reliability, and Quality Assurance (SR&QA) Requirements Documents during Participation in the Constellation Level II SR&QA Forum
Cameron, Kenneth D.; Gentz, Steven J.; Beil, Robert J.; Minute, Stephen A.; Currie, Nancy J.; Scott, Steven S.; Thomas, Walter B., III; Smiles, Michael D.; Schafer, Charles F.; Null, Cynthia H.; Bay, P. Michael; August 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 869021.07.07.07.99
Report No.(s): NASA/TM-2009-215914; NESC-RP-08-86/08-00476; L-19749; LF99-9326; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033666
At the request of the Exploration Systems Mission Directorate (ESMD) and the Constellation Program (CxP) Safety, Reliability; and Quality Assurance (SR&QA) Requirements Director, the NASA Engineering and Safety Center (NESC) participated in the Cx SR&QA Requirements forum. The Requirements Forum was held June 24-26; 2008, at GRC's Plum Brook Facility. The forums purpose was to gather all stakeholders into a focused meeting to help complete the process of refining the CxP to refine its Level II SR&QA requirements or defining project-specific requirements tailoring. Element prime contractors had raised specific questions about the wording and intent of many requirements in areas they felt were driving costs without adding commensurate value. NESC was asked to provide an independent and thorough review of requirements that contractors believed were driving Program costs, by active participation in the forum. This document contains information from the forum.
Author
CONSTELLATION PROGRAM; QUALITY CONTROL; REQUIREMENTS; RELIABILITY; COSTS; SAFETY
20090033668 NASA Johnson Space Center, Houston, TX, United States
Space Life Sciences Social Innovation
Llewellyn, Alicia; [2009]; In English; Original contains color illustrations
Report No.(s): JSC-CN-18822; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033668
This slide presentation reviews some of the problems in the world, that NASA is working to solve. It reviews some of the problems that NASA has solved in the past, and is working to solve now. Particularly of interest are some of the problems related to medical delivery in rural and remote areas.
CASI
LIFE SCIENCES; PROBLEM SOLVING; MEDICAL SERVICES
20090033672 NASA Marshall Space Flight Center, Huntsville, AL, United States
Application of Digital Radiography to Weld Inspection for the Space Shuttle External Fuel Tank
Ussery, Warren; July 20, 2009; In English; American Society for Nondestructive Testing (ASNT) Digital Imaging 12th, 20-22, Jul. 2009, Mashantucket, CT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): NAS8-00016
Report No.(s): M09-0598; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033672
This slide presentation reviews NASA's use of digital radiography to inspect the welds of the external tanks used to hold the cryogenic fuels for the Space Shuttle Main Engines. NASA has had a goal of replacing a significant portion of film used to inspect the welds, with digital radiography. The presentation reviews the objectives for converting to a digital system from film, the characteristics of the digital system, the Probability of detection study, the qualification and implementation of the system.
CASI
DIGITAL SYSTEMS; EXTERNAL TANKS; RADIOGRAPHY; WELDED JOINTS; FAULT DETECTION
20090033675 NASA Marshall Space Flight Center, Huntsville, AL, United States
The Crop Evaluation Research for Environmental Strategies (CERES) Remote Sensing 2008 Project Activities
Casas, Joseph C.; Glaser, John A.; Copenhaver, Kenneth L.; May, George; July 05, 2009; In English; International Symposium on Space Technology and Science, 5-12 Jul. 2009, Tsukuba, Japan
Report No.(s): M09-0564; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033675
In recent years, the use of Plant Incorporated Protectant (PIP) corn by American producers has been increasing dramatically. PIP corn contains genetically inserted traits that produce toxins in the plant that provide narrowly targeted protection against specific insect pests. The plant producing t oxms can offer significant reductions in the application of broad -spectrum pesticides that have ecological and human health consequences. PIP corn as a percentage of total corn acreage planted in the US is expected to continue to increase as these protective traits are "stacked" with other desirable traits by seed companies, and producers are seeing considerable increases in corn yield as a result. The introduction of corn as a bio-fuel source for ethanol has increased production by over 6 million hectares in 2007. The United States Environmental Protection Agency (USEPA), which is responsible for the registration of PIP crops under the Federal Insecticide, Fungicide and Rodenticide Act, views the use of PIP corn as positive. Broad spectrum pesticide use has declined since the PIP traits have been introduced. As the agricultural landscape sees a higher percentage of corn acres using the PIP technology, the risk of the targeted insect pest populations developing resistance to the toxins, thereby rendering the in will increase as well. This result would negate the effectiveness of the PIP corn traits and could reduce production of a US field corn crop valued at $33 billion dollars in 2006 and place US food and now energy security at risk. Concerns over insect pest resistance development to PIP traits have led the USEPA to team with NASA and the Institute for Technology Development (ITD) to develop geo-spatial technologies designed to proactively monitor the corn production landscape for insect pest infestation and possible resistance development. USEPA resistance management simulation models are combined with NASA remote sensi ng products to monitor the corn landscape for resistance development. The two agencies have entered into an agreement which could potentially lead to the development of next generation NASA sensors that will more specifically address the requirements of the USEPA's resistance development strategy and offer opportunities to study the ever changing ecosystem complexities. The USEPA/NASA/ITD team has developed a broad research project entitled CERES (Crop Evaluation Research for Environmental Strategies). CERES is a research effort leading to decision support system tools that are designed to integrate multi-resolution NASA remote sensing data products and USEPA geo -spatial models to monitor the potential for insect pest resistance development from the regional to the landscape and then to the field level.
Author
ECOSYSTEMS; REMOTE SENSING; FARM CROPS; ENVIRONMENT PROTECTION; DECISION SUPPORT SYSTEMS; ETHYL ALCOHOL; INSECTICIDES; PROTECTION; AGRICULTURE
20090033676 NASA Marshall Space Flight Center, Huntsville, AL, United States
The 50 Constellation Priority Sites
Noble, S.; Joosten, K.; Eppler, D.; Gruener, J.; Mendell, W.; French, R.; Plescia, J.; Spudis, P.; Wargo, M.; Robinson, M.; Lucey, P.; July 21, 2009; In English; Lunar Science Forum, 21-23 Jul. 2009, Mountain View, CA, United States; Original contains color illustrations
Report No.(s): M09-0644; Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033676
The Constellation program (CxP) has developed a list of 50 sites of interest on the Moon which will be targeted by the LRO narrow angle camera. The list has also been provided to the M~ team to supplement their targeting list. This list does not represent a "site selection" process; rather the goal was to find "representative" sites and terrains to understand the range of possible surface conditions for human lunar exploration to aid engineering design and operational planning. The list compilers leveraged heavily on past site selection work (e.g. Geoscience and a Lunar Base Workshop - 1988, Site Selection Strategy for a Lunar Outpost - 1990, Exploration Systems Architecture Study (ESAS) - 2005). Considerations included scientific, resource utilization, and operational merits, and a desire to span lunar terrain types. The targets have been organized into two "tiers" of 25 sites each to provide a relative priority ranking in the event of mutual interference. A LEAG SAT (special action team) was established to validate and recommend modifications to the list. This SAT was chaired by Dr. Paul Lucey. They provided their final results to CxP in May. Dr. Wendell Mendell will organize an on-going analysis of the data as they come down to ensure data quality and determine if and when a site has sufficient data to be retired from the list. The list was compiled using the best available data, however, it is understood that with the flood of new lunar data, minor modifications or adjustments may be required.
