SpotLight

NASA's STS-119 Mission: Boosting the Station Power

2009-04-12T11:44:00.000+05:30

The International Space Station is able to host three additional space dwellers thanks to the combined efforts of NASA's STS-119 astronauts and the Expedition 18 crew.

Space shuttle Discovery races toward space on mission STS-119. Photo credit: NASA/Sandra Joseph, Kevin O'Connell › High-res Image

At 7:43 p.m. EDT on March 15, 2009, space shuttle Discovery lifted off into a cloudless twilight sky over NASA's Kennedy Space Center in Florida. Secured in Discovery's payload bay was the S6 truss, a final set of U.S. solar arrays and a distillation assembly to get the station’s water recycling system up to full operation.

Veteran astronaut Lee Archambault commanded the crew of seven, which included Pilot Tony Antonelli, Mission Specialists Joseph Acaba, Steve Swanson, Richard Arnold, John Phillips and Japan Aerospace Exploration Agency astronaut Koichi Wakata.

Although technical issues delayed liftoff for more than a month, the March 15 launch countdown proceeded smoothly. After reaching orbit, the crew members removed their orange flight suits and began the first of many tasks.

The shuttle's orbiter boom sensor system was used to examine the spacecraft's thermal protection system. Data from the heat shield inspection was transmitted to Earth where technicians combed the images for any debris damage that could have occurred during launch.
As the crew prepared the orbiter docking system for rendezvous with the station, spacesuits were inspected for the mission's three spacewalks. Archambault deftly guided the spacecraft through a "backflip" maneuver, allowing the station’s Expedition 18 Commander Michael Fincke and Flight Engineer Sandra Magnus to take photos of Discovery's heat shield.

Once docked with the station, the hatches opened between the two spacecraft. After a hearty greeting from the station crew, Wakata officially replaced Magnus as flight engineer aboard the orbital scientific complex.

Then, preparations for the first spacewalk went into high gear. Phillips and Magnus used the station's robotic Canadarm2 to grapple the 31,000-pound, 45-foot-long S6 truss segment carefully out of the shuttle's payload bay and over to the shuttle's robotic arm operated by Antonelli and Acaba.

Mission Specialist Richard Arnold participates in the third spacewalk as construction and maintenance continue on the International Space Station. Photo credit: NASA/JSC
› High-res Image

Swanson and Arnold were first to set foot out in space to install the final segment of the station's backbone and solar arrays. Their task was completed successfully in about 6 1/2 hours.

With the unfurling of two, one acre-sized "wings," the orbiting outpost now is able to draw on 120 kilowatts of usable electricity and its capacity to perform science experiments has doubled.

President Barack Obama is joined by members of Congress, including former astronaut Sen. Bill Nelson, and school children as he talks with astronauts on the International Space Station from the Roosevelt Room at the White House. Photo credit: White House Photo/Pete Souza
› High-res Image

After the successful deployment of the new solar arrays, Fincke and Magnus replaced a failed distillation unit on the complex's urine processor and water purification recycling system.

The newly activated system was put through its paces and 15 pounds of reclaimed drinking water was collected and returned to Earth aboard Discovery. It will be analyzed before station crew members are given the go-ahead to drink the recycled water.

The second spacewalk performed by Swanson and Acaba took about 6 1/2-hours. The space outing was dedicated to preparing a work site for new batteries that will be delivered on space shuttle Endeavour's STS-127 mission, and installation of a Global Positioning System antenna on Japan's Kibo laboratory. This was Acaba's first venture into the expanse of space.

The third and final spacewalk of the STS-119 mission had Acaba and Arnold relocating one of two crew equipment carts from one side of the mobile transporter to the other. This move provides clearance for assembly tasks on shuttle Endeavour's upcoming STS-127 mission including attachment of the Japanese Exposed Facility onto its science laboratory.

On the final day at the outpost, the shuttle and station crews gathered in the Harmony module for a long distance phone call from President Barack Obama. The president, school children and congressional members quizzed the 10 crew members about their mission and what life is like in space. Later, the crew members turned their attention to last-minute checklist items.

With Launch Complex 39's Vehicle Assembly Building as backdrop, space shuttle Discovery touches down on Runway 15 at NASA's Kennedy Space Center in Florida. Photo credit: NASA/Chuck Tintera
› High-res Image

With the complex mission behind them, it was time to say farewell to the Expedition 18 crew members. After 129 days aboard the station, Magnus boarded Discovery for a ride home.

After undocking, the astronauts performed one last inspection of Discovery's thermal protection system and began their journey back to Earth.

The first landing opportunity at Kennedy was waved off because of high wind. With one more spin around the planet, the wind lessened and mission control gave Discovery the "go" for deorbit burn. The shuttle glided to a perfect landing at Kennedy's Shuttle Landing Facility at 3:14 p.m. EDT on March 28, successfully completing NASA's 13-day, STS-119 mission.

The crew members returned to Kennedy's crew quarters for a family reunion and medical checkup. The next day, the crew flew back to NASA's Johnson Space Center in Houston where they were honored with a homecoming celebration at nearby Ellington Field.

With the International Space Station "powered-up," the stage is set for future assembly tasks, scientific experiments and NASA's upcoming space shuttle missions.

NASA's Kepler Spacecraft Arrives in Florida

2009-01-29T09:41:00.000+05:30

NASA's Kepler Spacecraft Arrives in Florida

Photo credit: NASA/Kim Shiflett

The Kepler flight segment arrived at the Astrotech Space Operations Facility in Titusville, Fla. on Jan. 6 for launch processing. To view video of the arrival go to Kepler spacecraft arrives in Florida. To view additional photos of the Kepler launch vehicle visit the KSC photo page.

Landing Practice, Comm Checks and Shuttle Installs on Tap for Wednesday

2009-01-29T09:28:00.000+05:30

|Today's activities for the STS-119 crew members include administrative work and briefings at NASA's Johnson Space Center in Houston.

Later in the day, Commander Lee Archambault and Pilot Tony Antonelli will fly to White Sands Space Harbor in Las Cruces, N.M., to practice landing techniques in NASA's shuttle training aircraft.

At NASA's Kennedy Space Center in Florida, engineers have wrapped up communication checks between shuttle landing sites -- Dryden Flight Research Center in Edwards, Calif., White Sands, Johnson and Kennedy.

Meanwhile, technicians are preparing to install space shuttle Discovery's gaseous hydrogen flow control valves, set to arrive today. The new valve is meant to synchronize the gas pressure between the external fuel tank and the engines, creating an even flow.

Technicians also are performing the solid rocket booster debris containment modification and work is expected to be complete today. This modification is projected to make the bolts that hold down the boosters on the mobile launcher platform safely fall back to the launch pad and away from the spacecraft at liftoff.

On Feb. 3, NASA managers will meet at Kennedy for the executive-level Flight Readiness Review to discuss the preparedness of Discovery and the ground teams for launch. An announcement will be made and broadcast on NASA TV at the conclusion of the meeting to set the mission's official launch date.

Image: STS-119 Mission Specialist Steve Swanson dons a training version of the Extravehicular Mobility Unit spacesuit prior to being submerged in the waters of the Neutral Buoyancy Laboratory near NASA's Johnson Space Center in Houston. Photo credit: NASA/JSC
› View High-res Image
› Meet the STS-119 Crew
› Mission Overview

Space shuttle Discovery's STS-119 crew is set to fly the S6 truss segment and install the final set of power-generating solar arrays to the International Space Station.

The S6 truss, with its set of large U.S. solar arrays, will complete the backbone of the station and provide one-fourth of the total power needed to support a crew of six.

The two solar array wings each have 115-foot-long arrays, for a total wing span of 240 feet. They will generate 66 kilowatts of electricity -- enough to provide about 30 2,800-square-foot homes with power.

Commander Lee Archambault will lead Discovery's crew of seven, along with Pilot Tony Antonelli, and Mission Specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold and Japan Aerospace Exploration Agency astronaut Koichi Wakata.

Wakata will replace Expedition 18 Flight Engineer Sandra Magnus, who will return to Earth with the STS-119 crew. Wakata will serve as a flight engineer for Expeditions 18 and 19, and return to Earth with the STS-127 crew.

Discovery's STS-119 mission to the International Space Station is targeted to lift off at 7:32 a.m. EST, Feb. 12.

Additional Resources
› STS-119 Fact Sheet (562 Kb PDF)
› STS-119 Press Kit (4.9 Mb PDF)

2009-01-29T09:24:00.000+05:30

Image above: In the Astrotech Payload Processing Facility at Vandenberg Air Force Base in California, preparations are under way to fuel NASA's Orbiting Carbon Observatory, or OCO, with hydrazine thruster control propellant. Image credit: NASA/Robert Hargreaves Jr., VAFB › View Hi-Res Image

In processing activities on the Taurus launch vehicle in Building 1555 on north Vandenberg Air Force Base in California, thermal blanket and avionics subsystem installation is under way. Stage 1 is planned to be mated to Stage 2 between Jan. 24 and Jan. 26. Flight Simulation No. two is currently planned for Jan. 27. Flight Simulation No. 3 is currently planned for Feb. 11.

Stage 0, the stage providing the initial liftoff thrust, will be hoisted into position at the launch pad on Jan. 30. The spacecraft will be encapsulated into the payload fairing on Feb. 7. The spacecraft is planned to be integrated with the Taurus third stage on Feb. 3. Finally, the payload/upper launch vehicle integrated stack is planned to be hoisted atop Stage 0 on Feb. 16.

Launch Links:
› Launch Vehicle Status Reports
› OCO Spacecraft and Rocket Overview (PDF)

NASA's Carbon-Sniffing Satellite Sleuth Arrives at Launch Site

2009-01-29T09:22:00.001+05:30

|PASADENA, Calif. – NASA's first spacecraft dedicated to studying carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth's climate, has arrived at Vandenberg Air Force Base, Calif., to begin final launch preparations.

The Orbiting Carbon Observatory arrived Tues., Nov. 11, at its launch site on California's central coast after completing a cross-country trip by truck from its manufacturer, Orbital Sciences Corp. in Dulles, Va. The spacecraft left Orbital on Nov. 8. After final tests, the spacecraft will be integrated onto an Orbital Sciences Taurus rocket in preparation for its planned January 2009 launch.

The observatory will help solve some of the lingering mysteries in our understanding of Earth's carbon cycle and its primary atmospheric component, carbon dioxide, a chemical compound that is produced both naturally and through human activities. Each year, humans release more than 30 billion tons of carbon dioxide into the atmosphere through the burning of fossil fuels. As much as 5.5 billion tons of additional carbon dioxide are released each year by biomass burning, forest fires and land-use practices such as "slash-and-burn" agriculture. These activities have increased atmospheric carbon dioxide levels by almost 20 percent during the past 50 years.

Greenhouse gases like carbon dioxide trap the sun's heat within Earth's atmosphere, warming it and keeping it at habitable temperatures. However, scientists have concluded that increases in carbon dioxide resulting from human activities have thrown Earth's natural carbon cycle out of balance, increasing global temperatures and changing the planet's climate.

While scientists have a good understanding of carbon dioxide emissions resulting from burning fossil fuels, their understanding of carbon dioxide from other human-produced and natural sources is relatively poor. They know from ground measurements that only 40 to 50 percent of the carbon humans emit remains in Earth's atmosphere; the other 50 to 60 percent, they believe, is absorbed by Earth's ocean and land plants.

Scientists do not know, however, precisely where the absorbed carbon dioxide from human emissions is stored, what natural processes are absorbing it, or whether those processes will continue to work to limit increases in atmospheric carbon dioxide in the future, as they do now. The observatory's space-based measurements of atmospheric carbon dioxide will have the precision, resolution and coverage needed to provide the first complete picture of both human and natural sources of carbon dioxide emissions. It will show the places where they are absorbed, known as "sinks," at regional scales everywhere on Earth. Its data will reduce uncertainties in forecasts of how much carbon dioxide is in the atmosphere and improve the accuracy of global climate change predictions.

The observatory's science instrument features three first-of-a-kind, high-resolution spectrometers that spread reflected sunlight into its various colors. By analyzing these spectra, scientists can detect what gases are in Earth's atmosphere and determine their amounts. The spectrometers are specifically tuned to measure the amount of reflected sunlight absorbed by carbon dioxide and molecular oxygen. These measurements will be analyzed to yield monthly estimates of atmospheric carbon dioxide over 1,000-square-kilometer (386-square-mile) regions of Earth's surface to an accuracy of 0.3 to 0.5 percent. Scientists will analyze these data using global atmospheric chemical transport models, similar to those used to predict the weather, to locate carbon dioxide sources and sinks.

The observatory will launch into a 705-kilometer (438-mile) near-polar, sun-synchronous orbit inclined 98.2 degrees to Earth's equator, mapping the globe once every 16 days. The mission is designed to last two years. It will fly in formation with the five other NASA missions that are part of the "A-Train," or afternoon constellation, of Earth Observing System satellites that cross the equator each day shortly after noon. This coordinated flight formation will enable researchers to correlate the observatory's data with data from the other NASA spacecraft, including nearly simultaneous carbon dioxide measurements from the Atmospheric Infrared Sounder instrument on NASA's Aqua satellite.

The Orbiting Carbon Observatory is a NASA Earth System Science Pathfinder Program mission managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for NASA's Science Mission Directorate in Washington. Orbital Sciences provides mission operations under JPL's leadership. Hamilton Sundstrand in Pomona, Calif., designed and built the observatory's science instrument. NASA's Launch Services Program at NASA's Kennedy Space Center in Florida is responsible for launch management. JPL is managed for NASA by the California Institute of Technology in Pasadena.

For more information about the Orbiting Carbon Observatory, visit: http://oco.jpl.nasa.gov .

STS-126 Mission

2008-10-01T15:18:00.001+05:30

Image above: These seven astronauts take a break from training to pose for the STS-126 crew portrait. Astronaut Christopher J. Ferguson, commander, is at center; and astronaut Eric A. Boe, pilot, is third from the right. Remaining crew members, pictured from left to right, are astronauts Sandra H. Magnus, Stephen G. Bowen, Donald R. Pettit, Robert S. (Shane) Kimbrough and Heidemarie M. Stefanyshyn-Piper, all mission specialists. Image credit: NASA

|Veteran space flier Navy Capt. Christopher J. Ferguson will command the STS-126 mission aboard Endeavour to deliver equipment to the International Space Station that will enable larger crews to reside aboard the complex. Air Force Lt. Col. Eric A. Boe will serve as the pilot. The mission specialists are Navy Capt. Stephen G. Bowen, Army Lt. Col. Robert S. Kimbrough, Navy Capt. Heidemarie M. Stefanyshyn-Piper and NASA astronauts Donald R. Pettit and Sandra H. Magnus.

Magnus will remain on the station, replacing Expedition 17/18 Flight Engineer Gregory E. Chamitoff, who returns to Earth with the STS-126 crew. Magnus will serve as a flight engineer and NASA science officer for Expedition 18. Magnus will return to Earth on shuttle mission STS-119.

Endeavour will carry a reusable logistics module that will hold supplies and equipment, including additional crew quarters, a second treadmill, equipment for the regenerative life support system and spare hardware.

STS-126 is the 27th shuttle mission to the International Space Station.

NASA Assigns Crew For Space Shuttle Discovery's Sts-129 Mission

2008-10-01T14:59:00.000+05:30

WASHINGTON -- NASA has assigned the crew for space shuttle Discovery's STS-129 mission. The flight will deliver two experiment racks to the International Space Station.

Marine Col. Charlie Hobaugh will command the mission, which is targeted to launch in October 2009. Navy Capt. Barry Wilmore will serve as the pilot. Mission Specialists are Robert Satcher, Navy Capt. Michael Foreman, Marine Lt. Col. Randy Bresnik and Leland Melvin. Wilmore, Satcher and Bresnik will be making their first trips to space.

The mission will return Canadian Space Agency astronaut and station crew member Robert Thirsk to Earth. This is slated to be the final space shuttle crew rotation flight to or from the space station.

Discovery will deliver parts to the space station, including two spare gyroscopes. The mission will feature four spacewalks.
Hobaugh flew as the pilot on STS-104 in 2001 and STS-118 in 2007. He was born in Bar Harbor, Maine. Hobaugh earned a bachelor's degree in aerospace engineering from the U.S. Naval Academy. He was selected as an astronaut in 1996.

Wilmore was born in Murfreesboro, Tenn., and grew up in Mt. Juliet. He has bachelor's and master's degrees in electrical engineering from Tennessee Technological University, and a master's degree in aviation systems from University of Tennessee. He was selected as an astronaut in 2000.

Foreman was born in Columbus, Ohio, but considers Wadsworth his hometown. He earned a bachelor's degree in aerospace engineering from the U.S. Naval Academy and a master's degree in aeronautical engineering from the U.S. Naval Postgraduate School. Foreman flew as a mission specialist on STS-123 in 2008 and performed three spacewalks. He was selected as an astronaut in 1998.

Satcher was selected as an astronaut in 2004. He earned a doctorate in chemical engineering from the Massachusetts Institute of Technology. He also is a graduate of Harvard Medical School. He was born in Hampton, Va.

Bresnik, also selected as an astronaut in 2004. He was born in Fort Knox, Ky., but considers Santa Monica, Calif., his hometown. Bresnik earned a bachelor's degree in mathematics from The Citadel and a master's degree in aviation systems from the University of Tennessee.
Melvin flew as a mission specialist on the STS-122 mission in 2008. He was born in Lynchburg, Va. Melvin earned a bachelor's degree in chemistry from the University of Richmond and a master's degree in materials science engineering from the University of Virginia. He was selected as an astronaut in 1998.

Thirsk will be concluding his long-duration stay on the station when STS-129 launches. He is scheduled to arrive at the complex in May 2009 aboard a Soyuz spacecraft and serve as a flight engineer during parts of Expeditions 20 and 21.

