Wednesday, September 30, 2009

Ice on Mars

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has revealed frozen water hiding just below the surface of mid-latitude Mars. The spacecraft's observations were obtained from orbit after meteorites excavated fresh craters on the Red Planet.

Scientists controlling instruments on the orbiter found bright ice exposed at five Martian sites with new craters that range in depth from approximately 1.5 feet to 8 feet. The craters did not exist in earlier images of the same sites. Some of the craters show a thin layer of bright ice atop darker underlying material. The bright patches darkened in the weeks following initial observations, as the freshly exposed ice vaporized into the thin Martian atmosphere. One of the new craters had a bright patch of material large enough for one of the orbiter's instruments to confirm it is water ice.

The finds indicate water ice occurs beneath Mars' surface halfway between the north pole and the equator, a lower latitude than expected in the Martian climate.

"This ice is a relic of a more humid climate from perhaps just several thousand years ago," said Shane Byrne of the University of Arizona.

Byrne is a member of the team operating the orbiter's High Resolution Imaging Science Experiment, or HiRISE camera, which captured the unprecedented images. Byrne and 17 co-authors report the findings in the Sept. 25 edition of the journal Science.

"We now know we can use new impact sites as probes to look for ice in the shallow subsurface," said Megan Kennedy of Malin Space Science Systems in San Diego, a co-author of the paper and member of the team operating the orbiter's Context Camera.

During a typical week, the Context Camera returns more than 200 images of Mars that cover a total area greater than California. The camera team examines each image, sometimes finding dark spots that fresh,
small craters make in terrain covered with dust. Checking earlier photos of the same areas can confirm a feature is new. The team has found more than 100 fresh impact sites, mostly closer to the equator than the ones that revealed ice.

An image from the camera on Aug. 10, 2008, showed apparent cratering that occurred after an image of the same ground was taken 67 days earlier. The opportunity to study such a fresh impact site prompted a
look by the orbiter's higher resolution camera on Sept. 12, 2009, confirming a cluster of small craters.

"Something unusual jumped out," Byrne said. "We observed bright material at the bottoms of the craters with a very distinct color. It looked a lot like ice."

The bright material at that site did not cover enough area for a spectrometer instrument on the orbiter to determine its composition. However, a Sept. 18, 2008, image of a different mid-latitude site showed a crater that had not existed eight months earlier. This crater had a larger area of bright material.

"We were excited about it, so we did a quick-turnaround observation," said co-author Kim Seelos of Johns Hopkins University Applied Physics Laboratory in Laurel, Md., "Everyone thought it was water ice, but it was important to get the spectrum for confirmation."

The Mars orbiter is designed to facilitate coordination and quick response by the science teams, making it possible to detect and understand rapidly changing features. The ice exposed by fresh impacts suggests that NASA's Viking 2 lander, digging into mid-latitude Mars in 1976, might have struck ice if it had dug four inches deeper.

The Viking 2 mission, which consisted of an orbiter and a lander, launched in September 1975 and became one of the first two space probes to land successfully on the Martian surface. The Viking 1 and 2 landers characterized the structure and composition of the atmosphere and surface. They also conducted on-the-spot biological tests for life on another planet.

NASA's Jet Propulsion Laboratory in Pasadena manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft. The Context Camera was built and is operated by Malin. The University of Arizona operates the HiRISE camera, which Ball
Aerospace & Technologies Corp., in Boulder, Colo., built. The Johns Hopkins University Applied Physics Laboratory led the effort to build the Compact Reconnaissance Imaging Spectrometer and operates it in coordination with an international team of researchers.

To view images of the craters and learn more about the Mars Reconnaissance Orbiter, visit:

Radial Channels Carved by Dry Ice

Spider-shaped features in the south polar region of Mars are carved by vaporizing dry ice in a dynamic seasonal process. This image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter includes several of the distinctive features in an area 1.2 kilometers (three-fourths of a mile) wide. It is one of the HiRISE camera team's featured images this week.

The features are cut into the ground, not built up above the surrounding surface. Sunlight is coming from the right, from about 15 degrees above the horizon. Scientists call these features "araneiform," which means spider-like.

Mars' carbon-dioxide atmosphere partially condenses every winter to form polar caps of dry ice. These seasonal caps sublimate (change directly from solid to gas, just as dry ice does on Earth) in the spring. Carbon-dioxide gas coming from the bottom surface of the ice builds up pressure and carves channels into the ground as it flows toward a point where it escapes back into the atmosphere. Often the channels are radial in nature, with the escape point for the gas becoming the center for one of these araneiform features.

In this image, taken during southern-hemisphere summer, all the seasonal frost is gone from the area. The channels carved into the ground are typically 1 to 2 meters (3 to 7 feet) deep.

The dynamic Martian polar processes that form features like these are described at and

This view is a portion of a HiRISE observation taken on Aug. 23, 2009, at 87.0 degrees south latitude and 86.5 degrees east longitude. The full-frame image is available at

Image Credit: NASA/JPL-Caltech/University of Arizona

MESSENGER Gains Critical Gravity Assist for Mercury Orbital Observations

MESSENGER successfully flew by Mercury yesterday, gaining a critical gravity assist that will enable it to enter orbit about Mercury in 2011 and capturing images of five percent of the planet never before seen. With more than 90 percent of the planet’s surface already imaged, MESSENGER’s science team had drafted an ambitious observation campaign designed to tease out additional details from features uncovered during the first two flybys. But an unexpected signal loss prior to closest approach hampered those plans.

At approximately 5:55 p.m., the spacecraft passed by Mercury at an altitude of 142 miles and at a relative velocity of more than 12,000 miles per hour according to Doppler residual measurements logged just prior to the closet approach point. As the spacecraft approached the planet, MESSENGER’s Wide Angle Camera captured this striking view, which shows portions of Mercury's surface that had remained unseen by spacecraft even after the three flybys by Mariner 10 in 1974 and 1975 and MESSENGER’s two earlier flybys in 2008.

“This third and final flyby was MESSENGER’s last opportunity to use the gravity of Mercury to meet the demands of the cruise trajectory without using the probe’s limited supply of on-board propellant,” says MESSENGER Mission Systems Engineer Eric Finnegan of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md.

A portion of the complicated encounter was executed in eclipse, when the spacecraft is in Mercury’s shadow and the spacecraft – absent solar power – was to operate on its internal batteries for 18 minutes. Ten minutes after entering eclipse and four minutes prior to the closet approach point, the carrier signal from the spacecraft was lost, earlier than expected.

According to Finnegan, the spacecraft autonomously transitioned to a safe operating mode, which pauses the execution of the command load and "safes the instruments," while maintaining knowledge of its operational state and preserving all data on the solid-state recorder.

“We believe this mode transition was initiated by the on-board fault management system due to an unexpected configuration of the power system during eclipse,” Finnegan says. MESSENGER was returned to operational mode at 12:30 a.m. with all systems reporting nominal operations. All on-board stored data were returned to the ground by early morning and are being analyzed to confirm the full sequence of events.

“Although the events did not transpire as planned, the primary purpose of the flyby, the gravity assist, appears to be completely successful,” Finnegan adds. “Furthermore, all approach observing sequences have been captured, filling in additional area of previously unexplored terrain and further exploring the exosphere of Mercury.”

“MESSENGER’s mission operations and engineering teams deserve high commendation for their professional and efficient approach to last night’s spacecraft safe-mode transition,” says MESSENGER Principal Investigator Sean Solomon, of the Carnegie Institution of Washington. “They quickly diagnosed the initial problem, restored the spacecraft to its normal operating mode, and developed plans to recover as much of our post-encounter science observations as possible. Most importantly, we are on course to Mercury orbit insertion less than 18 months from now, so we know that we will be returning to Mercury and will be able to observe the innermost planet in exquisite detail.”

Additional information and features from this encounter will be available online at Be sure to check back frequently to see the latest released images and science results!

NASA's TRMM Satellite Sees Tropical Storm Ketsana's Record Flooding in Northern Philippines

The latest tropical system to the hit the Philippines, Tropical Storm Ketsana (known locally as "Tropical Storm Ondoy"), has resulted in record flooding in the capital of Manila on the island of Luzon in the northern Philippines.

