Aeronautics and Space Activities

Half a century after Congress enacted the National Aeronautics and Space Act of 1958, NASA is taking the next step in the Agency’s proud tradition of exploration. As President Bush stated in 2004, when NASA’s new focus on space exploration was announced, “We choose to explore space because doing so improves our lives, and lifts our national spirit.”

NASA’s Lunar Architecture Team is looking at plans for space suits, habitats, and rovers; the Agency is considering small, pressurized rovers that would travel in pairs.

The first generation of NASA reached the Moon with the Apollo program and unlocked the solar system with a rich legacy of robotic missions and satellites. Aeronautical vehicles pushed the air-space boundary and helped enable gains in aerospace and aviation. The space shuttle and International Space Station (ISS) mark the second generation of NASA’s exploration journey. NASA has extended the sphere of human influence off the planet to 200 nautical miles into space, and now embarks on a new generational endeavor defined by its inspirational, bold, and practical spirit. With establishment of a lunar outpost, NASA will extend human influence to another planetary body, allowing exploration of the Moon, attainment of economic and scientific benefits, and the development of the ability to continue to extend the sphere of human influence to Mars and beyond.

This bold, new journey requires the strengths of the whole NASA team. The Exploration Systems Mission Directorate must develop the capabilities and technology that will enable sustained and affordable human and robotic exploration and ensure the health and performance of crews during long-duration space exploration, including robotic precursor missions, human transportation elements, and life support systems. The Space Operations Mission Directorate activities provide the communications, operational tests and evaluations, and mission operations competencies and assets. The Science Mission Directorate informs and is informed by our mutual solar system exploration activities. The Aeronautics Research Mission Directorate underpins the Agency’s ability to create new vehicles and expand our operational regimes.

Exploration Systems Mission Directorate

NASA’s Exploration Systems Mission Directorate (ESMD) develops capabilities and supporting research and technology that will make human and robotic exploration possible. It also makes sure that astronaut explorers are safe, healthy, and can perform their work during long-duration space exploration. In the near-term, ESMD does this by developing robotic precursor missions, human transportation elements, and life-support systems.

Lunar Outpost Plans Taking Shape

NASA’s blueprints for an outpost on the Moon are shaping up. The Agency’s Lunar Architecture Team has been hard at work, looking at concepts for habitation, rovers, and space suits.

NASA will return astronauts to the Moon by 2020, using the Ares and Orion spacecraft already under development. Astronauts will set up a lunar outpost—possibly near a South Pole site called Shackleton Crater—where they will conduct scientific research, as well as test technologies and techniques for possible exploration of Mars and other destinations.

The concept for lunar rovers currently includes features such as all-direction crab steering with six wheels and a driver’s perch that can pivot 360 degrees.

Even though Shackleton Crater entices NASA scientists and engineers, they do not want to limit their options. To provide for maximum flexibility, NASA is designing hardware that would work at any number of sites on the Moon. Data from the Lunar Reconnaissance Orbiter mission, a Moon-mapping mission set to launch in October 2008, might suggest that another lunar site would be best suited for the outpost.

NASA officials had been looking at having future moonwalkers bring smaller elements to the Moon and assemble them on site, but the Lunar Architecture Team found that sending larger modules ahead of time on a cargo lander would help the outpost get up and running more quickly. The team is also discussing the possibility of a mobile habitat module that would allow one module of the outpost to relocate to other lunar destinations as mission needs dictate.

NASA is also considering small, pressurized rovers that could be key to productive operations on the Moon’s surface. Engineers envision rovers that would travel in pairs—two astronauts in each rover—and could be driven nearly 125 miles away from the outpost to conduct science or other activities. If one rover had mechanical problems, the astronauts could ride home in the other.

Astronauts inside the rovers would not need special clothing, because the pressurized rovers would have what is called a “shirt-sleeve environment.” Space suits would be attached to the exterior of the rover. NASA’s lunar architects are calling them “step in” space suits, because astronauts could crawl directly from the rovers into the suits to begin a moonwalk.

NASA is also looking to industry for proposals for a next-generation space suit. The Agency hopes to have a contractor onboard sometime this year.

NASA will spend the next several months communicating the work of the Lunar Architecture Team to potential partners—the aerospace community, industry, and international space agencies—to get valuable feedback that will help NASA further refine plans for the Moon outpost. The Agency’s goal is to have finalized plans by 2012 to get “boots on the Moon” by 2020.

NASA’s Newest Concept Vehicle Takes Off-Roading Out of This World

In a car commercial, it would sound odd: active suspension, six-wheel drive with independent steering for each wheel, no doors, no windows, no seats, and the only color available is gold.

But NASA’s latest concept vehicle is meant to go way off-road, as in 240,000 miles from the nearest pavement, and drive on the Moon. Since NASA is working to send astronauts to the Moon by 2020 to set up a lunar outpost, it is going to need new wheels to help with scientific research and prepare for journeys to more distant destinations.

Built at Johnson Space Center, the new design is one concept for a future lunar truck. The vehicle provides an idea of what the transportation possibilities may be when astronauts start exploring the Moon. Other than a few basic requirements, the primary instruction given to the designers was to throw away assumptions made on NASA’s previous rovers and come up with new ideas.

“To be honest with you, it was scary when we started,” said Lucien Junkin, a Johnson robotics engineer and the design lead for the prototype rover. “They tasked us last October to build the next-generation rover and challenge the conventional wisdom. The idea is that, in the future, NASA can put this side-by-side with alternate designs and start to pick their features.”

One of the first standards to go was the traditional expectation that a vehicle should have four wheels. Mars rovers Spirit and Opportunity, still cruising around the Red Planet, have already proved the value of a couple of extra wheels. When one of Spirit’s six wheels became inoperable, the rover had no problem rolling on using the remaining five.

With the number of wheels decided, the next question was how those wheels should turn. On a car, the front wheels turn a few inches in either direction, and both wheels point in the same direction. On this rover, all six wheels can pivot individually in any direction, regardless of where any other wheel points. To parallel park, a driver could pull up next to the parking place, turn all the wheels to the right, and slide right in.

Of course, astronauts will not have trouble finding a parking space on the Moon, but the feature, called crab steering, has advantages for a vehicle designed to drive into the craters of the Moon. If a slope is too steep to drive down safely, the vehicle could drive sideways instead—no backing up or three-point turns required. The all-wheels, all-ways steering also could come in handy when unloading and docking payloads or plugging into a habitat for recharging.