Video of the STS-129 crew members will air on NASA Television's Video File. For downlink and scheduling information and links to streaming video, visit:

http://www.nasa.gov/ntv

For complete astronaut biographical information, visit:

http://www.jsc.nasa.gov/Bios

For more information about NASA's Space Shuttle Program, visit:

http://www.nasa.gov/shuttle

NASA Mars Lander Scoops First Soil Sample for Laboratory Analysis

2008-06-07T18:08:00.000+05:30

NASA Mars Lander Scoops First Soil Sample for Laboratory Analysis
06.06.08 -- NASA's Phoenix Mars Lander made its first dig into Martian soil for science studies and is poised to deliver the scoopful to a laboratory instrument on the lander deck.
Full story
Listen to June 6 media telecon
Images for June 6 media telecon
Image 1 - Martian Soil Ready for Robotic Laboratory Analysis
Image 2 - Soil Sample Poised at TEGA Door
Image 3 - Dodo and Baby Bear Trenches

Next media telecon: Monday, June 9, 2 p.m. Eastern

Other ways to follow the mission:
› Share Your Comments with NASA
› Phoenix on the social-networking site Twitter

Latest Images

› Scale of Phoenix Optical Microscope Images
› Telltale animation
› Telltale animation

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Raw Images from Surface Stereo Imager

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Raw Image Mosaics

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NASA's Phoenix Mars Lander Ready to Gather Samples

2008-06-05T17:17:00.000+05:30

06.04.08 -- Two practice rounds of digging and dumping the clumpy soil at the Martian arctic site this week gave scientists and engineers confidence to begin using Phoenix's Robotic Arm to deliver soil samples to instruments on the lander deck.
› Full story
› Listen to Phoenix media telecon--June 3, 2008

Phoenix Media Telecons Scheduled - Posted June 4, 2008
NASA and the University of Arizona, Tucson, will hold media teleconferences at 2 p.m. EDT (11 a.m. PDT) on Thursday and Friday, June 5 and 6, to report on the latest news from NASA's Phoenix Mars Lander mission.

Briefing participants include Peter Smith, principal investigator, University of Arizona; and other mission team members.

To participate in the telecon, reporters must contact the JPL Media Relations Office at 818-354-5011 by 1:30 p.m. EDT (10:30 a.m. PDT) to obtain the call-in number and passcode.

You can also listen on www.nasa.gov/newsaudio

Other ways to follow the mission:
› Share Your Comments with NASA
› Phoenix on the social-networking site Twitter

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View Archives

Discovery's Crew Dresses for Liftoff

2008-05-31T22:42:00.000+05:30

Image above: NASA astronaut Greg Chamitoff puts on his launch and entry suit before heading out to the launch pad where space shuttle Discovery waits to take him to the International Space Station. Chamitoff will trade places with current station resident Garrett Reisman. Photo credit: NASA TV
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May 31
12:50 p.m. EDT
The six men and one woman who will fly space shuttle Discovery into orbit later today are putting on their spacesuits in preparation for launch. Each astronaut will don their helmets and gloves before technicians pump air into the suit to check for leaks.

Launch remains scheduled for 5:02 p.m. EDT from NASA's Kennedy Space Center in Florida. The countdown has encountered no technical problems and the afternoon forecast remains optimistic.

The astronauts are getting suited inside the same room astronauts have suited up for space since the Apollo program. Though outfitted with recliners, the room is also equipped with an air system used for leak checks. A team of specialists help the astronauts into the suits and perform the tests.

After the testing is finished, the seven crew members of Discovery will ride to the launch pad in the Astrovan.

STS-124 Mission Information
STS-124 Mission Summary (539 Kb PDF)
STS-124 Press Kit (7 Mb PDF)
Meet the Crew

Two Days Before Launch

2008-05-30T15:00:00.000+05:30

Image above: A technician loads replacement parts onto space shuttle Discovery for the International Space Station's toilet. The crews of Discovery and the station will install the new components during STS-124. Photo credit: NASA/Dimitri Gerondidakis
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May 29
New parts to fix an intermittent problem with the Russian toilet on the International Space Station arrived in the United States last night and were packed inside space shuttle Discovery well before dawn at NASA's Kennedy Space Center in Florida.

The crew of Discovery and the residents of the International Space Station will install the new parts, including a pump, during the STS-124 mission that is scheduled to launch Saturday at 5:02 p.m. EDT. The three station residents already in orbit currently are using alternatives to the toilet.

The main toilet on the station works for solid waste disposal but requires additional steps for liquid waste. It also takes two crew members and 10 minutes of maintenance after three flushes, said Kirk Shireman, deputy International Space Station program manager.

"It is very inconvenient at this time because it requires a lot of manual intervention," Shireman said.

The good news for the station is that there are no trouble signs for Discovery as it nears launch day.

"The vehicle and the crew and the weather and the (launch) team are all ready to go," said LeRoy Cain, chairman of the Mission Management Team, the group that oversees all aspects of the flight.

The weather forecast calls for an 80 percent chance of acceptable conditions at launch time, said Kathy Winters, shuttle weather officer.

"We're going to definitely have good weather," she said.

Discovery's 14-day flight will carry the largest payload so far to the station and includes three spacewalks. It is the second of three missions that will launch components to complete the Japan Aerospace Exploration Agency's Kibo laboratory. The crew will install Kibo's large Japanese Pressurized Module and Kibo's robotic arm system. Discovery also will deliver new station crew member Greg Chamitoff and bring back Flight Engineer Garrett Reisman, who will end a three-month stay aboard the outpost.

STS-124 Mission Information
› STS-124 Mission Summary (539 Kb PDF)
› STS-124 Press Kit (7 Mb PDF)
› Meet the Crew

GLAST :: Gama ray large area space telescope

2008-05-29T22:27:00.000+05:30

Launch Countdown Rehearsal Completed

The GLAST launch team assembled Wednesday in the Mission Director's Center at Cape Canaveral Air Force Station in Florida to conduct a dress rehearsal of the countdown. On Tuesday, technicians at the launch pad enclosed the GLAST spacecraft inside the fairing atop the Delta II rocket. The fairing serves to protect the spacecraft during its ride to space.

Image above: The first half of the payload fairing is moved into place around NASA's Gamma-Ray Large Area Space Telescope within the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Photo credit: NASA/Jim Grossmann
› View larger image
› View GLAST Image Gallery

Last week, the Flight Program Verification was conducted. This is an electrical and mechanical test of the rocket and spacecraft working together as a single, integrated system during countdown and launch milestones. With this test completed, spacecraft closeouts began. Technicians successfully completed the state-of-health checks for the spacecraft after its rollout from Astrotech to Cape Canaveral Air Force Station's Launch Pad 17-B on May 17.

Liftoff is set for no earlier than June 3 during a window that runs from 11:45 a.m. to 1:40 p.m. EDT.

GLAST: Exploring the Extreme Universe

NASA's Gamma-Ray Large Area Space Telescope (GLAST) is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. With a huge leap in all key capabilities, GLAST data will enable scientists to answer persistent questions across a broad range of topics, including supermassive black-hole systems, pulsars, the origin of cosmic rays, and searches for signals of new physics.

The mission is an astrophysics and particle physics partnership, developed by NASA in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

Countdown Clock Ticks Toward Saturday Launch

2008-05-29T13:15:00.000+05:30

Image above: Along with his STS-124 crewmates, Commander Mark Kelly arrives at the Shuttle Landing Facility at NASA's Kennedy Space Center aboard a T-38 jet trainer to get ready for launch. Photo credit: NASA/Kim Shiflett
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May 28
Countdown clocks at NASA's Kennedy Space Center in Florida began counting down from the T-43 hour mark at 3 p.m. EDT today. The launch team is tracking no issues as technicians continue preparing space shuttle Discovery for liftoff on May 31 at 5:02 p.m. EDT.

There is a possibility for isolated coastal showers on the morning of launch, but the weather forecast is good overall, with an 80% chance of favorable weather at liftoff time.

The seven-member STS-124 crew arrived at Kennedy at about 12:30 p.m. today, touching down at the Shuttle Landing Facility in T-38 jets. "Discovery's perched on the pad, Kibo is ready to go, the weather looks good, and we're about as ready as we could possibly be," said Mission Specialist Mike Fossum. "I think it's time to go fly."

Discovery's 14-day flight will carry the largest payload so far to the station and includes three spacewalks. It is the second of three missions that will launch components to complete the Japan Aerospace Exploration Agency's Kibo laboratory. The crew will install Kibo's large Japanese Pressurized Module and Kibo's robotic arm system. Discovery also will deliver new station crew member Greg Chamitoff and bring back Flight Engineer Garrett Reisman, who will end a three-month stay aboard the outpost.

STS-124 Mission Information
› STS-124 Mission Summary (539 Kb PDF)
› STS-124 Press Kit (7 Mb PDF)
› Meet the Crew

Phoenix Mars Lander

2008-05-26T17:45:00.000+05:30

Phoenix Reports Good Health After Mars Landing
05.25.08 -- A NASA spacecraft today sent pictures showing itself in good condition after making the first successful landing in a polar region of Mars.
Read more

On the Phoenix Blog: Landing Day
05.25.08 -- Follow the mission team's landing blog. Comments are no longer being taken.
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› Landing Press Kit (3Mb)

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Mission Management

The Phoenix mission is led by Peter Smith at the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and development partnership at Lockheed Martin, Denver. International contributions are provided by the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute. Further information about Phoenix is online at http://www.nasa.gov/phoenix and http://phoenix.lpl.arizona.edu .

___________________________________________________________________

|Mission Overview

Mars is a cold desert planet with no liquid water on its surface. But in the Martian arctic, water ice lurks just below ground level. Discoveries made by the Mars Odyssey Orbiter in 2002 show large amounts of subsurface water ice in the northern arctic plain. The Phoenix lander targets this circumpolar region using a robotic arm to dig through the protective top soil layer to the water ice below and ultimately, to bring both soil and water ice to the lander platform for sophisticated scientific analysis.

Image right: This map centered on the north pole of Mars is based on gamma rays from the element hydrogen -- mainly in the form of water ice. Regions of high ice content are shown in violet and blue and those low in ice content are shown in red. The very ice-rich region at the north pole is due to a permanent polar cap of water ice on the surface. Elsewhere in this region, the ice is buried under several to a few tens of centimeters of dry soil. Image Credit: NASA/JPL/UA
+ Larger view

The complement of the Phoenix spacecraft and its scientific instruments are ideally suited to uncover clues to the geologic history and biological potential of the Martian arctic. Phoenix will be the first mission to return data from either polar region providing an important contribution to the overall Mars science strategy "Follow the Water" and will be instrumental in achieving the four science goals of NASA's long-term Mars Exploration Program.

--Determine whether Life ever arose on Mars

--Characterize the Climate of Mars

--Characterize the Geology of Mars

--Prepare for Human Exploration

The Phoenix Mission has two bold objectives to support these goals, which are to (1) study the history of water in the Martian arctic and (2) search for evidence of a habitable zone and assess the biological potential of the ice-soil boundary.

Related information: + Mission objectives

Solar Variability: Striking a Balance with Climate Change

2008-05-11T17:04:00.000+05:30

05.07.08

> View the solar balance Web video
> Download the video
Credit: NASA Goddard Space Flight Center The sun has powered almost everything on Earth since life began, including its climate. The sun also delivers an annual and seasonal impact, changing the character of each hemisphere as Earth's orientation shifts through the year. Since the Industrial Revolution, however, new forces have begun to exert significant influence on Earth's climate.

"For the last 20 to 30 years, we believe greenhouse gases have been the dominant influence on recent climate change," said Robert Cahalan, climatologist at NASA’s Goddard Space Flight Center in Greenbelt, Md.

For the past three decades NASA scientists have investigated the unique relationship between the sun and Earth. Using space-based tools, like the Solar Radiation and Climate Experiment (SORCE), they have studied how much solar energy illuminates Earth, and explored what happens to that energy once it penetrates the atmosphere. The amount of energy that reaches Earth's outer atmosphere is called the total solar irradiance. Total solar irradiance is variable over many different timescales, ranging from seconds to centuries due to changes in solar activity.

The sun goes through roughly an 11-year cycle of activity, from stormy to quiet and back again. Solar activity often occurs near sunspots, dark regions on the sun caused by concentrated magnetic fields. The solar irradiance measurement is much higher during solar maximum, when sunspot cycle and solar activity is high, versus solar minimum, when the sun is quiet and there are usually no sunspots.

The sun radiates huge amounts of electromagnetic energy in all directions. Earth is only one small recipient of the sun's energy; the sun's rays extend far out into the solar system, illuminating all the other planets. Credit: NASA
> Larger image "The fluctuations in the solar cycle impacts Earth's global temperature by about 0.1 degree Celsius, slightly hotter during solar maximum and cooler during solar minimum," said Thomas Woods, solar scientist at the University of Colorado in Boulder. "The sun is currently at its minimum, and the next solar maximum is expected in 2012."

Using SORCE, scientists have learned that about 1,361 watts per square meter of solar energy reaches Earth's outermost atmosphere during the sun's quietest period. But when the sun is active, 1.3 watts per square meter (0.1 percent) more energy reaches Earth. "This TSI measurement is very important to climate models that are trying to assess Earth-based forces on climate change," said Cahalan.

Over the past century, Earth's average temperature has increased by approximately 0.6 degrees Celsius (1.1 degrees Fahrenheit). Solar heating accounts for about 0.15 C, or 25 percent, of this change, according to computer modeling results published by NASA Goddard Institute for Space Studies researcher David Rind in 2004. Earth's climate depends on the delicate balance between incoming solar radiation, outgoing thermal radiation and the composition of Earth's atmosphere. Even small changes in these parameters can affect climate. Around 30 percent of the solar energy that strikes Earth is reflected back into space. Clouds, atmospheric aerosols, snow, ice, sand, ocean surface and even rooftops play a role in deflecting the incoming rays. The remaining 70 percent of solar energy is absorbed by land, ocean, and atmosphere.

"Greenhouse gases block about 40 percent of outgoing thermal radiation that emanates from Earth," Woods said. The resulting imbalance between incoming solar radiation and outgoing thermal radiation will likely cause Earth to heat up over the next century, accelerating the melting polar ice caps, causing sea levels to rise and increasing the probability of more violent global weather patterns.

Non-Human Influences on Climate Change

Before the Industrial Age, the sun and volcanic eruptions were the major influences on Earth's climate change. Earth warmed and cooled in cycles. Major cool periods were ice ages, with the most recent ending about 11,000 years ago.

"Right now, we are in between major ice ages, in a period that has been called the Holocene,” said Cahalan. “Over recent decades, however, we have moved into a human-dominated climate that some have termed the Anthropocene. The major change in Earth's climate is now really dominated by human activity, which has never happened before."

The sun is relatively calm compared to other stars. "We don't know what the sun is going to do a hundred years from now," said Doug Rabin, a solar physicist at Goddard. "It could be considerably more active and therefore have more influence on Earth's climate."

Or, it could be calmer, creating a cooler climate on Earth similar to what happened in the late 17th century. Almost no sunspots were observed on the sun's surface during the period from 1650 to 1715. This extended absence of solar activity may have been partly responsible for the Little Ice Age in Europe and may reflect cyclic or irregular changes in the sun's output over hundreds of years. During this period, winters in Europe were longer and colder by about 1 C than they are today.

Since then, there seems to have been on average a slow increase in solar activity. Unless we find a way to reduce the amount of greenhouse gases we put into the atmosphere, such as carbon dioxide from fossil fuel burning, the solar influence is not expected to dominate climate change. But the solar variations are expected to continue to modulate both warming and cooling trends at the level of 0.1 to 0.2 degrees Celsius (0.18 to 0.26 Fahrenheit) over many years.

Future Measurements of Solar Variability

For three decades, a suite of NASA and European Space Agency satellites have provided scientists with critical measurements of total solar irradiance. The Total Irradiance Monitor, also known as the TIM instrument, was launched in 2003 as part of the NASA’s SORCE mission, and provides irradiance measurements with state-of-the-art accuracy. TIM has been rebuilt as part of the Glory mission, scheduled to launch in 2009. Glory's TIM instrument will continue an uninterrupted 30-year record of solar irradiance measurements and will help researchers better understand the sun's direct and indirect effects on climate. Glory will also collect data on aerosols, one of the least understood pieces of the climate puzzle.

Related links:

> More on SORCE from NASA's Earth Observatory
> More on SORCE from NASA's Goddard Space Flight Center
> More on SORCE from the University of Colorado
> The University of Colorado's Laboratory for Atmospheric and Space Physics

Rani Gran
NASA's Goddard Space Flight Center

NASA at 50:

2008-05-11T16:49:00.000+05:30

|05.08.08

NASA LLRV in flight, 1967. NASA photo. President John F. Kennedy's 1961 challenge to put a man on the moon and return him safely to Earth by decade's end electrified much of the country, but it floored most NASA engineers.

Not that going into space was a new idea to engineers at NASA, or its predecessor, the National Advisory Committee for Aeronautics. NACA engineers had been discussing putting humans into space since the early 1950s. But contemplating orbital flight is not the same thing as planning for an excursion to the moon's surface.

Interestingly, two organizations were simultaneously thinking about the same thing: regardless of what vehicle NASA settled on to get to the moon, astronauts would need something to simulate, here on Earth, the descent to and landing on the moon. The two organizations were NASA's Flight Research Center at Edwards, Calif., and the Bell Aircraft Corp. in Niagara Falls, N.Y.

Among the challenges was simulating the moon's gravity, which is only a sixth of Earth's. How, in the early 1960s, are you going to do this with a wingless aircraft? What method will you use to negate five-sixths of the Earth's gravitational pull in flight? How will you compensate for the fuel you burn off while in flight? (Keep in mind the state of computing in 1962, and especially, of portable computers.)

And how are you going to reproduce the moon's lack of atmosphere right here on Earth? Flying in a vacuum is quite different from flying in an atmosphere, more different that you would expect, as the astronauts later attested. Even small wind gusts will affect a simulation like the one in question.

Apollo 11's Buzz Aldrin views an LLRV while visiting NASA Dryden in 2007. NASA photo.What NASA and Bell came up with was the Lunar Landing Research Vehicle, or LLRV. The LLRV – quickly dubbed the Flying Bedstead – was powered by a General Electric CF-700, the fan-jet version of the J-85 engine, mounted inside two gimbaled rings. The dual gimbals enabled the engine to provide true vertical thrust—perpendicular to the Earth's surface—while allowing the rest of the vehicle to rotate freely in pitch and roll.

Eight thrusters were fixed to the frame as lift rockets, capable of producing 500 pounds of thrust each. These were used for lift when flying a lunar landing simulation.

For maneuvering, the engineers chose 16 smaller thrusters, four at each corner of the vehicle. These were fired in pairs, one up and one down at opposite corners of the vehicle. Half of the 16 thrusters were adjustable on the ground to vary their output from 18 to 90 pounds thrust so engineers could experiment to find which setting was best suited for training.

The craft carried two fuels: JP-4 for the jet engine and hydrogen peroxide for the thrusters. The hydrogen peroxide was a 90 percent pure solution, and was pressurized with helium to ensure a constant flow to the thrusters.