So far 140 people have died in the resultant flooding and mudslides with at least 32 more still missing. Ketsana began as a tropical depression in the west- central Philippine Sea on the morning of September 25, 2009 about 500 miles (~800 km) east-southeast of the central Luzon coast. The system was upgraded to a minimal tropical storm on the evening of the 25th (morning of the 26th local time) as it tracked westward towards Luzon. Ketsana maintained minimal tropical storm intensity as it crossed central Luzon on the afternoon of the 26th (local time).

The main deluge in the Manila area, located on the western side of Luzon, began around 8:00 a.m. local time (00 UTC September 26) even though the center of Ketsana had yet to make landfall on the eastern side of the island. A record 13.43 inches of rain fell in Manila in the 6 hours between 8:00 a.m. and 2:00 p.m. local time, which is equivalent to about a month's worth of rain for the area.

The reason for the enhanced rainfall over on the Manila-side of the island as the storm approached was the interaction between Ketsana's low-level circulation and the seasonal southwest monsoon. The southwest monsoon comes about from the summertime heating of the Asian landmass. As warm air rises over the continent it induces low pressure as the surface, which draws air in from surrounding regions. The southwest monsoon typically runs from June to September in the Philippines and draws warm, humid air up from the southwest across the South China Sea and into the islands where it can interact with the topography. Ketsana's counterclockwise circulation enhanced the effect, which resulted in the torrential rains.

Armed with both a passive microwave sensor and a space-borne precipitation radar, the primary objective of the Tropical Rainfall Measuring Mission satellite (better known as TRMM) is to measure rainfall from space.

For increased coverage, TRMM can be used to calibrate rainfall estimates from other additional satellites. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center is used to monitor rainfall over the global Tropics.

TMPA rainfall totals are shown here for the 7-day period from September 21 to 28, 2009 for the northern Philippines and the surrounding region. The highest rainfall totals occur in an east-west band over central Luzon, including Manila, south of storm's track (indicated by the solid black line). Amounts in this region are on the order of 375 mm (~15 inches, shown in dark yellow) to over 475 mm (~19 inches, shown in orange). The highest recorded amount near Manila was 585.5 mm (almost 24 inches). After passing through the Philippines, Ketsana intensified into a minimal typhoon over the central South China Sea and is expected to make landfall along the central coast of Vietnam.

To see an animation of the calculated flood potential for this event, click here:

Heavy rain amounts (from satellites) and flood potential calculations (from a hydrological model) are updated every three hours globally with the results shown on the "Global Flood and Landslide Monitoring" TRMM web site pages located at:

TRMM is a joint mission between NASA and the Japanese space agency JAXA.

NASA Partners to Revolutionize Personal Transportation

The morning commute may never be the same.

NASA officials have signed an agreement with Unimodal Systems, LLC to collaborate on the use of NASA-developed control software and human factors techniques to evaluate acceleration, jerk and vibration of an advanced transportation vehicle system. The control software was originally designed to control robots and other applications. The collaboration will help NASA better understand the software’s usefulness, human performance and safety.

“This collaborative effort is anticipated to help NASA with its aeronautics and space activities, while Unimodal gets to develop the next generation high-speed transportation system,” said Jeffery Smith, deputy chief of the Entrepreneurial Initiatives Division at NASA Ames Research Center, Moffett Field, Calif. “NASA will receive valuable feedback from our systems software usage.”

Per the agreement, Unimodal will contribute its SkyTran vehicle, currently located at NASA Ames Research Park, and its advanced transportation technology; NASA will provide its Plan Execution Interchange Language (PLEXIL) and Universal Executive (UE) software to control the vehicle.

In the future, SkyTran will use small vehicles running on elevated, magnetically levitated (maglev) guideways, which distinguishes it from other railed systems. The vehicles are lightweight, personal compartments that can transport up to three passengers. Travelers board the pod-like vehicles and type their destinations into a small computer. Using intelligent control system software, SkyTran will run non-stop point-to-point service without interrupting the flow of traffic.

These vehicles will eventually travel up to 150 mph and move 14,000 people per hour, both locally and regionally. SkyTran will serve as a feeder system to other transit systems, such as BART and high-speed rail.

"SkyTran’s personal rapid transit has generated serious interest with local, regional and state transportation leaders who are considering funding the building of the Unimodal maglev PRT system in the NASA Research Park,” said Michael Marlaire, director of NASA Research Park at Ames. “This construction and new R&D partnership may usher a new ‘green’ technology maglev PRT system into Silicon Valley."

“We’re working with NASA and aerospace engineers to ensure aerospace-level standards that exceed the safety records of current transportation systems,” explained Christopher Perkins, chief executive officer of Unimodal Systems, LLC, based in NASA Research Park

Both organizations will mutually benefit. NASA will receive feedback on its software’s usefulness in ground-based propulsion systems, while Unimodal will develop a transportation system designed to eliminate traffic congestion, mitigate greenhouse gases and reduce dependence on foreign oil.

“For cities across the nation, SkyTran will create greentech jobs and launch a new era of public-private partnerships that will make public transit affordable to install, and profitable to operate," said Perkins.

Ready for Liftoff

The Soyuz rocket is seen shortly after arrival to the launch pad on Monday, Sept. 28, 2009, at the Baikonur Cosmodrome in Kazakhstan. The Soyuz is scheduled to launch the crew of Expedition 21 and a spaceflight participant on Sept. 30, 2009.

NASA Ice Campaign Takes Flight in Antarctica

Early in the 20th century, a succession of adventurers and scientists pioneered the exploration of Antarctica. A century later, they're still at it, albeit with a different set of tools. This fall, a team of modern explorers will fly over Earth's southern ice-covered regions to study changes to its sea ice, ice sheets, and glaciers as part of NASA's Operation Ice Bridge.

Starting next month, NASA will fly its DC-8, a 157-foot-long airborne laboratory that can accommodate many instruments. The fall 2009 campaign is one of few excursions to the remote continent made by the DC-8, the largest aircraft in NASA's airborne science fleet.

The plane is scheduled to leave NASA's Dryden Flight Research Center in Edwards, Calif., on October 12 and fly to Punta Arenas, Chile, where the plane, crew and researchers will be based for through mid-November. For six weeks, the Ice Bridge team will traverse the Southern Ocean for up to 17 flights over West Antarctica, the Antarctic Peninsula, and coastal areas where sea ice is prevalent. Each round-trip flight lasts about 11 hours, two-thirds of that time devoted to getting to and from Antarctica.

Operation Ice Bridge is a six-year campaign of annual flights to each of Earth's polar regions. The first flights in March and April carried researchers over Greenland and the Arctic Ocean. This fall's Antarctic campaign, led by principal investigator Seelye Martin of the University of Washington, will begin the first sustained airborne research effort of its kind over the continent. Data collected by researchers will help scientists bridge the gap between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- which is operating the last of its three lasers -- and ICESat-II, scheduled to launch in 2014.

The Ice Bridge flights will help scientists maintain the record of changes to sea ice and ice sheets that have been collected since 2003 by ICESat. The flights will lack the continent-wide coverage that can be achieved by satellite, so researchers carefully select key target locations. But the flights will also turn up new information not possible from orbit, such as the shape of the terrain below the ice.

"Space-based instruments like the ICESat lasers are the only way to find out where change is occurring in remote, continent-sized ice sheets like Antarctica," said Tom Wagner, cryosphere program scientist at NASA Headquarters in Washington, D.C. "But aircraft missions like Ice Bridge allow us to follow up with more detailed studies and make other measurements critical to modeling sea level rise."

Lasers and Radars

ICESat launched in January 2003 and since then, its sole instrument -- a precise laser altimeter -- has helped scientists map ice sheet elevation, calculate sea ice thickness, and monitor how both have changed.

"With ICESat, we have seen significant changes, things we wouldn't otherwise know were taking place," said Jay Zwally of NASA's Goddard Space Flight Center in Greenbelt, Md., and ICESat investigator on the mission. For example, shifts in surface elevation have previously revealed the draining and filling of lakes below Antarctica's ice.