Introducing crab steering drove the concept in several other ways. If the rover’s wheels turn to drive in a different direction, the driver needs to be able to do the same. The driver stands at the steering mechanism, because sitting in a space suit is not comfortable or practical. The astronaut’s perch—steering mechanism, driver, and all—can pivot 360 degrees.

“The Apollo astronauts couldn’t back up at all because they couldn’t see where they were going in reverse,” said Rob Ambrose, assistant chief of the Automation, Robotics, and Simulation Division at Johnson. “If you have a payload on the back or are plugging into something, it could be really important to keep your eyes directly on it.”

The vehicle also can be the ultimate low-rider. It can lower its belly to the ground, making it easier for astronauts in space suits to climb on and off. Individual wheels or sections can be raised and lowered to keep the vehicle level when driving on uneven ground.

Some, all, or none of these features may be selected for the design of a rover that eventually goes to the Moon. Even though NASA’s lunar architects currently envision pressurized rovers that would travel in pairs, with two astronauts in each rover, the new prototype vehicle is meant to provide ideas as those future designs are developed.

“This rover concept changed the whole paradigm,” said Diane Hope, program element manager for NASA’s Exploration Technology Development Program at Langley Research Center, which sponsored the vehicle’s development. “It’s not something I would have expected. It provides an alternative approach.”

NASA Team Demonstrates Robot Technology for Moon Exploration

During the 3rd Space Exploration Conference, February 26-28, 2007, in Denver, NASA exhibited a robot rover equipped with a drill designed to find water and oxygen-rich soil on the Moon.

“Resources are the key to sustainable outposts on the Moon and Mars,” said Bill Larson, deputy manager of the In Situ Resource Utilization (ISRU) project. “It’s too expensive to bring everything from Earth. This is the first step toward understanding the potential for lunar resources and developing the knowledge needed to extract them economically.”

A conceptual illustration shows a lunar robot rover equipped with a drill designed to find water and oxygen-rich soil.

The engineering challenge was daunting. A robot rover designed for prospecting within lunar craters has to operate in continual darkness at extremely cold temperatures with little power. The Moon has one-sixth the gravity of Earth, so a lightweight rover will have a difficult job resisting drilling forces and remaining stable. Lunar soil, known as regolith, is abrasive and compact, so if a drill strikes ice, it likely will have the consistency of concrete.

Meeting these challenges in one system took ingenuity and teamwork. Engineers demonstrated a drill capable of digging samples of regolith in Pittsburgh last December. The demonstration used a laser light camera to select a site for drilling, and then commanded the four-wheeled rover to lower the drill and collect 3-foot samples of soil and rock.

“These are tasks that have never been done and are really difficult to do on the Moon,” said John Caruso, demonstration integration lead for ISRU and Human Robotics Systems at Glenn Research Center.

In 2008, the team plans to equip the rover with ISRU’s Regolith and Environment Science and Oxygen and Lunar Volatile Extraction experiment, known as RESOLVE. Led by engineers at Kennedy Space Center, the RESOLVE experiment package will add the ability to crush a regolith sample into small, uniform pieces and heat them.

The process will release gasses deposited on the Moon’s surface during billions of years of exposure to the solar wind and bombardment by asteroids and comets. Hydrogen is used to draw oxygen out of iron oxides in the regolith to form water. The water then can be electrolyzed to split it back into pure hydrogen and oxygen, a process tested earlier this year by engineers at Johnson.

“We’re taking hardware from two different technology programs within NASA and combining them to demonstrate a capability that might be used on the Moon,” said Gerald Sanders, manager of the ISRU project. “And even if the exact technologies are not used on the Moon, the lessons learned and the relationships formed will influence the next generation of hardware.”

Engineers participated in the ground-based rover concept demonstration from four NASA centers; the Canadian Space Agency; the Northern Centre for Advanced Technology, in Sudbury, Ontario; and Carnegie Mellon University’s Robotics Institute, in Pittsburgh.

Carnegie Mellon was responsible for the robot’s design and testing, and the Northern Centre for Advanced Technology built the drilling system. Glenn contributed the rover’s power management system. NASA’s Ames Research Center built a system that navigates the rover in the dark. The Canadian Space Agency funded a Neptec camera that builds 3-D images of terrain using laser light.

All the elements together represent a collaboration of the Human Robotic Systems and ISRU projects at Johnson, which are part of Langley’s Exploration Technology Development Program.

NASA Readies Hardware for Test of Astronaut Escape System

Returning humans to the Moon by 2020 may seem like a distant goal, but NASA’s Constellation Program already has scheduled the first test flight toward that goal to take place in less than a year.

The 90-second flight will not leave Earth’s atmosphere, but it will be an important first step toward demonstrating how NASA intends to build safety into its next generation of spacecraft, including the Ares I and V rockets and the Orion crew capsule.

The first in a series of unmanned abort tests, known as Pad Abort-1 or PA-1, is scheduled for late 2008 at the U.S. Army’s White Sands Missile Range in New Mexico.

The tests will help verify that NASA’s newly developed spacecraft launch abort system can provide a safe escape route for astronauts in the Orion crew capsule in the event of a problem on the launch pad or during ascent into low-Earth orbit atop the Ares I rocket.

Orion is the Constellation Program’s new crew exploration vehicle, set to carry as many as four crew members to lunar orbit and return its crew safely to Earth after missions to the Moon’s surface. The 5-meter (16.5-foot)-wide, cone-shaped capsule also will provide transport services to the International Space Station (ISS) for as many as six crew members. Before launching to the Moon or to the ISS, however, system tests on Earth have to prove that the technologies work.

The pad abort test will simulate an emergency on the launch pad. Upon command from a nearby control center, a dummy Orion crew module—which would sit on top of a rocket for an actual launch—will be ejected directly from the launch pad by its rocket-propelled launch abort system to about 1 mile in altitude and nearly 1 mile downrange.

That is why engineers and technicians at Langley, Dryden Flight Research Center, and industry partners on the Orion Project are taking particular care to fabricate and equip the first flight test articles with extreme precision.

In preparation for the next generation of exploration vehicles, NASA’s Constellation Program has scheduled the first unmanned abort test for 2008.

Engineers and technicians at Langley designed and fabricated the structural shell of the simulated crew module for the first pad abort test and now are conducting a series of ground checks on the structure. The crew module simulator accurately replicates the size, outer shape, and mass characteristics of the Orion crew module.