Bell delivered the first LLRV to the Flight Research Center in the spring of 1964. The second vehicle followed not long after. Ground tests began once the first vehicle was uncrated and assembled, and in October of that year Joe Walker, the center's chief pilot, took the LLRV up for its first flight. The CF-700 engine could produce 4,200 pounds of thrust under ideal conditions, barely enough for a thrust-to-weight ratio of 1.05 to 1.

Perhaps more remarkable than anything else about it, the LLRV was a fly-by-wire aircraft — one of the very first — controlled by three analog computers. There was no mechanical backup control system of any kind, primarily because of weight considerations.

In preparation for the first flight the vehicle was towed to South Base at Edwards and covered with two tarpaulins. That night it snowed and when the crew arrived the next day there were eight inches of snow on the vehicle.

The flight tests at the Flight Research Center convinced NASA that the LLRV was a viable training tool, and the agency contracted with Bell for three additional vehicles. Built according to modifications made at the Flight Research Center to the two LLRVs, the three new vehicles were dubbed Lunar Landing Training Vehicles, or LLTVs.

Although the Apollo astronauts used other Lunar Lander simulators, to a man they all said later that the LLTV was the most realistic trainer. Neil Armstrong went so far as to say on his return that the LLTV was so good at simulating the lunar landing that he was entirely comfortable with what he was doing when he made his actual descent to the moon that memorable day in July 1969.

The second LLRV still resides at the Flight Research Center, now known as the NASA Dryden Flight Research Center. Meant to go to Houston to train Apollo astronauts as had the first LLRV and the three improved LLTVs, it never left the center. Instead, it was cannibalized for parts to support the training program at the Manned Spacecraft Center, now NASA's Johnson Space Center. The second LLRV underwent a partial restoration in the late 1990s for use in filming of the television mini-series "From the Earth to the Moon" about the Apollo program, and it is now an historical highlight during tours of NASA Dryden.

By Christian Gelzer
Chief Historian
NASA Dryden Flight Research Center

Expedition 17 launched

2008-04-22T22:35:00.000+05:30

Expedition 17 launched to the International Space Station on April 8, 2008. For the latest news and information on their mission, visit the main station page. + Read more

Image above: Cosmonaut Oleg D. Kononenko, Expedition 17 flight engineer representing Russia's Federal Space Agency, participates in an Extravehicular Mobility Unit (EMU) spacesuit fit check in the Space Station Airlock Test Article (SSATA) in the Crew Systems Laboratory at the Johnson Space Center. Cosmonaut Sergei A. Volkov, commander representing Russia's Federal Space Agency, assisted Kononenko. Image credit: NASA

Crew Profiles

Commander Sergei Volkov

Cosmonaut Sergei Volkov will command the Expedition 17 mission, his first spaceflight. Since January 2000, he has been part of a group of test cosmonauts training for missions to the International Space Station.
› Biography →
› Interview
Flight Engineer Oleg Kononenko

Cosmonaut Oleg Kononenko will serve Expedition 17 as a flight engineer. He was qualified for flight assignment as a test cosmonaut in 1998. This is Kononenko's first space flight.
› Biography →
› Interview
Flight Engineer Garrett E. Reisman

Astronaut Garrett Reisman will fly to the station aboard space shuttle Endeavour on STS-123 and join Expedition 16 as a flight engineer. He will stay aboard the station to join Expedition 17. In 2003 Reisman worked underwater as a crew member for NEEMO 5. This is Reisman's first space flight.
› Biography →
› Interview
Flight Engineer Gregory E. Chamitoff

Astronaut Gregory E. Chamitoff is scheduled to fly to the station on shuttle mission STS-124 and return to Earth aboard STS-126. Chamitoff previously served as a crew member on the Aquarius undersea research habitat for nine days as part of the NEEMO 3 mission. This is Chamitoff's first space flight.
› Biography →
› Interview
Spaceflight Participant So-yeon Yi

South Korean astronaut So-yeon Yi will launch to the International Space Station on a Soyuz spacecraft with the Expedition 17 crew and return on a Soyuz spacecraft with the Expedition 16 crew under a commercial agreement with the Russian Federal Space Agency.

Expedition 16 Lands Safely; New Crew Performs Reboost Test

2008-04-22T22:16:00.000+05:30

Image : Expedition 16 Commander Peggy Whitson waves to a crowd of well wishers from the top of the airplane steps as she arrives at Chkalovsky airport, Star City along with Flight Engineer and Soyuz Commander Yuri Malenchenko and South Korean So-yeon Yi. Whitson, Malechenko and Yi landed their Soyuz TMA-11 spacecraft on April 19, 2008 in central Kazakhstan to complete 192 days in space for Whitson and Malenchenko and 11 days in orbit for Yi. Photo Credit: (NASA/Bill Ingalls)
+ View high-res

The Expedition 16 crew members are in good spirits after they safely landed their Soyuz spacecraft Saturday in the steppes of Kazakhstan at approximately 4:30 a.m. EDT. Spaceflight participant So-yeon Yi also returned to Earth aboard the Soyuz. The landing was about 295 miles from the expected landing site, delaying the recovery forces' arrival to the spacecraft by approximately 45 minutes.

Now at Star City, Russia, Astronaut Peggy Whitson and cosmonaut Yuri Malenchenko launched to the International Space Station on Oct. 10, 2007, and spent 192 days in space. They will spend the next several weeks there for standard debriefs and rehabilitation.

The Russian Federal Space Agency, Roskosmos, and Energia representatives have established a commission to investigate the cause of the ballistic reentry. This was the second consecutive ballistic entry for a Soyuz spacecraft and the third Soyuz ballistic entry in the history of the International Space Station.

+ Read more about the Expedition 16 landing

On Monday, Expedition 17 crew members conducted a test of the Jules Verne Automated Transfer Vehicle's reboost engines. Those engines can be used to lift the orbit of the station to a higher altitude while the cargo craft is docked to the orbiting complex. Another test will be conducted on Thursday, setting the station in the proper configuration for the arrival of space shuttle Discovery on the STS-124 mission in June.

Flight Engineer Garrett Reisman also conducted a ham radio session with patients of the Arnold Palmer Hospital for Children in Orlando, Fla.

+ Read more about Expedition 17
+ Read more about Expedition 16
+ View crew timelines
+ Read more about the European Automated Transfer Vehicle

International Space Station Calendar

Find out when the U.S. launched its first satellite and other historical tidbits with photos that highlight 50 years of NASA milestones and a decade of space station assembly.

+ Download calendar (8.6 Mb PDF)

Spotlighting to the Supernova_Xplosions

2008-04-07T22:58:00.000+05:30

The below two photographs are of the same part of the sky. The photo on the left was taken in 1987 during the supernova explosion of SN 1987A, while the right hand photo was taken beforehand. Supernovae are one of the most energetic explosions in nature, making them like a 10²⁸ megaton bomb (i.e., a few octillion nuclear warheads).

"After" and "Before" pictures of Supernova 1987A

Types of Supernovae

Supernovae are divided into two basic physical types:

Type Ia.

These result from some binary star systems in which a carbon-oxygen white dwarf is accreting matter from a companion. (What kind of companion star is best suited to produce Type Ia supernovae is hotly debated.) In a popular scenario, so much mass piles up on the white dwarf that its core reaches a critical density of 2 x 10⁹ g/cm³. This is enough to result in an uncontrolled fusion of carbon and oxygen, thus detonating the star.

Type II.

These supernovae occur at the end of a massive star's lifetime, when its nuclear fuel is exhausted and it is no longer supported by the release of nuclear energy. If the star's iron core is massive enough then it will collapse and become a supernova.

However, these types of supernovae were originally classified based on the existence of hydrogen spectral lines: Type Ia do not show hydrogen lines, while Type II do.

In general this observational classification agrees with the physical classification outlined above, because massive stars have atmospheres (made of mostly hydrogen) while white dwarf stars are bare. However, if the original star was so massive that its strong stellar wind had already blown off the hydrogen from its atmosphere by the time of the explosion, then it too will not show hydrogen spectral lines. These supernovae are often called Type Ib supernovae, despite really being part of the Type II class of supernovae. Looking at this discrepancy between our modern classification (based on a true difference in how supernovae explode), and the historical classification (based on early observations) shows how classifications in science can change over time as we better understand the natural world.

What Causes a Star to Blow Up?

Gravity gives the supernova its energy. For Type II supernovae, mass flows into the core by the continued making of iron from nuclear fusion. Once the core has gained so much mass that it cannot withstand its own weight, the core implodes. This implosion can usually be brought to a halt by neutrons, the only things in nature that can stop such a gravitational collapse. Even neutrons sometimes fail depending on the mass of the star's core. When the collapse is abruptly stopped by the neutrons, matter bounces off the hard iron core, thus turning the implosion into an explosion: ka-BOOM!!!

For Type Ia supernova, the energy comes from the run-away fusion of carbon and oxygen in the core of the white dwarf.

Where Does the Core Go?

When the core is lighter than about 5 solar masses, it is believed that the neutrons are successful in halting the collapse of the star creating a neutron star. Neutron stars can sometimes be observed as pulsars or X-ray Binaries.

When the core is heavier (M_core > ~ 5 solar masses), nothing in the known universe is able to stop the core collapse, so the core completely falls into itself, creating a black hole, an object so dense that even light cannot escape its gravitational grasp.

To understand the phenomenon of core collapse better, consider an analogy to a rocket escaping the Earth's gravity. According to Newton's law of gravity, the energy it takes to completely separate two things is given by:

E = G M m / r

where G is the Gravitational constant, M is the mass of the Earth, m is the mass of the rocket and r is the distance between them (the radius of the Earth). When the rocket is shot off at a given velocity v, its energy is:

E = 1/2 m v²

For the rocket to escape the Earth's gravitational field, this energy must be as least as great as the gravitational energy described in the first equation. Thus, to determine if the rocket will completely break free from the Earth's grasp, we set the two equations equal to one another and solve for v:

v = ( 2 G M / r )^1/2

This result is called the escape velocity. For the Earth, the escape velocity is 11 km/sec.

Next imagine a star's central core in the role of the Earth in the above analogy. Consider what would happen if during the core collapse, the central core became so dense (i.e., the radius became very small while its mass stays the same) that something would have to travel faster than light to escape. Whenever this phenomenon occurs (i.e., M_core > ~ 5 solar masses), the supernova creates a black hole from the core of the original star. Now the escape velocity greater than the speed of light -- 300,000 km/sec.

Where Does Most of the Star Go?

The core is only the very small center of an extremely large star that for many millions of years had been making many (but not all) of the elements that we find here on Earth. When a star's core collapses, an enormous blast wave is created with the energy of about 10²⁸ mega-tons. This blast wave plows the star's atmosphere into interstellar space, propelling the elements created in the explosion outward as the star becomes a supernova remnant.

Are We Made of Stardust?

Many of the more common elements were made through nuclear fusion in the cores of stars, but many were not as well. Because nuclear fusion reactions that make elements heavier than iron require more energy than they give off, such reactions do not occur under stable conditions that occur in stars. Supernovae, on the other hand, are not stable, so they can make these heavy elements beyond iron.

In addition to making elements, supernovae scatter the elements (made by both the star and supernova) out in to the interstellar medium. These are the elements that make up stars, planets and everything on Earth -- including ourselves.

How Often Do Supernovae Occur?

Although many supernovae have been seen in nearby galaxies, supernova explosions are relatively rare events in our own Galaxy, happening once a century or so on average. The last nearby supernova explosion occurred in 1680, It was thought to be just a normal star at the time, but it caused a discrepancy in the observer's star catalogue which historians finally resolved 300 years later, after the supernova remnant (Cassiopeia A) was discovered and its age estimated. Before 1680, the two most recent supernova explosions were observed by the great astronomers Tycho and Kepler in 1572 and 1604 respectively.

In 1987 there was a supernova explosion in the Large Magellanic Cloud, a companion galaxy to the Milky Way. Supernova 1987A, which is shown at the top of the page, is close enough to continuously observe as it changes over time thus greatly expanding astronomers' understanding of this fascinating phenomenon.

[For further reading...A good book written for the non-scientist is:The Supernova Story, by Laurence A. Marschall, Â©1988, Plenum Press, ISBN:0306429551.]

Spotlighting to the BlackHoles

2008-04-07T22:37:00.000+05:30

|Einstein's general theory of relativity describes gravity as a curvature of spacetime caused by the presence of matter. If the curvature is fairly weak, Newton's laws of gravity can explain most of what is observed. For example, the regular motions of the planets. Very massive or dense objects generate much stronger gravity. The most compact objects imaginable are predicted by General Relativity to have such strong gravity that nothing, not even light, can escape their grip.

Scientists today call such an object a black hole. Why black? Though the history of the term is interesting, the main reason is that no light can escape from inside a black hole: it has, in effect, disappeared from the visible universe.

Do black holes actually exist? Most physicists believe they do, basing their views on a growing body of observations. In fact, present theories of how the cosmos began rest in part on Einstein's work and predict the existence of both singularities and the black holes that contain them. Yet Einstein himself vigorously denied their reality, believing, as did most of his contemporaries, that black holes were a mere mathematical curiosity. He died in 1955, before the term "black hole" was coined or understood and observational evidence for black holes began to mount.

Why Study Black Holes?

Here are some good reasons:

Human curiosity: they are among the most bizzare objects thought to exist in the universe.
They should be strong sources of gravitational waves.
As such, black holes should reveal much about gravity, a fundamental force in the cosmos.
Confirmation that they exist will strengthen confidence in current models of cosmic evolution, from the Big Bang to the present universe.

Black holes are all very well in theory, but if they really exist, how do they form?

General Relativity[Einstein's 1916 paper on General Relativity]

In 1916 Einstein expanded his Special Theory to include the effect of gravitation on the shape of space and the flow of time.This theory, referred to as the General Theory of Relativity, proposed that matter causes space to curve.

Picture a bowling ball on a stretched rubber sheet.

The large ball will cause a deformation in the sheet's surface. A baseball dropped onto the sheet will roll toward the bowling ball. Einstein theorized that smaller masses travel toward larger masses not because they are "attracted" by a mysterious force, but because the smaller objects travel through space that is warped by the larger object. Physicists illustrate this idea using embedding diagrams.

Contrary to appearances, an embedding diagram does not depict the three-dimensional "space" of our everyday experience. Rather it shows how a 2D slice through familiar 3D space is curved downwards when embedded in flattened hyperspace. We cannot fully envision this hyperspace; it contains seven dimensions, including one for time! Flattening it to 3D allows us to represent the curvature. Embedding diagrams can help us visualize the implications of Einstein's General Theory of Relativity.

The Flow of Spacetime

Another way of thinking of the curvature of spacetime was elegantly described by Hans von Baeyer. In a prize-winning essay he conceives of spacetime as an invisible stream flowing ever onward, bending in response to objects in it s path, carrying everything in the universe along its twists and turns.

This is a basic postulate of the Theory of General Relativity. It states that a uniform gravitational field (like that near the Earth) is equivalent to a uniform acceleration.

What this means, in effect, is that a person cannot tell the difference between (a) standing on the Earth, feeling the effects of gravity as a downward pull and (b) standing in a very smooth elevator that is accelerating upwards at just the right rate of exactly 32 feet per second squared.

In both cases, a person would feel the same downward pull of gravity. Einstein asserted that these effects were actually the same. A far cry from Newton's view of gravity as a force acting at a distance!

Gravitational Time Dilation

Einstein's Special Theory of Relativity predicted that time does not flow at a fixed rate: moving clocks appear to tick more slowly relative to their stationary counterparts. But this effect only becomes really significant at very high velocities that app roach the speed of light.

When "generalized" to include gravitation, the equations of relativity predict that gravity, or the curvature of spacetime by matter, not only stretches or shrinks distances (depending on their direction with respect to the gravitational field) but also w ill appear to slow down or "dilate" the flow of time.

In most circumstances in the universe, such time dilation is miniscule, but it can become very significant when spacetime is curved by a massive object such as a black hole. For example, an observer far from a black hole would observe time passing extremely slowly for an astronaut falling through the hole's boundary. In fact, the distant observer would never see the hapless victim actually fall in. His or her time, as measured by the observer, would appear to stand still. The slowing of time near a very simple black hole has been simulated on supercomputers at NCSA and visualized in a computer-generated animation.

Grappling With Relativity

In the decade after its publication in 1916, Einstein's Theory of General Relativity led to a burst of experimental activity in which many of its predictions were vindicated. These predictions were encapsulated in a series of field equations that laid the foundation for all subsequent research into relativity and partly for modern cosmology as well.

The Math Behind Einstein's Vision

The mathematics behind the Einstein Field Equations not only presented a formidable challenge to solve, but also led to seemingly bizarre consequences, particularly those of black holes and gravitational waves. At the time they were postulated, both were dismissed by many experts as mathematical aberrations. It remains to be seen whether either truly exist.

[For further reading please go to nasa.gov

▐Krishnaap.com

Expeditions of Nasa

2008-04-01T22:42:00.000+05:30

Expedition 17

Commander Sergei Volkov, Flight Engineer Oleg Kononenko and spaceflight participant So-yeon Yi are scheduled to launch to the station on April 8, 2008. Garrett E. Reisman and Gregory E. Chamitoff will serve as flight engineers during Expedition 17.

Expedition 16

Commander Peggy A. Whitson, Flight Engineer Yuri Malenchenko and spaceflight participant Sheikh Muszaphar Shukor launched to the station on October 10, 2007. Clayton Anderson, Daniel M. Tani, LÃ©opold Eyharts and Garrett E. Reisman will serve as flight engineers during Expedition 16.

Expedition 15

Commander Fyodor Yurchikhin and Flight Engineer Oleg Kotov began Expedition 15 on April 7, 2007. Sunita Williams and Clayton Anderson have served as flight engineers during Expedition 15.

Expedition 14

Commander Michael Lopez-Alegria and Flight Engineer Mikhail Tyurin began their Expedition in September 2006. European Space Agency astronaut Thomas Reiter remained with Expedition 14 after Expedition 13 departed from the station. Flight Engineer Sunita Williams replaced Reiter when Space Shuttle Discovery dropped her off on mission STS-116.

Expedition 13

Commander Pavel Vinogradov and Flight Engineer Jeff Williams lived in space for 183 days. They began their mission in March 2006 and returned to Earth in September 2006. European Space Agency astronaut Thomas Reiter joined the crew in July 2006 returning the station to a three-person crew.