Author
CONSTELLATION PROGRAM; MOON; PLANNING; LUNAR SURFACE; SELENOLOGY; LUNAR LANDING SITES
20090033680 NASA Marshall Space Flight Center, Huntsville, AL, United States
Lunar Mapping and Modeling Project
Noble, Sarah K.; French, Raymond; Nall,Mark; Muery, Kimberly; July 21, 2009; In English; Lunar Science Forum, 21-23 Jul. 2009, Mountain View, CA, United States; Original contains color illustrations
Report No.(s): M09-0645; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033680
The Lunar Mapping and Modeling Project (LMMP) has been created to manage the development of a suite of lunar mapping and modeling products that support the Constellation Program (CxP) and other lunar exploration activities, including the planning, design, development, test and operations associated with lunar sortie missions, crewed and robotic operations on the surface, and the establishment of a lunar outpost. The project draws on expertise from several NASA and non-NASA organizations (MSFC, ARC, GSFC, JPL, CRREL and USGS). LMMP will utilize data predominately from the Lunar Reconnaissance Orbiter, but also historical and international lunar mission data (e.g. Apollo, Lunar Orbiter, Kaguya, Chandrayaan-1), as available and appropriate, to meet Constellation s data needs. LMMP will provide access to this data through a single, common, intuitive and easy to use NASA portal that transparently accesses appropriately sanctioned portions of the widely dispersed and distributed collections of lunar data, products and tools. LMMP will provide such products as DEMs, hazard assessment maps, lighting maps and models, gravity models, and resource maps. We are working closely with the LRO team to prevent duplication of efforts and ensure the highest quality data products. While Constellation is our primary customer, LMMP is striving to be as useful as possible to the lunar science community, the lunar education and public outreach (E/PO) community, and anyone else interested in accessing or utilizing lunar data.
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CONSTELLATION PROGRAM; LUNAR MAPS; LUNAR SURFACE; MAPPING
20090033682 NASA Marshall Space Flight Center, Huntsville, AL, United States
The Uppermost Surface of the Moon
Noble, Sarah K.; July 21, 2009; In English; Lunar Science Forum, 21-23 Jul. 2009, Mountain View, CA, United States; Original contains color illustrations
Report No.(s): M09-0646; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033682
The Ap16 Clam shell Sampling Devices (CSSDs) were designed to sample the uppermost surface of lunar soil. The two devices used beta cloth (69003) and velvet (69004) to collect soil from the top 100 and 500 micrometers of the soil, respectively. Due to the difficulty of the sampling method, little material was collected and as a result little research has been done on these samples. Initial studies attempted to look at the material which had fallen off of the fabrics and was subsequently collected from inside the sample containers. However, this material was highly fractionated and did not provide an adequate picture of the uppermost surface. Recently, samples were obtained directly from the beta cloth using carbon tape. While still fractionated, these samples provide a unique glimpse into the undisturbed soil exposed at the lunar surface.
Derived from text
LUNAR SOIL; LUNAR SURFACE; MOON; SOIL SAMPLING; FABRICS; GRANULAR MATERIALS
20090033684 NASA Glenn Research Center, Cleveland, OH United States
Moisture-Induced Delayed Alumina Scale Spallation on a Ni(Pt)Al Coating
Smialek, James L; Apr. 2009; In English
Contract(s)/Grant(s): FA8650-06-2-5211-AO15Proj-2241
Report No.(s): AD-A502974; AFRL-RX-WP-TP-2009-4150; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033684
http://hdl.handle.net/100.2/ADA502974
Delayed scale failure was examined for samples of a Ni(Pt)Al-coated CMSX4 single crystal superalloy, cyclically oxidized at 1150 degrees C for 2000 hr. One sample exhibited accentuated coating grain boundary wrinkling, initiating local alumina scale spallation to bare metal, resulting in a final weight loss of 3.3 milligrams/(square centimeter). Spallation under ambient conditions was monitored with time after cooldown and was found to continue for times up to 24 hr, producing up to 0.05 milligrams/(square centimeter) additional loss for each hold, and accumulating 0.7 milligrams/(square centimeter) (20% of the total) over the course of the test. After test termination, water immersion produced an additional 0.15 milligrams/(square centimeter) loss. (A duplicate sample produced much less wrinkling and time dependent spalling, maintaining a net weight gain). The results are consistent with the general phenomena of moisture-induced delayed spallation (MIDS) of mature, distressed alumina scales formed on oxidation resistant MAl alloys. Relative ambient humidity is discussed as the factor controlling adsorbed moisture, reaction with the substrate, and hydrogen effects on interface strength.
Author
ALUMINUM ALLOYS; ALUMINUM OXIDES; COATING; DELAY; HEAT RESISTANT ALLOYS; MOISTURE; NICKEL ALLOYS; PLATINUM ALLOYS; SPALLATION
20090033685 NASA Marshall Space Flight Center, Huntsville, AL, United States
Spatial Analysis of Environmental Factors Related to Lyme Disease in Alabama by Means of NASA Earth Observation Systems
Renneboog, Nathan; Capilouto, Emily G.; Firsing, Stephen L., III; Levy, Kyle; McAllister, Marilyn; Roa, Kathryn; Setia,Shveta; Xie, Lili; Burnett, Donna; Luvall, Jeffrey C.; July 26, 2009; In English; (POSTER) UAB DEVELOP Student Poster for Summer '09/DEVELOP Stakeholders meeting, 29 Jul. 2009, Birmingham, AL, United States; Original contains color illustrations
Report No.(s): M09-0656; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033685
This slide presentation reviews the epidemiology of Lyme Disease that accounts for more than 95% or vector borne diseases in the United States. The history, symptoms and the life cycle of the tick, the transmitting agent of Lyme Disease, a map that shows the cases reported to the CDC between1990 and 2006 and the number of cases in Alabama by year from 1986 to 2007. A NASA project is described, the goals of which are to (1) Demonstrate the presence of the chain of infection of Lyme disease in Alabama (2) Identify areas with environmental factors that support tick population using NASA Earth Observation Systems data in selected areas of Alabama and (3) Increase community awareness of Lyme disease and recommend primary and secondary prevention strategies. The remote sensing methods included: Analyzed Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and DigitalGlobe Quickbird satellite imagery from summer months and Performed image analyses in ER Mapper 7.1. Views from the ASTER and Quickbird land cover are shown, the Normalized Difference Vegetation Index (NDVI) algorithm was applied to all ASTER and Quickbird imagery. The use of the images to obtain the level of soil moisture is reviewed, and this analysis was used along with the NDVI, was used to identify the areas that support the tick population.
CASI
EARTH OBSERVATIONS (FROM SPACE); INFECTIOUS DISEASES; REMOTE SENSING; SATELLITE IMAGERY; SIGNS AND SYMPTOMS; IMAGE ANALYSIS; EARTH OBSERVING SYSTEM (EOS); INSECTS
20090033695 NASA Langley Research Center, Hampton, VA, United States
Shuttle Ground Support Equipment (GSE) T-0 Umbilical to Space Shuttle Program (SSP) Flight Elements Consultation
Wilson, Timmy R.; Kichak, Robert A.; McManamen, John P.; Kramer-White, Julie; Raju, Ivatury S.; Beil, Robert J.; Weeks, John F.; Elliott, Kenny B.; June 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 869021.05.07.04.99
Report No.(s): NASA/TM-2009-215753; NESC-RP-07-01/05-012-E; LF99-8879; No Copyright; Avail.: CASI: A11, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033695
The NASA Engineering and Safety Center (NESC) was tasked with assessing the validity of an alternate opinion that surfaced during the investigation of recurrent failures at the Space Shuttle T-0 umbilical interface. The most visible problem occurred during the Space Transportation System (STS)-112 launch when pyrotechnics used to separate Solid Rocket Booster (SRB) Hold-Down Post (HDP) frangible nuts failed to fire. Subsequent investigations recommended several improvements to the Ground Support Equipment (GSE) and processing changes were implemented, including replacement of ground-half cables and connectors between flights, along with wiring modifications to make critical circuits quad-redundant across the interface. The alternate opinions maintained that insufficient data existed to exonerate the design, that additional data needed to be gathered under launch conditions, and that the interface should be further modified to ensure additional margin existed to preclude failure. The results of the assessment are contained in this report.