“The next step is to ship the completed crew module simulator to Dryden, where they will outfit it with the smarts—the computers, the electronics, the instrumentation—all the systems that need to work in conjunction with the structure,” said Phil Brown, manager of the Langley Orion Flight Test Article Project.

After the instrumented dummy crew module is delivered to White Sands, it will be integrated with the PA-1 launch abort system flight test article, a vertical tower containing the escape rocket motor and a guiding rocket motor currently under construction at Orbital Sciences Corporation, in Dulles, Virginia. The combined crew module and launch abort system will be placed on the launch pad being constructed especially for the abort flight test series.

During the pad abort test sequence, the escape system’s main abort motor will fire for several seconds, rapidly lifting the simulated crew module from the test launch pad, after which the escape system will detach, and three 116-foot-diameter parachutes will deploy to slow the module for landing.

The test will provide early data for design reviews to follow and will be followed by an ascent abort test in 2009 and a second pad abort test scheduled for 2010, both at White Sands. A parallel series of higher-altitude launch tests will commence at Kennedy in 2009.

“These flight tests will either confirm that our system works or help us identify and correct any defects that surface,” said Greg Stover, manager of the Orion Launch Abort System Project Office, located at Langley. “Our goal is that on every manned mission, the launch abort system will be the most reliable system that we hopefully never have to use.”

In addition to Langley, Dryden, and Kennedy, the Orion Project launch abort system team and the abort flight test team includes members from Johnson, Glenn, and Marshall Space Flight Center in Huntsville—as well as Orion Project prime contractor, Lockheed Martin Corporation, of Denver, and its subcontractor, Orbital Sciences.

The Orion Project Office, located at Johnson, is leading the development of the Orion spacecraft for the Constellation Program, which also includes the Ares I and Ares V launch vehicles, the Altair human lunar lander, and lunar surface systems to support sustained crew habitation.

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Space Operations Mission Directorate

The Space Operations Mission Directorate provides NASA with leadership and management of the Agency’s space operations related to human exploration in and beyond low-Earth orbit. Space Operations also oversees low-level requirements development, policy, and programmatic oversight. Current exploration activities in low-Earth orbit include the space shuttle and International Space Station (ISS) programs. The directorate is similarly responsible for Agency leadership and management of NASA space operations related to launch services, space transportation, and space communications in support of both human and robotic exploration programs. Its main challenges include: completing assembly of the ISS; utilizing, operating, and sustaining the ISS; commercial space launch acquisition; future space communications architecture; and transition from the space shuttle to future launch vehicles.

Dextre: Canadian Robotics for the International Space Station

Dextre is the third and final component of the Mobile Servicing System (MSS) developed by Canada for the ISS. The two-armed Special Purpose Dexterous Manipulator complements the mobile base and the robotic arm Canadarm2 already installed and operating on the station. These make the MSS a vital tool for external station maintenance. With advanced stabilization and handling capabilities, Dextre can perform delicate human-scale tasks such as removing and replacing small exterior components. Operated by crew members inside the station or by flight controllers on the ground, it also is equipped with lights, video equipment, a stowage platform, and three robotic tools.

The technology behind Dextre evolved from its famous predecessor, Canadarm2. Dextre is the world’s first on-orbit servicing robot with an operational mission, and it lays the foundation for future satellite servicing and space exploration capabilities.

While one arm is used to anchor and stabilize the system, the other can perform fine manipulation tasks such as removing and replacing station components, opening and closing covers, and deploying or retracting mechanisms. Dextre can either be attached to the end of Canadarm2 or ride independently on the mobile base system. To grab objects, Dextre has special grippers with a built-in socket wrench, camera, and lights. The two pan/tilt cameras below its rotating torso provide operators with additional views of the work area.

Currently, astronauts execute many tasks that can only be performed during long, arduous, and potentially dangerous spacewalks. Delivery of this element increases crew safety and reduces the amount of time that astronauts must spend outside the station for routine maintenance. They should, therefore, have more time for scientific activities.

Some of the many tasks Dextre will perform include:

• Installing and removing small payloads such as batteries, power switching units, and computers
• Providing power to payloads
• Manipulating, installing, and removing scientific payloads

A typical task for Dextre would be to replace a depleted battery (100 kg) and engage all the connectors. This involves bolting and unbolting, as well as millimeter-level positioning accuracy for aligning and inserting the new battery.

The Canadarm2 aboard the International Space Station has multiple joints and is capable of maneuvering payloads as massive as 116,000 kilograms, equivalent to a fully loaded bus. Pictured above, astronaut Stephen Robinson rides Canadarm2 during the STS-114 mission of the Space Shuttle Discovery to the ISS in August 2005.

This kind of task demands high precision and a gentle touch. To achieve this, Dextre has a unique technology: precise sensing of the forces and torque in its grip with automatic compensation to ensure the payload glides smoothly into its mounting fixture. Dextre can pivot at the waist, and its shoulders support two identical arms with seven offset joints that allow for great freedom of movement. The waist joint allows the operator to change the position of the tools, cameras, and temporary stowage on the lower body with respect to the arms on the upper body. Dextre is designed to move only one arm at a time for several reasons: to maintain stability, to harmonize activities with Canadarm on the shuttle and Canadarm2 on the station, and to minimize the possibility of self-collision.

At the end of each arm is an orbital replacement unit/tool change-out mechanism, or OTCM—parallel jaws that hold a payload or tool with a vice-like grip. Each OTCM has a retractable motorized socket wrench to turn bolts and mate or detach mechanisms, as well as a camera and lights for close-up viewing. A retractable umbilical connector can provide power, data, and video connection feed-through to payloads.

From a workstation aboard the ISS, astronauts can operate all the Mobile Servicing System components, namely Canadarm2, the mobile base, and Dextre. To prepare for operating each component, astronauts and cosmonauts undergo rigorous training at the Canadian Space Agency’s Operations Engineering Training Facility at the John H. Chapman Space Centre, in Longueuil, Quebec.

Renowned for its expertise in space robotics, Canada’s contribution to the International Space Station—a unique collaborative project with the United States, Japan, Russia, and several European nations—is the Mobile Servicing System. Combining two robotic elements and a mobile platform, they are designed to work together or independently. The first element, Canadarm2, whose technical name is the Space Station Remote Manipulator System, was delivered and installed by Canadian Space Agency astronaut Chris Hadfield in 2001. The mobile base system was added to the station in 2002. Dextre launched aboard Space Shuttle Endeavour flight STS-123.