Expedition 12

Commander William McArthur and Flight Engineer Valery Tokarev served aboard the International Space Station from October 2005 through April 2006. McArthur had visited the station in October 2000 during shuttle mission STS-92.

Expedition 11

Commander Sergei Krikalev and Flight Engineer John Phillips lived and worked aboard the International Space Station from April 2005 through October 2005. Krikalev had served on the station previously as part of the Expedition 1 crew, and Phillips visited the station as part of the STS-100 crew.

Expedition

Commander Leroy Chiao and Flight Engineer Salizhan Sharipov began their mission aboard the International Space Station in October 2004. They returned to Earth in April 2005.

Expedition

Commander Gennady Padalka and Flight Engineer Mike Fincke performed four spacewalks during their mission. They stayed aboard the International Space Station from April 2004 through October 2004.

Expedition

Commander Michael Foale and Flight Engineer Alexander Kaleri lived in space for 195 days. They began their mission in October 2003 and returned to Earth in April 2004.

Expedition

Commander Yuri Malenchenko and Flight Engineer Ed Lu journeyed to the International Space Station aboard a Soyuz rocket. They became the first two-person station crew and stayed in orbit from April 2003 until October 2003.

Expedition

Commander Kenneth Bowersox and Flight Engineers Donald Pettit and Nikolai Budarin lived and worked aboard the International Space Station from November 2002 through May 2003. Space Shuttle Columbia and the STS-107 crew were lost in February 2003.

Expedition

Commander Valery Korzun and Flight Engineers Peggy Whitson and Sergei Treschev resided aboard the International Space Station from June 2002 through December 2002. Whitson became the first NASA Space Station Science Officer.

Expedition

Expedition 4 was Commander Yury Onufrienko's second long-duration flight. Flight Engineers Carl Walz and Dan Bursch broke the U.S. space flight endurance record with 196 days in space. Their mission lasted from December 2001 until June 2002.

Expedition

Commander Frank Culbertson and Flight Engineers Vladimir Dezhurov and Mikhail Tyurin occupied the International Space Station for 117 days from August 2001 through December 2001.

Expedition

Commander Yury Usachev and Flight Engineers James Voss and Susan Helms occupied the International Space Station for 148 days. They began their mission in March 2001 and returned to Earth in August 2001.

Expedition

Commander William Shepherd and Flight Engineers Yuri Gidzenko and Sergei Krikalev were the first residents of the International Space Station. Their mission lasted from October 2000 to March 2001.

NASA Launches Airborne Study of Arctic Atmosphere, Air Pollution

2008-04-01T22:41:00.000+05:30

Image above: Chris Cantrell and Becky Anderson of the National Center for Atmospheric Research, Boulder, Colo., assess an instrumentâs operation on NASA's DC-8 aircraft during preparations for the ARCTAS field campaign. Credit: NASA

The recent decline of Arctic sea ice is one indication that this region is undergoing significant environmental changes related to climate warming. To investigate the atmosphere's role in this climate-sensitive region, NASA and its partners have begun the most extensive field campaign ever to study the chemistry of the Arctic's lower atmosphere.

The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign is poised to help scientists identify how air pollution contributes to climate changes in the Arctic.

> Read more

The Jules Verne Approaches the Station

2008-04-01T22:33:00.000+05:30

Image above: The Jules Verne Automated Transfer Vehicle approaches the International Space Station. Credit: NASA TV

The Jules Verne Automated Transfer Vehicle approached the International Space Station on Monday for its "Demo Day 2" practice maneuvers. It moved to within 36 feet of the Zvezda Service Module in a rehearsal for docking on Thursday.

The Jules Verne reached its closest point to the station at 12:38 p.m. EDT, at which time it was commanded by the crew to retreat to a point 62 feet away. From there it executed an "escape" command to depart the station for its three-day phasing prior to final approach and docking around 10:41 a.m. Thursday.

During its first approach Saturday, the ATV fired its engines several times to bring it approximately two miles from the station. Once in position, the Jules Verne conducted thruster firings and other systems tests before it pulled back into a phasing orbit.

+ View crew timelines
+ Read more about Expedition 16
+ Read more about the European Automated Transfer Vehicle

Dedication and Perspiration Builds The Next Generation Life Support System

2007-09-15T22:44:00.000+05:30

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

For almost 20 years, NASA engineers at Marshall have led the design and development of the International Space Station life support system, called the Regenerative Environmental Control and Life Support System, or ECLSS. 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.

Image above, right: Marshall Center employees exercise on bikes and treadmills and other equipment inside a mockup of an International Space Station module to test part of the Exploration Water Recovery System life support system that could someday provide drinking water to people living on the moon. Image credit: NASA/MSFC

The Clean Water Diary
Read about the experiences of one volunteer as she participates in the Exploration Water Recovery System test at the Marshall Center. In the end, will she drink it?

+ Week 1: Do I Have to Drink It?

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. The system reclaims urine and condensation from perspiration and through a series of treatment processes, creates water clean enough to drink.

"To support human life on the moon, weâll 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 minimize the amount of materials we need to bring up to space to support future crews."

For the next six weeks, Marshall will test this new hardware. The goal of this test is to examine the efficiency of the water processor to remove different types of contaminants from the waste water. 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 are participating in the Exploration Water Recovery System test. For the study, 20 employees exercise 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. Individuals also "donate" urine as part of this test.

Image to right: The Exploration Water Recovery System captures perspiration and urine and through a series of rigorous treatment processes creates clean water. On top of the rack there are two cylinders: the one on the right "boils" water out of the solution leaving most of the contaminants behind and the other, on the left, captures and concentrates the contaminants. Further treatment processes "polish" the water, shown in the filter element in the lower left of the rack, until it meets stringent purity standards for human use. Image credit: NASA/MSFC

Before stepping into the module for a session, participants are provided with a white T-shirt to wear, a towel for drying off and a bottle of water or a sports energy drink to consume as they exercise. They weigh-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 also brush their teeth, wipe themselves down with wet towels and the men even shave -- simulating the daily routine of a station crew member -- to get every bit of moisture into the atmosphere. Participants even microwave meals inside the module to generate water vapor and the aroma from the food.

Image to right: One of the test participants, Robert Engberg, hangs up his washcloth after a workout. Sopping wet T-shirts and used washcloths are left hanging inside overnight to evaporate more sweat out of them. Image credit: NASA/MSFC

"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."

Dauna Coulter, an avid runner and writer with Schafer Corporation supporting Marshallâs Office of Strategic Analysis and Communications, will journal her experiences participating in the test.

Contact: Jennifer Morcone, Marshall Space Flight Center
256.544.0034

Desert RATS Test Lunar Exploration Concepts

2007-09-15T22:33:00.000+05:30

As NASA prepares for future missions to the moon, work is already underway here on Earth to test the planetary rovers, robots and futuristic spacesuits needed for the journey.

Image Left: Two space suit engineers in the SCOUT (Science Crew Operations and Utility Testbed) rover head out to their field site. Credit: Blair Allen/NASA Edge.

Desert RATS (Research and Technology Studies) highlights the partnership between humans and robots in space exploration. This year's event field tested advanced concepts that may be used for missions to the moon, which NASA plans to begin by 2020. The tests took place in the Arizona desert near a site used to train for the first moon landings during the Apollo Program in the 1960s.

Engineers tested concepts for assembly of a lunar outpost, such as using robots and a lunar rover to perform a site survey and set up solar arrays and cables for power supply.

+ Video Podcast: On the Scene with the Desert RATS
+ Blog: NASA Edge Meets the RATS

More on NASA's Future Exploration Plans:
+ Administrator Michael Griffin: Why Explore Space?
+ The How and Why of Returning to the Moon | + View Videos
+ Video: Return to the Moon -- The Journey Begins Now
+ Constellation Program: Ares and Orion
+ Robotic Exploration

Global Exploration Strategy:
+ Global Exploration Strategy Framework, May 31, 2007
+ NASA Unveils Global Exploration Strategy, Lunar Architecture
+ Global Exploration Strategy Frequently Asked Questions
+ Dec. 4, 2006, Briefing Transcripts (76 Kb PDF)
+ Dec. 4, 2006, Briefing Charts (3.5 MB PDF)




		Apollo Pioneers Share Lessons Learned Apollo-era engineers visited NASA Headquarters in Washington on the 38th anniversary of the Apollo 11 moon landing. + Read More

		Camping on the Moon If you climbed a mountain so high its peak poked through Earth's atmosphere, you'd know what it will be like to camp on the moon. + Read More

		'Why Explore Space?' By Administrator Griffin Today, NASA is moving forward with a new focus for the manned space program: to go out beyond Earth orbit for purposes of human exploration and scientific discovery. + Read More

		Why The Moon? Why should we return to the moon? The global space community responded with six common areas of interest. + Read More

		2nd Space Exploration Conference Top leaders from industry, academia, NASA and other agencies meet to focus on implementing the Vision for Space Exploration. + Read More + Visit AIAA Conference Web Site

		Droids in the Desert Arizona tourists may think theyâve stumbled upon a science fiction movie set if they find themselves near the stateâs famed Meteor Crater in early September. + Read More

		NASA Invests in Private Sector Space Flight Two partners chosen to develop reliable, cost-effective access to Earth orbit. + Read More

		Wide Awake on the Sea of Tranquillity Why Neil Armstrong and Buzz Aldrin couldn't fall asleep in the Sea of Tranquillity. + Read More + Listen to Story

	+ View Archive

The Prius of Space

2007-09-15T22:31:00.000+05:30

Some spacecraft achieve greatness,
And some have greatness thrust from them.

If you drive a car - and you know who you are - you have invariably come upon the dreaded dilemma of refueling. When the needle on your gas gauge wavers over the unseemly 'E,' you have to ask yourself one question - Do I stop at the next gas station or press on, hoping for a fuel oasis somewhere down the road? But what if you need to motor somewhere three billion-plus miles off the beaten path - somewhere where neither regular nor premium unleaded have so far feared to tread?

Image right: Deep Space 1's ion engine. Image credit: NASA/JPL
+ Larger view
+ Related: Anatomy of an Ion Engine

Such is the case for NASA's latest deep space explorer, Dawn. The 2,600 pound spacecraft's mission is to reconnoiter the asteroid belt's two biggest occupants - the massive asteroid Vesta and the even more massive dwarf planet Ceres. To do so, Dawn will not just scream past its prey snapping off a flurry of images as it zooms by. No, not this spacecraft.

"Dawn will be history's first mission to go out into the solar system, orbit and explore a distant body, and then go on to a totally different celestial body and explore that one," said Dawn project manager Keyur Patel of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "To do all that you need a spacecraft with a lot under the hood."

What Patel considers a lot under the hood is definitely not the exo-atmospheric equivalent of a muscle car's 426 Hemi engine. After all, it is about a different type of performance up there - the kind where smooth, reliable operation and gas mileage count more than the capability to burn rubber. What it takes up there is a deep-space qualified engine, a whole bunch of juice and the same kind of gas used in photographic flash bulbs and some car headlights.

The engine is called NASA Solar Electric Propulsion Technology Applications Readiness. Most people in the deep space exploration business just refer to it as "ion propulsion." The juice is, of course, electricity, courtesy of 54 feet of electricity-producing solar array. The gas is xenon, an inert, colorless gas that is four times heavier than air and is the propellant of choice for asteroid explorers everywhere.

"Each of our three ion engines weighs in at 20 pounds and is about the size of a basketball," said Patel. "From such a little engine you can get this blue beam of rocket exhaust that shoots out at 89,000 miles per hour. The fuel efficiency of an ion engine is an order of a magnitude higher than chemical rockets and can reduce the mass of fuel onboard a spacecraft up to 90 percent. It is a remarkable system."

Praise like that does raise an important question. If ion engines are so hyper-efficient, how come NASA does not use them for all their rockets and spacecraft?

"For the same reason a drag racer would not use a fuel efficient Prius to compete in the quarter mile," said John Brophy, Dawn's ion propulsion systems manager. "Not enough get up and go."

The kind of get up and go Brophy is talking about is power - horsepower to hurtle a top fuel dragster down the track, or the massive amounts of thrust to give a rocket enough get up and go to go - out there.

"We have a powerful rocket to cover those initial 175 miles," added Brophy. "Our Delta II Heavy will give the Dawn spacecraft enough energy to leave Earth's atmosphere and its gravitational sphere of influence. But getting into space is just the beginning. There will still be a lot of motoring ahead."

A lot of motoring is right. Over the course of its eight year mission, first to Vesta and then off to Ceres, Dawn's three ion engines will accumulate 2,000 days of operation - that is 5.5 years of happy motoring!

Why so much engine time? It is as simple as a plain piece of paper.

"Hold a piece of notebook paper in your hand. The weight of that paper pushing against your hand is the same as the thrust provided by one of Dawn's ion engines -- at full throttle I might add," said Brophy. "If you had an ion engine firing here on Earth, it would not be able to push a skateboard across a sidewalk!"

Lucky for Dawn there are no sidewalks in space - and as far as we know no skateboards. What there is up there is plenty of space, so soon after the spacecraft escapes Earth's gravity, one of its ion engines can kick in and begin the long, efficient chase of its first asteroid belt target, Vesta.

At first glance, Dawn's full throttle, pedal-to-the-metal, performance is a not-so-inspiring 0-to-60 mph in 4 days. But consider this - because of its incredible efficiency, it expends only 40 ounces of xenon propellant during that time. And then take into consideration that after those four days of full-throttle thrusting, it will do another four days - and then another four. By the end of 12 days the spacecraft will have increased its velocity by over 180 miles per hour, with more days and weeks and months of continuous thrusting to come. After a year Dawn's ion propulsion system will have increased the spacecraft's speed by 5,500 mph while consuming the equivalent of only 15 gallons of fuel. By the end of its mission Dawn will have accumulated more than 5 years of total thrust time, giving it an effective change in speed of about 23,000 mph.

"In the end it is about the science," added Patel. "What we find when Dawn gets to Vesta and Ceres will re-write the history books on the beginning of our solar system. But how we get there is almost as remarkable, 1.8 billion miles to Vesta, months flying around it performing science adjusting our orbits as we go. Then we travel another billion miles to Ceres where we do it all over again. That is a lot to ask of a beam of blue light."

Those space aficionados who want to keep their "ion" the mission should note the launch period for Dawn's voyage to Vesta and Ceres opens September 26 from Cape Canaveral Air Force Station's Pad 17-B.

NASA Selects Ares I Upper Stage Production Contractor

2007-09-02T22:34:00.000+05:30

Image above: (left to right) Brewster Shaw, vice president/general manager, Boeing Space Exploration, Doug Cooke, NASA deputy associate administrator, Exploration Systems, Danny Davis, NASA Ares I upper stage element manager, Steve Cook, NASA Ares Project manager and Jeff Hanley, NASA Constellation Program manager, pose for a photo in front of a model of an Ares I rocket.
Credit: NASA/Bill Ingalls

NASA has selected The Boeing Co., Huntsville, Ala., as the contractor to provide manufacturing support for design and construction of the upper stage of the Ares I rocket. Ares I will launch astronauts to the International Space Station and eventually help return humans to the moon.

+ News Release
+ Photo




		Constellation Programmatic Environmental Impact Statement NASA has prepared the Draft Constellation Programmatic Environmental Impact Statement and is seeking public input and comment. + Read More + Download Draft PEIS (PDF 22MB)

		A New Spin on the Constellation Program NASA's Vertical Spin Tunnel puts a scale model of the Orion Crew Vehicle design to the test. + Read More

		NASA's Gantry: A Bridge to the Future NASA's gantry at Langley Research Center in Virginia is a piece of national history. + Read More + View Video

NASA's Phoenix Mars Mission

2007-08-31T23:02:00.000+05:30




	Mars-Bound Phoenix Adjusts Course Successfully 08.10.07 -- NASA's Phoenix Mars Lander today accomplished the first and largest of six course corrections planned during the spacecraft's flight from Earth to Mars. + Read more

Discovery's Crew to Deliver Harmony

2007-08-31T22:59:00.000+05:30




	Image above: Inside the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, STS-120 crew members familiarize themselves with Harmony in preparation for their mission to deliver the module to the International Space Station. From left are Mission Specialist Scott Parazynski, Commander Pam Melroy and Mission Specialist Stephanie Wilson. Image credit: NASA/Kim Shifflet + View larger image Discovery Remains on Target for October Even with the work in progress on the external tank, the STS-120 launch remains targeted for Oct. 23. Since the schedule leading to Discovery's liftoff contains about five extra days, mission managers believe it provides enough room to make the changes and still launch on time. During the STS-118 launch, foam loss from the liquid oxygen feedline brackets on the external tank caused thermal tile damage to Endeavour. While a change to the brackets was already in progress on tanks now in production, the problem on the tank for STS-120 is being remedied by using different foam on the brackets. At the Kennedy Space Center in Florida, workers from the Michoud Assembly Facility in New Orleans are replacing the existing foam and underlying thermal protective agent on the brackets with lightweight foam. The process should take approximately nine days. Mission Information + STS-120 Mission Overview




		STS-118: Investing in Future Exploration During the STS-118 mission, astronauts added a segment to the International Space Station's backbone and reached out to tomorrow's explorers. + Read More

		Completing the Mission After 21 Years NASA's Ed Campion, public affairs officer for NASA's Teacher-in-Space program in 1986 and a witness to Challenger's launch that January day, offers his thoughts before the launch of STS-118. + Read More

		Space Shuttle Hand Held Wireless Scanner A new space shuttle tile inspection method using NASA-built, wireless scanners will replace manual inspection of the tiles beginning with the STS-118 mission. + View

STS-125 Shuttle Mission Imagery

2007-08-31T22:51:00.000+05:30

Astronaut John M. Grunsfeld, mission
specialist

JSC2006-E-11466 (19 Jan. 2006) --- Astronaut Gregory C. Johnson, pilot


	JSC2001-00425 (20 Feb. 2001) --- Astronaut Andrew J. Feustel, mission specialist

JSC2000-07600 (November 2000) --- Astronaut K. Megan McArthur, mission specialist

JSC2004-E-32185 (5 May 2004) --- Astronaut Scott D. Altman, commander

JSC2001-02670 (24 Sept. 2001) --- Astronaut Michael J. Massimino, mission specialist

JSC2000-07306 (November 2000) --- Astronaut Michael T. Good, mission specialist

Mission STS-118: Investing in Future Exploration

2007-08-31T22:28:00.000+05:30

|Every mission that adds to the International Space Station brings the first-of-its-kind orbiting research facility one step closer to completion. But the STS-118 mission went one step further by also reaching out directly from space to the next generation of explorers.