Author
GROUND SUPPORT EQUIPMENT; SPACE SHUTTLES; CONNECTORS; SPACE SHUTTLE BOOSTERS; SPACE TRANSPORTATION SYSTEM FLIGHTS; LAUNCHING; PYROTECHNICS
20090033697 NASA Dryden Flight Research Center, Edwards, CA, United States
Solder Joint Health Monitoring Testbed
Delaney, Michael M.; Flynn, James G.; Browder, Mark E.; August 31, 2009; In English; Military/Aerospace Programmable Logic Device 2009 (MAPLD 2009), 31 Aug. - 3 Sep. 2009, Greenbelt, MD, United States; Original contains color and black and white illustrations
Report No.(s): DFRC-1054; No Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033697
A method of monitoring the health of selected solder joints, called SJ-BIST, has been developed by Ridgetop Group Inc. under a Small Business Innovative Research (SBIR) contract. The primary goal of this research program is to test and validate this method in a flight environment using realistically seeded faults in selected solder joints. An additional objective is to gather environmental data for future development of physics-based and data-driven prognostics algorithms. A test board is being designed using a Xilinx FPGA. These boards will be tested both in flight and on the ground using a shaker table and an altitude chamber.
Derived from text
SYSTEMS HEALTH MONITORING; SOLDERED JOINTS; ALGORITHMS; SYSTEMS ENGINEERING
Additions to the NASA Aeronautics and Space Database as of 10/07/2009
20090033727 NASA Ames Research Center, Moffett Field, CA, United States
STS-107 Debris Characterization Using Re-entry Imaging
Raiche, George A.; January 15, 2009; In English; STS-107 Debris Characterization Using Re-entry Imaging, 15 Jan. 2005, Hilo, HI, United States; Original contains color and black and white illustrations
Report No.(s): ARC-E-DAA-TN337; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033727
Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.
Author
DEBRIS; IMAGING TECHNIQUES; REENTRY; COLUMBIA (ORBITER); SPACECRAFT BREAKUP; WRECKAGE
20090033728 NASA Ames Research Center, Moffett Field, CA, United States
Shock Layer Radiation Measurements and Analysis for Mars Entry
Bose, Deepak; Grinstead, Jay Henderson; Bogdanoff, David W.; Wright, Michael J.; September 30, 2009; In English; 3rd International Workshop on Radiation of High Temperature Gases in Atmospheric Entry, 30 Sep. - 3 Oct. 2008, Heraklion, Greece; Original contains black and white illustrations
Contract(s)/Grant(s): NNA4BC25C; M-ISP-03-18
Report No.(s): ARC-E-DAA-TN315; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033728
NASA's In-Space Propulsion program is supporting the development of shock radiation transport models for aerocapture missions to Mars. A comprehensive test series in the NASA Antes Electric Arc Shock Tube facility at a representative flight condition was recently completed. The facility optical instrumentation enabled spectral measurements of shocked gas radiation from the vacuum ultraviolet to the near infrared. The instrumentation captured the nonequilibrium post-shock excitation and relaxation dynamics of dispersed spectral features. A description of the shock tube facility, optical instrumentation, and examples of the test data are presented. Comparisons of measured spectra with model predictions are also made.
Author
SHOCK LAYERS; MARS MISSIONS; NEAR INFRARED RADIATION; FAR ULTRAVIOLET RADIATION; SPECTRUM ANALYSIS; RADIATION TRANSPORT; OPTICAL MEASUREMENT
20090033730 NASA Johnson Space Center, Houston, TX, United States
Laser Peening Effects on Friction Stir Welding
Hatameleh, Omar; September 09, 2009; In English; 7th Symposium in Optics in Industry, 9-12 Sep. 2009, Guadalajara, Mexico; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18754; No Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033730
The laser peening process can result in considerable improvement to crack initiation, propagation, and mechanical properties in FSW which equates to longer hardware service life Processed hardware safety is improved by producing higher failure tolerant hardware, and reducing risk. Lowering hardware maintenance cost produces longer hardware service life, and lower hardware down time. Application of this proposed technology will result in substantial benefits and savings throughout the life of the treated components
Author
FRICTION STIR WELDING; MECHANICAL PROPERTIES; CRACK INITIATION; FAULT TOLERANCE; SERVICE LIFE; LASERS
20090033737 NASA Langley Research Center, Hampton, VA, United States
Investigation of Helicopter Longeron Cracks
Newman, John A.; Baughman, James; Wallace, Terryl A.; September 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698259.02.07.07.03.02
Report No.(s): NASA/TP-2009-215791; L-19704; LF99-9060; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033737
Four cracked longerons, containing a total of eight cracks, were provided for study. Cracked regions were cut from the longerons. Load was applied to open the cracks, enabling crack surface examination. Examination revealed that crack propagation was driven by fatigue loading in all eight cases. Fatigue crack initiation appears to have occurred on the top edge of the longerons near geometric changes that affect component bending stiffness. Additionally, metallurgical analysis has revealed a local depletion in alloying elements in the crack initiation regions that may be a contributing factor. Fatigue crack propagation appeared to be initially driven by opening-mode loading, but at a crack length of approximately 0.5 inches (12.7 mm), there is evidence of mixed-mode crack loading. For the longest cracks studied, shear-mode displacements destroyed crack-surface features of interest over significant portions of the crack surfaces.
Author
CRACK INITIATION; LONGERONS; HELICOPTERS; SURFACE CRACKS; CRACK PROPAGATION; FATIGUE (MATERIALS)
20090033738 NASA Glenn Research Center, Cleveland, OH, United States
Active Fail-Safe Micro-Array Flow Control for Advanced Embedded Propulsion Systems
Anderson, Bernhard H.; Mace, James L.; Mani, Mori; August 2009; In English; 47th Aerospace Sciences Meeting, 5-8 Jan. 2009, Orlando, FL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 984754.02.07.03.13.02
Report No.(s): NASA/TM-2009-215596; AIAA Paper 2009-0741; E-16887; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033738
The primary objective of this research effort was to develop and analytically demonstrate enhanced first generation active "fail-safe" hybrid flow-control techniques to simultaneously manage the boundary layer on the vehicle fore-body and to control the secondary flow generated within modern serpentine or embedded inlet S-duct configurations. The enhanced first-generation technique focused on both micro-vanes and micro-ramps highly-integrated with micro -jets to provide nonlinear augmentation for the "strength' or effectiveness of highly-integrated flow control systems. The study focused on the micro -jet mass flow ratio (Wjet/Waip) range from 0.10 to 0.30 percent and jet total pressure ratios (Pjet/Po) from 1.0 to 3.0. The engine bleed airflow range under study represents about a 10 fold decrease in micro -jet airflow than previously required. Therefore, by pre-conditioning, or injecting a very small amount of high-pressure jet flow into the vortex generated by the micro-vane and/or micro-ramp, active flow control is achieved and substantial augmentation of the controlling flow is realized.
Author
FLOW DISTRIBUTION; PROPULSION SYSTEM CONFIGURATIONS; AERODYNAMIC CONFIGURATIONS; SYSTEMS INTEGRATION; BOUNDARY LAYERS; FAIL-SAFE SYSTEMS; JET FLOW; MASS FLOW
20090033743 NASA Langley Research Center, Hampton, VA, United States
Shuttle Orbiter-like Cargo Carrier on Crew Launch Vehicle
Martinovic, Zoran; September 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 304029.01.04.02.02
Report No.(s): NASA/TM-2009-215793; L-19711; LF99-9125; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033743
The following document summarizes the results of a conceptual design study for which the goal was to investigate the possibility of using a crew launch vehicle to deliver the remaining International Space Station elements should the Space Shuttle orbiter not be available to complete that task. Conceptual designs and structural weight estimates for two designs are presented. A previously developed systematic approach that was based on finite-element analysis and structural sizing was used to estimate growth of structural weight from analytical to "as built" conditions.
