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Showing posts with label Satellites. Show all posts
Showing posts with label Satellites. Show all posts

Monday, January 03, 2011

Discovery External Tank Repairs Begin Monday as Engineers Analyze Data

Technicians working on space shuttle Discovery's external fuel tank in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida are off for the New Year holiday weekend. On Monday, they'll begin repairs on three support beams, called stringers, that recently were detected to have small cracks on their tops.

Engineers at various NASA centers continue to analyze data from testing and X-ray type image scans collected during the past week of all 108 stringers on the outside of the external tank's ‪intertank section. The image scans showed four small cracks on three stringers on the opposite side of the tank from Discovery. Managers decided Thursday to have those cracks repaired in a similar fashion to repairs made on cracks on two stringers found after Discovery's Nov. 5 launch attempt.

The repair work is estimated to take 2–3 days. Any further work will be evaluated thoroughly during the week after additional data and analysis are reviewed.

Managers also continue to evaluate an option to perform known and practiced modifications on some stringers. Before breaking for the holiday, technicians reconfigured scaffolding to provide access for the modification work, should it be required. A decision may be made on that work as early as Monday.







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Wednesday, December 08, 2010

SpaceX Falcon 9

The first SpaceX Falcon 9 demonstration launch for NASA's Commercial Orbital Transportation Services program is scheduled for Wednesday, Dec. 8, from Launch Complex 40 at Cape Canaveral Air Force Station in Florida. The launch window extends from 9 a.m. to 12:22 p.m. EST.

Tuesday, August 24, 2010

Launch Preps Move Ahead for Mission to International Space Station


During space shuttle Discovery's final spaceflight, the STS-133 crew members will take important spare parts to the International Space Station along with the Express Logistics Carrier-4. Discovery is being readied for flight inside Kennedy's Orbiter Processing Facility-3 while its solid rocket boosters are stacked inside the nearby Vehicle Assembly Building. STS-133 is slated to launch Nov. 1.

Thursday, August 19, 2010

Tropically Speaking, NASA Investigates Precipitation Shapes, Sizes for Severity

Rain drops are fat and snowflakes are fluffy, but why does it matter in terms of predicting severe storms?

We've all seen fat rain drops, skinny rain drops, round hailstones, fluffy snowflakes and even ice needles. This summer, NASA researchers are going to get a look at just how much these shapes influence severe storm weather. To do it, they'll have to look inside the guts of some of the world's fiercest storms. NASA recently assembled a team of hurricane scientists from across the country to carry out high-altitude-aircraft surveillance to explore in detail how storms form, intensify and dissipate.

Earth scientists and engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., have redesigned one of their instruments, the Advanced Microwave Precipitation Radiometer, or AMPR, to better observe the different shapes of precipitation. In August and September, AMPR will fly at an altitude of 60,000 feet over the Gulf of Mexico and Atlantic Ocean. It will sit in the bomb bay of a WB-57 airplane, which is based at the NASA Johnson Space Center's Ellington Field in Houston.

AMPR will sit in the bomb bay of a WB-57 airplane, where it will scan the surfaces below to measure both how hard it’s raining and the type of precipitation being produced by a storm. (NASA/JSC)

During these flights, AMPR researchers will test a new build -- the instrument is an upgraded version of the original AMPR built at NASA Marshall in the early 1990s -- and use it to participate in NASA's upcoming hurricane study, the Genesis and Rapid Intensification Processes field campaign, better known as GRIP. The campaign involves three planes mounted with 14 different instruments, including AMPR. The instruments will all work together to create the most complete view of a hurricane to date.

Researchers hope the hurricane campaign will help them answer some of nature's most perplexing questions. As tropical storms grow, they produce massive amounts of rain -- a key element in the development of full-scale hurricanes. Scientists will use AMPR along with the other instruments, such as data from the Tropical Rainfall Measuring Mission or TRMM satellite, to figure out just how hard it's raining inside these ferocious storms, and how much of that rain is associated with the production of ice during intensification.

"If you don't know how hard it's raining or where the rain is forming in the atmosphere, you don't know hurricanes," said Dr. Walt Petersen, AMPR principle investigator and Marshall Center earth scientist. "AMPR provides us an opportunity to see their precipitation structure by using an instrument like those currently flying on, for example, the TRMM and Aqua satellites in space."

That's because AMPR doesn't just give scientists new information about hurricanes. The instrument also enables them to test equipment currently in space. Every day, numerous weather satellites orbit Earth to measure the rainfall rate of storms across the globe. They work much like AMPR except over much larger scales. Because they're so far above the Earth and moving so fast, they can take only one measurement every few miles along their track. Scientists can correct for such coarse measurements, but to do so they need highly accurate data. AMPR can take several measurements per mile, giving scientists the data they need to verify that weather satellites continue to provide accurate data.