The 13-day mission was highlighted by a series of conversations between students on Earth and crew members including teacher-turned-astronaut Barbara Morgan, as well as installation of the S5 truss and external stowage platform 3. The crew also transferred equipment and supplies to the station on the flight, which was the last for the SPACEHAB module.

Space Shuttle Endeavour rose from its oceanside launch pad on time at 6:36 p.m. EDT on Aug. 8, 2007. The liftoff from Kennedy Space Center in Florida marked Endeavour's return to space after spending four-and-a-half years in an extensive overhaul period. The newly improved orbiter performed well during the climb to orbit.

Image to right: Space Shuttle Endeavour roars skyward on the STS-118 mission. Image credit: NASA/John Kechele, Scott Haun, Tom Farrar

The first full day in space focused on inspecting the orbiter's heat-resistant thermal protection system. The crew used the orbiter boom sensor system to methodically sweep over Endeavour's wings, nose cap and orbital maneuvering system in search of possible damage sustained during launch. The day concluded with a review of tools to be used during the upcoming rendezvous and docking with the International Space Station.

Flight Day 3 began with Commander Scott Kelly putting Endeavour through the rendezvous pitch maneuver, a slow-motion backflip below the station. This allowed Expedition 15 Commander Fyodor Yurchikhin and station Flight Engineers Oleg Kotov and Clay Anderson to take video and still images of the orbiter's underbelly. The images taken during the maneuver revealed areas of tile damage, and managers chose to do a focused inspection the next day to get a better look.

After docking, the shuttle and station crews opened the hatches between them and warmly greeted one another in a welcome ceremony. The day also featured the first activation of the new Station-Shuttle Power Transfer System, which enables the orbiter to draw power from the space station for an extended stay.

Image to right: Endeavour rotates through the rendezvous pitch maneuver, allowing the space station crew to photograph the vehicle's thermal protection system. Image credit: NASA

Mission Specialists Dave Williams and Rick Mastracchio ventured out of the station's Quest airlock on Flight Day 4 for the first of the mission's four spacewalks. During the six-hour outing, the duo provided assistance as Pilot Charlie Hobaugh used the station's robotic arm to attach the new S5 truss segment on the starboard side of the station's backbone truss structure. Mission Specialist Tracy Caldwell served as the spacewalk coordinator during each of the mission's excursions.

A more focused inspection of Endeavour's thermal protection system the following day revealed one particular area of concern: a 3.5-inch-by-2-inch gouge in the tile, apparently a result of foam that broke off the external tank during launch, bounced off one of the tank's struts and impacted the orbiter's underside. NASA's Mission Management Team, which meets daily during space shuttle missions, began several days of analysis on the tile issue to determine the best course of action. The team also announced the mission would be extended from 11 to 14 days due to the perfect operation of the new power transfer system, and added a fourth spacewalk to the itinerary.

On Flight Day 6, Williams and Mastracchio participated in the mission's second spacewalk, replacing a failed control moment gyroscope with a new, fully functioning unit. There are four such gyroscopes on the station: two to maintain the outpost's orientation and two backup units.

Image to right: The Expedition 15 and STS-118 crews gather in the Destiny laboratory on the International Space Station. ISS crew members on the front row, from left: Flight Engineer Clayton C. Anderson, Commander Fyodor Yurchikhin and Flight Engineer Oleg Kotov. STS-118 crew members on the middle row, from left: Alvin Drew, Barbara R. Morgan and the Canadian Space Agency's Dave Williams, all mission specialists, and Commander Scott Kelly. STS-118 crewmembers on the back row, from left: Pilot Charlie Hobaugh, along with Mission Specialists Rick Mastracchio and Tracy Caldwell. Image credit: NASA

Caldwell celebrated her birthday in space on Flight Day 7. Despite the festive occasion, the day's to-do list was a long one. Using the shuttle's robotic arm, Caldwell and Mission Specialist Morgan carefully removed an external stowage platform from Endeavour's payload bay. With Hobaugh and Expedition 15 Flight Engineer Clay Anderson using the station's arm, the astronauts secured external stowage platform 3 to the station's P3 truss.

The day's activities continued with a question-and-answer session from space with students gathered at the Discovery Center of Boise, Idaho. During the event, Williams, Morgan, Anderson and Mission Specialist Alvin Drew answered a wide variety of questions submitted by inquisitive students, such as, "How does being a teacher relate to being an astronaut?"

"Astronauts and teachers actually do the same thing," Morgan answered. "We explore, we discover and we share -- and the great thing about being a teacher is we get to do that with kids."

Flight Day 8 was highlighted by the mission's third spacewalk, during which Mastracchio and Anderson spent more than five hours preparing the P6 truss and solar arrays for their move to the end of the P5 truss during the upcoming STS-120 mission.

Mission Control ended the spacewalk early after Mastracchio discovered a small hole near the thumb of his left glove. The hole was in the second of five layers and did not cause any leak or danger to him. However, as a precaution, he returned to the Quest airlock while Anderson completed his final task.

Image to left: Mission Specialist Rick Mastracchio (shown) and Expedition 15 Flight Engineer Clay Anderson (out of frame) participate in the mission's third spacewalk. Image credit: NASA

Morgan and Drew spoke with students at the Challenger Center in Alexandria, Va., on Flight Day 9. June Scobee Rodgers, widow of Challenger Commander Dick Scobee, hosted the educational event in which students again had the chance to speak with the astronauts.

Later that day, the Mission Management Team announced its decision not to conduct a spacewalk to repair the tile. Days of testing and analysis on the ground had shown that the gouge was not a danger to the crew or the orbiter, and a spacewalk to repair it would have carried an additional set of risks.

Another concern soon appeared as computer models indicated the powerful Hurricane Dean could affect NASA's Johnson Space Center in Houston, home of Mission Control. Faced with the possibility that Johnson may need to close in the coming days, mission managers ultimately decided Endeavour would undock from the station one day earlier in order to land Aug. 21, one day ahead of schedule.

The mission's fourth and final spacewalk highlighted Flight Day 11, as Williams and Anderson spent about five hours working to install an antenna and a stand for the shuttle's robotic arm extension boom, as well as retrieve experiments from the station's exterior for analysis on Earth. Following the final spacewalk, the shuttle and station crews said farewell and the hatch closed.

Image to right: Backdropped by a blue Earth, the International Space Station, in its new configuration, moves away from Space Shuttle Endeavour. Image credit: NASA

Shortly after Endeavour undocked from the station the next morning, Mastracchio and Caldwell used the orbiter boom sensor system to conduct one final "late inspection" of the shuttle's protective tiles to ensure the thermal protection system was ready to withstand the trials of re-entry.

With Hurricane Dean now headed toward Mexico, managers chose not to close Johnson Space Center. Endeavour's landing schedule was not changed.

The astronauts spent their final full day in space stowing equipment and supplies and testing the orbiter's steering jets and flight control surfaces in final preparations for landing.

The STS-118 mission ended on Aug. 21 as smoothly as it started. After a perfect deorbit burn and a safe journey through Earth's atmosphere, Endeavour touched down on Kennedy Space Center's Runway 15 at 12:32 p.m. EDT, wrapping up a nearly 5.3-million-mile voyage designed to inspire future generations.

Anna Heiney
NASA's John F. Kennedy Space Center

Fasten Your Seat Belts, Turbulence Ahead - Lessons From Titan

2007-08-31T22:22:00.000+05:30

This story is republished with permission from the European Space Agency.

|Ever spilled your drink on an airline due to turbulence? Researchers on both sides of the Atlantic are finding new ways to understand the phenomenon - both in Earth's atmosphere and in that of Saturn's moon, Titan, aided by Huygens probe data. The study of one is helping the other.

Turbulence plays an important role in Earth's weather system, and can be more than an inconvenience - hundreds of injuries have occurred on commercial flights due to turbulence.

Image right: Artist concept showing the descent and landing of Huygens. Image credit: NASA/JPL/ESA
+ Browse version of image

Giles Harrison, atmospheric physicist at the University of Reading in the United Kingdom, devised an inexpensive way to measure the effects of turbulence using weather balloons. The instrument package contains a magnetic field sensor which measures fluctuations in Earth's magnetic field due to turbulence. As Earth's magnetic field is very stable, the measurements of magnetic changes taken with the weather balloon showed the effects of turbulence on the sensor, since the balloon itself was moving very violently.

All bodies, planets and moons, are subject to the same principles of physics. So by working together, researchers looking at Earth and those looking at our planetary neighbors can really test their models of the processes taking place and gain new insights into both.

Planetary scientist Ralph Lorenz, at the Johns Hopkins University Applied Physics Laboratory in Baltimore, Md., found Harrison's results key to making sense of data from the European Space Agency's Huygens probe, which descended by parachute through Titan's atmosphere in January 2005. The Huygens probe was delivered to Titan aboard NASA's Cassini spacecraft. Cassini continues to orbit Saturn on a four-year prime mission to study the planet, its rings, moons and magnetosphere.

The Surface Science Package onboard Huygens included a set of tilt sensors, which measured motions of the probe during its descent. These tilt sensors acted much like a drink in a glass, using a small slug of liquid to measure tilt angle.

As the probe plummeted under the parachute through Titan's atmosphere, there was a lot of buffeting, even though the atmosphere itself was fairly still. Knowing the signature of cloud-induced turbulence in Harrison's balloon data from Earth inspired Lorenz to look for a similar effect in the Huygens data using the tilt sensor.

"Huygens' tilt history was just this long, squiggly, complex mess, but seeing the fingerprint of cloud turbulence in Harrison's work showed me what to look for," said Lorenz.

Armed with that information, Lorenz found that a 20-minute period of Huygens' 2.5-hour descent, around an altitude of 20 kilometers (12 miles), was affected by this kind of in-cloud turbulence. Having experimented with instrumentation on small models, even frisbees, to understand the dynamics of aerospace vehicles like the probe, Lorenz was familiar with the sensors used by Harrison.

Lorenz's analysis helped identify a turbulent cloud layer in Titan's atmosphere - a significant result for the investigation of Titan's meteorology. In the process, he also found a way to improve Harrison's magnetic sensor arrangement on the weather balloon, simply by changing its orientation.

Mark Leese, project manager for the Surface Science Package on Huygens at The Open University in the United Kingdom, said "We knew Huygens had a bumpy ride down to Titan's surface, now we can separate out 20 minutes of air turbulence ? probably due to a cloud layer - from other effects such as cross winds or air buffeting due to the irregular shape of the probe."

Notes for editors:

Lorenz's analysis, with co-authors J. Zarnecki, M. Towner, M. Leese, A. Ball, B. Hathi, A. Hagermann and N. Ghafoor, appears in the online version of the Planetary and Space Science journal. It is expected to appear in print in November.

The original work by Harrison and Hogan was published last year in the Journal of Atmospheric and Oceanic Technology. An exchange of ideas between Lorenz and Harrison appears in the August 2007 issue of the Journal of Oceanic and Atmospheric Technology.

Harrison's work is supported by the Paul Instrument Fund of the Royal Society. Lorenz is supported by NASA's Cassini Project. The Science and Technology Facilities Council funds UK participation in the Cassini Huygens mission, in particular, the research at The Open University.

Weather balloons carry measuring packages known as radiosondes, which make measurements (soundings) of air temperature, moisture and wind direction used for weather forecasting. The balloons are filled with helium or hydrogen gas and the measurements are sent back to the surface by radio. When the balloon bursts, usually at 15 to 20 kilometers (9.3 to 12.4 miles) altitude, the instruments fall to Earth by parachute.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. JPL designed and assembled the Cassini orbiter.

Development of the Huygens Titan probe was managed by the European Space Agency's European Space Technology and Research Center. The Italian Space Agency managed the realization of the high-gain antenna and the other instruments of its participation.

For more information:

Ralph Lorenz, John Hopkins University Applied Physics Laboratory, USA Email : ralph.lorenz@jhuapl.edu

Jean-Pierre Lebreton, ESA Huygens Project Scientist Email : jean-pierre.lebreton@esa.int

Giles Harrison, Department of Metrology, University of Reading, UK Email : R.G.Harrison@reading.ac.uk

or Mark Leese, The Open University, UK Email: m.r.leese@open.ac

2007-08-22T18:31:00.000+05:30


	+ NASA Home > Mission Sections > Space Shuttle




	Crew Excited About Endeavour's Success Image above: Space Shuttle Endeavour landed Aug. 21, 2007, at Kennedy Space Center in Florida. The perfect landing capped a construction and supply mission to the International Space Station. Image: NASA/Chuck Tintera + View Hi-Res Image of Landing A couple hours after landing back at Kennedy Space Center, the crew of STS-118 spoke enthusiastically about their 13 days in orbit and work on the International Space Station. "It was a great experience and the space station is really, I think, a stepping stone to going back to the moon and on to Mars some day," commander Scott Kelly said. Teacher-turned-astronaut Barbara Morgan said she is still getting used to gravity again, but that spaceflight was a great experience that she hopes more teachers get to share in. "The flight was absolutely wonderful," she said. "I felt like I was upside-down the whole first day." Canadian astronaut Dave Williams said the thrill never gets dull. "It's truly the ride of a lifetime," Williams said of the launch Aug. 8. "Look over your shoulder and you can see Hurricane Dean." The flight delivered a new segment to the International Space Station, along with 5,800 pounds of supplies and equipment. As far as the ding in a couple of heat shield tiles, Kelly said it did not bother him much. "I was a little bit underwhelmed by the size of the gouge," he said. "To see it, it looked rather small." Photos of Tile Damage + View Hi-Res Image of Tile Damage + View Hi-Res Image of Tile Taken in Space Mission Information + STS-118 Mission Overview + STS-118 Fact Sheet (900 Kb PDF) + STS-118 NASA TV Schedule




	Official Landing Times Main gear touchdown: 12:32:16 p.m. EDT Nose gear touchdown: 12:32:29 p.m. EDT Wheels stop: 12:33:20 p.m. EDT Total miles: 5.3 million	Â




	Landing Control Center: + Landing Blog + Landing 101 Landing Day Galleries + View Videos + View Images Launch Control Center: + Launch Team + Launch Blog + Countdown 101 Launch Day Galleries + View Videos + View Images Astronaut Webcast + View Webcast

Â


	Education Spotlight Bring STS-118 to your home or classroom with features, games, activities and more. + STS-118 Education Site




	STS-118: Endeavour's Mission in Photos Endeavour and crew spent nine days at the International Space Station, installing a new truss and replacing a failed gyroscope. + View Photo Galler

	Endeavour Lands! After a successful mission, Space Shuttle Endeavour makes a perfect touchdown at Kennedy Space Center. + View this Video

	Photosynth: Endeavour's Tiles Explore Endeavour's belly in a 3-D environment with Microsoft's Photosynth. + View Gallery

	Barbara Morgan Talks With Students on Ham Radio + Play Audio (MP3) + Read Transcript

	+ View Archives

STS-118 Crew Launches Into Space; images

2007-08-13T21:57:00.000+05:30

Phoenix takes flight!

2007-08-05T23:16:00.000+05:30

BY WILLIAM HARWOOD for Krishnaap_SpotLight
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 4, 2007

NASA's $420 million Phoenix Mars lander blasted off early today and began a 10-month voyage to the red planet, bound for the northern polar plains where scientists believe vast deposits of ice are hidden just beneath the frozen surface.

Running a day late because of stormy weather that slowed launch processing, the United Launch Alliance Boeing 2 rocket roared to life at 5:26:34 a.m. and quickly climbed away from launch complex 17 at the Cape Canaveral Air Force Station. The international space station emerged from Earth's shadow seconds before liftoff, a brilliant "star" above the launch pad, and as the Delta 2 went supersonic, it streaked past Mars gleaming red in the morning sky 122 million miles away, a clearly visible target for NASA's newest robotic explorer.

The Delta's first two stages performed normally to put the Phoenix lander and its interplanetary cruise stage into a preliminary parking orbit 106 miles up. A final boost by the lander's solid-fuel third stage motor took place on time about 84 minutes after launch to accelerate the spacecraft to the required departure velocity.

A ground station at Goldstone, Calif., picked up telemetry from the spacecraft almost immediately - 9 seconds after its transmitter turned on - but it took a few minutes for word of a healthy spacecraft to filter out to reporters and other NASA managers not directly involved in the checkout procedure. But at an 11 a.m. news conference, officials said Phoenix was in near perfect health with all systems operating normally. The Delta 2 rocket put the craft on a near-ideal trajectory and if all goes well, Phoenix will reach Mars on May 25, 2008.

"While we're really happy that we now have ourselves on our way, that's great, it's 295 days to our entry, descent and landing where we get to do everything that was done today, but we do it in reverse," said Barry Goldstein, Phoenix project manager at the Jet Propulsion Laboratory in Pasadena, Calif. "We go from the velocity we're at now down to 5 mph in seven minutes. It'll be a lot of fun."

Data collected by NASA's orbiting Mars Odyssey spacecraft indicates vast amounts of ice within a few feet of the surface of Mars at extreme northern latitudes, possibly the remnant of an ancient ocean. Phoenix is equipped with an eight-foot robot arm that can dig nearly two feet into the soil next to the lander to tap into that ice and deliver samples to compact instruments and furnaces that will look for signs of organic compounds.

While the relatively low-cost Phoenix is not equipped with instruments to search for signs of biological activity, mission scientists are hopeful the spacecraft will be able to determine whether the environment at the ice-soil boundary represents a modern habitable zone.

"I see this mission as a stepping stone towards the search for life on other planets," said Peter Smith, principal investigator at the University of Arizona. "We're hoping to find a place that we consider really a habitable zone on Mars. To me, if we can find that out, that would be a tremendous success. We're also really interested in following up on the discovery of water ice by the Odyssey spacecraft in 2002 and trying to understand how the ice got there and what it's source was and what its history has been."

NASA's Mars Pathfinder lander and rover and the two Mars Exploration Rovers currently weathering a global dust storm on opposite sides of the red planet were built to study the geology of Mars and to confirm the presence of surface water in the distant past. Phoenix will concentrate on water known to exist today.

"We want to understand the ice properties," Smith said. "This is a big part of Mars. It's part of the NASA theme of follow the water. Well, we're for the first time getting kind of a fist-full, so to speak, of water and soil and we're going to analyze it.

"We intend to go where we know there's ice near the surface. Our entire mission is trying to understand the history of this ice, in particular does it melt over time and provide a habitat for some sort of Martian biology?"