Space Station Provides New ‘Window’ for International Polar Year

It has happened only three other times in history. But this time, the International Polar Year will have unprecedented access to an out-of-this-world platform—210 miles up in space.

The International Polar Year is a collaborative effort to study the Arctic and the Antarctic from March 2007 to March 2009. Crew members on the ISS are supporting the scientific program by taking new snapshots of Earth’s polar regions—the areas of the globe surrounding the North and South poles—from the unique vantage point of space.

It has been 50 years since the last event like this, with previous polar years observed in 1882, 1932, and 1957. This year will have the largest number of participants, with thousands of scientists from more than 60 countries examining the polar regions in a wide range of topics, including surface and atmospheric temperatures, changes in snow and ice, and the shrinkage of glaciers. They also hope to dip into unexplored areas.

Because the ISS provides a unique venue for observing polar phenomena, NASA has invited scientists participating in the polar program to submit requests for relevant imagery to be photographed from space.

As part of the Crew Earth Observations experiment, space station astronauts photograph designated sites and dynamic events on the Earth’s surface using digital cameras equipped with a variety of lenses. Depending on the station’s position and weather in the target regions, astronauts can collect high-resolution digital photos of a specific location or lower-resolution photos that cover very large areas.

During the timeframe of the International Polar Year, polar observations are a scientific focus for the Crew Earth Observations experiment (CEO-IPY).

Previous space station crew members have photographed such phenomena as auroras, polar mesospheric clouds and patterns, and calving of sea ice. Although the station does not cross the poles, astronauts can look toward the poles to document these phenomena.

“Polar regions are rich in phenomena obtuse to our daily temperate-region lives and naturally draw one’s scientific attention, whether on or off of Earth,” said NASA astronaut Don Pettit, the leader of the effort to link polar scientists with the space station. “I want IPY scientists on Earth to have access to the space station perspective, where observations can be made on the length scale of half a continent and will complement observations made on Earth or by higher orbiting satellites.”

The Crew Earth Observations imagery Web site for CEO-IPY, <http://eol.jsc.nasa.gov/ipy/>, provides an online form that allows polar region investigators to interact with Earth observation scientists and define and submit their imagery requests.

“This information is integrated into daily communications with the station astronauts about their photo targets, so that crew members know what kind of photos would help the scientists, and when those areas will be visible through the windows of the station,” said Cindy Evans, a NASA scientist who has been developing the online scientific resources.

Sweating Over the Next-Generation Life Support System

Shown here, astronaut Sunita Williams exercises aboard the International Space Station. The Exploration Water Recovery System collects perspiration, respiration, and urine and processes them into drinking water.

Marshall Space Flight Center employees are back at it—donating time and energy—exercising on treadmills, rowers, and bikes to test aspects of a life support system that could someday provide drinking water to people living on the Moon or Mars.

On Earth, nature provides the air we breathe, the water we drink, and natural resources that support life. In space, life support resources must be brought up with a crew, recycled or produced from resources available, or a combination of the two. For almost 20 years, NASA engineers at Marshall have led the design and development of the ISS life support system, called the Regenerative Environmental Control and Life Support System, or ECLSS.

In 2007, the ECLSS Oxygen Generation System was installed in the station’s Destiny laboratory, and now, along with the Russian Elektron system, it will provide breathing air for future space station crews. The other component to ECLSS, the Water Recovery and Management System, takes in crew perspiration, respiration, and urine, and turns them into drinking water. The station’s Water Recovery and Management System is planned to be delivered and installed in 2008.

Looking ahead to extended Moon missions, when re-supply will be over 240,000 miles away, Marshall engineers have assembled key aspects of the station’s ECLSS waste water processor technology to explore how this system might work on a future lunar habitat. This redesigned hardware, the Exploration Water Recovery System, is a novel combination of proven air and water purification technologies and optimizes the treatment of various wastewater streams.

“To support human life on the Moon, we’ll need robust and efficient life support systems that can work well without a large amount of consumables,” said Monsi Roman, Exploration Life Support project manager. “Our hope is to mature current life support technologies to be able to minimize the amount of materials we need to bring up to space to support future crews.”

For several weeks, Marshall tested this new hardware. The goal of this test was to examine the efficiency of the water processor to remove different types of contaminants from the wastewater. NASA engineers want to determine how to increase the system efficiency and extend the life of expendables needed to keep clean water flowing.

More than 50 employees participated in the Exploration Water Recovery System test. For the study, 20 employees exercised for an hour a day, generating water vapor through perspiration and respiration in the Regenerative ECLSS Module Simulator—a mockup of a space module filled with treadmills, a bicycle, rowing machine, and other exercise equipment. The men also donated urine as part of this test.

Before stepping into the module for a session, participants were provided with a T-shirt to wear, a towel for drying off, and a bottle of water or a sports energy drink to consume as they exercised. They weighed-in on a computerized scale, with the bottle of water in-hand. Sopping wet T-shirts and used towels are left hanging inside overnight to evaporate more sweat out of them. Participants brushed their teeth, wiped themselves down with wet towels and the men even shaved—simulating the daily routine of a station crew member—to get every bit of moisture into the atmosphere. Participants even microwaved meals inside the module to generate water vapor.

“We know this equipment can create water cleaner than water from municipal water systems here on Earth,” said Keith Parrish, ECLSS Test Facility manager. “We hope we can refine the process so future crews will need fewer supplies to generate water for longer space missions—whether on the Moon or Mars.”

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Science Mission Directorate

The Science Mission Directorate engages the Nation’s science community, sponsors scientific research, and develops and deploys satellites and probes in collaboration with NASA’s partners around the world to answer fundamental questions requiring the view from and into space. The directorate seeks to understand the origins, evolution, and destiny of the universe and to understand the nature of the strange phenomena that shape it.

NASA Spacecraft Streams Back Surprises from Mercury

After a journey of more than 2 billion miles and 3½ years, NASA’s MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft made its flyby on Jan. 14, 2008, the first sent to orbit the planet closest to our Sun. The spacecraft’s cameras and other sophisticated, high-technology instruments collected more than 1,200 images and made other science observations. Data included the first up-close measurements of Mercury since the Mariner 10 spacecraft’s third and final flyby on March 16, 1975.

MESSENGER’s flyby of Mercury showed some of the major never-before-seen terrain in the inner solar system.

MESSENGER’s flyby of Mercury gave scientists an entirely new look at a planet once thought to have characteristics similar to those of Earth’s Moon. Researchers are amazed by the wealth of images and data that show a unique world with a diversity of geological processes and a very different magnetosphere from the one discovered and sampled more than 30 years ago.

