SCAN_89-01

89-01 SOLAR ASTRONOMY
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Effect of Space Radiation Processing on Lunar Soil Surface Chemistry: X-Ray Photoelectron Spectroscopy Studies
Document ID:
20090022140
Report #:
JSC-CN-18403
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Dukes, C. (Virginia Univ.) Loeffler, M.J. (Virginia Univ.) Baragiola, R. (Virginia Univ.) Christoffersen, R. (Jacobs Engineering Group, Inc.) Keller, J. (NASA Johnson Space Center)
Published:
20090101
Source:
NASA Johnson Space Center (Houston, TX, United States) Virginia Univ. (Charlottesville, VA, United States)
Pages:
1
Contract #:
None
Abstract:
Current understanding of the chemistry and microstructure of the surfaces of lunar soil grains is dominated by a reference frame derived mainly from electron microscopy observations [e.g. 1,2]. These studies have shown that the outermost 10-100 nm of grain surfaces in mature lunar soil finest fractions have been modified by the combined effects of solar wind exposure, surface deposition of vapors and accretion of impact melt products [1,2]. These processes produce surface-correlated nanophase Feo, host grain amorphization, formation of surface patinas and other complex changes [1,2]. What is less well understood is how these changes are reflected directly at the surface, defined as the outermost 1-5 atomic monolayers, a region not easily chemically characterized by TEM. We are currently employing X-ray Photoelectron Spectroscopy (XPS) to study the surface chemistry of lunar soil samples that have been previously studied by TEM. This work includes modification of the grain surfaces by in situ irradiation with ions at solar wind energies to better understand how irradiated surfaces in lunar grains change their chemistry once exposed to ambient conditions on earth.
Language:
English
Notes:
72nd Meteoritical Society Meeting Nancy 13 - 18 Jul. 2009

Title:
Resolving the Azimuthal Ambiguity in Vector Magnetogram Data with the Divergence-Free Condition: Theoretical Examination
Document ID:
20090022172
Report #:
None
Available Online:
http://dx.doi.org/10.1007/s11207-007-9096-1
Sales Agency:
Other Sources Copyright
Author(s):
Crouch, A. (Northwest Research Associates, Inc.) Barnes, G. (Northwest Research Associates, Inc.)
Journal:
Solar Physics, Volume: Volume 247 , Page: 25-37
Published:
20080101
Source:
Northwest Research Associates, Inc. (Boulder, CO, United States)
Pages:
1
Contract #:
NNH05CC75C
Abstract:
We demonstrate that the azimuthal ambiguity that is present in solar vector magnetogram data can be resolved with line-of-sight and horizontal heliographic derivative information by using the divergence-free property of magnetic fields without additional assumptions. We discuss the specific derivative information that is sufficient to resolve the ambiguity away from disk center, with particular emphasis on the line-of-sight derivative of the various components of the magnetic field. Conversely, we also show cases where ambiguity resolution fails because sufficient line-of-sight derivative information is not available. For example, knowledge of only the line-of-sight derivative of the line-of-sight component of the field is not sufficient to resolve the ambiguity away from disk center.
Language:
English

89-02 STELLAR ASTRONOMY AND COSMOLOGY
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

89-03 METEORS AND METEORITES
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Sm-Nd, Rb-Sr, and Mn-Cr Ages of Yamato 74013
Document ID:
20090022115
Report #:
JSC-CN-18407
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Nyquist, L. E. (NASA Johnson Space Center) Shih, C.- Y. (Jacobs Sverdrup Technology, Inc.) Reese, Y.D. (Muniz Engineering, Inc.)
Published:
20090603
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
2
Contract #:
None
Abstract:
Yamato 74013 is one of 29 paired diogenites having granoblastic textures. The Ar-39 - Ar-40 age of Y-74097 is approximately 1100 Ma. Rb-Sr and Sm-Nd analyses of Y-74013, -74037, -74097, and -74136 suggested that multiple young metamorphic events disturbed their isotopic systems. Masuda et al. reported that REE abundances were heterogeneous even within the same sample (Y-74010) for sample sizes less than approximately 2 g. Both they and Nyquist et al. reported data for some samples showing significant LREE enrichment. In addition to its granoblastic texture, Y-74013 is characterized by large, isolated clots of chromite up to 5 mm in diameter. Takeda et al. suggested that these diogenites originally represented a single or very small number of coarse orthopyroxene crystals that were recrystallized by shock processes. They further suggested that initial crystallization may have occurred very early within the deep crust of the HED parent body. Here we report the chronology of Y-74013 as recorded in chronometers based on long-lived Rb-87 and Sm-147, intermediate- lived Sm-146, and short-lived Mn-53.
Language:
English
Notes:
32nd Symposium on Antarctic Meteorites Tokyo 3 - 4 Jun. 2009