After ICESat, scientists will rely on an airborne laser called the Airborne Topographic Mapper (ATM), developed at NASA Wallops Flight Facility in Wallops Island, Va. ATM pulses laser light in circular scans on the ground, and those pulses reflect back to the aircraft and are converted into elevation maps of the ice surface. By flying ATM over the same swath of ground covered by ICESat, researchers can compare the two data sets and calibrate them so that aircraft can continue the record keeping after the satellite data ends. They can also make more detailed elevation studies over dynamic areas, such as the Crane glacier on the Antarctic Peninsula, which sped up following the collapse of the Larsen Ice Shelf in 2002.

In addition, University of Kansas scientists will fly the Multichannel Coherent Radar Depth Sounder, which measures ice sheet thickness. It can also map the varied terrain below the ice, which is important for computer modeling of the future behavior of the ice.

The Laser Vegetation Imaging Sensor, developed at Goddard, will map large areas of sea ice and glacier zones. And a gravimeter, managed by Columbia University, will measure the shape of seawater-filled cavities at the edge of some major fast-moving major glaciers. Finally, a snow radar from University of Kansas will measure the thickness of snow on top of sea ice and glaciers, allowing researchers to differentiate between snow and ice and make more accurate thickness measurements.


The Antarctic continent may be remote, but it plays a significant role in Earth's climate system. The expanse is home to glaciers and ice sheets that hold frozen about 90 percent of Earth's freshwater -- a large potential contribution to sea level rise should all the ice melt.

How and where are Antarctica's ice sheets, glaciers, and sea ice changing? Compared to the Arctic, where sea ice has long been on the decline, sea ice in Antarctica is growing in some coastal areas. Snow and ice have been accumulating in some land regions in the east. West Antarctica and the Peninsula, however, have seen more dramatic warming and rapid ice loss.

"We don't see the same sea ice changes in Antarctica that we see in the Arctic, and the reason is that the system is more complex," said Thorsten Markus of NASA Goddard, the principal sea ice investigator for the mission. "But the fact that we don't see the same changes in Antarctica that we see in the Arctic doesn’t make it less important to study those changes. It's really important for us to understand the global climate system."

With the DC-8 limited to just a few hours over Antarctica on each flight, mission planners have carefully selected targets of current and potential rapid change.

One such target is West Antarctica's Pine Island Glacier. "That glacier is one of the great unknowns because its bed -- where the glacier contacts rock -- is below sea level," Martin said. "So if there's a surge or dramatic change, seawater could get under the glacier and we could be looking at very rapid change."

Other proposed targets along the Amundsen coast include the Thwaites, Smith, and Kohler glaciers and the Getz Ice Shelf. Researchers also intend to study the myriad glaciers and ice shelves on the Peninsula, which has been undergoing dramatic changes.

Tuesday, September 29, 2009

NASA Goddard Shoots the Moon to Track LRO

On certain nights, an arresting green line pierces the sky above NASA's Goddard Space Flight Center in Greenbelt, Md. It's a laser directed at the moon, visible when the air is humid. No, we're not repelling an invasion. Instead, we're tracking our own spacecraft.

28 times per second, engineers at NASA Goddard fire a laser that travels about 250,000 miles to hit the minivan-sized Lunar Reconnaissance Orbiter (LRO) spacecraft moving at nearly 3,600 miles per hour as it orbits the moon.

The first laser ranging effort to track a spacecraft beyond low-Earth orbit on a daily basis produces distance measurements accurate to about four inches (10 centimeters). For comparison, the microwave stations tracking LRO measure its range to a precision of about 65 feet (20 meters).

"Current lunar maps are not as accurate as we’ll need to return people safely to the moon," said Ronald Zellar of NASA Goddard, team lead for the LRO laser ranging system. "In order to make an accurate map, first you need to know where you are. Knowing the precise range to LRO is necessary for its instruments to produce much more accurate maps, with errors reduced to the size of humans or rovers."

"A further benefit of laser ranging to LRO is that it can improve knowledge of the moon's orientation and gravity, which are central to understanding its interior structure and to precision navigation," said Gregory Neumann, a Geophysicist at NASA Goddard.
Engineers use a telescope at the ground station on the Goddard campus to direct laser pulses toward LRO. The range to LRO is calculated by measuring how long it took the laser to reach the spacecraft.

The laser ranging to LRO is one way, meaning that the laser is directed at LRO, which records the time of arrival and sends the data back to ground stations on Earth by its radio telemetry link. This is the first time repeated, one-way tracking has been used for spacecraft ranging. Typical satellite laser ranging, used for spacecraft in low-Earth orbit, is two way, meaning the laser is simply reflected off the spacecraft and the time of flight recorded when it returns to the ground.

The advantage of LRO's one-way system is that a less expensive, lower-power laser system can be used -- especially important since the distance to LRO is hundreds of times greater than that to most Earth-orbiting spacecraft. Also, only a small receiver is needed on the spacecraft instead of a large retro-reflector array.

LRO's laser tracking presents unique challenges, however. First, there's the issue of avoiding interference. The laser pulses from Earth are received by a small telescope on LRO and transferred to the spacecraft’s laser altimeter instrument. The detector on this instrument performs double-duty, detecting both the laser ranging pulses as well as the pulses from its own laser reflected off the lunar surface. The instrument’s laser is used to build three-dimensional (topographic) maps of the lunar landscape and those pulses could hit the detector at the same time as the laser ranging pulses from Earth, confusing the data. So the pulses from Earth have to be carefully timed to avoid interfering with the instrument’s operation. Since the instrument sends laser pulses 28 times per second to the lunar surface, the laser ranging pulses are sent at the same rate but shifted in time to avoid interference. "It's like shooting at a spinning coin from a mile away and being able to hit it on the edge as it spins," said Neumann.

Another challenge is precise time measurement. Since the range to LRO is calculated by measuring how long it took the laser to reach the spacecraft, any variations in the time measurements will produce variations in the range estimates. LRO has a timing system that uses a crystal oscillator -- the heart of which is a vibrating crystal -- to measure time precisely. The oscillator is accurate to one part in a trillion over an hour. However, the rate at which the crystal vibrates changes with temperature, so the crystal is housed in a small oven which must be carefully controlled to maintain a stable temperature.

Then there's the difficulty of hitting a moving target. Since LRO is constantly moving in its orbit, the ground station must fire the laser pulses at a point in front of the spacecraft to compensate for the spacecraft's motion while the pulse is in-flight toward the moon. This is one of the reasons why LRO still relies on the traditional microwave tracking systems. They need the position of the spacecraft to know where to point the laser. The laser spot is 12 miles wide when it gets to the moon. Although this seems large on a human scale, it’s small in space and it would be easy to miss a tiny spacecraft moving 3,600 miles per hour. Even though the precision isn’t as great, without the microwave tracking system, the laser ranging system won’t work. This requires the LRO Mission Operations Center to track, predict, and communicate the position of the spacecraft to the laser ranging ground station.

Finally, there's the problem of bad weather; specifically, clouds. The laser can't penetrate thick cloud cover, so laser ranging is not available in those situations. Fortunately, there's plenty of opportunity to collect data over the course of LRO's one-year mission. "We're ranging to LRO whenever the moon is visible, 24 hours a day, 7 days a week," said Jan McGarry of NASA Goddard, ground system lead for laser ranging.

"Two-way satellite laser ranging (SLR) was developed at NASA Goddard in the 1960s," adds McGarry. "Since then, SLR has become a global effort, with about 30 countries participating and about 40 satellites carrying laser reflectors. NASA has eight SLR stations around the world, and Goddard is responsible for them. NASA is part of the global International Laser Ranging Service, an organization that provides a coordinated administration for all participating SLR stations and analysis centers." LRO's laser ranging effort is funded by the LRO project.

This Month in Exploration - Sep 09

Visit "This Month in Exploration" every month to find out how aviation and space exploration have changed throughout the years, improving life for humans on Earth and in space. While reflecting on the events that led to NASA's formation and its rich history of accomplishments, "This Month in Exploration" will reveal where the agency is leading us -- to the moon, Mars and beyond.

September 6, 1809: Sir George Cayley completed a detailed essay about his theories and research regarding heavier-than-air flight entitled "On Aerial Navigation." Sir Cayley, sometimes called the Father of Aviation, was the first to identify the four aerodynamic forces of flight weight, lift, drag, and thrust, and their relationship. He was the first investigator to apply the research methods and tools of science and engineering to the solution of the problems of flight. He also described many of the concepts and elements of the modern airplane, and was the first to build a successful human-carrying glider.