Author
FINITE ELEMENT METHOD; LAUNCH VEHICLES; INTERNATIONAL SPACE STATION; SPACE SHUTTLE ORBITERS; SPACECREWS; CARGO
20090033744 NASA Glenn Research Center, Cleveland, OH, United States
A Very Large Eddy Simulation of the Nonreacting Flow in a Single-Element Lean Direct Injection Combustor Using PRNS with a Nonlinear Subscale Model
Shih, Tsan-Hsing; Liu, Nan-Suey; August 2009; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 561581.02.08.03.16.02
Report No.(s): NASA/TM-2009-215644; E-16956; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033744
Very large eddy simulation (VLES) of the nonreacting turbulent flow in a single-element lean direct injection (LDI) combustor has been successfully performed via the approach known as the partially resolved numerical simulation (PRNS/VLES) using a nonlinear subscale model. The grid is the same as the one used in a previous RANS simulation, which was considered as too coarse for a traditional LES simulation. In this study, we first carry out a steady RANS simulation to provide the initial flow field for the subsequent PRNS/VLES simulation. We have also carried out an unsteady RANS (URANS) simulation for the purpose of comparing its results with that of the PRNS/VLES simulation. In addition, these calculated results are compared with the experimental data. The present effort has demonstrated that the PRNS/VLES approach, while using a RANS type of grid, is able to reveal the dynamically important, unsteady large-scale turbulent structures occurring in the flow field of a single-element LDI combustor. The interactions of these coherent structures play a critical role in the dispersion of the fuel, hence, the mixing between the fuel and the oxidizer in a combustor.
Author
LARGE EDDY SIMULATION; TURBULENT FLOW; COMPUTATIONAL FLUID DYNAMICS; FLOW DISTRIBUTION; INJECTION
20090033745 NASA Glenn Research Center, Cleveland, OH, United States
The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy
Gabb, Timothy P.; Telesman, Jack; Hazel, Brian; Mourer, David P.; August 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 698259.02.07.03.04.02
Report No.(s): NASA/TM-2009-215629; E-16940; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033745
The effects of hot corrosion pits on low cycle fatigue life and failure modes of the disk superalloy ME3 were investigated. Low cycle fatigue specimens were subjected to hot corrosion exposures producing pits, then tested at low and high temperatures. Fatigue lives and failure initiation points were compared to those of specimens without corrosion pits. Several tests were interrupted to estimate the fraction of fatigue life that fatigue cracks initiated at pits. Corrosion pits significantly reduced fatigue life by 60 to 98 percent. Fatigue cracks initiated at a very small fraction of life for high temperature tests, but initiated at higher fractions in tests at low temperature. Critical pit sizes required to promote fatigue cracking were estimated, based on measurements of pits initiating cracks on fracture surfaces.
Author
HEAT RESISTANT ALLOYS; HOT CORROSION; FATIGUE (MATERIALS); FAILURE MODES; SURFACE CRACKS; HIGH TEMPERATURE TESTS; FRACTURE STRENGTH
20090033749 NASA Glenn Research Center, Cleveland, OH, United States
Compressor Study to Meet Large Civil Tilt Rotor Engine Requirements
Veres, Joseph P.; August 2009; In English; 65th Annual Forum and Technology Display, 27-29 May 2009, Grapevine, TX, United States; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.02.02
Report No.(s): NASA/TM-2009-215641; E-16952; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033749
A vehicle concept study has been made to meet the requirements of the Large Civil Tilt Rotorcraft vehicle mission. A vehicle concept was determined, and a notional turboshaft engine system study was conducted. The engine study defined requirements for the major engine components, including the compressor. The compressor design-point goal was to deliver a pressure ratio of 31:1 at an inlet weight flow of 28.4 lbm/sec. To perform a conceptual design of two potential compressor configurations to meet the design requirement, a mean-line compressor flow analysis and design code were used. The first configuration is an eight-stage axial compressor. Some challenges of the all-axial compressor are the small blade spans of the rear-block stages being 0.28 in., resulting in the last-stage blade tip clearance-to-span ratio of 2.4 percent. The second configuration is a seven-stage axial compressor, with a centrifugal stage having a 0.28-in. impeller-exit blade span. The compressors conceptual designs helped estimate the flow path dimensions, rotor leading and trailing edge blade angles, flow conditions, and velocity triangles for each stage.
Author
COMPRESSORS; TURBOCOMPRESSORS; TILT ROTOR AIRCRAFT; LEADING EDGES; ROTARY WING AIRCRAFT; ENGINE DESIGN; FLOW VELOCITY; CENTRIFUGAL FORCE; TRAILING EDGES
20090033760 NASA Glenn Research Center, Cleveland, OH, United States
Effects of Thermal Exposure on the Optical Properties of LORD Aeroglaze A276
Ellis, David L.; Jaworske, Donald A.; August 2009; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 463169.04.03.05.01
Report No.(s): NASA/TM-2009-215652; E-16965; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033760
A lunar outpost will require electrical energy. One potential source is fission surface power where heat from a reactor is converted into electricity utilizing an energy conversion system, and waste heat will need to be rejected from the system. The Second Generation Radiator Demonstration Unit is a technology demonstration unit leading towards operational radiators. To approximate the infrared emittance of the lunar outpost radiators, a low-cost coating compatible with the test conditions was sought. LORD Aeroglaze A276 has a similar emittance, but its performance in air and vacuum at the desired operating temperatures was unknown. This study determined that the emittance remained above 0.86 for all conditions tested and that LORD Aeroglaze A276 is a suitable surrogate coating for the Second Generation Radiator Demonstration Unit.
Author
COATING; EMITTANCE; LUNAR BASES; ENERGY CONVERSION; OPERATING TEMPERATURE; OPTICAL PROPERTIES; INFRARED RADIATION; ELECTRICITY
20090033766 NASA Glenn Research Center, Cleveland, OH, United States
The NASA In-Space Propulsion Technology Project, Products, and Mission Applicability
Anderson, David J.; Pencil, Eric; Liou, Larry; Dankanich, John; Munk, Michelle M.; Kremic, Tibor; August 2009; In English; 2009 Aerospace Conference, 7-14 Mar. 2009, Big Sky, MT, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 346620.01.03.01
Report No.(s): NASA/TM-2009-215649; Paper no. 1176; E-169649; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033766
The In-Space Propulsion Technology (ISPT) Project, funded by NASA s Science Mission Directorate (SMD), is continuing to invest in propulsion technologies that will enable or enhance NASA robotic science missions. This overview provides development status, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of aerocapture, electric propulsion, advanced chemical thrusters, and systems analysis tools. Aerocapture investments improved: guidance, navigation, and control models of blunt-body rigid aeroshells; atmospheric models for Earth, Titan, Mars, and Venus; and models for aerothermal effects. Investments in electric propulsion technologies focused on completing NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6 to 7 kW throttle-able gridded ion system. The project is also concluding its High Voltage Hall Accelerator (HiVHAC) mid-term product specifically designed for a low-cost electric propulsion option. The primary chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. The project is also delivering products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. In-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations.
Author
ELECTRIC PROPULSION; ION PROPULSION; CHEMICAL PROPULSION; AEROCAPTURE; PROPULSION SYSTEM PERFORMANCE; HALL ACCELERATORS; ION ENGINES; LIQUID ROCKET PROPELLANTS; PROPULSION SYSTEM CONFIGURATIONS
20090033769 NASA Glenn Research Center, Cleveland, OH, United States
NASA PS400: A New Temperature Solid Lubricant Coating for High Temperature Wear Applications
DellaCorte, C.; Edmonds, B. J.; August 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 877868.02.07.03.01.01.14
Report No.(s): NASA/TM-2009-215678; E-17044; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033769
A new solid lubricant coating, NASA PS400, has been developed for high temperature tribological applications. This plasma sprayed coating is a variant of the patented PS304 coating and has been formulated to provide higher density, smoother surface finish and better dimensional stability than PS304. PS400 is comprised of a nickel-molybdenum binder that provides strength, creep resistance and extreme oxidative and dimensional stability. Chromium oxide, silver and barium-calcium fluoride eutectic are added to the binder to form PS400.Tribological properties were evaluated with a pin-on-disk test rig in sliding contact to 650 C. Coating material samples were exposed to air, argon and vacuum at 760 C followed by cross section microscopic analysis to assess microstructure stability. Oil-Free microturbine engine hot section foil bearing tests were undertaken to assess PS400 s suitability for hot foil gas bearing applications. The preliminary results indicate that PS400 exhibits tribological characteristics comparable to the PS304 coating but with enhanced creep resistance and dimensional stability suitable for demanding, dynamic applications.