Title:
Amorphous Silicates in Primitive Meteoritic Materials: Acfer 094 and IDPs
Document ID:
20090022151
Report #:
JSC-CN-18405
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Keller, L. P. (ARES Corp.) Nakamura-Messenger, K. (ARES Corp.) Messenger, S. (ARES Corp.) Walker, Robert M. (ARES Corp.)
Published:
20090101
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
1
Contract #:
None
Abstract:
The abundance of presolar grains is one measure of the primitive nature of meteoritic materials. Presolar silicates are abundant in meteorites whose matrices are dominated by amorphous silicates such as the unique carbonaceous chondrite Acfer 094. Presolar silicates are even more abundant in chondritic-porous interplanetary dust particles (CP-IDPs). Amorphous silicates in the form of GEMS (glass with embedded metal and sulfides) grains are a major component of CP IDPs. We are studying amorphous silicates in Acfer 094 matrix in order to determine whether they are related to the GEMS grains in CPIDPs
Language:
English
Notes:
72nd Annual Meeting of the Meteoritical Society Nancy 13-18 Jul. 2009

Title:
Rb-Sr Isotopic Studies Of Antarctic Lherzolitic Shergottite Yamato 984028
Document ID:
20090022361
Report #:
JSC-CN-18429
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Shih, C.-Y. (Jacobs Sverdrup Technology, Inc.) Nyquist, L. E. (NASA Johnson Space Center) Reese, Y. (Muniz Engineering, Inc.) Misawa, K. (National Institute of Polar Research)
Published:
20090603
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
2
Contract #:
None
Abstract:
Yamato 984028 is a Martian meteorite found in the Yamato Mountains of Antarctica. It is classified as a lherzolitic shergottite and petrographically resembles several other lherzolitic shergottites, i.e. ALHA 77005, LEW 88516, Y-793605 and Y-000027/47/97 [e.g. 2-5]. These meteorites have similarly young crystallization ages (152-185 Ma) as enriched basaltic shergottites (157-203 Ma), but have very different ejection ages (approximately 4 Ma vs. approximately 2.5 Ma), thus they came from different martian target crater areas. Lherzolitic shergottites have mg-values approximately 0.70 and represent the most mafic olivine-pyroxene cumulates. Their parental magmas were melts derived probably from the primitive Martian mantle. Here we present Rb-Sr isotopic data for Y-984028 and compare these data with those obtained from other lherzolitic and olivine-phyric basaltic shergottites to better understand the isotopic characteristics of their primitive mantle source regions. Corresponding Sm-Nd analyses for Y-984028 are in progress.
Language:
English
Notes:
32nd Symposium on Antarctic Meteorites Tokyo 3 - 4 Jun. 2009

Title:
Ar-Ar and I-Xe Ages and Thermal Histories of Three Unusual Metal-Rich Meteorites
Document ID:
20090022377
Report #:
JSC-CN-18430
Sales Agency:
Other Sources Copyright
Author(s):
Bogard, Donald D. (ARES Corp.) Garrison, Daniel H. (Barrios Technology, Inc.)
Published:
20090101
Source:
ARES Corp. (Houston, TX, United States)
Pages:
50
Contract #:
None
Abstract:
Portales Valley, Sombrerete, and Northwest Africa (NWA) 176 are three unrelated meteorites, which consist of silicate mixed with substantial amounts of metal and which likely formed at elevated temperatures as a consequence of early impacts on their parent bodies. Measured Ar-39-Ar-40 ages of these meteorites are 4460+/-20 Ma and 4480+/-15 Ma (two samples of Portales Valley), 4542+/-15 Ma, and 4525+/-20 Ma, respectively. The Ar-Ar data for Portales Valley show no evidence of later open system behavior suggested by some other chronometers. Measured I-129-Xe-129 ages of these three meteorites are 4561.6+/-0.5 Ma, approx.4540 Ma, and 4562.2+/-1.2 Ma, respectively (relative to Shallowater =4563.3 Ma). From stepwise temperature release data, we determined the diffusion characteristics for Ar and Xe in our samples and calculated approximate closure temperatures for the K-Ar and I-Xe chronometers. Adopting results and interpretations about these meteorites from some previous workers, we evaluated all these data against various thermal cooling models. We conclude that Portales Valley formed approx.4561 Ma ago, cooled quickly to below the I-Xe closure temperature, then cooled deep within the parent body at a rate of approx.4 C/Ma through K-Ar closure. We conclude that Sombrerete formed approx.4562 Ma ago and cooled relatively quickly. NWA 176 likely formed and cooled quickly 4.54-4.55 Ga ago, or later than formation times of most meteorite parent bodies. For all three meteorites, the Ar-Ar ages are in better agreement with the preferred thermal models if we increase these ages by approx.20 Ma to correct for probably errors in K-40 decay parameters in current use, as previously suggested by others. The role of impact heating and possible disruption and partial reassembly of meteorite parent bodies to form some meteorites likely was an important process in the early solar system.
Language:
English
Notes:
Submitted to Geochimica et Cosmochim Acta, December 2009