100 Years Ago

September 7, 1909: The U.S. Army established its first aerodrome in College Park, Maryland. An aerodrome is a location from which aircraft flight operations take place, whether on land or at sea.

90 Years Ago

September 6, 1919: Maj. R. W. Schroeder and Lt. G. A. Elfrey set a new unofficial two-man world altitude record of 28,250 feet in a Packard-LePere Liberty 400 at Dayton, Ohio. Maj Schroeder used an oxygen system and special oxygen.

September 18, 1919: Roland Rohlfs set an official world altitude record of 31,420 feet in a Curtiss L-3 triplane

80 Years Ago

September 30, 1929: Another rocket powered glider, the Opel Sander Rak.1 , made a successful two-mile flight near Frankfurt-am-Main, Germany.

75 Years Ago

September 9, 1934: The American Rocket Society (ARS) launched Rocket No. 4 to 400 feet altitude at Marine Island, Staten Island, N.Y. These early rocket experiments were designed not only to explore the technical issues involved with launching a rocket into space, but also to promote public and scientific interest.

September 15, 1934: The Aeromedical Laboratory, the primary location of physiological research on the effects of high altitude flight during WWII, was founded at Wright Field, Dayton, Ohio.

50 Years Ago

September 17, 1959:The first powered X-15 flight with A. Scott Crossfield at the controls occurred in Edwards, CA. The X-15 demonstrated the first application of hypersonic theory and wind tunnel work to an actual flight vehicle, and examined pilot performance and physiology within and outside the Earth's atmosphere.

September 9, 1959: The Atlas 10-D, also known as Big Joe 1, was launched from Cape Canaveral. The mission was to test the Mercury capsule boilerplate heat shield. Built in two segments, the main body was fabricated with thin sheets of corrugated Inconel alloy.

45 Years Ago

September 5, 1964: The first of six Orbiting Geophysical Observatory (OGO) satellites was launched from Cape Kennedy at 9:23 p.m., EDT. The purpose of the satellites was to study Earth’s atmosphere, magnetosphere, and the space between Earth and the moon. Data was received from 20 experiments.

35 Years Ago

September 1, 1974: The interplanetary scientific probe Pioneer 11 approached the planet Jupiter, sending back the first polar images of the planet. This mission gathered data on Jupiter’s magnetic field, measured distributions of high-energy electrons and protons in the radiation belts, measured planetary geophysical characteristics and studied gravity and the atmosphere. It then headed on toward an encounter with Saturn and an eventual departure from the solar system.

30 Years Ago

September 1, 1979: The probe Pioneer 11 passed the rings of Saturn at a distance of 13,000 miles above its cloud tops.

September 20, 1979: The High Energy Astronomical Observatory (HEAO) 3 was launched at 1:28 a.m., EDT from the Eastern Space and Missile Center. The spacecraft was designed to detect cosmic ray particles and gamma-ray photons to further the understanding of magnetic fields and interstellar matter.

25 Years Ago

September 8, 1984: The Navigation System with Timing and Ranging (NavStar) 10 was launched from the Western Space and Missile Center. NavStar, later renamed the Global Positioning System (GPS), was designed to provide all-weather, twenty-four hour navigation capabilities for all U.S. military forces, but has also become an integral part of civilian industrial and recreational applications. It was developed by the U. S. Department of Defense.

15 Years Ago

September 9-13 1994: The space shuttle Discovery (STS-64) was launched at 6:33 p.m., EDT from Kennedy Space Center. It landed at Edwards Air Force Base, CA ten days later. On September 13, the crew of STS 64 released the Spartan 1 (also known as Spartan 201) platform. The platform was captured back after a few days. Spartan 1 carried optical instruments to measure the speed and acceleration of the solar wind in the corona.

September 30, 1994: The space shuttle Endeavour (STS-68) launched at 7:16 a.m. EDT from Kennedy Space Center. It carried the Space Radar Laboratory (SRL), part of NASA's Mission to Planet Earth. Unusual events were studied from space, including an erupting volcano in Russia and islands of Japan after an earthquake.

Present Day

September 15, 2009: NASA, on behalf of the Missile Defense Agency, will launch the STSS Demonstrators Program - Missile Defense Agency aboard the United Launch Alliance Delta II from Cape Canaveral Air Force Station between 8 - 9 p.m. EDT. The STSS Demonstrators Program will provide missile tracking technology about ballistic missiles globally.

Thursday, September 24, 2009

Centaur is No Longer the Bridesmaid

Centaur was the unnamed companion to the Atlas V rocket when it launched from Cape Canaveral, Fla., on June 18, 2009. Their mission: lift NASA's Lunar Reconnaissance Orbiter (LRO) into its lunar orbit. Piggybacking a ride on the Centaur was also the Lunar Crater Observation and Sensing Satellite (LCROSS) that will impact the moon in October. But something is different about this mission for Centaur: instead of quietly parking itself in a long-duration orbit of the earth, Centaur accompanied the two spacecraft on their journey toward the moon. What is more, Centaur will be the center of attention for a few glorious minutes this October.

The main LCROSS mission objective is to confirm the presence or absence of water ice in a permanently shadowed crater near a lunar polar region. Mission scientists have determined that the best way to do this is to send one or more objects into the surface of the moon to generate a large plume that can be studied to determine the presence of water ice. LCROSS is a small spacecraft, and besides not being able to make a major impact, its primary role is to observe a larger impact. That creates the opportunity for Centaur to take center stage.

LCROSS, still attached to its Centaur upper stage rocket, executed a fly-by of the moon on June 23, 2009 and entered into an elongated Earth orbit to position LCROSS for impact on a lunar pole. On final approach, the shepherding spacecraft and Centaur will separate. The Centaur will act as a heavy impactor to create a debris plume that will rise above the lunar surface. Projected impact at the lunar South Pole is currently: Oct 9, 2009 at 7:30 a.m. EDT. The Centaur will excavate a crater approximately 20 meters wide and almost 3 meters deep. More than 250 metric tons of lunar dust will be lofted above the surface of the moon.

Following four minutes behind, the shepherding spacecraft will fly through the debris plume, collecting and relaying data back to Earth before impacting the lunar surface and creating a second debris plume.

For almost 30 years, the NASA Glenn Research Center in Cleveland, Ohio, was responsible for the technical and cost and schedule management of the Centaur rocket. This program had an extraordinary operational success record. It was developed as an upper stage launch vehicle to be used with a first stage booster rocket, the Atlas rocket. Centaur's first mission objective was to send the unmanned Surveyor spacecraft to the Moon. Centaur has been used to boost satellites into orbit and propel probes into space. Mariner, Pioneer, Viking and Voyager spacecraft all got a boost from Centaur and provided invaluable data on these planets. Centaur also helped to revolutionize communication and expand the frontiers of space. In all, Glenn used Centaur for more than 100 unmanned launches. Centaur has quietly continued as the upper stage of the Atlas family of rockets from United Launch Alliance and the retired Titan IV from Lockheed Martin.

For each of its previous missions, Centaur quietly did its job and retreated out of the limelight. This time, Centaur is going out in style!

Go Centaur!

David DeFelice NASA Glenn Research Center

Note: NASA’s Ames Research Center, Moffett Field, Calif., is overseeing the development of the LCROSS mission with its spacecraft and integration partner, Northrop Grumman, Redondo Beach, Calif.

NASA's Spitzer Spots Clump of Swirling Planetary Material

PASADENA, Calif. -- Astronomers have witnessed odd behavior around a young star. Something, perhaps another star or a planet, appears to be pushing a clump of planet-forming material around. The observations, made with NASA's Spitzer Space Telescope, offer a rare look into the early stages of planet formation.

Planets form out of swirling disks of gas and dust. Spitzer observed infrared light coming from one such disk around a young star, called LRLL 31, over a period of five months. To the astronomers' surprise, the light varied in unexpected ways, and in as little time as one week. Planets take millions of years to form, so it's rare to see anything change on time scales we humans can perceive.