The spacecraft showed that Mercury has huge cliffs with structures snaking up hundreds of miles across the planet’s face. These cliffs preserve a record of patterns of fault activity from early in the planet’s history. The spacecraft also revealed impact craters that appear very different from lunar craters.

Instruments provided a topographic profile of craters and other geological features on the night side of Mercury. The spacecraft also discovered a unique feature that scientists dubbed “The Spider.” This formation never has been seen on Mercury before and nothing like it has been observed on the Moon. It lies in the middle of a large impact crater called the Caloris basin and consists of more than 100 narrow, flat-floored troughs radiating from a complex central region.

Now that the spacecraft has shown scientists the full extent of the Caloris basin, its diameter has been revised upward from the Mariner 10 estimate of 800 miles to perhaps as large as 960 miles from rim to rim. The plains inside the Caloris basin are distinctive and more reflective than the exterior plains. Impact basins on the Moon have opposite characteristics.

The magnetosphere and magnetic field of Mercury during the flyby appeared to be different from the Mariner 10 observations. The spacecraft found the planet’s magnetic field was generally quiet but showed several signatures indicating significant pressure within the magnetosphere.

Magnetic fields like Earth’s and their resulting magnetospheres are generated by electrical dynamos in the form of a liquid metallic outer core deep in the planet’s center. Of the four terrestrial planets, only Mercury and Earth exhibit such a phenomenon. The magnetic field deflects the solar wind from the Sun, producing a protective bubble around Earth that shields the surface of our planet from those energetic particles and other sources farther out in the galaxy.

Similar variations are expected for Mercury’s magnetic field, but the precise nature of its field and the time scales for internal changes are unknown. The next two flybys and the year-long orbital phase will shed more light on these processes.

The spacecraft’s suite of instruments has provided insight into the mineral makeup of the surface terrain and detected ultraviolet emissions from sodium, calcium, and hydrogen in Mercury’s exosphere. It also has explored the sodium-rich exospheric “tail,” which extends more than 25,000 miles from the planet.

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Astronomers Detect First Organic Molecule on an Exoplanet

Extrasolar planet HD 189733b with its parent star peeking above its top edge. Astronomers used the Hubble Space Telescope to detect methane and water vapor in the Jupiter-sized planet’s atmosphere.

A team of astronomers led by Mark Swain of NASA’s Jet Propulsion Laboratory (JPL) has made the first detection ever of an organic molecule in the atmosphere of a Jupiter-sized planet orbiting another star. The breakthrough, made with NASA’s Hubble Space Telescope, is an important step in eventually identifying signs of life on a planet outside our solar system.

The molecule found by Hubble is methane, which can play a key role in prebiotic chemistry—the chemical reactions considered necessary to form life as we know it. This discovery proves that Hubble and upcoming space missions, such as NASA’s James Webb Space Telescope, can detect organic molecules on planets around other stars by using spectroscopy, which splits light into its components to reveal the “fingerprints” of various chemicals.

“This is a crucial stepping stone to eventually characterizing prebiotic molecules on planets where life could exist,” said Swain, lead author of a paper that appeared in the March 20, 2008 issue of Nature.

The discovery comes after extensive observations made in May 2007 with Hubble’s Near Infrared Camera and Multi-Object Spectrometer. It also confirms the existence of water molecules in the planet’s atmosphere, a discovery made originally by NASA’s Spitzer Space Telescope in 2007. “With this observation there is no question whether there is water or not—water is present,” said Swain.

NASA’s Hubble Space Telescope has helped astronomers identify organic molecules in the atmosphere of a planet orbiting another star.

The planet, called HD 189733b, is located 63 light-years away in the constellation Vulpecula. Though it is now known to have methane and water, the planet is so massive and so hot it is considered an unlikely host for life; HD 189733b is so close to its parent star it takes just over 2 days to complete an orbit, and its atmosphere swelters at 1,700 °F, about the same temperature as the melting point of silver.

Though the star-hugging planet is too hot for life as we know it, “This observation is proof that spectroscopy can eventually be done on a cooler and potentially habitable Earth-sized planet orbiting a dimmer red dwarf-type star,” Swain said. The ultimate goal of studies like these is to identify prebiotic molecules in the atmospheres of planets in the “habitable zones” around other stars, where temperatures are right for water to remain liquid rather than freeze or evaporate away.

“These measurements are an important step to our ultimate goal of determining the conditions, such as temperature, pressure, winds, clouds, etc., and the chemistry on planets where life could exist. Infrared spectroscopy is really the key to these studies because it is best matched to detecting molecules,” said Swain.

Cassini Flies through Watery Plumes of Saturn Moon

NASA’s Cassini spacecraft performed a flyby of Saturn’s moon Enceladus on March 12, 2008, flying about 15 kilometers per second (32,000 mph) through icy water geyser-like jets. The spacecraft snatched up precious samples that might point to a water ocean or organics inside the little moon.

NASA’s Cassini spacecraft performed a flyby of Saturn’s moon Enceladus, snatching up precious samples in the icy geyser-like jets.

Scientists believe the geysers could provide evidence that liquid water is trapped under the icy crust of Enceladus. The geysers emanate from fractures running along the moon’s South Pole, spewing out water vapor at approximately 400 meters per second (800 mph).

The new data provide a much more detailed look at the fractures that modify the surface and will give a significantly improved comparison between the geologic history of the moon’s North and South Poles.

New images show that compared to much of the Southern Hemisphere on Enceladus—the south polar region in particular—the north polar region is much older and pitted with craters of various sizes. These craters are captured at different stages of disruption and alteration by tectonic activity, and probably from past heating from below. Many of the craters seem sliced by small parallel cracks that appear to be ubiquitous throughout the old cratered terrains on Enceladus.

These new images are showing us in great detail how the moon’s North Pole differs from the South, an important comparison for working out the moon’s obviously complex geological history.

The flyby was designed so that Cassini’s particle analyzers could dissect the “body” of the plume for information on the density, size, composition, and speed of the particles. Among other things, scientists will use the data gathered to figure out whether the gasses from the plume match the gasses that make up the halo of particles around Enceladus. This may help determine how the plumes formed.

Two elements comprise the spacecraft: the Cassini orbiter and the Huygens probe. In 2004, Cassini-Huygens reached Saturn and its moons.