Author
SOLID LUBRICANTS; HIGH TEMPERATURE; FOIL BEARINGS; FRICTION; TRIBOLOGY; CHROMIUM OXIDES; MOLYBDENUM; NICKEL
20090033772 NASA Langley Research Center, Hampton, VA, United States
Position Paper External Tank Thermal Protection System (TPS) Manually Sprayed fly-as-is Foam Certification
Stadler, John H.; August 2009; In English; Original contains black and white illustrations
Contract(s)/Grant(s): WBS 869021.01.07.01.01
Report No.(s): NASA/TM-2009-215917; NESC-PB-04-10; L-19752; LF99-9332; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033772
During manufacture of the existing External Tanks (ETs), the Thermal Protection System (TPS) foam manual spray application processes lacked the enhanced controls/procedures to ensure that defects produced were less than the critical size. Therefore the only remaining option to certify the "fly-as-is" foam is to verify ET120 tank hardware meets the new foam debris requirements. The ET project has undertaken a significant effort studying the existing "fly-as-is" TPS foam. This paper contains the findings of the study.
Author
THERMAL PROTECTION; EXTERNAL TANKS; FOAMS; CERTIFICATION; DEBRIS; DEFECTS
20090033773 Wyle Labs., Inc., Houston, TX, United States
Infectious Considerations in Space Flight
Haddon, Robert; September 15, 2009; In English; Cleveland Clinic Foundation, 15 Sep. 2009, Cleveland, OH, United States; Original contains color and black and white illustrations
Report No.(s): JSC-CN-18838; Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033773
Slightly more than 500 people have flown in space, most of them for short periods of time. The total number of person years in space is small. Given this fact, and given rigorous astronaut screening, it is not surprising that the accumulated infectious disease experience in space is also small, and mostly, theoretical. As the human space presence expands, we may expect mission length, total accumulated person years and the environmental complexity to increase. Add to the mix both changes in human immunity and microbial virulence, and it becomes realistic to consider infectious scenarios and the means to mitigate them. This lecture will cover the inhabited space environment from the perspective of host-microbe interactions, current relevant research, and the current countermeasures used. Future challenges will be discussed and there will be opportunity to ask questions about Space Operations. The audience is encouraged to think about what medical tools you would choose to have in different types of mission, what you would be willing to leave behind, and how you would compensate for the necessary trade offs in mission design.
Derived from text
AEROSPACE ENVIRONMENTS; INFECTIOUS DISEASES; MANNED SPACE FLIGHT; IMMUNE SYSTEMS; MICROBIOLOGY; AEROSPACE MEDICINE
20090033774 NASA Langley Research Center, Hampton, VA, United States
Laura Users Manual: 5.1-41601
Mazaheri, Alireza; Gnoffo, Peter A.; Johnston, Christopher O.; Kleb, Bil; August 2009; In English
Contract(s)/Grant(s): WBS 37781606030308
Report No.(s): NASA/TM-2009-215783; L-19726; LF99-9183; Copyright; Avail.: CASI: A04, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033774
This users manual provides in-depth information concerning installation and execution of LAURA, version 5. LAURA is a structured, multi-block, computational aerothermodynamic simulation code. Version 5 represents a major refactoring of the original Fortran 77 LAURA code toward a modular structure afforded by Fortran 95. The refactoring improved usability and maintainability by eliminating the requirement for problem-dependent re-compilations, providing more intuitive distribution of functionality, and simplifying interfaces required for multiphysics coupling. As a result, LAURA now shares gas-physics modules, MPI modules, and other low-level modules with the FUN3D unstructured-grid code. In addition to internal refactoring, several new features and capabilities have been added, e.g., a GNU-standard installation process, parallel load balancing, automatic trajectory point sequencing, free-energy minimization, and coupled ablation and flowfield radiation.
Author
AEROTHERMODYNAMICS; ABLATION; APPLICATIONS PROGRAMS (COMPUTERS); COMPUTER PROGRAMS; COMPUTERIZED SIMULATION; UNSTRUCTURED GRIDS (MATHEMATICS); MAINTAINABILITY
20090033783 NASA Langley Research Center, Hampton, VA, United States
A Simple Sensor Model for THUNDER Actuators
Campbell, Joel F.; Bryant, Robert G.; September 2009; In English; Original contains color illustrations
Contract(s)/Grant(s): WBS 129985.05.07.98.42.02
Report No.(s): LF99-7603; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033783
A quasi-static (low frequency) model is developed for THUNDER actuators configured as displacement sensors based on a simple Raleigh-Ritz technique. This model is used to calculate charge as a function of displacement. Using this and the calculated capacitance, voltage vs. displacement and voltage vs. electrical load curves are generated and compared with measurements. It is shown this model gives acceptable results and is useful for determining rough estimates of sensor output for various loads, laminate configurations and thicknesses.
Author
ACTUATORS; CAPACITANCE; ELECTRIC POTENTIAL; STATIC MODELS; ESTIMATES
20090033784 Georgia Tech Research Inst., Atlanta, GA, United States
Unsteady Extinction of Opposed Jet Ethylene/Methane HIFiRE Surrogate Fuel Mixtures vs Air
Vaden, Sarah N.; Debes, Rachel L.; Lash, E. Lara; Burk, Rachel S.; Boyd, C. Merritt; Wilson, Lloyd G.; Pellett, Gerald L.; August 03, 2009; In English; 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 3 - 5 Aug. 2009, Denver, CO, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 736466.11.01.07.43.06
Report No.(s): AIAA Paper 2009-4879; LF99-8201; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033784
A unique idealized study of the subject fuel vs. air systems was conducted using an Oscillatory-input Opposed Jet Burner (OOJB) system and a newly refined analysis. Extensive dynamic-extinction measurements were obtained on unanchored (free-floating) laminar Counter Flow Diffusion Flames (CFDFs) at 1-atm, stabilized by steady input velocities (e.g., U(sub air)) and perturbed by superimposed in-phase sinusoidal velocity inputs at fuel and air nozzle exits. Ethylene (C2H4) and methane (CH4), and intermediate 64/36 and 15/85 molar percent mixtures were studied. The latter gaseous surrogates were chosen earlier to mimic ignition and respective steady Flame Strengths (FS = U(sub air)) of vaporized and cracked, and un-cracked, JP-7 "like" kerosene for a Hypersonic International Flight Research Experimentation (HIFiRE) scramjet. For steady idealized flameholding, the 100% C2H4 flame is respectively approx. 1.3 and approx.2.7 times stronger than a 64/36 mix and CH4; but is still 12.0 times weaker than a 100% H2-air flame. Limited Hot-Wire (HW) measurements of velocity oscillations at convergent-nozzle exits, and more extensive Probe Microphone (PM) measurements of acoustic pressures, were used to normalize Dynamic FSs, which decayed linearly with pk/pk U(sub air) (velocity magnitude, HW), and also pk/pk P (pressure magnitude, PM). Thus Dynamic Flame Weakening (DFW) is defined as % decrease in FS per Pascal of pk/pk P oscillation, namely, DFW = -100 d(U(sub air)/U(sub air),0Hz)/d(pkpk P). Key findings are: (1) Ethylene flames are uniquely strong and resilient to extinction by oscillating inflows below 150 Hz; (2) Methane flames are uniquely weak; (3) Ethylene / methane surrogate flames are disproportionately strong with respect to ethylene content; and (4) Flame weakening is consistent with limited published results on forced unsteady CFDFs. Thus from 0 to approx. 10 Hz and slightly higher, lagging diffusive responses of key species led to progressive phase lags (relative to inputs) in the oscillating flames, and caused maximum weakening. At 20 to 150 Hz, diffusion-rate-limited effects diminished, causing flames to "regain strengnth," and eventually become completely insensitive beyond 300 Hz. Detailed mechanistic understanding is needed. Overall, ethylene flames are remarkably resilient to dynamic extinction by oscillating inflows. They are the strongest, with the notable exception of H2. For HIFiRE tests, the 64%/36% surrogate disproportionally retains the high dynamic FS of ethylene, so the potential for loss of scramjet flameholding (flameout) due to low frequency oscillations is significantly mitigated.