One possible explanation is that a close companion to the star -- either a star or a developing planet -- could be shoving planet-forming material together, causing its thickness to vary as it spins around the star.

"We don't know if planets have formed, or will form, but we are gaining a better understanding of the properties and dynamics of the fine dust that could either become, or indirectly shape, a planet," said James Muzerolle of the Space Telescope Science Institute, Baltimore, Md. Muzerolle is first author of a paper accepted for publication in the Astrophysical Journal Letters. "This is a unique, real-time glimpse into the lengthy process of building planets."

One theory of planet formation suggests that planets start out as dusty grains swirling around a star in a disk. They slowly bulk up in size, collecting more and more mass like sticky snow. As the planets get bigger and bigger, they carve out gaps in the dust, until a so-called transitional disk takes shape with a large doughnut-like hole at its center. Over time, this disk fades and a new type of disk emerges, made up of debris from collisions between planets, asteroids and comets. Ultimately, a more settled, mature solar system like our own forms.

Before Spitzer was launched in 2003, only a few transitional disks with gaps or holes were known. With Spitzer's improved infrared vision, dozens have now been found. The space telescope sensed the warm glow of the disks and indirectly mapped out their structures.

Muzerolle and his team set out to study a family of young stars, many with known transitional disks. The stars are about two to three million years old and about 1,000 light-years away, in the IC 348 star-forming region of the constellation Perseus. A few of the stars showed surprising hints of variations. The astronomers followed up on one, LRLL 31, studying the star over five months with all three of Spitzer's instruments.

The observations showed that light from the inner region of the star's disk changes every few weeks, and, in one instance, in only one week. "Transition disks are rare enough, so to see one with this type of variability is really exciting," said co-author Kevin Flaherty of the University of Arizona, Tucson.

Both the intensity and the wavelength of infrared light varied over time. For instance, when the amount of light seen at shorter wavelengths went up, the brightness at longer wavelengths went down, and vice versa.

Muzerolle and his team say that a companion to the star, circling in a gap in the system's disk, could explain the data. "A companion in the gap of an almost edge-on disk would periodically change the height of the inner disk rim as it circles around the star: a higher rim would emit more light at shorter wavelengths because it is larger and hot, but at the same time, the high rim would shadow the cool material of the outer disk, causing a decrease in the longer-wavelength light. A low rim would do the opposite. This is exactly what we observe in our data," said Elise Furlan, a co-author from NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The companion would have to be close in order to move the material around so fast -- about one-tenth the distance between Earth and the sun.

The astronomers plan to follow up with ground-based telescopes to see if a companion is tugging on the star hard enough to be perceived. Spitzer will also observe the system again in its "warm" mission to see if the changes are periodic, as would be expected with an orbiting companion. Spitzer ran out of coolant in May of this year, and is now operating at a slightly warmer temperature with two infrared channels still functioning.

"For astronomers, watching anything in real-time is exciting," said Muzerolle. "It's like we're biologists getting to watch cells grow in a petri dish, only our specimen is light-years away."

Other authors are Zoltan Balog, Max Planck Institute for Astronomy, Germany; Paul S. Smith and George Rieke, University of Arizona; Lori Allen, National Optical Astronomy Observatory, Tucson; Nuria Calvet, University of Michigan, Ann Arbor; Paola D'Alessio, National Autonomous University of Mexico; S. Thomas Megeath, University of Toledo, Ohio; August Muench, Harvard-Smithsonian Center for Astrophysics, Cambridge; William H. Sherry, National Solar Observatory, Tucson.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA.

Monday, September 21, 2009

Shuttle's Ferry Flight Presented Challenging Weather

One of the pilots for Discovery's 747 Shuttle Carrier Aircraft says today's final leg of the ferry flight presented the most challenging weather situation he's dealt with in the more than 10 cross-country piggyback treks he's flown.
The Shuttle Carrier Aircraft arrived at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida at 12:05 p.m. EDT.
Discovery will be detached from the modified jumbo jet during the next 14-18 hours. Tuesday, the shuttle will be towed to Orbiter Processing Facility-3 where the Multi-Purpose Logistics Module Leonardo will be removed from the payload bay and the shuttle will be prepared for its next mission, STS-131. Discovery is targeted for launch to the International Space Station in March 2010.
Discovery's 2,500 mile ferry flight began at 9:20 a.m. EDT Sunday after taking off from Edwards Air Force Base in California. The shuttle landed there Sept. 11 to end its STS-128 mission to the space station. The Shuttle Carrier Aircraft made three stops yesterday. Two were refueling stops, one at Rick Husband International Airport in Amarillo, Texas, the other at Ft. Worth Naval Air Station, Texas. The third and final stop Sunday was at Barksdale Air Force Base in Shreveport, La., where Discovery stayed overnight. The ferry flight team departed Barksdale at about 9:40 a.m. EDT today and traveled non-stop to Kennedy, maneuvering around storms along the way

NASA Invites Media to Ames for LCROSS Impact Events

MOFFETT FIELD, Calif. -- NASA's Lunar Crater Observation and Sensing Satellite mission, known as LCROSS, will culminate with two lunar impacts at approximately 4:30 a.m. PDT on Oct. 9. The mission will search for water ice in the Cabeus A crater near the moon's south pole. Reporters are invited to observe the event and participate in pre-impact and post-impact media briefings Oct. 9 at NASA's Ames Research Center at Moffett Field, Calif.

The deadline for U.S. reporters to apply for accreditation is Monday, Oct. 5. International journalists planning to cover the LCROSS impacts from Ames must apply for accreditation no later than Friday, Sept. 25. Media representatives applying for credentials should submit requests to:

Journalists should confirm they have been accredited before they travel. No substitution of credentials is allowed at any NASA facility.

Once approved, two forms of government-issued identification, one with a photo, will be required to receive an access badge for Ames to cover the pre- impact media briefing, impact event and post-impact conference. For further information about accreditation, contact Jonas Dino at 650-604-5612.

Sunday, September 20, 2009

NASA and ATK Successfully Test Ares First Stage Motor

NASA and industry engineers lit up the Utah sky on Sept. 10, 2009, with the initial full-scale, full-duration test firing of the first stage motor for the Ares I rocket. The Ares I is a crew launch vehicle in development for NASA's Constellation Program.

ATK Space Systems conducted the successful stationary firing of the five-segment solid development motor 1, or DM-1. ATK Space Systems, a division of Alliant Techsystems of Brigham City, Utah, is the prime contractor for the Ares I first stage. Engineers will use the measurements gathered from the test to evaluate thrust, roll control, acoustics and motor vibrations. This data will provide valuable information as NASA develops the Ares I and Ares V vehicles. Another ground test is planned for summer 2010.

"With this test, we have taken lessons learned from many years of experience in solid rocket motor development and have built on that foundation," said Alex Priskos, first stage manager for Ares Projects at NASA's Marshall Space Flight Center in Huntsville, Ala. "Our team collected data from 650 sensors today to evaluate the motor's performance. This test and those that follow are essential to understanding as many aspects of our motor as possible, including strengths and weaknesses, and ultimately delivering the safest and most reliable motor possible."

This was the second attempt to conduct the two-minute rocket test at ATK's test stand in Promontory, Utah. The first test on Aug. 27 was canceled with 20 seconds left in the countdown because of a problem with a component of the ground controller unit, which sends power to the system that moves the nozzle during the test. Through a detailed investigation, the engineering team pinpointed the problem and replaced the faulty part.

The first stage motor will generate up to 3.6 million pounds of thrust, or lifting power, at launch. Although similar to the solid rocket boosters that help power the space shuttle to orbit, the Ares development motor includes several upgrades and technology improvements implemented by NASA and ATK engineers.

Motor upgrades from a shuttle booster include the addition of a fifth segment, a larger nozzle throat, and upgraded insulation and liner. The forward motor segment also has been improved for performance by adding another fin, or slot in the propellant. This change provides additional surface area for burning the solid fuel, which results in greater thrust.

The DM-1 nozzle throat is three inches wider in diameter than the nozzle used for the shuttle. The bigger nozzle throat allows the motor to handle the additional thrust from the five-segment booster. It also meets NASA's structural requirements to stay within the pressure capacity of the existing steel cases -- the large, barrel-shaped cylinders that house the fuel -- ensuring safety and reliability. Upgrades also were made to the insulation and liner that protect the first stage's steel cases.