90-01 GRAVITATION
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

90-02 ASTROPHYSICAL PLASMAS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

91-01 THE MOON
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
The Evolution and Development of the Lunar Regolith and Implications for Lunar Surface Operations and Construction
Document ID:
20090022120
Report #:
JSC-CN-18408
Sales Agency:
Other Sources Copyright
Author(s):
McKay, David (NASA Johnson Space Center)
Published:
20090611
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
1
Contract #:
None
Abstract:
The lunar regolith consists of about 90% submillimeter particles traditionally termed lunar soil. The remainder consists of larger particles ranging up to boulder size rocks. At the lower size end, soil particles in the 10s of nanometer sizes are present in all soil samples. Lunar regolith overlies bedrock which consists of either lava flows in mare regions or impact-produced megaregolith in highland regions. Lunar regolith has been produced over billions of years by a combination of breaking and communition of bedrock by meteorite bombardment coupled with a variety of complex space weathering processes including solar wind implantation, solar flare and cosmic ray bombardment with attendant radiation damage, melting, vaporization, and vapor condensation driven by impact, and gardening and turnover of the resultant soil. Lunar regolith is poorly sorted compared to most terrestrial soils, and has interesting engineering properties including strong grain adhesion, over-compacted soil density, an abundance of agglutinates with sharp corners, and a variety of properties related to soil maturity. The NASA program has supported a variety of engineering test research projects, the production of bricks by solar or microwave sintering, the production of concrete, the in situ sintering and glazing of regolith by microwave, and the extraction of useful resources such as oxygen, hydrogen, iron, aluminum, silicon and other products. Future requirements for a lunar surface base or outpost will include construction of protective berms, construction of paved roadways, construction of shelters, movement and emplacement of regolith for radiation shielding and thermal control, and extraction of useful products. One early need is for light weight but powerful digging, trenching, and regolith-moving equipment.
Language:
English
Notes:
International Distinguished Scholars Symposia on Seven Future Technologies: Extreme Engineering Seoul 11 Jun. 2009

Title:
Trajectory Model of Lunar Dust Particles
Document ID:
20090022219
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 42-43
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States)
Pages:
2
Contract #:
None
Abstract:
The goal of this work was to predict the trajectories of blowing lunar regolith (soil) particles when a spacecraft lands on or launches from the Moon. The blown regolith is known to travel at very high velocity and to damage any hardware located nearby on the Moon. It is important to understand the trajectories so we can develop technologies to mitigate the blast effects for the launch and landing zones at a lunar outpost. A mathematical model was implemented in software to predict the trajectory of a single spherical mass acted on by the gas jet from the nozzle of a lunar lander.
Language:
English