During Cassini’s closest approach, two instruments were collecting data—the cosmic dust analyzer and the ion and neutral mass spectrometer. An unexplained software hiccup with Cassini’s cosmic dust analyzer instrument prevented it from collecting any data during the closest approach, although the instrument did get data before and after the approach. During the flyby, the instrument was switching between two versions of software programs. The new version was designed to increase the ability to count particle hits by several hundred hits per second. The other four fields and particles instruments, in addition to the ion and neutral mass spectrometer, did capture all of their data, which will complement the overall composition studies and elucidate the unique plume environment of Enceladus.

Cassini’s instruments discovered evidence for the geyser-like jets on Enceladus in 2005, finding that the continuous eruptions of ice water create a gigantic halo of ice dust and gas around Enceladus, which helps supply material to Saturn’s E-ring.

This was the first of four Cassini flybys of Enceladus this year, during which, the spacecraft came within 50 kilometers (30 miles) of the surface at closest approach, 200 kilometers (120 miles) while flying through the plume. Future trips may bring Cassini even closer to the surface of Enceladus. Cassini completes its prime mission, a 4-year tour of Saturn, this summer. From then on, a proposed extended mission would include seven more Enceladus flybys, beginning in late summer.

NASA Spacecraft Photographs Avalanches on Mars

A NASA spacecraft in orbit around Mars took the first-ever image of active avalanches near the Red Planet’s North Pole. The image showed tan clouds billowing away from the foot of a towering slope, where ice and dust have just cascaded down.

In February 2008, the High Resolution Imaging Science Experiment (HiRISE) on NASA’s Mars Reconaissance Orbiter captured this image of dust billowing away from an avalanche.

The High Resolution Imaging Science Experiment (HiRISE) on NASA’s Mars Reconnaissance Orbiter took the photograph on February 19, 2008, and this is one of approximately 2,400 HiRISE images recently released. The full image reveals features as small as a desk in a strip of terrain 3.7 miles wide and more than 10 times that long, at 84 degrees north latitude. Reddish layers known to be rich in water ice make up the face of a steep slope more than 2,300 feet tall, running the length of the image.

More ice than dust probably makes up the material that fell from the upper portion of the scarp. Imaging of the site during coming months will track any changes in the new deposit at the base of the slope. That will help researchers estimate what proportion is ice.

Another notable HiRISE image released showed a blue crescent Earth and its moon, as seen by the Mars Reconnaissance Orbiter. The west coast of South America is visible in the photo. Still other images allow viewers to explore a wide variety of Martian terrains, such as dramatic canyons and rhythmic patterns of sand dunes.

The camera is one of six science instruments on the orbiter. The spacecraft reached Mars in March 2006 and has returned more data than all other current and past missions to Mars combined.

NASA Satellite Detects Record Gamma Ray Burst Explosion Halfway Across Universe

A powerful stellar explosion detected March 19, 2008, by NASA’s Swift satellite shattered the record for the most distant object that could be seen with the naked eye.

The explosion was a gamma ray burst. Most gamma ray bursts occur when massive stars run out of nuclear fuel. Their cores collapse to form black holes or neutron stars, releasing an intense burst of high-energy gamma rays and ejecting particle jets that rip through space at nearly the speed of light like turbocharged cosmic blowtorches. When the jets plow into surrounding interstellar clouds, they heat the gas, often generating bright afterglows. Gamma ray bursts are the most luminous explosions in the universe since the Big Bang.

Swift’s Burst Alert Telescope picked up the burst at 2:12 a.m. Eastern Time, March 19, and then pinpointed the coordinates. Telescopes in space and on the ground quickly moved to observe the afterglow. The burst is named “GRB 080319B,” because it was the second gamma ray burst detected that day.

Swift’s Burst Alert Telescope picked up this gamma ray burst, one of the most luminous explosions in the universe.

Swift’s other two instruments, the X-ray Telescope and the Ultraviolet/Optical Telescope, also observed brilliant afterglows. Several ground-based telescopes saw the afterglow brighten to visual magnitudes between 5 and 6 in the logarithmic magnitude scale used by astronomers. The brighter an object is, the lower its magnitude number. From a dark location in the countryside, people with normal vision can see stars slightly fainter than magnitude 6. That means the afterglow would have been dim, but visible to the naked eye.

Later that evening, the Very Large Telescope, in Chile, and the Hobby-Eberly Telescope, in Texas, measured the burst’s redshift at 0.94. A redshift is a measure of the distance to an object. A redshift of 0.94 translates into a distance of 7.5 billion light-years, meaning the explosion visible now took place 7.5 billion years ago, a time when the universe was less than half its current age and Earth had yet to form. This is more than halfway across the visible universe.

GRB 080319B’s optical afterglow was 2.5 million times more luminous than the most luminous supernova ever recorded, making it the most intrinsically bright object ever observed by humans in the universe. The most distant previous object that could have been seen by the naked eye is the nearby galaxy M33, a relatively short 2.9 million light-years from Earth.

Analysis of GRB 080319B is underway, because astronomers don’t know why this burst and its afterglow were so bright. One possibility is the burst was more energetic than others, perhaps because of the mass, spin, or magnetic field of the progenitor star or its jet. Or perhaps it concentrated its energy in a narrow jet that was aimed directly at Earth.

Swift is managed by Goddard Space Flight Center. It was built and is being operated in collaboration with Penn State, the Los Alamos National Laboratory, and General Dynamics, in the United States; the University of Leicester and Mullard Space Science Laboratory, in the United Kingdom; Brera Observatory and the Italian Space Agency, in Italy; plus partners in Germany and Japan.

First-Ever 3-D Images of the Sun

NASA’s twin Solar Terrestrial Relations Observatory (STEREO) spacecraft made the first three-dimensional images of the Sun. The new view will greatly aid scientists’ ability to understand solar physics and thereby improve space weather forecasting.

The improvement with STEREO’s 3-D view is like going from a regular X-ray to a 3-D CAT scan in the medical field.

The STEREO spacecraft were launched October 25, 2006. On January 21, 2007, they completed a series of complex maneuvers, including flying by the Moon, to position the spacecraft in their mission orbits. The two observatories are now orbiting the Sun, one slightly ahead of Earth and one slightly behind, separating from each other by approximately 45 degrees per year. Just as the slight offset between a person’s eyes provides depth perception, the separation of these spacecraft allow 3-D images of the Sun.

NASA’s twin STEREO spacecraft captured the first three-dimensional images of the Sun, which are aiding scientists’ ability to understand solar physics.