Author
CONVERGENT NOZZLES; DIFFUSION FLAMES; JP-7 JET FUEL; METHANE; ETHYLENE; LAMINAR FLOW; FLAMEOUT; SUPERSONIC COMBUSTION RAMJET ENGINES
20090033792 NASA Langley Research Center, Hampton, VA, United States
Simulation of the Thermographic Response of Near Surface Flaws in Reinforced Carbon-Carbon Panels
Winfree, William P.; Howell, Patricia A.; Burke, Eric R.; July 26, 2009; In English; QNDE 2009 - Quantitative Nondestructive Evaluation Conference, 26-31 Jul. 2009, Kingston, RI, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 736466.08.01.07.43
Report No.(s): LF99-8707; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033792
Thermographic inspection is a viable technique for detecting in-service damage in reinforced carbon-carbon (RCC) composites that are used for thermal protection in the leading edge of the shuttle orbiter. A thermographic technique for detection of near surface flaws in RCC composite structures is presented. A finite element model of the heat diffusion in structures with expected flaw configurations is in good agreement with the experimental measurements.
Author
THERMOGRAPHY; INSPECTION; CARBON-CARBON COMPOSITES; DAMAGE; LEADING EDGES; THERMAL PROTECTION
20090033794 NASA Langley Research Center, Hampton, VA, United States
The Use of Meteorlogical Data to Improve Contrail Detection in Thermal Imagery over Ireland.
Whelan, Gillian M.; Cawkwell, Fiona; Mannstein, Hermann; Minnis, Patrick; September 08, 2009; In English; RSPSoc Annual Conference, 8-11 Sept. 2009, Leicester, United Kingdom; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 967701.02.02.01.13
Report No.(s): LF99-8777; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033794
Aircraft induced contrails have been found to have a net warming influence on the climate system, with strong regional dependence. Persistent linear contrails are detectable in 1 Km thermal imagery and, using an automated Contrail Detection Algorithm (CDA), can be identified on the basis of their different properties at the 11 and 12 m w av.el enTgthshe algorithm s ability to distinguish contrails from other linear features depends on the sensitivity of its tuning parameters. In order to keep the number of false identifications low, the algorithm imposes strict limits on contrail size, linearity and intensity. This paper investigates whether including additional information (i.e. meteorological data) within the CDA may allow for these criteria to be less rigorous, thus increasing the contrail-detection rate, without increasing the false alarm rate.
Author
CONTRAILS; METEOROLOGICAL PARAMETERS; LINEARITY; DETECTION; THERMAL MAPPING
20090033796 NASA Langley Research Center, Hampton, VA, United States
Lightning Pin Injection Testing on MOSFETS
Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.; Koppen, Sandra V.; Mielnik, John J.; Vaughan, Roger K.; Wysocki, Philip F.; Celaya, Jose R.; Saha, Sankalita; September 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 645846.02.07.07.12.02
Report No.(s): NASA/TM-2009-215794; L-19713; LF99-9139; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033796
Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation.
Author
DEGRADATION; METAL OXIDE SEMICONDUCTORS; FIELD EFFECT TRANSISTORS; LIGHTNING; THERMAL STRESSES; THRESHOLD VOLTAGE; DIRECT CURRENT; ELECTROMECHANICAL DEVICES
20090033804 Binghamton Univ., Binghamton, NY, United States
Motion Cueing Algorithm Modification for Improved Turbulence Simulation
Ercole, Anthony V.; Cardullo, Frank M.; Zaychik, Kirill; Kelly, Lon C.; Houck, Jacob; August 10, 2009; In English; AIAA Modeling and Simulation Technologies Conference, 10-13 Aug. 2009, Chicago, IL, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 160961.01.01.01
Report No.(s): AIAA Paper 2009-6247; LF99-9191; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033804
Atmospheric turbulence cueing produced by flight simulator motion systems has been less than satisfactory because the turbulence profiles have been attenuated by the motion cueing algorithms. Cardullo and Ellor initially addressed this problem by directly porting the turbulence model output to the motion system. Reid and Robinson addressed the problem by employing a parallel aircraft model, which is only stimulated by the turbulence inputs and adding a filter specially designed to pass the higher turbulence frequencies. There have been advances in motion cueing algorithm development at the Man-Machine Systems Laboratory, at SUNY Binghamton. In particular, the system used to generate turbulence cues has been studied. The Reid approach, implemented by Telban and Cardullo, was employed to augment the optimal motion cueing algorithm installed at the NASA LaRC Simulation Laboratory, driving the Visual Motion Simulator. In this implementation, the output of the primary flight channel was added to the output of the turbulence channel and then sent through a non-linear cueing filter. The cueing filter is an adaptive filter; therefore, it is not desirable for the output of the turbulence channel to be augmented by this type of filter. The likelihood of the signal becoming divergent was also an issue in this design. After testing on-site it became apparent that the architecture of the turbulence algorithm was generating unacceptable cues. As mentioned above, this cueing algorithm comprised a filter that was designed to operate at low bandwidth. Therefore, the turbulence was also filtered, augmenting the cues generated by the model. If any filtering is to be done to the turbulence, it will utilize a filter with a much higher bandwidth, above the frequencies produced by the aircraft response to turbulence. The authors have developed an implementation wherein only the signal from the primary flight channel passes through the nonlinear cueing filter. This paper discusses three new algorithms. Testing shows that the new methods provide the pilot with a more realistic sensation of turbulence; the cues are not attenuated by algorithm. Results of offline testing show the credibility of the models. Offline test verification was based primarily on the evaluation of the power spectral density of the outputs and the time response.
Author
ALGORITHMS; FLIGHT SIMULATORS; MOTION SIMULATORS; TURBULENCE MODELS; ATMOSPHERIC TURBULENCE
20090033805 NASA Langley Research Center, Hampton, VA, United States
Effectiveness of Shield Termination Techniques Tested with TEM Cell and Bulk Current Injection
Bradley, Arthur T.; Hare, Richard J.; August 17, 2009; In English; IEEE EMC 2009 Symposium, 17-21 Aug. 2009, Austin, TX, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 736466.08.01.07.01
Report No.(s): LF99-9338; No Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033805
This paper presents experimental results of the effectiveness of various shield termination techniques. Each termination technique is evaluated by two independent noise injection methods; transverse electromagnetic (TEM) cell operated from 3 MHz 400 MHz, and bulk current injection (BCI) operated from 50 kHz 400 MHz. Both single carrier and broadband injection tests were investigated. Recommendations as to how to achieve the best shield transfer impedance (i.e. reduced coupled noise) are made based on the empirical data. Finally, the noise injection techniques themselves are indirectly evaluated by comparing the results obtained from the TEM Cell to those from BCI.
Author
TRANSVERSE MOMENTUM; ELECTRIC CURRENT; CARRIER INJECTION; ELECTRICAL ENGINEERING; ELECTROMAGNETISM
20090033807 NASA Langley Research Center, Hampton, VA, United States
Development of the One-Sided Nonlinear Adaptive Doppler Shift Estimation
Beyon, Jeffrey Y.; Koch, Grady J.; Singh, Upendra N.; Kavaya, Michael J.; Serror, Judith A.; August 31, 2009; In English; SPIE Europe Remote Sensing, 31 Aug. - 2 Sep. 2009, Berlin, Germany; Original contains color and black and white illustrations
Report No.(s): 7479-21; LF99-9253; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033807
The new development of a one-sided nonlinear adaptive shift estimation technique (NADSET) is introduced. The background of the algorithm and a brief overview of NADSET are presented. The new technique is applied to the wind parameter estimates from a 2-micron wavelength coherent Doppler lidar system called VALIDAR located in NASA Langley Research Center in Virginia. The new technique enhances wind parameters such as Doppler shift and power estimates in low Signal-To-Noise-Ratio (SNR) regimes using the estimates in high SNR regimes as the algorithm scans the range bins from low to high altitude. The original NADSET utilizes the statistics in both the lower and the higher range bins to refine the wind parameter estimates in between. The results of the two different approaches of NADSET are compared.