Unlike NASA's hugely successful Mars Exploration Rovers, Phoenix will not bounce to a landing cocooned in protective airbags. Instead, it will use a dozen pulsing, computer-controlled rocket motors to make its final descent to a soft landing near the northern polar cap. The last time NASA tried that, the ill-fated Mars Polar Lander simply disappeared, the presumed victim of a premature engine shutdown.

This time around, using hardware left over from the polar lander project and a subsequent mission that was canceled in the wake of the 1999 failure, NASA managers believe they have done all that can reasonably be expected to ensure success. Along with fixing the sensor/software glitch believed to be responsible for the Mars Polar Lander's demise, engineers with spacecraft builder Lockheed Martin and NASA's Jet Propulsion Laboratory found and fixed a variety of other shortcomings in an exhaustive effort to ensure success.

"This team has put an enormous amount of energy into retiring and finding all sorts of problems," Goldstein said before launch. "We are very confident that we basically have retired everything that we can think of. But the simple fact of the matter is, landing on Mars is difficult. Probably the most difficult thing about it is not the things we can think of, it's things we can't think of.

"I'm confident we have worked as hard as any group of people can. Am I confident in the landing? I'll be nervous. If my fingernails survive that day, it will be a miracle. It's not the things that we know that will hurt us. It's the things we don't know."

But if the appropriately named Phoenix mission works, NASA will open a new chapter in its on-going exploration of Mars.

Based on high-resolution images from the Mars Reconnaissance Orbiter, mission planners ruled out one landing site because of boulder fields that could cause major problems for a legged lander. The current landing zone is located at 67 degrees north latitude, roughly equivalent to Iceland or northern Siberia on Earth. MRO pictures indicate a very smooth terrain. The target landing ellipse measures 12 miles wide by 93 miles long. The entry, descent and landing profile is complex, fast-paced and computer controlled. At the time of landing, Earth and Mars will be 171 million miles apart, so far it will take radio signals 15.3 minutes to make a one-way trip. Data from Phoenix will be relayed back to Earth throughout the descent by NASA's Mars Odyssey and Mars Reconnaissance Orbiter, but realtime commanding will not be possible. Phoenix's survival will depend on its flight software, the martian weather, the terrain at the landing site and a certain amount of luck.

"Mars has been known as a spacecraft eater," Goldstein said. "We have been fairly successful recently with the MER (landers). But that doesn't make it any easier the next time around."

Seven minutes before it hits the discernible atmosphere, Phoenix will separate from its interplanetary cruise stage and reorient itself to put its heat shield forward. Atmospheric entry will occur five minutes later at an altitude of 77.7 miles and a velocity of 3.5 miles per second. Over the next three minutes, the spacecraft will experience peak heating and a deceleration of 9.3 times the force of Earth's gravity at sea level.

Now at an altitude of 7.8 miles, a large braking parachute will deploy and 15 seconds later, the no-longer-needed heat shield will fall away. The spacecraft's three landing legs will snap open and a radar altimeter will fire up to compute the spacecraft's altitude and sink rate.

Then, in the most dramatic phase of the descent, the lander will separate from its parachute about 3,000 feet above the martian surface. Three seconds later, 12 small rocket motors will begin firing to slow the descent and bleed off horizontal velocity. Unlike the throttled engines on the Viking landers three decades ago, Phoenix relies on pulsing on-off cycles to control the craft's descent rate and orientation. The engines will shut down when sensors on the landing legs contact the surface.

For 15 minutes, Phoenix will wait for any dust kicked up by landing to settle out before deploying its two fan-like circular solar arrays. A meteorology mast and the lander's main stereo camera will deploy and engineers will begin a complex sequence of operations to thoroughly check out the robot's systems.

A successful soft landing "is a very difficult thing to do," Goldstein said. "We have gone away from the Pathfinder and MER (airbag) landing system for a reason. We have to have an ability to land a larger payload on the surface as we try to expand the Mars program. Eventually, there will have to be a landing system for people. They are not going to want to bounce around in airbags."

Phoenix is designed to operate for at least three months and possibly longer. But engineers say the sort of extended life enjoyed by the Mars Exploration Rovers is not an option for Phoenix.

"The real killer is the ice caps coming down," Goldstein said. "We expect to be encased in solid CO2 at some point, according to what the scientists are telling us. Will we check to see if it thaws out and comes back to life (the following summer)? Sure, but we didn't design this vehicle to survive cryogenic freezing."

Additional coverage for subscribers:
VIDEO: PHOENIX LAUNCHES! PLAY
VIDEO: POST-FLIGHT COMMENTS FROM LAUNCH MANAGER PLAY
VIDEO: WIDE-SCREEN FROM PATRICK AFB CAMERA PLAY
VIDEO: TRACKER FOLLOWS ROCKET TO MECO PLAY
VIDEO: LAUNCH AS SEEN FROM THE PRESS SITE PLAY
VIDEO: PAD'S MOBILE GANTRY ROLLED BACK FOR LAUNCH PLAY
VIDEO: NARRATED HIGHLIGHTS OF PHOENIX CAMPAIGN PLAY
VIDEO: NARRATED HIGHLIGHTS OF ROCKET CAMPAIGN PLAY
VIDEO: THE PRE-LAUNCH NEWS CONFERENCE PLAY
VIDEO: OVERVIEW OF PHOENIX MISSION TO MARS PLAY
VIDEO: ANIMATION OF PHOENIX WITH NARRATION PLAY
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Progress to Launch to Space Station

2007-07-31T22:50:00.001+05:30

A new Progress cargo carrier is scheduled to launch to the International Space Station at 1:34 p.m. EDT Thursday, Aug. 2, with more than 2.5 tons of fuel, air, water and other supplies and equipment aboard. The station's 26th Progress unpiloted spacecraft will bring to the orbiting laboratory almost 1,600 pounds of propellant, more than 100 pounds of air and oxygen, more than 465 pounds of water and 2,954 pounds of dry cargo. Total cargo weight is 5,111 pounds. Image to right: Backdropped by the blackness of space, an unpiloted Progress supply vehicle approaches the International Space Station in May 2007. Credit: NASA Among the dry cargo are spares for Russian computers that had problems during the STS-117 mission of Atlantis to the station in June. P26 will launch from the Baikonur Cosmodrome in Kazakhstan. It is scheduled to dock with the station Sunday, Aug. 5, at about 2:38 p.m. The spacecraft will use the automated Kurs system to dock at the aft port of the Zvezda Service Module. Expedition 15 Commander Fyodor Yurchikhin will be at the manual TORU docking system controls, should his intervention become necessary. Once Expedition 15 crew members, Yurchikhin and flight engineers Oleg Kotov and Clay Anderson, have unloaded the cargo, P26 will be filled with trash and station discards. It will be undocked from the station with its load of trash and deorbited, to burn in the Earth's atmosphere. The Progress is similar in appearance and some design elements to the Soyuz spacecraft, which brings crew members to the station, serves as a lifeboat while they are there and returns them to Earth. The aft module, the instrumentation and propulsion module, is nearly identical. But the second of the three Progress sections is a refueling module, and the third, uppermost as the Progress sits on the launch pad, is a cargo module. On the Soyuz, the descent module, where the crew is seated on launch and which returns them to Earth, is the middle module and the third is called the orbital module.

"Go" for Launch

2007-07-27T23:07:00.000+05:30

Endeavour is "Go" for LaunchLaunch Date: Aug. 7Launch Time: 7:02 p.m. EDTImage above: STS-118 crew members get a close look at the payloads installed in Space Shuttle Endeavour. Seen in the foreground are Mission Specialists Dave Williams (center), who represents the Canadian Space Agency, and Tracy Caldwell (right). Photo credit: NASA/George Shelton+ View Full Size Image07.26.07 - 3:20 p.m. EDTSpace Shuttle Endeavour is ready to fly, NASA managers concluded today after wrapping up the two-day flight readiness review at Kennedy Space Center in Florida. Launch of Endeavour on the STS-118 mission is officially set for Aug. 7."On behalf of all the people that work on Endeavour, both here and really across the country, it's a great, great feeling to have Endeavour back on the pad," said Shuttle Launch Director Mike Leinbach. "We're looking forward to a great launch."The Shuttle Mission Management Team conducts the review two weeks prior to each space shuttle mission. The group thoroughly evaluates all activities and elements necessary for the safe and successful performance of shuttle mission operations -- from the prelaunch phase through post-landing -- including the readiness of the vehicle, flight crew and payloads.The 22nd flight to the International Space Station, STS-118 will be the first flight for Endeavour since 2002, and the first mission for Mission Specialist Barbara Morgan, the teacher-turned-astronaut whose association with NASA began more than 20 years ago.Mission Information+ STS-118 Mission Overview + STS-118 Fact Sheet (900 Kb PDF)+ STS-118 Briefing Animations + STS-117 Mission Archive

STS-120 to Deliver Harmony Node to ISS October's STS-120 mission will bring the Harmony module, christened after a school contest, that will provide attachment points for European and Japanese laboratory modules.+ Read More

SPACEHAB Ready for Last Mission The last SPACEHAB mission is scheduled to carry more than 5,000 pounds of spare parts and cargo into space.+ Read More

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07.26.07 - NASA Gives 'Go' for Shuttle Endeavour Launch on Aug. 7 On Thursday, NASA managers set Aug. 7 as the official launch date for space shuttle Endeavour's STS-118 mission to the International Space Station.+ Read More

07.10.07 - Canadian Astronaut to Discuss Role on Next Shuttle Flight Canadian Space Agency astronaut and physician Dave Williams, who is set to launch in August aboard NASA's space shuttle Endeavour, will be available for satellite interviews from 2 to 4 p.m. CDT on Friday, July 13.+ Read More

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Worldbook @ Nasa

2007-07-11T22:23:00.000+05:30

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The planet Mars, like Earth, has clouds in its atmosphere and a deposit of ice at its north pole. But unlike Earth, Mars has no liquid water on its surface. The rustlike color of Mars comes from the large amount of iron in the planet's soil. Image credit: NASA/JPL/Malin Space Science Systems

Mars is the fourth planet from the sun. The planet is one of Earth's "next-door neighbors" in space. Earth is the third planet from the sun, and Jupiter is the fifth. Like Earth, Jupiter, the sun, and the remainder of the solar system, Mars is about 4.6 billion years old.

Mars is named for the ancient Roman god of war. The Romans copied the Greeks in naming the planet for a war god; the Greeks called the planet Ares (AIR eez). The Romans and Greeks associated the planet with war because its color resembles the color of blood. Viewed from Earth, Mars is a bright reddish-orange. It owes its color to iron-rich minerals in its soil. This color is also similar to the color of rust, which is composed of iron and oxygen.

Scientists have observed Mars through telescopes based on Earth and in space. Space probes have carried telescopes and other instruments to Mars. Early probes were designed to observe the planet as they flew past it. Later, spacecraft orbited Mars and even landed there. But no human being has ever set foot on Mars.

Scientists have found strong evidence that water once flowed on the surface of Mars. The evidence includes channels, valleys, and gullies on the planet's surface. If this interpretation of the evidence is correct, water may still lie in cracks and pores in subsurface rock. A space probe has also discovered vast amounts of ice beneath the surface, most of it near the south pole.

In addition, a group of researchers has claimed to have found evidence that living things once dwelled on Mars. That evidence consists of certain materials in meteorites found on Earth. But the group's interpretation of the evidence has not convinced most scientists.

The Martian surface has many spectacular features, including a canyon system that is much deeper and much longer than the Grand Canyon in the United States. Mars also has mountains that are much higher than Mount Everest, Earth's highest peak.

Above the surface of Mars lies an atmosphere that is about 100 times less dense than the atmosphere of Earth. But the Martian atmosphere is dense enough to support a weather system that includes clouds and winds. Tremendous dust storms sometimes rage over the entire planet.

Mars is much colder than Earth. Temperatures at the Martian surface vary from as low as about -195 degrees F (-125 degrees C) near the poles during the winter to as much as 70 degrees F (20 degrees C) at midday near the equator. The average temperature on Mars is about -80 degrees F (-60 degrees C).

A sunset on Mars creates a glow due to the presence of tiny dust particles in the atmosphere. This photo is a combination of four images taken by Mars Pathfinder, which landed on Mars in 1997. Image credit: NASA/JPL

Mars is so different from Earth mostly because Mars is much farther from the sun and much smaller than Earth. The average distance from Mars to the sun is about 141,620,000 miles (227,920,000 kilometers). This distance is roughly 1 1/2 times the distance from Earth to the sun. The average radius (distance from its center to its surface) of Mars is 2,107 miles (3,390 kilometers), about half the radius of Earth.

Characteristics of Mars

Orbit and rotation

Like the other planets in the solar system, Mars travels around the sun in an elliptical (oval) orbit. But the orbit of Mars is slightly more "stretched out" than the orbits of Earth and most of the other planets. The distance from Mars to the sun can be as little as about 128,390,000 miles (206,620,000 kilometers) or as much as about 154,860,000 miles (249,230,000 kilometers). Mars travels around the sun once every 687 Earth days; this is the length of the Martian year.

The distance between Earth and Mars depends on the positions of the two planets in their orbits. It can be as small as about 33,900,000 miles (54,500,000 kilometers) or as large as about 249,000,000 miles (401,300,000 kilometers).

Like Earth, Mars rotates on its axis from west to east. The Martian solar day is 24 hours 39 minutes 35 seconds long. This is the length of time that Mars takes to turn around once with respect to the sun. The Earth day of 24 hours is also a solar day.

The axis of Mars is not perpendicular to the planet's orbital plane, an imaginary plane that includes all points in the orbit. Rather, the axis is tilted from the perpendicular position. The angle of the tilt, called the planet's obliquity, is 25.19¡ for Mars, compared with 23.45¡ for Earth. The obliquity of Mars, like that of Earth, causes the amount of sunlight falling on certain parts of the planet to vary widely during the year. As a result, Mars, like Earth, has seasons.

Mass and density

Mars has a mass (amount of matter) of 7.08 X 1020 tons (6.42 X 1020 metric tons). The latter number would be written out as 642 followed by 18 zeroes. Earth is about 10 times as massive as Mars. Mars's density (mass divided by volume) is about 3.933 grams per cubic centimeter. This is roughly 70 percent of the density of Earth.

Gravitational force

Because Mars is so much smaller and less dense than Earth, the force due to gravity at the Martian surface is only about 38 percent of that on Earth. Thus, a person standing on Mars would feel as if his or her weight had decreased by 62 percent. And if that person dropped a rock, the rock would fall to the surface more slowly than the same rock would fall to Earth.

Physical features of Mars

Scientists do not yet know much about the interior of Mars. A good method of study would be to place a network of motion sensors called seismometers on the surface. Those instruments would measure tiny movements of the surface, and scientists would use the measurements to learn what lies beneath. Researchers commonly use this technique to study Earth's interior.

Scientists have four main sources of information on the interior of Mars: (1) calculations involving the planet's mass, density, gravity, and rotational properties; (2) knowledge of other planets; (3) analysis of Martian meteorites that fall to Earth; and (4) data gathered by orbiting space probes. They think that Mars probably has three main layers, as Earth has: (1) a crust of rock, (2) a mantle of denser rock beneath the crust, and (3) a core made mostly of iron.

Crust

Scientists suspect that the average thickness of the Martian crust is about 30 miles (50 kilometers). Most of the northern hemisphere lies at a lower elevation than the southern hemisphere. Thus, the crust may be thinner in the north than in the south.

The surface of Mars was sampled for signs of life by the Viking 2 lander in 1976. A mechanical sampling arm dug the grooves near the round rock at the lower left. The cylinder at the right covered the sampling device and was ejected after landing. The cylinder is about 12 inches (30 centimeters) long. Image credit: NASA/National Space Science Data Center

Much of the crust is probably composed of a volcanic rock called basalt (buh SAWLT). Basalt is also common in the crusts of Earth and the moon. Some Martian crustal rocks, particularly in the northern hemisphere, may be a form of andesite. Andesite is also a volcanic rock found on Earth, but it contains more silica than basalt does. Silica is a compound of silicon and oxygen.

Mantle

The mantle of Mars is probably similar in composition to Earth's mantle. Most of Earth's mantle rock is peridotite (PEHR uh DOH tyt), which is made up chiefly of silicon, oxygen, iron, and magnesium. The most abundant mineral in peridotite is olivine (OL uh veen).

The main source of heat inside Mars must be the same as that inside Earth: radioactive decay, the breakup of the nuclei of atoms of elements such as uranium, potassium, and thorium. Due to radioactive heating, the average temperature of the Martian mantle may be roughly 2700 degrees F (1500 degrees C).

Core

Mars probably has a core composed of iron, nickel, and sulfur. The density of Mars gives some indication of the size of the core. Mars is much less dense than Earth. Therefore, the radius of Mars's core relative to the overall radius of Mars must be smaller than the radius of Earth's core relative to the overall radius of Earth. The radius of the Martian core is probably between 900 and 1,200 miles (1,500 and 2,000 kilometers).

Unlike Earth's core, which is partially molten (melted), the core of Mars probably is solid. Scientists suspect that the core is solid because Mars does not have a significant magnetic field. A magnetic field is an influence that a magnetic object creates in the region around it. Motion within a planet's molten core makes the core a magnetic object. The motion occurs due to the rotation of the planet.

Data from Mars Global Surveyor show that some of the planet's oldest rocks formed in the presence of a strong magnetic field. Thus, in the distant past, Mars may have had a hotter interior and a molten core.

Surface features

Mars has many of the kinds of surface features that are common on Earth. These include plains, canyons, volcanoes, valleys, gullies, and polar ice. But craters occur throughout the surface of Mars, while they are rare on Earth. In addition, fine-grained reddish dust covers almost all the Martian surface.

Plains

Many regions of Mars consist of flat, low-lying plains. Most of these areas are in the northern hemisphere. The lowest of the northern regions are among the flattest, smoothest places in the solar system. They may be so smooth because they were built up from deposits of sediment (tiny particles that settle to the bottom of a liquid). There is ample evidence that water once flowed across the Martian surface. The water would have tended to collect in the lowest spots on the planet and thus would have deposited sediments there.