Violent solar weather originates in the Sun’s atmosphere, or corona, and can disrupt satellites, radio communication, and power grids on Earth. The corona resembles wispy smoke plumes, which flow outward along the Sun’s tangled magnetic fields. It is difficult for scientists to tell which structures are in front and which are behind.

With STEREO’s 3-D imagery, scientists will be able to discern where matter and energy flows in the solar atmosphere much more precisely than with the 2-D views previously available. This will help scientists understand the complex physics going on.

STEREO’s depth perception also will help improve space weather forecasts. Of particular concern is a destructive type of solar eruption called a Coronal Mass Ejection (CME). CMEs are eruptions of electrically charged gas, called plasma, from the Sun’s atmosphere. A CME cloud can contain billions of tons of plasma and move at a million miles per hour.

The Surface Stereo Imager captured this image on Sol 11 (June 5, 2008). The robotic arm carries a soil sample towards the partially open door of the Thermal and Evolved-Gas Analyzer’s number four cell, or oven.

The CME cloud is laced with magnetic fields, and CMEs directed toward Earth smash into our planet’s magnetic field. If the CME magnetic fields have the proper orientation, they dump energy and particles into Earth’s magnetic field, causing magnetic storms that can overload power line equipment and radiation storms that disrupt satellites.

Satellite and utility operators can take precautions to minimize CME damage, but they need an accurate forecast of when the CME will arrive. To do this, forecasters need to know the location of the front of the CME cloud. STEREO will allow scientists to accurately locate the CME cloud front. Knowing where the front of the CME cloud is will improve estimates of the arrival time from within a day or so to just a few hours. STEREO also will help forecasters estimate how severe the resulting magnetic storm will be.

STEREO’s first 3-D images were provided by JPL. STEREO is the third mission in NASA’s Solar Terrestrial Probes program within NASA’s Science Mission Directorate. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory designed and built the spacecraft and is responsible for mission operations. The STEREO imaging and particle-detecting instruments were designed and built by scientific institutions in the United States, United Kingdom, France, Germany, Belgium, Netherlands, and Switzerland.

Phoenix Mars Lander Analyzes Particles for Water

In this artist rendition, the Phoenix lander begins to dig a trench through the upper soil layer on the arctic plains of Mars. The polar water ice cap is shown in the far distance. Corby Waste of the Jet Propulsion Laboratory created this image.	The Phoenix Mars Lander’s Surface Stereo Imager took this image of the solar panel and the lander’s Robotic Arm while facing west during Phoenix’s Sol 16, or June 10, 2008.  The robotic arm is delivering the sample in the scoop to the Optical Microscope.

Launched in August 2007, the Phoenix Mars Lander Mission is the first in NASA’s Mars Scout class, combining legacy and innovation in a framework of a true partnership: government, academia, and industry. Phoenix is designed to study the history of water and habitability potential in the Martian arctic’s ice-rich soil.

Led by principal investigator Peter Smith, of the University of Arizona’s Lunar and Planetary Laboratory, the science team aims to answer the following questions: 1) Can the Martian arctic support life? 2) What is the history of water at the landing site? 3) How is the Martian climate affected by polar dynamics?

To answer these questions, Phoenix uses some of the most sophisticated and advanced technology ever sent to Mars. A robust robotic arm built by JPL digs through and delivers soil and ice samples to the mission’s experiments. On the deck, miniature ovens and a mass spectrometer provide chemical analysis of trace matter, and a chemistry lab characterizes the soil and ice chemistry. Imaging systems designed by the University of Arizona, University of Neuchâtel (Switzerland), Max Planck Institute (Germany), and Malin Space Science Systems (California) will render unprecedented, detailed views of Mars. The lander’s meteorological station furnished by the Canadian Space Agency marks the first significant involvement of Canada in a mission to Mars.

Three close-ups of Martian soil appear in this composite from the Optical Microscope on the Phoenix Mars lander. The top of the composite particle (left box) has a green tinge, possibly indicating olivine. The bottom of the particle has been reimaged in black and white (middle box), showing that this is a clump of finer particles. The right box shows a rounded, glassy particle. The scale bar is 1 millimeter. This was taken on June 11, 2008 or Phoenix Sol 17.

From the Science Operations Center in Tucson, the Phoenix science and engineering teams began commanding the lander once it arrived safely on Mars and began transmitting data to Earth. This powerful team has high hopes for this to be the first mission to “touch” and examine water on Mars—ultimately, to pave the way for future robotic missions and possibly, human exploration.

On June 11, 2008, two instruments on the lander deck—a microscope and a Thermal and Evolved-Gas Analyzer (TEGA), or “oven” instrument—began inspecting soil samples delivered by the scoop on Phoenix’s robotic arm. The sample includes some larger, black, glassy particles as well as smaller reddish ones. The fine particles in the soil sample closely resemble particles of airborne dust examined earlier by the microscope.

“The oven is working very well and living up to our expectations,” said Phoenix co-investigator and TEGA team leader, Bill Boynton, of the University of Arizona. Phoenix has eight separate tiny ovens to bake the samples at three different temperature ranges and sniff the soil to look for volatile ingredients (such as water). Studying dust on Mars helps scientists understand atmospheric dust on Earth, which is important because dust is a significant factor in global climate change.

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Aeronautics Research Mission Directorate

NASA’s Aeronautics Research Mission Directorate, led by Dr. Jaiwon Shin, conducts cutting-edge, fundamental research in traditional and emerging disciplines to help transform the Nation’s air transportation system, and to support future air and space vehicles. Its goals are to improve airspace capacity and mobility, improve aviation safety, and improve aircraft performance while reducing noise, emissions, and fuel burn.

NASA Researchers Design New Chip

NASA researchers have designed and built a new circuit chip that can take the heat like never before. In the past, integrated circuit chips could not withstand more than a few hours of high temperatures before failing. This silicon carbide (SiC) chip exceeded 5,000 hours of continuous operation at 500 °C—a breakthrough that represents a 500-fold increase in what had previously been achieved. Such highly durable integrated packaging is being developed to enable extremely functional but physically small circuitry for hot sections of jet engines.

This breakthrough silicon carbide chip exceeded 5,000 hours of continuous operation at 500 °C.

Electronics to control combustion affect people everyday. In 100-200 °C high-temperature environments, electronic chips made from silicon are crucial to modern jet and automobile engine performance. Look under the cowling of a modern jet engine or under the hood of a modern automobile, and you will find wires leading to and from electronic sensors and controls to electronic engine control unit circuitry. But silicon cannot function durably in the much hotter 400-500 °C environments where even more capable electronic sensing and control is needed.