Author
DOPPLER EFFECT; DOPPLER RADAR; SIGNAL TO NOISE RATIOS; WIND MEASUREMENT; PARAMETER IDENTIFICATION; OPTICAL RADAR; ESTIMATES
Additions to the NASA Aeronautics and Space Database as of 10/08/2009
20090033820 Research Inst. for Advanced Computer Science, Moffett Field, CA, United States
Communication Optimizations for a Wireless Distributed Prognostic Framework
Saha, Sankalita; Saha, Bhaskar; Goebel, Kai; March 07, 2009; In English; 2009 IEEE Aerospace Conference, 7-14 Mar. 2009, Big Sky, MT, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 645846.02.07.01.01
Report No.(s): ARC-E-DAA-TN-246; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033820
Distributed architecture for prognostics is an essential step in prognostic research in order to enable feasible real-time system health management. Communication overhead is an important design problem for such systems. In this paper we focus on communication issues faced in the distributed implementation of an important class of algorithms for prognostics - particle filters. In spite of being computation and memory intensive, particle filters lend well to distributed implementation except for one significant step - resampling. We propose new resampling scheme called parameterized resampling that attempts to reduce communication between collaborating nodes in a distributed wireless sensor network. Analysis and comparison with relevant resampling schemes is also presented. A battery health management system is used as a target application. A new resampling scheme for distributed implementation of particle filters has been discussed in this paper. Analysis and comparison of this new scheme with existing resampling schemes in the context for minimizing communication overhead have also been discussed. Our proposed new resampling scheme performs significantly better compared to other schemes by attempting to reduce both the communication message length as well as number total communication messages exchanged while not compromising prediction accuracy and precision. Future work will explore the effects of the new resampling scheme in the overall computational performance of the whole system as well as full implementation of the new schemes on the Sun SPOT devices. Exploring different network architectures for efficient communication is an importance future research direction as well.
Author
ELECTRIC BATTERIES; DESIGN ANALYSIS; REAL TIME OPERATION; MANAGEMENT SYSTEMS; OPTIMIZATION; PRECISION
20090033821 Research Inst. for Advanced Computer Science, Moffett Field, CA, United States
Evaluating Algorithm Performance Metrics Tailored for Prognostics
Saxena, Abhinav; Celaya, Jose; Saha, Bhaskar; Saha, Sankalita; Goebel, Kai; March 07, 2009; In English; 2009 IEEE Aerospace Conference, 7 - 14 Mar. 2009, Big Sky, MT, United States; Original contains color illustrations
Contract(s)/Grant(s): WBS 645846.02.07.01.01
Report No.(s): ARC-E-DAA-TN-245; Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033821
Prognostics has taken a center stage in Condition Based Maintenance (CBM) where it is desired to estimate Remaining Useful Life (RUL) of the system so that remedial measures may be taken in advance to avoid catastrophic events or unwanted downtimes. Validation of such predictions is an important but difficult proposition and a lack of appropriate evaluation methods renders prognostics meaningless. Evaluation methods currently used in the research community are not standardized and in many cases do not sufficiently assess key performance aspects expected out of a prognostics algorithm. In this paper we introduce several new evaluation metrics tailored for prognostics and show that they can effectively evaluate various algorithms as compared to other conventional metrics. Specifically four algorithms namely; Relevance Vector Machine (RVM), Gaussian Process Regression (GPR), Artificial Neural Network (ANN), and Polynomial Regression (PR) are compared. These algorithms vary in complexity and their ability to manage uncertainty around predicted estimates. Results show that the new metrics rank these algorithms in different manner and depending on the requirements and constraints suitable metrics may be chosen. Beyond these results, these metrics offer ideas about how metrics suitable to prognostics may be designed so that the evaluation procedure can be standardized. 1
Author
NEURAL NETS; ESTIMATES; MAINTENANCE; STANDARDIZATION; ALGORITHMS
20090033822 Research Inst. for Advanced Computer Science, Moffett Field, CA, United States
Prognostics for Electronics Components of Avionics Systems
Celaya, Jose R.; Saha, Bhaskar; Wysocki, Philip F.; Goebel, Kai F.; March 07, 2009; In English; 2009 IEEE Aerospace Conference, 7-14 Mar. 2009, Big Sky, MT, United States; Original contains color and black and white illustrations
Contract(s)/Grant(s): WBS 645846.02.07.01.01
Report No.(s): ARC-E-DAA-TN-244; Copyright; Avail.: CASI: A02, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033822
Electronics components have and increasingly critical role in avionics systems and for the development of future aircraft systems. Prognostics of such components is becoming a very important research filed as a result of the need to provide aircraft systems with system level health management. This paper reports on a prognostics application for electronics components of avionics systems, in particular, its application to the Isolated Gate Bipolar Transistor (IGBT). The remaining useful life prediction for the IGBT is based on the particle filter framework, leveraging data from an accelerated aging tests on IGBTs. The accelerated aging test provided thermal-electrical overstress by applying thermal cycling to the device. In-situ state monitoring, including measurements of the steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.
Author
AVIONICS; LIFE (DURABILITY); THERMAL CYCLING TESTS; ACCELERATED LIFE TESTS; BIPOLAR TRANSISTORS; ELECTRIC POTENTIAL; SYSTEMS ENGINEERING
Additions to the NASA Aeronautics and Space Database as of 10/09/2009
20090033934 NASA Goddard Space Flight Center, Greenbelt, MD, United States
The Astrophysics Science Division Annual Report 2008
Oegerle, William; Reddy, Francis; Tyler, Pat; March 2009; In English; Original contains color and black and white illustrations
Contract(s)/Grant(s): NG07EK67C
Report No.(s): NASA/TM-2009-214182; 200902507; Copyright; Avail.: CASI: A05, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033934
The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. This report includes the Division's activities during 2008.
Author
ASTROPHYSICS; GAMMA RAY TELESCOPES; X RAY TIMING EXPLORER; COSMOLOGY; AEROSPACE SCIENCES
20090033937 NASA Dryden Flight Research Center, Edwards, CA, United States
IRAC Full-Scale Flight Testbed Capabilities
Lee, James A.; Pahle, Joseph; Cogan, Bruce R.; Hanson, Curtis E.; Bosworth, John T.; August 09, 2009; In English; NASA IRAC RFI Response Workshop, 9 Aug. 2009, Chicago, IL, United States; Original contains color and black and white illustrations
Report No.(s): DFRC-1044; No Copyright; Avail.: CASI: A03, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033937
Overview: Provide validation of adaptive control law concepts through full scale flight evaluation in a representative avionics architecture. Develop an understanding of aircraft dynamics of current vehicles in damaged and upset conditions Real-world conditions include: a) Turbulence, sensor noise, feedback biases; and b) Coupling between pilot and adaptive system. Simulated damage includes 1) "B" matrix (surface) failures; and 2) "A" matrix failures. Evaluate robustness of control systems to anticipated and unanticipated failures.
Author
ADAPTIVE CONTROL; FLIGHT TESTS; ROBUSTNESS (MATHEMATICS); AVIONICS; CONTROL THEORY
20090033997 NASA Goddard Space Flight Center, Greenbelt, MD, United States
International VLBI Service for Geodesy and Astrometry 2008 Annual Report
Behrend, Dirk; Baver, Karen D.; August 2009; In English; Original contains color and black and white illustrations
Report No.(s): NASA/TP-2009-214183; Rept-200902253; Copyright; Avail.: CASI: A18, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033997
This volume of reports is the 2008 Annual Report of the International VLBI Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the components of IVS. The 2008 Annual Report documents the work of these IVS components over the period January 1, 2008 through December 31, 2008. The reports document changes, activities, and progress of the IVS. The entire contents of this Annual Report also appear on the IVS Web site at http://ivscc.gsfc.nasa.gov/publications/ar2008.