Title:
Numerically Modeling the Erosion of Lunar Soil by Rocket Exhaust Plumes
Document ID:
20090022221
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 40-41
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States)
Pages:
2
Contract #:
None
Abstract:
In preparation for the Apollo program, Leonard Roberts of the NASA Langley Research Center developed a remarkable analytical theory that predicts the blowing of lunar soil and dust beneath a rocket exhaust plume. Roberts assumed that the erosion rate was determined by the excess shear stress in the gas (the amount of shear stress greater than what causes grains to roll). The acceleration of particles to their final velocity in the gas consumes a portion of the shear stress. The erosion rate continues to increase until the excess shear stress is exactly consumed, thus determining the erosion rate. Roberts calculated the largest and smallest particles that could be eroded based on forces at the particle scale, but the erosion rate equation assumed that only one particle size existed in the soil. He assumed that particle ejection angles were determined entirely by the shape of the terrain, which acts like a ballistic ramp, with the particle aerodynamics being negligible. The predicted erosion rate and the upper limit of particle size appeared to be within an order of magnitude of small-scale terrestrial experiments but could not be tested more quantitatively at the time. The lower limit of particle size and the predictions of ejection angle were not tested. We observed in the Apollo landing videos that the ejection angles of particles streaming out from individual craters were time-varying and correlated to the Lunar Module thrust, thus implying that particle aerodynamics dominate. We modified Roberts theory in two ways. First, we used ad hoc the ejection angles measured in the Apollo landing videos, in lieu of developing a more sophisticated method. Second, we integrated Roberts equations over the lunar-particle size distribution and obtained a compact expression that could be implemented in a numerical code. We also added a material damage model that predicts the number and size of divots which the impinging particles will cause in hardware surrounding the landing rocket. Then, we performed a long-range ballistics analysis for the ejected particulates.
Language:
English

Title:
RESOLVE Projects: Lunar Water Resource Demonstration and Regolith Volatile Characterization
Document ID:
20090022232
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 36-37
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States)
Pages:
2
Contract #:
None
Abstract:
To sustain affordable human and robotic space exploration, the ability to live off the land at the exploration site will be essential. NASA calls this ability in situ resource utilization (ISRU) and is focusing on finding ways to sustain missions first on the Moon and then on Mars. The ISRU project aims to develop capabilities to technology readiness level 6 for the Robotic Lunar Exploration Program and early human missions returning to the Moon. NASA is concentrating on three primary areas of ISRU: (1) excavating, handling, and moving lunar regolith, (2) extracting oxygen from lunar regolith, and (3) finding, characterizing, extracting, separating, and storing volatile lunar resources, especially in the permanently shadowed polar craters. To meet the challenges related to technology development for these three primary focus areas, the Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) project was initiated in February 2005, through funding by the Exploration Systems Mission Directorate. RESOLVE's objectives are to develop requirements and conceptual designs and to perform breadboard concept verification testing of each experiment module. The final goal is to deliver a flight prototype unit that has been tested in a relevant lunar polar environment. Here we report progress toward the third primary area creating ways to find, characterize, extract, separate, and store volatile lunar resources. The tasks include studying thermal, chemical, and electrical ways to collect such volatile resources as hydrogen, water, nitrogen, methane, and ammonia. We approached this effort through two subtasks: lunar water resource demonstration (LWRD) and regolith volatile characterization (RVC).
Language:
English

Title:
Particle Ejection and Levitation Technology (PELT)
Document ID:
20090022233
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 30-31
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States) University of Central Florida (Orlando, FL, United States)
Pages:
2
Contract #:
None
Abstract:
Each of the six Apollo landers touched down at unique sites on the lunar surface. Aside from the Apollo 12 landing site located 180 meters from the Surveyor III lander, plume impingement effects on ground hardware during the landings were not a problem. The planned return to the Moon requires numerous landings at the same site. Since the top few centimeters of lunar soil are loosely packed regolith, plume impingement from the lander will eject the granular material at high velocities. A picture shows what the astronauts viewed from the window of the Apollo 14 lander. There was tremendous dust excavation beneath the vehicle. With high-vacuum conditions on the Moon (10 (exp -14) to 10 (exp -12) torr), motion of all particles is completely ballistic. Estimates derived from damage to Surveyor III caused by the Apollo 12 lander show that the speed of the ejected regolith particles varies from 100 m/s to 2,000 m/s. It is imperative to understand the physics of plume impingement to safely design landing sites for future Moon missions. Aerospace scientists and engineers have examined and analyzed images from Apollo video extensively in an effort to determine the theoretical effects of rocket exhaust impingement. KSC has joined the University of Central Florida (UCF) to develop an instrument that will measure the 3-D vector of dust flow caused by plume impingement during descent of landers. The data collected from the instrument will augment the theoretical studies and analysis of the Apollo videos.
Language:
English