The motor cases are flight proven hardware used on shuttle launches for more than three decades. The cases used in this ground test have collectively flown on 48 previous missions, including STS-1, the first shuttle flight.

Marshall manages the Ares Projects and is responsible for design and development of the Ares I rocket and Ares V heavy cargo launch vehicle. NASA's Johnson Space Center in Houston manages the Constellation Program, which includes the Ares I, Ares V, Orion crew module and Altair lunar lander. The program also includes multiple project teams at NASA centers and contract organizations around the United States.

Saturday, September 19, 2009

Search of Dark Asteroids (and Other Sneaky Things)

In modern warfare, though, ninjas would be sitting ducks. Their black clothes may be hard to see at night with the naked eye, but their warm bodies would be clearly visible to a soldier wearing infrared goggles. To hunt for the "ninjas" of the cosmos -- dim objects that lurk in the vast dark spaces between planets and stars -- scientists are building by far the most sensitive set of wide-angle infrared goggles ever, a space telescope called the Wide-field Infrared Survey Explorer, or WISE.

WISE will scan the entire sky at infrared wavelengths, creating the most comprehensive catalog yet of dark and dim objects in the cosmos: vast dust clouds, brown dwarf stars, asteroids -- even large, nearby asteroids that might pose a threat to Earth. Surveys of nearby asteroids based on visible-light telescopes could be skewed toward asteroids with more-reflective surfaces. "If there's a significant population of asteroids nearby that are very dark, they will have been missed by these previous surveys," says Edward Wright, principal investigator for the mission and a physicist at UCLA.

The full-sky infrared map produced by WISE will reveal even these darker asteroids, mapping the locations and sizes of roughly 200,000 asteroids and giving scientists a clearer idea of how many large and potentially dangerous asteroids are nearby. WISE will also help answer questions about the formation of stars and the evolution and structure of galaxies, including our own Milky Way galaxy.

And the discoveries won't likely stop there.

"When you look at the sky with new sensitivity and a new wavelength band, like WISE is going to do, you're going to find new things that you didn't know were out there," Wright says. Stars emit visible light in part because they're so hot. But cooler objects like asteroids emit light too, just at longer, infrared wavelengths that are invisible to the unaided eye. In fact, any object warmer than absolute zero will emit at least some infrared light.

Unfortunately, this fact makes building an infrared telescope rather difficult. Without a coolant, the telescope itself would glow in infrared light just like as other warm objects do. It would be like building a normal, visible-light telescope out of Times Square billboard lights: The telescope would be blinded by its own glow.

To solve this problem, WISE will cool its components to about 15 degrees Celsius above absolute zero (minus 258 degrees Celsius, or minus 433 degrees Fahrenheit) using a block of solid hydrogen. Mission scientists chose solid hydrogen over liquid helium, which is often used in research for cooling materials to near absolute zero, because a smaller volume of solid hydrogen can do the job. "The cooling power is much higher for hydrogen than for helium," Wright explains. When launching a telescope into space, being smaller and lighter saves money.

Previous space telescopes such as the Infrared Astronomical Satellite have mapped the sky at infrared wavelengths before, but WISE will be hundreds of times more sensitive. While other missions could only see diffuse sources of infrared light such as large dust clouds, WISE will be able to see asteroids and other point sources.

After it launches into orbit as early as this December, WISE will spend six months mapping the sky, during which it will download its data to ground stations four times each day. Analyzing that data should give scientists some new insights into the cosmos. For example, one theory posits that most of the stars in the universe were formed in the press of colliding galaxies. When galaxies collide, interstellar clouds of gas and dust smash together, compressing the clouds and starting a self-perpetuating cycle of gravitational collapse. The result is a flurry of star birth. Newborn stars are usually concealed by the dusty clouds in which they are born. Ordinary light cannot escape, but infrared light can.

WISE will be able to detect infrared emissions from the most active star-forming regions. This will help scientists know how rapidly stars are formed during galactic collisions, which could indicate how many of the universe's stars were formed this way. WISE will also target dim "failed stars" called brown dwarfs that outnumber ordinary stars by a wide margin. Mapping brown dwarfs in the Milky Way may reveal much about the structure and evolution of our own galaxy.

Friday, September 18, 2009

Learning How Materials Work in Space to Make Them Better on Earth

What's about the size of a large refrigerator, weighs a ton and may help pave the way for new and improved metals or glasses here on Earth?

It's the Materials Science Research Rack -- a new laboratory on board the International Space Station.

This facility will allow researchers to study a variety of materials -- including metals, alloys, semiconductors, ceramics, and glasses to see how the materials form, and learn how to control their properties. The results from experiments conducted in the facility could lead to the development of materials with improved properties on Earth.

Materials science research is a multidisciplinary endeavor studying the relationships between the processing conditions and properties of materials. The research rack -- measuring 6 feet high, 3.5 feet wide and 40 inches deep -- will provide a powerful, multi-user materials science laboratory in a microgravity, or near weightless, environment. Researchers can benefit from studying materials in space because they can isolate the fundamental heat and mass transfer processes involved that are frequently masked by gravity on the ground.

The research rack will provide hardware to control the thermal, environmental and vacuum conditions of experiments; monitor experiments with video; and supply power and data handling for specific experiment instrumentation.

"Materials science is an integral part of our everyday life," said Sandor Lehoczky, project scientist for the rack at NASA's Marshall Space Flight Center in Huntsville, Ala. "The goal of materials processing in space is to develop a better understanding of how processing affects materials properties without the complication of gravity causing density effects on the processes. With this knowledge, reliable predictions can be made about the conditions required on Earth to achieve improved materials."

The Materials Science Research Rack is an automated facility with two different furnace inserts in which sample cartridges will be processed to temperatures up to 2,500 degrees Fahrenheit. Initially, 13 sample cartridge assemblies will be processed, each containing mixtures of metal alloys. The cartridges are placed -- one at a time -- inside the furnace insert for processing. Once a cartridge is in place, the experiment can be run by automatic command or conducted via telemetry commands from the ground. Processed samples will be returned to Earth for evaluation and comparison of their properties to samples similarly processed on the ground.

The research rack was launched to the space station aboard space shuttle Discovery on August 28. It was installed in the U.S. Destiny Laboratory Sept. 2. The development of the rack was a cooperative effort between NASA and the European Space Agency. The rack accommodates the European Space Agency’s Materials Science Laboratory -- designed to provide controlled, materials processing conditions and advanced diagnostics. The Materials Science Laboratory has the capability to handle different furnace inserts. Metallurgical research will be conducted in the laboratory to gain a better understanding of industrial metallurgical processes, such as casting, welding and other advanced melting processes.

Masten Space Systems Attempts to Qualify For Lunar Lander Challenge

Masten Space Systems unsuccessfully attempted a Level 1 flight on Sept. 16 as part of the Centennial Challenges - Lunar Lander Challenge at the company’s test facility at California’s Mojave Air and Space Port.

In order to qualify for Level 1 prize money, a rocket vehicle must lift off from one concrete pad, ascend to approximately 50 meters, travel horizontally, and land on a second pad. After refueling at that pad, the vehicle must repeat the flight back to a landing on the original pad within two and half hours. The vehicle must remain aloft for at least 90 seconds on both flights.

Masten’s rocket vehicle completed a near-perfect flight of 93 seconds duration from one launch pad to another with an accurate landing. However, the vehicle was unable to complete the round trip because of engine damage. The engine problem did not appear to affect the performance of the first flight, but the team decided to not risk another flight with a degraded engine.

After several years of development by the Masten team, this was the team’s first flight attempt in the Lunar Lander Challenge. They conducted the first free-flight test of their vehicle a day earlier on Sept. 15. This attempt was for the Level 1 second prize of $150,000. Armadillo Aerospace claimed the Level 1 first prize in 2008.

Masten Space Systems already has registered for two more flight attempts on Oct. 7-8 and Oct. 28-29. The company plans to try again for the Level 1 prize, as well as the more demanding Level 2 prize. In addition to Armadillo Aerospace, which qualified for the Level 2 prize on Sept. 12, two other lunar lander teams will be vying for NASA prize money during the next six weeks.