Author
GEODESY; ASTROMETRY; VERY LONG BASE INTERFEROMETRY; GEOPHYSICS; RADIO ASTRONOMY; GEODYNAMICS; EARTH ORIENTATION
20090033998 Norwegian Defence Research Establishment, Norway
FFI Technology Development Center - Software Development
Andersen, Per Helge; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 31; In English
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033998
FFI's contribution to the IVS as a Technology Development Center focuses primarily on the development and validation of the GEOSAT software for a combined analysis at the observation level of data from VLBI, GPS and SLR. This report shortly summarises the latest improvements of the GEOSAT software. FFI is currently an Analysis Center for IVS and ILRS, and a Technology Development Center for IVS
Author
VERY LONG BASE INTERFEROMETRY; COMPUTER PROGRAMS; SOFTWARE ENGINEERING; PROGRAM VERIFICATION (COMPUTERS); GLOBAL POSITIONING SYSTEM; GEOSAT SATELLITES; COMPUTER PROGRAMMING
20090033999 NASA Goddard Space Flight Center, Greenbelt, MD, United States
GSFC Technology Development Center Report
Himwich, Ed; Gipson, John; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 318-32; In English
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090033999
This report summarizes the activities of the GSFC Technology Development Center (TDC) for 2008 and forecasts planned activities for 2009. The GSFC TDC develops station software including the Field System, scheduling software (SKED), hardware including tools for station timing and meteorology, scheduling algorithms, and operational procedures. It provides a pool of individuals to assist with station implementation, check-out, upgrades, and training. 1. Technology Center Activities The GSFC IVS Technology Development Center (TDC) develops hardware, software, algorithms, and operational procedures. It provides manpower for station visits for training and upgrades. Other technology development areas at GSFC are covered by other IVS components such as the GSFC Analysis Center. The current staff of the GSFC TDC consists of John Gipson and Ed Himwich, both employed by NVI, Inc. The remainder of this report covers the status of the main areas of development that are currently being pursued.
Author
SOFTWARE ENGINEERING; COMPUTER PROGRAMS; MANPOWER; EDUCATION; ALGORITHMS
20090034000 Natural Resources Canada, Ottawa, Ontario, Canada
Canadian VLBI Technology Development Center
Petrachenko, Bill; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 315-31; In English; Original contains color illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090034000
The Canadian VLBI Technology Development Center (TDC) is actively involved in theoretical studies to define recommendations for the VLBI2010 system. In addition, two development programs at the Dominion Radio Astrophysical Observatory (DRAO) are of potential interest to VLBI2010. Composite antennas that are light, stiff, and cost effective are being developed, and a state-of-the-art correlator is being developed for the EVLA.
Author
VERY LONG BASE INTERFEROMETRY; ASTROPHYSICS; OBSERVATORIES; GEODETIC SURVEYS; CORRELATORS; EARTH RESOURCES
20090034001 Onsala Space Observatory, Sweden
Onsala Space Observatory - IVS Network Station
Haas, Rudiger; Elgered, Gunnar; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 146-14; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090034001
During 2008 the Onsala Space Observatory contributed as an IVS Network Station to 38 VLBI sessions organized by the IVS. Additionally, we performed 27 ultra-rapid dUT1-sessions together with partner telescopes in Japan and Finland. This report briefly summarizes the activities during the year 2008. In 2008 the observatory was involved in the five IVS series EUROPE, R1, T2, RDV, and RD08 plus the CONT08 campaign. In total, Onsala participated and acquired useful observations in 38 experiments, see Table 2. All experiments were recorded on Mark 5 modules. Most of the experiments whose data were correlated at the Bonn correlator were additionally recorded in parallel on the PCEVN computer that is daisy-chained to the Mark 5 computer. The observed data of these experiments were then transferred electronically using the Tsunami protocol, and no Mark 5 modules were actually sent to Bonn. Radio interference due to UMTS mobile telephone signals continued to be a disturbing factor for the S-band observations. Additionally, we suffered from problems with the telescope encoders.
Author
RADIO FREQUENCY INTERFERENCE; VERY LONG BASE INTERFEROMETRY; SUPERHIGH FREQUENCIES; CORRELATORS; OBSERVATORIES; TSUNAMI WAVES; ULTRAHIGH FREQUENCIES
20090034002 Observatoire de Paris, France
Paris Observatory (OPAR) Data Center
Barache, Christophe; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 236-23; In English; Original contains color illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090034002
This report summarizes the OPAR Data Center activities in 2008. Included is information about functions, architecture, status, future plans, and staff members of OPAR Data Center. The Paris Observatory (OPAR) has provided a Data Center for the International VLBI Service for Geodesy and Astrometry (IVS) since 1999. The OPAR as well as CDDIS and BKG is one of the three IVS Primary Data Centers. Their activities are done in close collaboration for the purposes of collecting files (data and analysis files), and making them available to the community as soon as they are submitted. The three data centers have a common protocol and each of them: has the same directory structure (with the same control file), has the same script, is able to receive all IVS files (auxiliary, database, products, documents), mirrors the other ones every three hours, gives free FTP access to the files.
Author
DATA ACQUISITION; VERY LONG BASE INTERFEROMETRY; DATA BASES; GEODESY; LIBRARIES; DIRECTORIES
20090034003 Naval Observatory, Washington, DC, United States
U.S. Naval Observatory VLBI Analysis Center
Boboltz, David A.; Fey, Alan L.; Bartlett, Jennifer L.; Dugan, Zachary; Kingham, Kerry A.; Hall, David M.; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 305-30; In English; Original contains black and white illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090034003
This report summarizes the activities of the VLBI Analysis Center at the United States Naval Observatory for calendar year 2008. Over the course of the year, Analysis Center personnel analyzed biweekly 24-hour experiments with designations IVS-R1 and IVS-R4 for use in-house and continued timely submission of IVS-R4 databases for distribution to the IVS. During the 2008 calendar year, the USNO Analysis Center produced two periodic global Terrestrial Reference Frame (TRF) solutions with designations usn2008a and usn2008b. Earth orientation parameters (EOP) based on these solutions, updated by the latest 24-hour (IVS-R1 and IVS-R4) experiments, were submitted to the IVS. Other activities in the 2008 calendar year included the continued submission of Sinex files based on new 24-hour experiments to the IVS. For the Celestial Reference Frame (CRF), Analysis Center personnel continued a program designed to increase the sky density of ICRF sources, especially in the Southern Hemisphere. Activities included scheduling, analyzing and submitting databases for IVS-CRF experiments, and the production of global CRF solutions designated crf2008a and crf2008b. In addition, Analysis Center personnel performed research into the next generation ICRF-2 and a future high-frequency reference frame based on the VLBA K/Q-band experiments. Activities planned for the 2009 calendar year include the continued production of EOP/TRF/CRF global solutions and continued research into future reference frames.
Author
VERY LONG BASE INTERFEROMETRY; CELESTIAL REFERENCE SYSTEMS; EARTH ORIENTATION; EXTREMELY HIGH FREQUENCIES; PLASMA HEATING; STRUCTURAL ANALYSIS; OBSERVATORIES; NAVY
20090034004 Naval Observatory, Washington, DC, United States
USNO Analysis Center for Source Structure Report
Fey, Alan L.; Boboltz, David A.; Ojha, Roopesh; Gaume, Ralph A.; Kingham, Kerry A.; International VLBI Service for Geodesy and Astrometry 2008 Annual Report; August 2009; pp. 309-31; In English; Original contains color illustrations
Copyright; Avail.: CASI: A01, Hardcopy
Avail Online: http://hdl.handle.net/2060/20090034004
This report summarizes the activities of the United States Naval Observatory Analysis Center for Source Structure for calendar year 2008. VLBA RDV experiments RDV67 and RDV69 were calibrated and imaged. Images from these two experiments, together with images from RD | |