Title:
Tribocharging Lunar Soil for Electrostatic Beneficiation
Document ID:
20090022234
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 38-39
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) University of Central Florida (Orlando, FL, United States) Arkansas Univ. (AR, United States)
Pages:
2
Contract #:
None
Abstract:
Future human lunar habitation requires using in situ materials for both structural components and oxygen production. Lunar bases must be constructed from thermal-and radiation-shielding materials that will provide significant protection from the harmful cosmic energy which normally bombards the lunar surface. In addition, shipping oxygen from Earth is weight-prohibitive, and therefore investigating the production of breathable oxygen from oxidized mineral components is a major ongoing NASA research initiative. Lunar regolith may meet the needs for both structural protection and oxygen production. Already a number of oxygen production technologies are being tested, and full-scale bricks made of lunar simulant have been sintered. The beneficiation, or separation, of lunar minerals into a refined industrial feedstock could make production processes more efficient, requiring less energy to operate and maintain and producing higher-performance end products. The method of electrostatic beneficiation used in this research charges mineral powders (lunar simulant) by contact with materials of a different composition. The simulant acquires either a positive or negative charge depending upon its composition relative to the charging material.
Language:
English

Title:
Using Lunar Module Shadows To Scale the Effects of Rocket Exhaust Plumes
Document ID:
20090022252
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 44-45
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States)
Pages:
2
Contract #:
None
Abstract:
Excavating granular materials beneath a vertical jet of gas involves several physical mechanisms. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. We performed a series of experiments and simulations (Figure 1) to provide a detailed view of the complex gas-soil interactions. Measurements taken from the Apollo lunar landing videos (Figure 2) and from photographs of the resulting terrain helped demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a fundamental level to support the ongoing design of higher fidelity numerical simulations and larger-scale experiments. These are needed to enable future lunar exploration wherein multiple hardware assets will be placed on the Moon within short distances of one another. The high-velocity spray of soil from the landing spacecraft must be accurately predicted and controlled or it could erode the surfaces of nearby hardware. This analysis indicated that the lunar dust is ejected at an angle of less than 3 degrees above the surface, the results of which can be mitigated by a modest berm of lunar soil. These results assume that future lunar landers will use a single engine. The analysis would need to be adjusted for a multiengine lander. Figure 3 is a detailed schematic of the Lunar Module camera calibration math model. In this chart, formulas relating the known quantities, such as sun angle and Lunar Module dimensions, to the unknown quantities are depicted. The camera angle PSI is determined by measurement of the imaged aspect ratio of a crater, where the crater is assumed to be circular. The final solution is the determination of the camera calibration factor, alpha. Figure 4 is a detailed schematic of the dust angle math model, which again relates known to unknown parameters. The known parameters now include the camera calibration factor and Lunar Module dimensions. The final computation is the ejected dust angle, as a function of Lunar Module altitude.
Language:
English

Title:
Electrostatic Characterization of Lunar Dust
Document ID:
20090022256
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 32-33
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States) Appalachian State Univ. (Boone, NC, United States)
Pages:
2
Contract #:
None
Abstract:
To ensure the safety and success of future lunar exploration missions, it is important to measure the toxicity of the lunar dust and its electrostatic properties. The electrostatic properties of lunar dust govern its behavior, from how the dust is deposited in an astronaut s lungs to how it contaminates equipment surfaces. NASA has identified the threat caused by lunar dust as one of the top two problems that need to be solved before returning to the Moon. To understand the electrostatic nature of lunar dust, NASA must answer the following questions: (1) how much charge can accumulate on the dust? (2) how long will the charge remain? and (3) can the dust be removed? These questions can be answered by measuring the electrostatic properties of the dust: its volume resistivity, charge decay, charge-to-mass ratio or chargeability, and dielectric properties.
Language:
English

91-02 PLANETARY SCIENCES AND EXPLORATION
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Constraining the Depth of a Martian Magma Ocean through Metal-Silicate Partitioning Experiments: The Role of Different Datasets and the Range of Pressure and Temperature Conditions
Document ID:
20090022123
Report #:
JSC-CN-18432
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Righter, K. (NASA Johnson Space Center) Chabot, N.L. (Johns Hopkins Univ.)
Published:
20090101
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
1
Contract #:
None
Abstract:
Mars accretion is known to be fast compared to Earth. Basaltic samples provide a probe into the interior and allow reconstruction of siderophile element contents of the mantle. These estimates can be used to estimate conditions of core formation, as for Earth. Although many assume that Mars went through a magma ocean stage, and possibly even complete melting, the siderophile element content of Mars mantle is consistent with relatively low pressure and temperature (PT) conditions, implying only shallow melting, near 7 GPa and 2073 K. This is a pressure range where some have proposed a change in siderophile element partitioning behavior. We will examine the databases used for parameterization and split them into a low and higher pressure regime to see if the methods used to reach this conclusion agree for the two sets of data.
Language:
English
Notes:
72nd Annual Meeting of the Meteoritical Society Nancy 13 - 18 Jul 2009