Canyons

The Valles Marineris system of valleys is about 2,500 miles (4,000 kilometers) long -- roughly one-fifth the distance around the planet Mars. Parts of the system are 6 miles (10 kilometers) deep. Image credit: NASA/National Space Science Data Center

Along the equator lies one of the most striking features on the planet, a system of canyons known as the Valles Marineris. The name is Latin for Valleys of Mariner; a space probe called Mariner 9 discovered the canyons in 1971. The canyons run roughly east-west for about 2,500 miles (4,000 kilometers), which is close to the width of Australia or the distance from Philadelphia to San Diego. Scientists believe that the Valles Marineris formed mostly by rifting, a splitting of the crust due to being stretched.

Individual canyons of the Valles Marineris are as much as 60 miles (100 kilometers) wide. The canyons merge in the central part of the system, in a region that is as much as 370 miles (600 kilometers) wide. The depth of the canyons is enormous, reaching 5 to 6 miles (8 to 10 kilometers) in some places.

Large channels emerge from the eastern end of the canyons, and some parts of the canyons have layered sediments. The channels and sediments indicate that the canyons may once have been partly filled with water.

Volcanoes

Mars has the largest volcanoes in the solar system. The tallest one, Olympus Mons (Latin for Mount Olympus), rises 17 miles (27 kilometers) above the surrounding plains. It is about 370 miles (600 kilometers) in diameter. Three other large volcanoes, called Arsia Mons, Ascraeus Mons, and Pavonis Mons, sit atop a broad uplifted region called Tharsis.

All these volcanoes have slopes that rise gradually, much like the slopes of Hawaiian volcanoes. Both the Martian and Hawaiian volcanoes are shield volcanoes. They formed from eruptions of lavas that can flow for long distances before solidifying.

Mars also has many other types of volcanic landforms. These range from small, steep-sided cones to enormous plains covered in solidified lava. Scientists do not know how recently the last volcano erupted on Mars -- some minor eruptions may still occur.

Craters and impact basins

Many meteoroids have struck Mars over its history, producing impact craters. Impact craters are rare on Earth for two reasons: (1) Those that formed early in the planet's history have eroded away, and (2) Earth developed a dense atmosphere, preventing meteorites that could have formed craters from reaching the planet's surface.

Martian craters are similar to craters on Earth's moon, the planet Mercury, and other objects in the solar systems. The craters have deep, bowl-shaped floors and raised rims. Large craters can also have central peaks that form when the crater floor rebounds upward after an impact.

On Mars, the number of craters varies dramatically from place to place. Much of the surface of the southern hemisphere is extremely old, and so has many craters. Other parts of the surface, especially in the northern hemisphere, are younger and thus have fewer craters.

Some volcanoes have few craters, indicating that they erupted recently. The lava from the volcanoes would have covered any craters that existed at the time of the eruptions. And not enough time has passed since the eruptions for many new craters to form.

Some of the impact craters have unusual-looking deposits of ejecta, material thrown out of the craters at impact. These deposits resemble mudflows that have solidified. This appearance suggests that the impacting bodies may have encountered water or ice beneath the ground.

Mars has a few large impact craters. The largest is Hellas Planitia in the southern hemisphere. Planitia is a Latin word that can mean low plain or basin; Hellas Planitia is also known as the Hellas impact basin. The crater has a diameter of about 1,400 miles (2,300 kilometers). The crater floor is about 5.5 miles (9 kilometers) lower than the surrounding plain.

Channels in a Martian crater, in an image taken in 2000 by the Mars Global Surveyor, suggest to scientists that liquid water may have flowed across the surface of Mars in recent times. Image credit: NASA

Channels, valleys, and gullies occur in many regions of Mars, apparently as a result of water erosion. The most striking of these features are known as outflow channels. These channels can be as wide as 60 miles (100 kilometers) and as long as 1,200 miles (2,000 kilometers). They appear to have been carved by enormous floods that rushed across the surface. In many cases, the water seems to have escaped suddenly from underground.

Many of the channels do not look like river systems on Earth, with the main river formed from smaller rivers and streams. Rather, those Martian channels arise fully formed from low-lying areas.

Other regions of Mars have much smaller features called valley networks. These networks look more like river systems on Earth. Martian valley networks are up to a few miles or kilometers wide and up to a few hundred miles or kilometers long. The networks are mostly ancient features. They suggest that the Martian climate may once have been warm enough to enable water to exist as a liquid.

The gullies are smaller still. Most of them lie at high latitudes. They may be a result of a leakage of a small amount of ground water to the surface within the past few million years.

Polar deposits

The most interesting features in the polar regions of Mars are thick stacks of finely layered deposits of material. Scientists believe that the layers consist of mixtures of water ice and dust. The deposits extend from the poles to latitudes of about 80 degrees in both hemispheres.

The atmosphere probably deposited the layers over long periods. The layers may provide evidence of seasonal weather activity and long-term changes in the Martian climate. One possible cause of climate changes is variation in the planet's obliquity. This variation alters the amount of sunlight falling on different parts of Mars. The variation in sunlight, in turn, may change the climate. Past climate changes could have affected the rate at which the atmosphere deposited dust and ice into layers.

Lying atop much of the layered deposits in both hemispheres are caps of water ice that remain frozen all year. The layers and overlying caps are several miles or kilometers thick.

In the wintertime, additional seasonal caps form from layers of frost. The seasonal caps are clearly visible through Earth-based telescopes. The frost consists of solid carbon dioxide (CO2) -- also known as "dry ice" -- that has condensed from CO2 gas in the atmosphere. In the deepest part of the winter, the frost extends from the poles to latitudes as low as 45 degrees -- halfway to the equator.

Atmosphere

The atmosphere of Mars contains much less oxygen (O2) than that of Earth. The O2 content of the Martian atmosphere is only 0.13 percent, compared with 21 percent in Earth's atmosphere. Carbon dioxide makes up 95.3 percent of the gas in the atmosphere of Mars. Other gases include nitrogen (N2), 2.7 percent; argon (Ar), 1.6 percent; carbon monoxide (CO), 0.07 percent; and water vapor (H2O), 0.03 percent.

Pressure

At the surface of Mars, the atmospheric pressure is typically only about 0.10 pound per square inch (0.7 kilopascal). This is roughly 0.7 percent of the atmospheric pressure at Earth's surface. When the seasons change on Mars, the atmospheric pressure at the surface there varies by 20 to 30 percent.

Each winter, the condensation of CO2 at the poles removes much gas from the atmosphere. When this happens, the atmospheric pressure due to CO2 gas decreases sharply. The opposite process occurs each summer. In addition, the atmospheric pressure varies as the weather changes during the day, much as on Earth.

Temperature

The atmosphere of Mars is coldest at high altitudes, from about 40 to 78 miles (65 to 125 kilometers) above the surface. At those altitudes, typical temperatures are below -200 degrees F (-130 degrees C). The temperature increases toward the surface, where daytime temperatures of -20 to -40 degrees F (-30 to -40 degrees C) are typical. In the lowest few miles or kilometers of the atmosphere, the temperature varies widely during the day. It can reach -150 degrees F (-100 degrees C) late at night, even near the equator.

Atmospheric temperatures can be warmer than normal when the atmosphere contains much dust. The dust absorbs sunlight and then transfers much of the resulting heat to the atmospheric gases.

Clouds

In the Martian atmosphere, thin clouds made up of particles of frozen CO2 can form at high altitudes. In addition, clouds, haze, and fog composed of particles of water ice are common. Haze and fog are especially frequent in the early morning. At that time, temperatures are the lowest, and water vapor is therefore most likely to condense.

Wind

The Martian atmosphere, like that of Earth, has a general circulation, a wind pattern that occurs over the entire planet. Scientists have studied the global wind patterns of Mars by observing the motions of clouds and changes in the appearance of wind-blown dust and sand on the surface.

Global-scale winds occur on Mars as a result of the same process that produces such winds on Earth. The sun heats the atmosphere more at low latitudes than at high latitudes. At low latitudes, the warm air rises, and cooler air flows in along the surface to take its place. The warm air then travels toward the cooler regions at higher latitudes. At the higher latitudes, the cooler air sinks, then travels toward the equator.

On Mars, the condensation and evaporation of CO2 at the poles influence the general circulation. When winter begins, atmospheric CO2 condenses at the poles, and more CO2 flows toward the poles to take its place. When spring arrives, CO2 frost evaporates, and the resulting gas flows away from the poles.

Surface winds on Mars are mostly gentle, with typical speeds of about 6 miles (10 kilometers) per hour. Scientists have observed wind gusts as high as 55 miles (90 kilometers) per hour. However, the gusts exert much less force than do equally fast winds on Earth. The winds of Mars have less force because of the lower density of the Martian atmosphere.

Dust storms

Some of the most spectacular weather occurs on Mars when dust blows in the wind. Small, swirling winds can lift dust off the surface for brief intervals. These winds create dust devils, tiny storms that look like tornadoes.

Large dust storms begin when wind lifts dust into the atmosphere. The dust then absorbs sunlight, warming the air around it. As the warmed air rises, more winds occur, lifting still more dust. As a result, the storm becomes stronger.

At larger scales, dust storms can blanket areas from more than 200 miles (320 kilometers) to a few thousand miles or kilometers across. The largest storms can cover the entire surface of Mars. Storms of that size are unusual, but they can last for months. The strongest storms can block almost the entire surface from view. Such storms occurred in 1971 and 2001.

Dust storms are most common when Mars is closest to the Sun. More storms occur then because that is when the sun heats the atmosphere the most.

Satellites

Mars has two tiny moons, Phobos and Deimos. The American astronomer Asaph Hall discovered them in 1877 and named them for the sons of Ares. Both satellites are irregularly shaped. The largest diameter of Phobos is about 17 miles (27 kilometers); that of Deimos, about 9 miles (15 kilometers).

The two satellites have many craters that formed when meteoroids struck them. The surface of Phobos also has a complicated pattern of grooves. These may be cracks that developed when an impact created the satellite's largest crater.

Scientists do not know where Phobos and Deimos formed. They may have come into existence in orbit around Mars at the same time the planet formed. Another possibility is that the satellites formed as asteroids near Mars. The gravitational force of Mars then pulled them into orbit around the planet. The color of both satellites is a dark gray that is similar to the color of some kinds of asteroids.

Evolution of Mars

Scientists know generally how Mars evolved after it formed about 4.6 billion years ago. Their knowledge comes from studies of craters and other surface features. Features that formed at various stages of the planet's evolution still exist on different parts of the surface. Researchers have developed an evolutionary scenario that accounts for the sizes, shapes, and locations of those features.

Researchers have ranked the relative ages of surface regions according to the number of impact craters observed. The greater the number of craters in a region, the older the surface there.

However, scientists have not yet determined exactly when the various evolutionary stages occurred. To do that, they would need to know the ages of rocks of surface features representing those stages. They could determine how old such rocks are if they could analyze samples of them in a laboratory. But no space probe has ever brought Martian rocks to Earth.

Scientists have divided the "lifetime" of Mars into three periods. From the earliest to the most recent, the periods are: (1) The Noachian (noh AY kee uhn), (2) the Hesperian, and (3) the Amazonian. Each period is named for a surface region that was created during that period.

The Noachian Period is named for Noachis Terra, a vast highland in the southern hemisphere. During the Noachian Period, a tremendous number of rocky objects of all sizes, ranging from small meteoroids to large asteroids, struck Mars. The impact of those objects created craters of all sizes. The Noachian was also a time of great volcanic activity.

In addition, water erosion probably carved the many small valley networks that mark Mars's surface during the Noachian Period. The presence of those valleys suggests that the climate may have been warmer during the Noachian Period than it is today.

The Hesperian Period

The intense meteoroid and asteroid bombardment of the Noachian Period gradually tapered off, marking the beginning of the Hesperian Period. This period is named for Hesperia Planum, a high plain in the lower latitudes of the southern hemisphere.

During the Hesperian Period, volcanic activity continued. Volcanic eruptions covered over Noachian craters in many parts of Mars. Most of the largest outflow channels on the planet are of Hesperian age.

The Amazonian Period, which is characterized by a low rate of cratering, continues to this day. The period is named for Amazonis Planitia, a low plain that is in the lower latitudes of the northern hemisphere.

Volcanic activity has occurred throughout the Amazonian Period, and some of the largest volcanoes on Mars are of Amazonian age. The youngest geologic materials on Mars, including the ice deposits at the poles, are also Amazonian.

Possibility of life

Mars might once have harbored life, and living things might exist there even today. Mars almost certainly has three ingredients that scientists believe are necessary for life: (1) chemical elements such as carbon, hydrogen, oxygen, and nitrogen that form the building blocks of living things, (2) a source of energy that living organisms can use, and (3) liquid water.

The essential chemical elements likely were present throughout the planet's history. Sunlight could be the energy source, but a second source of energy could be the heat inside Mars. On Earth, internal heat supports life in the deep ocean and in cracks in the crust.

Liquid water apparently carved Mars's large channels, its smaller valleys, and its young gullies. In addition, there are vast quantities of ice within about 3 feet (1 meter) of the surface near the south pole and perhaps near the north pole. Thus, water apparently has existed near the surface over much of the planet's history. And water is probably present beneath the surface today, kept liquid by Mars's internal heat.

A curved, rodlike structure shown in the center of this photo has been referred to as a fossilized Martian creature by some scientists. The structure is about 200 billionths of a meter long and is part of a Martian rock that was found on Earth. Image credit: NASA/Johnson Space Center

In 1996, scientists led by David S. McKay, a geologist at the National Aeronautics and Space Administration's Johnson Space Center in Houston, reported that scientists there had found evidence of microscopic Martian life. They discovered this evidence inside a meteorite that had made its way to Earth. The meteorite had been blasted from the surface of Mars, almost certainly by the impact of a much larger meteorite. The small meteorite had then journeyed to Earth, attracted by Earth's gravity. The trip may have taken millions of years.

The evidence included complex organic molecules, grains of a mineral called magnetite that can form within some kinds of bacteria, and tiny structures that resemble fossilized microbes. The scientists' conclusions are controversial, however. There is no general scientific agreement that Mars has ever harbored life.

History of Mars study

Observation from Earth

Observing Mars through Earth-based telescopes, early astronomers discovered polar caps that grow and shrink with the seasons. They also found light and dark markings that change their shape and location.

In the late 1800's, the Italian astronomer Giovanni V. Schiaparelli reported that he saw a network of fine dark lines. He called these lines canali, which is Italian for channels. But canali was generally mistranslated as canals. Many other astronomers also reported seeing such features. Among those observers was the American astronomer Percival Lowell, who referred to the features as canals. Lowell speculated that the canals had been built by a Martian civilization.

The canals turned out not to exist. In some cases, the observers had misinterpreted dark, blurry regions that they had actually seen. In other cases, there was no relationship between "canals" and real features.

However, the changing dark and light markings were real. Some scientists thought that the changing patterns might result from the growth and death of vegetation. Much later, other scientists suspected correctly that the cause was the Martian winds. Light and dark materials blow to and fro across the surface.

Observation by spacecraft

Robotic spacecraft began detailed observation of Mars in the 1960's. The United States launched Mariner 4 to Mars in 1964 and Mariners 6 and 7 in 1969. Each flew by Mars about half a year after its launch. The craft took pictures showing that Mars is a barren world, with craters like those on the moon. There was no sign of liquid water or life. The spacecraft observed few of the planet's most interesting features because they happened to fly by only heavily cratered regions.

In 1971, Mariner 9 went into orbit around Mars. This craft mapped about 80 percent of Mars. It made the first discoveries of the planet's canyons and volcanoes. It also found what appear to be dry riverbeds.

The Sojourner Rover examines a rock on Mars. The rover traveled from Earth aboard the Mars Pathfinder space probe, then rolled down a ramp to the surface. Sojourner is only 24 3/4 inches (63 centimeters) long. Image credit: NASA

The next major mission to Mars was Viking, launched by the United States in 1975. Viking consisted of two orbiters and two landers. Its main goal was to search for life. The orbiters scouted out landing sites for the landers, which touched down in July and September 1976. The landers took the first close-up pictures of the Martian surface, and they sampled the soil. They found no strong evidence for life.

The next two successful probes were Mars Pathfinder, which was a lander, and Mars Global Surveyor, an orbiter. The United States launched both craft in 1996. The main objective of Pathfinder was to demonstrate a new landing system. Inflated air bags cushioned the probe's landing in July 1997. Pathfinder also carried a small roving vehicle called Sojourner. The rover rolled down a ramp to the surface, and then moved from rock to rock. Pathfinder sent spectacular photos back to Earth, and Sojourner analyzed rocks and soil. People throughout the world watched television pictures of Sojourner doing its work.

Mars Global Surveyor studied the composition of the Martian surface, photographed the surface in detail, and measured its elevation. The space probe went into orbit around Mars in 1997. Image credit: NASA/JPL

Mars Global Surveyor carried a group of sophisticated scientific instruments. A laser altimeter used laser beams to determine the elevation of the Martian surface. This instrument produced maps of the entire surface that are accurate to within 1 yard or meter of elevation. An infrared spectrometer determined the composition of some of the minerals on the surface. A high-resolution camera revealed a host of new geologic features. These include layered sediments that may have been deposited in liquid water, and small gullies that appear to have been carved by water.

In April 2001, the United States launched the Mars Odyssey probe. The probe carried instruments to analyze the chemical composition of the Martian surface and the rocks just below the surface, to determine whether there is water ice on or beneath the surface, and to study the radiation near Mars. Mars Odyssey went into orbit around the planet in October 2001. In 2002, the probe discovered vast amounts of water ice beneath the surface. Most of the ice found is in the far southern part of the planet, south of 60 degrees south latitude. Scientists also suspect that there are large amounts of water ice north of 60 degrees north latitude. However, when the discovery was made, CO2 frost covered most of that area, preventing the probe from detecting underlying ice.

The water ice found in the south is in the upper 3 feet (1 meter) of soil. That soil is more than 50 percent water ice by volume. The total volume of the water ice discovered is roughly 2,500 cubic miles (10,400 cubic kilometers), more than enough to fill Lake Michigan twice.

The probe cannot detect evidence of water at depths greater than 3 feet. Thus, scientists cannot yet determine the total depth or the total volume of all the water ice on Mars.

Mars was photographed by the Hubble Space Telescope in August 2003 as the planet passed closer to Earth than it had in nearly 60,000 years. The photographs captured many features of the Martian surface, including dark, circular impact craters and the bright ice of the southern polar cap. Image credit: NASA, J. Bell (Cornell U.) and M. Wolff (SSI)

Mars passed closer to Earth in August 2003 than it had in nearly 60,000 years. In that year, scientists launched three new probes. The European Space Agency's Mars Express mission included an orbiter that carried scientific instruments and a lander designed to analyze the planet's soil for evidence of life. The United States launched two rovers, nicknamed Spirit and Opportunity, to explore different regions of the planet's surface.