"With as many as four teams competing this year, we may see a wide-open race for all of the remaining lunar lander prize money," said NASA’s Centennial Challenge program manager, Andrew Petro. "NASA and the commercial space industry benefit from the diversity of technical solutions that these teams devise and demonstrate."

The Lunar Lander Challenge competition is managed for NASA by the X Prize Foundation under a Space Act Agreement. NASA provides all of the prize funds. The Northrop Grumman Corporation is a commercial sponsor for the challenge, providing operating funds to the X Prize Foundation.

The Lunar Lander Challenge is one of six current Centennial Challenges managed by NASA’s Innovative Partnership Program. The Regolith Excavation Challenge will be held Oct. 17-18 at NASA’s Ames Research Center at Moffett Field, Calif. The Power Beaming and Astronaut Glove Challenges are planned for 2009, but details have not been finalized. The Green Flight Challenge for super-efficient aircraft will conclude in July 2011 in Santa Rosa, California.

The X-15, the Pilot and the Space Shuttle

Fifty years ago in 1959, test pilot Scott Crossfield threw the switch to ignite the twin XLR-11 engines of his North American Aviation X-15 rocket plane and begin the storied test program's first powered flight.

It was a real kick in the pants.

"The drop from the B-52 carrier aircraft was pretty abrupt, and then when you lit that rocket a second or two later you definitely felt it,” said Joe Engle, another X-15 test pilot and member of the same exclusive fraternity of flyboys that included Crossfield and the eventual first man on the moon, Neil Armstrong. All took the X-15 to speeds and altitudes that extended the frontiers of flight.
› Interactive Feature: X-15

The X-15 was a research scientist's dream. The experimental, rocket-boosted aircraft flew 199 flights with 12 different pilots at the controls from 1959 through 1968. It captured vital data on the effects of hypersonic flight on man and machine that proved invaluable to the nation's aeronautics researchers, including NASA and developers of the space shuttle.

"That first powered flight was a real milestone in a program that we still benefit from today," said Engle.

Engle knows what he’s talking about.

The Kansas native flew the X-15 for the U.S. Air Force 16 times from 1963 to 1965 and went on to command two missions of NASA's space shuttle.

Still an active pilot, the retired major general fondly recalled what it was like to fly the X-15 and how lessons learned then made possible the space shuttle program years later.

"It was a very busy airplane to fly, but it also was a beautiful airplane to fly; a very, very good solid flying vehicle. Particularly when you were subsonic, in the landing pattern— even at the lower supersonic speeds," Engle said.

Three times Engle flew an X-15 higher than 50 miles, officially qualifying him for Air Force astronaut wings and providing him a brief moment for sightseeing at the edge of space.

"I didn't really have time to soak up the view in the X-15 like I did later when I flew the space shuttle," Engle said.

"You could glance out and see the blackness of space above and the extremely bright Earth below. The horizon had the same bands of color you see from the shuttle, with black on top, then purple to deep indigo, then blues and whites.

"You were just so terribly busy flying the airplane, keeping everything under control and watching for any deviations. And in many cases, during re-entry flights for example, making sure the airplane was perfectly lined up as you started to enter the atmosphere."

Engle credits the X-15 for laying the foundation for many of the operational techniques of the space shuttle, and for providing designers with confidence that certain design and control concepts for the winged orbiter would work:
  • With similar flying characteristics, the X-15 proved the shuttle could re-enter the atmosphere and glide to a precision landing, in part relying on a maneuver known as Terminal Area Energy Management where speed and altitude are carefully controlled so the vehicle can reach the runway instead of falling short or overflying it.
  • Using technology developed and tested on the X-15, pilots learned how to transition control smoothly from reaction control jets at high altitudes or in space to wing- and tail-mounted control surfaces in the atmosphere closer to the ground.
  • While not a benefit to the space shuttle alone, the X-15 was the first flight test program to make extensive use of simulators to work out certain problems and train pilots before going up—a practice since employed for nearly every flight test program.
  • The X-15 flights proved the usefulness of having chase aircraft follow a test vehicle during its approach to the runway to make sure, as Engle put it: "Everything that is supposed to be up is up, and everything that is supposed to be down is down."
The X-15 was suggested in the early 1950s by Bell Aircraft's Walter Dornberger as a vehicle for exploring the realm of hypersonic flight, which was defined as a speed in excess of Mach 5, or five times the speed of sound. The earliest days of the X-15 program were shaped by the National Advisory Committee for Aeronautics, the federal agency which NASA replaced in 1958.

The NACA, Air Force and Navy all had an interest in the program and all provided resources, including pilots. Eventually the Navy stopped supporting the X-15 in order to concentrate on aircraft carrier operations, Engle said.

By the time contracts for the airframe and engine were signed with North American Aviation in 1955 and Reaction Motors in 1956, the program had goals of flying the X-15 to a speed of Mach 6 and an altitude of 225,000 feet.

"It was a pretty aggressive move, a pretty gutsy step. We had reached Mach 1, 2 and even 2.5 in other airplanes. But then we lost a pilot when he crashed in one of those airplanes after reaching Mach 3," Engle said. "So the next step was Mach 6?"

As the prime contractor for the X-15 airframe, North American Aviation was responsible for checking out the vehicle before turning it over to the NACA, Air Force and Navy team so research flights could begin. It was up to the company’s chief test pilot, Scott Crossfield, to take the controls for the initial flights.

Crossfield flew a handful of captive flights with the X-15 slung beneath the wing of a B-52 mother ship. Some were intentional and some were not, as initial attempts for a drop test were aborted. Crossfield and his rocket plane finally were released from the B-52 on June 8, 1959, to make an unpowered glide to the lakebed below at Edwards Air Force Base in California.

With the X-15’s primary rocket engine, the XLR-99, still a few months away from being ready to fly, two of the smaller XLR-11 rockets were installed into the X-15 for Crossfield to use in making the first powered flight on Sept. 17, 1959.

The X-15 worked as anticipated that day, reaching a modest altitude of 52,341 feet, but easily breaking the sound barrier and recording a top speed of Mach 2.11 during the nine-minute flight.

"It was a big step, you bet," Engle said. "It showed that the propulsion unit was compatible with the airframe and that it would work. Crossfield was able to demonstrate the airplane would launch, fly free from the B-52, and that it could go supersonic without picking up any handling problems going through the transonic region."

The X-15 set world records for altitude and speed, but more importantly the research conducted during those test missions provided data that would benefit future operations and investigations related to aeronautics and spaceflight.

"I think they far exceeded what they thought was going to be the design parameters for the X-15 program. They wanted to achieve Mach 6 and they got to Mach 6.7. The design altitude was 225,000 feet and (NASA pilot) Joe Walker got it to 354,200 feet," Engle said.

But reaching those numbers didn't automatically allow the X-15's designers and pilots to declare success, Engle said. The whole process they went through to get to that point is where the lessons were taught and learned, sometimes harshly. In 1967, Air Force pilot Michael Adams was killed in the crash of an X-15.

The Return of Buzz Lightyear

Disney's space ranger Buzz Lightyear returned from space on Sept. 11, aboard space shuttle Discovery's STS-128 mission after 15 months aboard the International Space Station. His time on the orbiting laboratory will celebrated in a ticker-tape parade together with his space station crewmates and former Apollo 11 moonwalker Buzz Aldrin on Oct. 2, at Walt Disney World in Florida.

While on the space station, Buzz supported NASA's education outreach program-- STEM (Science, Technology, Engineering and Mathematics)--by creating a series of fun educational online outreach programs. Following his return, Disney is partnering with NASA to create a new online educational game and an online mission patch competition for school kids across America. NASA will fly the winning patch in space. In addition, NASA plans to announce on Oct. 2, 2009, the details of a new exciting educational competition that will give students the opportunity to design an experiment for the astronauts on the space station.

Wednesday, September 16, 2009

Kepler Scientific Objectives

The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to:
  • Determine the percentage of terrestrial and larger planets that are in or near the habitable zone of a wide variety of stars
  • Determine the distribution of sizes and shapes of the orbits of these planets
  • Estimate how many planets there are in multiple-star systems
  • Determine the variety of orbit sizes and planet reflectivities, sizes, masses and densities of short-period giant planets
  • Identify additional members of each discovered planetary system using other techniques
  • Determine the properties of those stars that harbor planetary systems.