Title:
Redox Interactions between Iron and Carbon in Planetary Mantles: Implications for Degassing and Melting Processes
Document ID:
20090022169
Report #:
JSC-CN-18433
Available Online:
http://hdl.handle.net/2060/20090022169
Sales Agency:
CASI Hardcopy A01 No Copyright
Author(s):
Martin, A. (NASA Johnson Space Center) Righter, K. (NASA Johnson Space Center)
Published:
20090101
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
1
Contract #:
None
Abstract:
Carbon stability in planetary mantles has been studied by numerous authors because it is thought to be the source of C-bearing atmospheres and of C-rich lavas observed at the planetary surface. In the Earth, carbonaceous peridotites and eclogites compositions have been experimentally studied at mantle conditions [1] [2] [3]. [4] showed that the fO2 variations observed in martian meteorites can be explained by polybaric graphite-CO-CO2 equilibria in the Martian mantle. Based on thermodynamic calculations [4] and [5] inferred that the stable form of carbon in the source regions of the Martian basalts should be graphite (and/or diamond), and equilibrium with melts would be a source of CO2 for the martian atmosphere. Considering the high content of iron in the Martian mantle (approx.18.0 wt% FeO; [6]), compared to Earth s mantle (8.0 wt% FeO; [7]) Fe/C redox interactions should be studied in more detail.
Language:
English
Notes:
72nd Annual Meeting of the Meteoritical Society Nancy 13 - 18 Jul. 2009

Title:
Cassini/Huygens Probe Entry, Descent, and Landing (EDL) at Titan Independent Technical Assessment
Document ID:
20090022173
Report #:
NASA/TM-2009-215732, NESC-RP-05-67/04-069-I, L-19670, LF99-8787
Sales Agency:
CASI Hardcopy A06 Copyright
Author(s):
Powell, Richard W. (NASA Langley Research Center) Lockwood, Mary Kae (NASA Langley Research Center) Cruz, Juan R. (NASA Langley Research Center) Striepe, Scott A. (NASA Langley Research Center) Sutton, Kenneth (NASA Langley Research Center) Fisher, Jody (NASA Langley Research Center) Takashima, Naruhisa T. (NASA Langley Research Center) Justus, Jere (Morgan Research Corp.) Keller, Vernon W. (NASA Marshall Space Flight Center) Bose, Deepak (Eloret Corp.) Prabhu, Dinesh (Eloret Corp.) Chen, Y. K. (NASA Ames Research Center) Olejniczak, Joe (NASA Ames Research Center) Cruz, Juan R (NASA Ames Research Center) Duvall, Aleta (Morgan Research Corp.)
Published:
20090501
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
121
Contract #:
None
Abstract:
Starting in January 2004, the NESC has received several communications from knowledgeable technical experts at NASA expressing shared concerns (mainly at the Langley Research Center (LaRC) and Ames Research Center (ARC)) about Huygens mission success. It was suggested that NASA become more technically involved directly in the analysis of Huygens' entry, descent and landing (EDL) focusing on the parachute deployment trigger performance and the resultant effects on the operation of the parachute system, and the determination of the radiative heating environment at Titan by ESA and the corresponding thermal protection system (TPS) response. A NESC Team was formed and tasked to provide an independent assessment of these concerns. The results of that assessment are documented in this report.
Language:
English

93-01 COSMIC RADIATION
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Proton and Gamma Radiation Effects in Undoped, Single-doped and co-doped YLiF4 and LuLiF4
Document ID:
20090022382
Report #:
LF99-8173
Sales Agency:
Other Sources Copyright
Author(s):
Lee, Hyung (National Inst. of Aerospace) Bai, Yingxin (Science Systems and Applications, Inc.) Yu, Kirong (NASA Langley Research Center) Singh, U. (NASA Langley Research Center)
Published:
20090531
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
2
Contract #:
None
Abstract:
Proton and gamma radiation effects in various YLiF4 and LuLiF4 crystals have been investigated. The radiation induced color centers compared with six different kinds of crystal samples in ranges up to 200 krads and 200 MeV. The radiation induced absorption coefficients are strongly dependent on polarization and concentration of rare-earth ions.
Language:
English
Notes:
Conference on Lasers and Electro-Optics and International Quantum Electronics Conference (CLEO/IQEC 09) Baltimore, MD 31 May - 5 Jun. 2009

93-02 SOLAR RADIATION AND ACTIVITY
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

93-03 RADIATION BELTS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

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