In December 2003, Mars Express went into orbit around the planet and released its lander, Beagle 2. Mars Express immediately began transmitting pictures and other information about the planet, but mission managers could not contact Beagle 2 and feared it was lost. In early January 2004, the U.S. rover Spirit landed safely in an area called Gusev Crater. The rover Opportunity landed later that month in an area called Meridiani Planum. The rovers transmitted detailed photographs of Martian ground features and began analyzing rocks and soil for evidence that large amounts of liquid water once existed on the planet's surface.

In March 2004, U.S. scientists announced that they had concluded that Meridiani Planum once held large amounts of liquid water. Their evidence came from an outcropping of Martian bedrock found in the small crater in which Opportunity landed. The rover's analysis showed that the rock contained large amounts of sulfate salts, which contain sulfur and oxygen. On Earth, such high concentrations of sulfate salts occur only in rocks that formed in water or were exposed to water for long periods. The outcropping's surface also bore tiny pits similar to those found on Earth where salt crystals formed in wet rock and later dissolved or eroded away.

The rover Spirit rests on Mars in a composite image made up of photographs taken by a camera mounted above the rover's body. Spirit landed on Mars in early January 2004. The pole at the lower left is one of the antennas Spirit uses to communicate with NASA controllers. Image credit: NASA

The rover mission was scheduled to last only 90 days, but it was extended because Spirit and Opportunity continued to function well. In June 2004, Opportunity descended into a large crater that mission managers called Endurance and analyzed the layers of bedrock there. Also in June, Spirit arrived at a group of hills, called Columbia Hills, after a drive of over 2 miles (3 kilometers). The rovers continued to explore these sites for several months.

Contributor: Steven W. Squyres, Ph.D., Professor of Astronomy, Cornell University.

How to cite this article: To cite this article, World Book recommends the following format: Squyres, Steven W. "Mars." World Book Online Reference Center. 2004. World Book, Inc. (http://www.worldbookonline.com/wb/Article?id=ar346000

Feature

2007-04-23T13:18:00.000+05:30

International Teams Join Moonbuggy Race
04.02.07
Going back to the time of pioneer rocket developer Wernher von Braun, great advances in space technology have come from German engineers and scientists at Marshall Space Flight Center in Huntsville, Ala.Now, a new generation of German engineers and scientists is coming to town. They are students -- one as young as 13 years old -- and they are coming to compete in the 14th annual Great Moonbuggy Race, April 13-14, 2007, at the U.S. Space & Rocket Center in Huntsville.Traditionally, the Great Moonbuggy Race has challenged U.S. high school and college students to design and build a vehicle that addresses a series of engineering problems similar to those faced by the original lunar roving vehicle team. However, this year two student teams from outside the United States will enter the competition. One of the teams will travel from nearby Canada and the other will make a transatlantic trip from Germany.
The German Space Education Institute is sponsoring the German students. The institute was encouraged to select students and enter the competition by NASA's Jesco von Puttkamer, born in Leipzig, who came to Huntsville 45 years ago to join the von Braun team.Image to right: Students from the German moonbuggy team designed a mission patch representing their participation in the Great Moonbuggy Race. Credit: Jesco von PuttkamerVon Puttkamer said the German Space Education Institute, in Leipzig, Germany, has conducted student field trips to both Russian and NASA space centers as part of its efforts to educate German students about the space industry. The institute selected six of its field trip applicants -- all between the ages of 13 and 17 -- to build a moonbuggy for the Huntsville race.The students have prepared for the race in several ways, von Puttkamer said. They have studied astronomy, the history of spaceflight, and the space exploration plans of both the U.S. and Russia. They have toured German businesses, including an automobile plant, to learn more about transportation, the construction of lightweight vehicles (such as wheelchairs), and material strength. They have analyzed videos of the 2006 moonbuggy race, and the two students who will drive the moonbuggy are training for the physical challenges of pedaling through the crater-like obstacles.The team members even explored their creative sides by designing a mission patch depicting von Braun, a moonbuggy and railroad tracks going to Mars via the moon.The students studied and implemented marketing techniques as they sought financial support from sponsors. Von Puttkamer said the students are learning how to share their story with German talk shows, television stations and newspapers."This is much more difficult in Germany than in the USA, since the concept of grassroots initiative and commercial sponsoring is quite new there and still regarded with some suspicion and reluctance," von Puttkamer said. "But to have any chance at all, they must 'beat their drum' and learn about such personal marketing -- a good lesson for life."Another challenge is transporting the moonbuggy to the race, von Puttkamer said. The team must follow U.S. import procedures to bring their moonbuggy into the country. The moonbuggy will be transported in parts in the students' luggage. Each part must be no larger and no heavier than the size and weight limitations set by the airline for international air travel."It is important to understand the handicaps these students are working against, a real uphill battle against many odds," von Puttkamer said. "This is the very first time for them, whereas most of the other competing teams in April will have been at Huntsville before and have the benefit of many 'lessons learned.'"
The journey will be the first trip to the United States for five of the six German moonbuggy team members. The team's leader came to the U.S. in 2006 on a field trip to NASA centers, which included Marshall.Image to left: A moonbuggy team navigates an obstacle during a past competition. Credit: NASAVon Puttkamer lived in Huntsville in the 1960s when he worked at Marshall with von Braun. He came to NASA in 1962 upon personal invitation from von Braun. He was employed at Marshall in the aeroballistics division for 12 years. In 1974, von Puttkamer transferred to NASA Headquarters, where he still works today. He plans to attend the race, as he did last year, representing NASA's Space Operations Mission Directorate.The Canadian team is coming from Carleton University in Ottawa, Ontario. The students are members of the Carleton University Students for the Exploration and Development of Space. The college was contacted about sending a team to the race by self-described space fan Don McMillan. McMillan attended the moonbuggy race two years ago and returned home to Ottawa, eager for a school in his area to compete."I found the races inspiring and was impressed with all of the students' imagination and determination," McMillan said.McMillan is a graphic artist who has had a life-long interest in space, particularly the Apollo missions. He spent two years researching the original lunar roving vehicle and designing a three-dimensional model of the rover. Some of McMillan's lunar rover animations are featured on the Apollo Lunar Surface Journal Web site, which is hosted by the NASA History Office. He also designed a poster about the lunar rover and distributed copies of the poster to the 2005 moonbuggy race participants."After seeing the competition, I felt a competition such as this was important to students looking to the space industry as a career," McMillan said.
Related Resources+ Great Moonbuggy Race + Marshall Space Flight Center + NASA Education Web Site McMillan will attend the race this year with high hopes that his Canadian students will do well. "I hope we can bring this spirit of the competition back to other Canadian schools and enter even more teams next year," McMillan said.A total of 60 teams in the high school and college divisions will compete this year. In the high school division there are 36 high schools representing 14 states and Germany. Competing in the college race there are 25 universities and colleges from 13 states, Puerto Rico and Canada.Through competitions like the Great Moonbuggy Race, NASA continues its tradition of investing in the nation's future by emphasizing three major education goals -- attracting and retaining students in science, technology, engineering and mathematics disciplines; strengthening NASA and the nation's future workforce; and engaging Americans in NASA's mission. To compete effectively for the minds, imaginations and career ambitions of America's young people, NASA is focused on supporting formal and informal educators to engage and retain students in education efforts that encourage their pursuit of disciplines needed to achieve the Vision for Space Exploration.

AIM Set to Explore Polar Clouds

2007-04-19T13:53:00.000+05:30

At Vandenberg Air Force Base in Calif., NASA's AIM spacecraft was mated to the Pegasus XL rocket on April 4. An integrated flight simulation was successfully completed earlier this week. Technicians began to install the Pegasus fairing around the AIM spacecraft, followed by a black light inspection of the fairing and spacecraft. The spacecraft umbilical was disconnected and re-routed to allow the payload fairing to move into the clean room.The Pegasus rocket with the AIM spacecraft is planned to be installed onto the transporter on April 16. The L-1011 carrier aircraft is slated to arrive at Vandenberg Air Force Base the following day. The transportation of Pegasus/AIM to the runway for mating operations with the L-1011 is scheduled for April 22.The first opportunity for launch is on Wednesday, April 25 from Vandenberg aboard a Pegasus XL launch vehicle.+ Read Press Release

04.11.07

- AIM to Study Clouds at Edge Of Space NASA is preparing to launch the Aeronomy of Ice in the Mesosphere (AIM) spacecraft, the first mission dedicated to exploration of mysterious ice clouds that dot the edge of space in Earth's polar regions.+ Read More

04.06.07 - Expendable Launch Vehicle Status Report NASA's Aeronomy of Ice in the Mesosphere (AIM) spacecraft was mated to the Pegasus XL rocket on Wednesday. An integrated flight simulation is scheduled for early next week.+ Read More

04.05.07 - Media Briefing on Mission to Study Earth's Highest Clouds NASA will host a media teleconference on Wednesday, April 11 at 2 p.m. EDT to discuss science objectives of the Aeronomy of Ice in the Mesosphere (AIM) mission.

Click here to AIM fact sheet(PDF)

2007-04-01T13:35:00.000+05:30

Crew Moves Soyuz to Prep for New Arrivals

Crew Moves Soyuz to Prep for New Arrivals Image above: The Soyuz TMA-9 spacecraft undocks from the station's Zarya module. Image credit: NASA TV The Expedition 14 crew aboard the International Space Station welcomed an off-duty day Friday after a busy week of preparations for the arrival of the next crew in April. Commander Mike Lopez-Alegria and flight engineers Mikhail Tyurin and Suni Williams boarded their Soyuz TMA-9 spacecraft and undocked it from the Earth-facing port of the station's Zarya module at 6:30 p.m. EDT Thursday. With Tyurin at the controls, the craft was maneuvered to the aft port of the Zvezda module and docked at 6:54 p.m. The move was made to clear the Zarya port for the arrival of Expedition 15 Commander Fyodor Yurchikhin and Flight Engineer Oleg Kotov, along with spaceflight participant Charles Simonyi on April 9. + Read more about the Soyuz relocation On Tuesday, the unpiloted Progress 23 cargo craft was undocked from the aft port of the Zvezda service module. The cargo craft, filled with trash and unneeded items from the station, was commanded several hours after undocking to re-enter the Earth's atmosphere and burn up over the Pacific Ocean. The crew also continued science research aboard the orbital outpost this week, including a successful run with the Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) experiment. During a session with SPHERES, Williams set up a test in which three of the bowling-ball sized satellites flew together in formation within the station cabin for the first time. + Final Report of the ISS Independent Safety Task Force (3.7 Mb PDF)+ Read more about Expedition 14 + Read more about Expedition 15 + View Crew's Daily Timelines Space Station Astronaut to Run Marathon in Space Flight Engineer Suni Williams will run in the Boston Marathon in April as an official entrant from 210 miles above Earth aboard the International Space Station. She will run the race on a station treadmill, circling Earth at least twice in the process, running as fast as eight miles per hour but flying more than five miles each second. Williams, an accomplished marathoner, hopes her unique run will serve as an inspiration. "I encourage kids to start making physical fitness part of their daily lives," Williams said. "I think a big goal like a marathon will help get this message out there." + Read press release + View photo of Suni Williams running on station treadmill
Why Explore Space? Completing the International Space Station, explains NASA Administrator Mike Griffin, is an integral part of the Vision for Space Exploration. "Today," Griffin writes, "NASA is moving forward with a new focus for the manned space program: to go out beyond Earth orbit for purposes of human exploration and scientific discovery. And the International Space Station is now a stepping stone on the way, rather than being the end of the line." + Read More

Station Crew Moves Soyuz International Space Station Commander Mike Lopez-Alegria and flight engineers Mikhail Tyurin and Sunita Williams moved their Soyuz TMA spacecraft from the Earth-facing port of the station's Zarya module to the aft port of the Zvezda module Thursday.+ Read More

Spacewalkers Successfully Retract Progress Antenna International Space Station Flight Engineer Mikhail Tyurin and Commander Michael Lopez-Alegria retracted a balky antenna of an unpiloted Progress cargo carrier at the aft port of the Zvezda Service Module during a 6-hour, 18-minute spacewalk Thursday.+ Read More

Station Crew Conducts Three Back-to-Back Spacewalks The third spacewalk in nine days by International Space Station Commander Michael Lopez-Alegria and Flight Engineer Sunita Williams was completed Thursday, Feb. 8.+ Read More

Orbiting Astronauts Swear in Navy Sailors A special re-enlistment ceremony was held on Jan. 29 for 16 Navy sailors aboard the USS Dwight D. Eisenhower.+ Read More

'Why Explore Space?'By Administrator Griffin Today, NASA is moving forward with a new focus for the manned space program: to go out beyond Earth orbit for purposes of human exploration and scientific discovery.+ Read More

Progress Docks with Space Station A new Progress docked to the International Space Station at 9:59 p.m. EST Friday with more than 2.5 tons of fuel, oxygen, other supplies and equipment aboard.+ Read More

+ View Archives

2006-10-29T16:00:00.000+05:30

Preparing for Launch

Image above: Inside the SPACEHAB Payload Processing Facility at Port Canaveral, Fla., STS-116 mission specialists (from left) Joan Higginbotham, Sunita Williams and Nicholas Patrick look over flight hardware during the Crew Equipment Interface Test. Image Credit: NASA/Jack Pfaller

Inside Kennedy Space Center's Orbiter Processing Facility, technicians are wrapping up work on the orbiter Discovery in preparation for rollover to the Vehicle Assembly Building on Nov. 1. Once inside the massive building, Discovery will be mated to the external tank and solid rocket boosters. Rollout of the entire shuttle assembly to the seaside launch pad is scheduled for Nov. 8.

The STS-116 crew members recently visited Kennedy for the crew equipment interface test. The test is a routine part of astronaut training and launch preparations, and allows astronauts to get hands-on experience with the equipment and flight hardware they'll use during the mission.

During the STS-116 mission, Discovery will deliver the P5 integrated truss structure to the International Space Station, continuing the assembly of the orbiting outpost. Launch is scheduled for no earlier than Dec. 7.

2006-10-29T15:50:00.000+05:30

Expedition 14 Begins Unloading Progress

Image above: This photograph of the Progress 23 cargo craft taken by Flight Engineer Thomas Reiter highlights the Kurs Antenna that concerned flight directors prior to final latching on Thursday. Photo credit: NASA.

The Expedition 14 crew opened the hatches to the new Progress cargo capsule Friday morning and began unloading critical equipment including spare parts for a faulty Russian oxygen generator. The Progress 23 automatically docked to the aft end of the Zvezda service module at 10:29 a.m. EDT Thursday delivering over 2 1/2 tons of propellant, oxygen, spare parts, experiment hardware and life support components.

Russian controllers are analyzing data to determine if an antenna on the Progress supply ship has retracted as commanded. Concern with that antenna prompted flight controllers to delay fully latching the supply ship for about three hours Thursday afternoon. Russian flight controllers determined the antenna was not a problem and the Progress 23 was latched at 2 p.m. EDT.

Expedition 14 Commander Michael Lopez-Alegria and Flight Engineers Tyurin and Thomas Reiter cleared Zvezda's docking port Oct. 10 when they undocked their Soyuz TMA spacecraft then redocked to the Zarya module's Earth-facing port.

NASA and the Russian Federal Space Agency have named two astronauts and two cosmonauts to the next International Space Station crew, known as Expedition 15. Astronauts Clayton Anderson and Daniel Tani will travel to the station next year and work as flight engineers. Cosmonauts Fyodor Yurchikhin and Dr. Oleg Kotov will spend six months aboard the orbiting laboratory.
-krishnaap lightdesk

SpotLight

NASA's STS-119 Mission: Boosting the Station Power

NASA's Kepler Spacecraft Arrives in Florida

Landing Practice, Comm Checks and Shuttle Installs on Tap for Wednesday

NASA's Carbon-Sniffing Satellite Sleuth Arrives at Launch Site

STS-126 Mission

NASA Assigns Crew For Space Shuttle Discovery's Sts-129 Mission

NASA Mars Lander Scoops First Soil Sample for Laboratory Analysis

Latest Images

Raw Images from Surface Stereo Imager

Raw Image Mosaics

NASA's Phoenix Mars Lander Ready to Gather Samples

Latest Images

Discovery's Crew Dresses for Liftoff

Two Days Before Launch

GLAST :: Gama ray large area space telescope

Countdown Clock Ticks Toward Saturday Launch

Phoenix Mars Lander

Latest Images

Raw Images from Surface Stereo Imager

Raw Image Mosaics

Mission Management

Solar Variability: Striking a Balance with Climate Change

NASA at 50:

Expedition 17 launched

Crew Profiles

Commander Sergei Volkov

Flight Engineer Oleg Kononenko

Flight Engineer Garrett E. Reisman

Flight Engineer Gregory E. Chamitoff

Spaceflight Participant So-yeon Yi

Expedition 16 Lands Safely; New Crew Performs Reboost Test

Spotlighting to the Supernova_Xplosions

"After" and "Before" pictures of Supernova 1987A

Types of Supernovae

What Causes a Star to Blow Up?

Where Does the Core Go?

Where Does Most of the Star Go?

Are We Made of Stardust?

How Often Do Supernovae Occur?

[For further reading...A good book written for the non-scientist is:The Supernova Story, by Laurence A. Marschall, Â©1988, Plenum Press, ISBN:0306429551.]

Spotlighting to the BlackHoles

Why Study Black Holes?

General Relativity[Einstein's 1916 paper on General Relativity]

Picture a bowling ball on a stretched rubber sheet.

The Flow of Spacetime

Gravitational Time Dilation

Grappling With Relativity

The Math Behind Einstein's Vision

Expeditions of Nasa

NASA Launches Airborne Study of Arctic Atmosphere, Air Pollution

The Jules Verne Approaches the Station

Dedication and Perspiration Builds The Next Generation Life Support System

Desert RATS Test Lunar Exploration Concepts

The Prius of Space

NASA Selects Ares I Upper Stage Production Contractor

NASA's Phoenix Mars Mission

Discovery's Crew to Deliver Harmony

STS-125 Shuttle Mission Imagery

Mission STS-118: Investing in Future Exploration

Fasten Your Seat Belts, Turbulence Ahead - Lessons From Titan

STS-118 Crew Launches Into Space; images

Phoenix takes flight!

Progress to Launch to Space Station

"Go" for Launch

Worldbook @ Nasa

Feature

AIM Set to Explore Polar Clouds