Target Field of View

Since transits only last a fraction of a day, all the stars must be monitored continuously, that is, their brightnesses must be measured at least once every few hours. The ability to continuously view the stars being monitored dictates that the field of view (FOV) must never be blocked at any time during the year. Therefore, to avoid the Sun the FOV must be out of the ecliptic plane. The secondary requirement is that the FOV have the largest possible number of stars. This leads to the selection of a region in the Cygnus and Lyra constellations of our Galaxy as shown.

NASA's first mission capable of finding Earth-size and smaller planets around other stars

The centuries-old quest for other worlds like our Earth has been rejuvenated by the intense excitement and popular interest surrounding the discovery of hundreds of planets orbiting other stars. There is now clear evidence for substantial numbers of three types of exoplanets; gas giants, hot-super-Earths in short period orbits, and ice giants. The challenge now is to find terrestrial planets (i.e., those one half to twice the size of the Earth), especially those in the habitable zone→ of their stars where liquid water might exist on the surface of the planet.

The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone→ and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.

The Transit Method of Detecting Extrasolar Planets

When a planet passes in front of a star as viewed from Earth, the event is called a “transit”. On Earth, we can observe an occasional Venus or Mercury transit. These events are seen as a small black dot creeping across the Sun—Venus or Mercury blocks sunlight as the planet moves between the Sun and us. Kepler finds planets by looking for tiny dips in the brightness of a star when a planet crosses in front of it—we say the planet transits the star.

Once detected, the planet's orbital size can be calculated from the period (how long it takes the planet to orbit once around the star) and the mass of the star using Kepler's Third Law of planetary motion. The size of the planet is found from the depth of the transit (how much the brightness of the star drops) and the size of the star. From the orbital size and the temperature of the star, the planet's characteristic temperature can be calculated. From this the question of whether or not the planet is habitable (not necessarily inhabited) can be answered.

Kepler instrument

The Kepler instrument is a specially designed 0.95-meter diameter telescope called a photometer or light meter. It has a very large field of view for an astronomical telescope — 105 square degrees, which is comparable to the area of your hand held at arm's length. It needs that large a field in order to observe the necessary large number of stars. It stares at the same star field for the entire mission and continuously and simultaneously monitors the brightnesses of more than 100,000 stars for the life of the mission—3.5 or more years.

The photometer must be spacebased to obtain the photometric precision needed to reliably see an Earth-like transit and to avoid interruptions caused by day-night cycles, seasonal cycles and atmospheric perturbations, such as, extinction associated with ground-based observing.

Results from the Kepler mission will allow us to place our solar system within the context of planetary systems in the Galaxy.

Kepler and the Search for Life in Our Galaxy

There are so many stars in our galaxy that even if planets with complex life (animals and plants) are rare – say one for every billion stars – there could still be dozens here in the Milky Way. But we are just beginning to learn about worlds beyond our solar system, called exoplanets, so we really don't have a good idea of what the chances are for advanced life. That's where NASA's Kepler mission comes in.

Currently, we have only one example of complex life –- our own. So we have to use conditions that give rise to this kind of life when we go looking for it elsewhere in the Universe. Essential ingredients in the recipe for life as we know it include liquid water; an energy source, such as sunlight or chemicals from volcanic activity; and a supply of raw materials in the form of critical elements like carbon, oxygen, hydrogen, and nitrogen, to name just a few. The most likely places where all the ingredients will be present are rocky planets, like Earth, that are within the habitable zone of their parent stars.

The habitable zone is where the temperature is just right for liquid water to exist on the surface of an exoplanet. If the planet is too close to its star, it will be too hot, and you'll end up with a world like Venus, where the oceans have boiled away. Too far away, however, and you get something like Mars, where most, if not all, of the water on the surface is frozen.

The Kepler mission seeks to detect Earth-like, i.e., rocky planets in our galaxy within the habitable zone of their parent stars, by looking for planetary transit events. These are situations where the planet passes in front of its star as seen from our point of view, slightly dimming the star's brightness. Since planetary transit events are fleeting, and it is unknown how common they may be, Kepler will continuously observe some 100,000 sun-like stars (in about 100 square degrees of the sky in the Cygnus region) for four years.

Observing planetary transits is challenging, because the brightness changes are exceedingly small. For example, Earth is about one-hundredth the diameter of the sun, so from an alien point of view, when Earth passes in front of the sun, it obscures only a tiny area on the solar disk -- just one ten-thousandth. An alien watching Earth transit the sun would see our star's brightness drop by just one part in ten thousand. We expect similar faint eclipses when searching for Earth-like planets around sun-like stars. To detect such tiny changes in brightness, Kepler will be able to observe a brightness change as small as one part in one hundred thousand.

Other challenges for Kepler are brightness changes that arise from a natural variation within the star itself, rather than from a transiting planet. If a brightness change repeats at regular intervals, it's more likely to be from an exoplanet, since its orbit will make it transit at the same periods. Scientists with the mission will need to see the same change at least twice before it's considered a possible exoplanet. Since the mission has a limited time to make its observations, if a transit takes more than a year to repeat, it will be difficult to confirm as an exoplanet.

We can analyze a planetary transit event to discover basic characteristics of the planet. A large planet will block more starlight than a small one, so the size of the planet can be estimated by how much the star dims during the transit. A planet close to its star zips around it faster than one farther away, so the time between transits will give us an approximate distance of the planet from its star.

The planet will also tug at the star with its gravity. Much as the siren of a speeding ambulance changes pitch as it passes by – higher when it's moving closer, and lower when it's moving away -- this gravitational pull will cause the colors (spectrum) of the star's light to shift slightly – more blue if the star is moving toward us, more red if the star is moving away. Astronomers can observe this color shift with instruments that separate the star's light into its component colors, called its spectrum. By observing the amount of color shift in the star's spectrum, astronomers can get the mass of the planet relative to its parent star – more massive planets have a greater pull and will cause a larger color shift.

Most exoplanet detections so far have been made using this spectral shift. Such detections, however, tend to favor massive planets (about Jupiter’s size or larger). With current technology, it's extremely difficult to detect Earth-sized planets using this technique.

Kepler will also be used to make discoveries about the stars themselves. There are many stars that are binaries (double stars). These binaries may exhibit eclipses. The Kepler mission data analysis program has a pipeline data processing that can discriminate the eclipsing binaries among the stars observed and will be analyzed accordingly. Binary stars, including cataclysmic variables (e.g., exploding stars such as novae) and intrinsic variable stars, including pulsating variables, that are observed with the Kepler satellite will present unprecedented opportunities to further astrophysical research.

The Kepler observatory was placed in an Earth-following orbit March 6, 2009. This mission has been conceived by William Borucki and Dave Koch of NASA Ames Research Center, Moffett Field, Calif., and developed at NASA Ames.

Kepler is a NASA Discovery mission. NASA Ames is the home organization of the science principal investigator, and is responsible for the ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif. manages the Kepler mission development. Ball Aerospace & Technologies Corp. of Boulder, Colo., is responsible for developing the Kepler flight system and supporting mission operations.

Aerospace's rocket vehicle

Armadillo Aerospace successfully met the Level 2 requirements for the Centennial Challenges - Lunar Lander Challenge and qualified to win a $1 million dollar first place prize. The flights were conducted Sept. 12 at the Armadillo Aerospace test facility in Caddo Mills, Texas.

To qualify for the Level 2 prize, Armadillo Aerospace's rocket vehicle took off from one concrete pad, ascended horizontally, then landed on a second pad that featured boulders and craters to simulate the lunar surface. After refueling at that pad, the vehicle then repeated the flight back and landed at the original pad.

The vehicle completed the round trip, including fueling and refueling operations, in one hour and 47 minutes. That was well within the two and half hour time limit for the challenge. Armadillo Aerospace also met the requirement to remain aloft under rocket power for three minutes during each of the flights.

In this image, technicians Neil Milburn, Russ Blink and Mike Vinther are shown on the launch pad performing a vehicle inspection.