These new circuit chips will let us get closer to the combustion source and enable better sensing and control with fewer wires, connectors, and cooling requirements for the combustion sensing/control subsystems. The first use for this capability will likely be in the military and aerospace markets since they are much less cost-sensitive than other markets.

In the future, such electronics will enhance sensing and control of the combustion process that could lead to improved safety and fuel efficiency as well as reduced emissions from jet engines. Similar benefits are also possible for automotive engines, oil and natural gas well drilling, and anything requiring long-lasting electronic circuits in very hot environments, including robotic exploration on the hostile surface environment of Venus.

The next step in SiC chip development is to greatly increase the single-chip transistor count from less than 10 transistors upward toward 100 to 1,000 transistors per chip, which in turn would enable much greater 500 °C integrated circuit functionality beyond simple signal amplification. Since much of the knowledge on how to put more transistors on a single chip already exists from silicon-integrated circuit technology, we expect the scale-up process for durable 500 °C SiC-integrated circuitry to occur within 2 to 4 years.

NASA Increases Aviation Safety

Advancements in information technologies, such as data mining, are enabling the aviation community to pursue a more proactive approach for preventing accidents. In FY2007, NASA, in collaboration with the Federal Aviation Administration (FAA) and the commercial aviation community, established the Aviation Safety Information Analysis and Sharing (ASIAS) system, which is being used to integrate and analyze large sources of operational data in order to detect anomalies and/or dangerous trends before an accident occurs. NASA has also developed three new data-mining methods that are intended to help the aviation community to more efficiently collect and analyze the ASIAS data:

• The System-Level Morning Report (SLMR) helps airlines to automatically uncover small clusters of operationally atypical flights using data from operator activities such as airline Flight Operational Quality Assurance (FOQA) programs. These small clusters may be indicative of underlying safety hazards. The SLMR does not require any pre-specification of what constitutes “typical” flying patterns. This contributes to better efficiency and the ability to uncover unexpected safety issues. The SLMR could potentially be incorporated into FOQA as a routine processing service that would enable each airline to compare itself to the system-level results.
  
  
• SequenceMiner identifies anomalous sequences of switch activations or, more precisely, any unusual discrete parameter patterns within a flight phase. Detected anomalies include more or less frequent activations than expected and unusual switch sequencing. SequenceMiner can potentially identify problems associated with mode confusion, equipment troubleshooting, abnormal situation response, etc.
  
  
• Mariana auto-classifies aviation safety reports based on the contents of report narratives and a limited number of fixed fields such as the event flight phase. The classifications could potentially relate to event types, contributing factors, and other features of interest. Mariana could potentially produce more consistent Aviation Safety Action Program report classifications for airlines, promoting effective data integration across multiple users.

NASA’s Airspace Systems Program, the FAA’s Air Traffic Organization (ATO), and the Joint Planning and Development Office (JPDO) are working collaboratively to establish a process to transfer technologies from fundamental research and development (R&D) into implementation for the next-generation air transportation system, or NextGen. This process has top-level commitment from Shin and Victoria Cox, ATO’s vice president for Operations Planning Services. A coordinating committee that includes both FAA and NASA representatives oversees four research transition teams that are organized around the NextGen Concept of Operations framework. This framework connects the FAA’s Operational Evolution Partnership elements to NASA’s aeronautics research portfolio. The JPDO plays an important role in this transfer in that they keep everyone informed on the progress of the Integrated Work Plan. The teams are working to plan near-term R&D transition areas such as surface management, and in long-term transition areas such as dynamic airspace allocation.

Increasing Turbine Engine Efficiency

In the past, improvements in turbine engine efficiency, performance, noise, and emissions, have been achieved through combinations of new component designs, as well as new materials with higher temperature capability and lower weight. In the future, however, one of the most effective ways to increase engine performance will be to replace various static structures with adaptive or reconfigurable components.

Designs for everything from adaptive inlets, nozzles, flaps, and other control surfaces, to variable-geometry chevrons, reconfigurable blades, and active hinges for the operation of various doors and panels have been developed. Many of these concepts have been envisioned in the past, but could not be achieved because they relied upon electric, hydraulic, or pneumatic actuators that brought excessive weight penalties. NASA’s approach currently is to utilize advanced shape memory alloys (SMAs) in order to achieve these breakthroughs.

Newly developed high-temperature shape memory alloys are helping to reduce noise and improve efficiency in jet engines. NASA has sped the transfer of this technology from the laboratory to practical use worldwide.

The most viable SMAs have been based on binary nickel titanium (NiTi), but this class of SMA has a very low-temperature capability, generally in the range of -100 to 80 °C. Many of the envisioned applications in aeronautics require SMAs that have temperature capability far in excess of this level but that can still generate significant work output. The results of a 5-year development effort are now reaching maturity. Newly developed alloys, formed by ternary and quaternary additions to NiTi, are exhibiting temperature capability between 200-400 °C, while still maintaining high work capability levels.

One example of the successful use of high-temperature SMAs is known as an adaptive chevron. Chevrons placed on either the fan or core exhaust of jet engines have been shown to be very effective in reducing noise during the takeoff of commercial aircraft. However, conventional fixed-geometry chevrons represent a tradeoff in design that reduces noise but also imposes a small, but significant, performance penalty on aircraft engines. The solution would be an adaptive-geometry chevron that could mitigate noise during takeoff and be retracted during cruise so as not to affect performance. However, there are several daunting challenges to developing a successful adaptive-geometry chevron, especially for core exhaust applications. These include the need for very high actuation forces, a very limited volume for actuator placement, and high operating temperatures. Initial testing indicates that these challenges may be overcome through the use of a new chevron design developed by Continuum Dynamics Inc., that uses a high-temperature SMA alloy developed and supplied by NASA’s Glenn Research Center. This resulted in an overall concept with deflection performance that is at least five times more efficient than current approaches.

Another example of the successful use of high-temperature SMAs is known as active flow control. A compressor’s aerodynamics can improve efficiency but may be limited by the onset of compressor stall conditions. A strategy of advanced sensors that can detect the onset of incipient stall, which would then trigger small changes to the flow geometry, allows for a compressor that has both improved efficiency plus tolerance against stall conditions. A design utilizing a high-temperature SMA wire to actuate a control rod which is inserted into the air flow has been designed and successfully demonstrated. Two subsequent design iterations have reduced the size of the SMA actuator by a factor of 10, thus making the concept even more attractive.

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