Crashing waves in the deep ocean can generate enough energy to create a seismic "hum." (Bruce Molnia/U.S. Geological Survey)

"It's like the pixels in your computer screen," Petersen said. "When satellites take measurements, they have really big pixels, and we might lose some of the finer details of what's happening on the ground. AMPR has much smaller pixels, much higher resolution, and allows us to see a much clearer picture. It's a part of our arsenal to make sure what we're measuring from space makes sense. We'd hate to send something up and not have it accurately measure what's happening on the ground."

That information translates into better predictions of hurricane track and intensity -- how hard it's going to rain in a certain area when a hurricane hits, for example, aiding in early flood warnings.

AMPR doesn't just measure how hard rain falls. Within the last several years, the AMPR team has worked vigorously to upgrade the instrument. These upgrades will enable AMPR to more accurately detect what kind of precipitation is in the storm. By identifying the shape of the precipitation, AMPR may present scientists with recognizable signatures that define different types of precipitation. For example, varying combinations of fat or skinny rain drops, snow, ice or hail distributed throughout the depth of the storm will produce different brightness temperatures when viewed at different angles. A storm may develop and behave differently depending on these variations.

Engineers packed the 380-pound AMPR payload with a delicate set of instruments and computer hardware. AMPR gathers data by measuring the amount of microwave radiation rising from the surface beneath -- often the ocean. Because rain water is a better emitter of microwave radiation than ocean water, the radiation measured from rainfall is actually greater during a big storm. This measurement is converted to a "brightness temperature," which correlates to how much radiation is being generated. The more rain, the higher the brightness temperature.

Alternatively, if a hurricane's clouds are full of ice or hail, as they usually are, much of the microwave radiation is scattered away. The corresponding brightness temperature is much lower than the anticipated surface measurement. Scientists can use those changes to determine how hard it's raining inside a storm or how much ice a given storm might contain.

"Whether rain drops are fat or skinny, and whether ice is round or bumpy, these factors are critical when we're trying to estimate rainfall rates," Petersen explained. "Because of air drag, the rate at which these precipitation particles fall through the air depends on their thickness or shape. A fat rain drop falls more slowly than a hail stone of the same size, for example -- that factor enables you to determine rainfall rate."

This image over Southern Brazil, taken from the space shuttle by an astronaut in February 1984 and shows a mixture of cold and warm clouds. (NASA/JSC)

After the GRIP experiment ends in September, Petersen and his team will unload the data and begin analyzing it, adding their findings to the increasingly large body of hurricane knowledge.

"The GRIP experiment will give us information about how a hurricane circulates and how it intensifies. Basically we have a bunch of theories about the role of precipitation in hurricanes, and we need to test them. That's where instruments like AMPR come in."

After this summer’s hurricane study, AMPR will continue to fly in storm campaigns. It's already scheduled for a major joint NASA and U.S. Department of Energy study in April 2011 to support the Global Precipitation Measurement

Petersen loves the challenge. Storms have fascinated him ever since his junior year of high school, when lightning struck just inches away from him while he was at a drive-in movie.

"The thing that excites me is looking inside a storm that we can't fly into," he said. "We can't fly inside these big storms because they're just too nasty. The only way to get information about what's going on inside is to do what AMPR does.

"Being able to look at the guts of a storm and figure out what's going on, that's the key thing for me," he added.

With any luck, AMPR's look into hurricanes will put scientists one step closer to predicting some of the world's fiercest storms.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/ampr.html

Thursday, August 12, 2010

Fermi Detects 'Shocking' Surprise from Supernova's Little Cousin

Astronomers using NASA's Fermi Gamma-ray Space Telescope have detected gamma-rays from a nova for the first time, a finding that stunned observers and theorists alike. The discovery overturns the notion that novae explosions lack the power to emit such high-energy radiation.

A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion.

"In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year," said Elizabeth Hays, a Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly."

Fermi's Large Area Telescope saw no sign of a nova in 19 days of data prior to March 10 (left), but the eruption is obvious in data from the following 19 days (right). The images show the rate of gamma rays with energies greater than 100 million electron volts (100 MeV); brighter colors indicate higher rates. Credit: NASA/DOE/Fermi LAT Collaboration

Gamma rays are the most energetic form of light, and Fermi's Large Area Telescope (LAT) detected the nova for 15 days. Scientists believe the emission arose as a million-mile-per-hour shock wave raced from the site of the explosion.

A paper detailing the discovery will appear in the Aug. 13 edition of the journal Science.

The story opened in Japan during the predawn hours of March 11, when amateur astronomers Koichi Nishiyama and Fujio Kabashima in Miyaki-cho, Saga Prefecture, imaged a dramatic change in the brightness of a star in the constellation Cygnus. They realized that the star, known as V407 Cyg, was 10 times brighter than in an image they had taken three days earlier.

The team relayed the nova discovery to Hiroyuki Maehara at Kyoto University, who notified astronomers around the world for follow-up observations. Before this notice became widely available, the outburst was independently reported by three other Japanese amateurs: Tadashi Kojima, Tsumagoi-mura Agatsuma-gun, Gunma prefecture; Kazuo Sakaniwa, Higashichikuma-gun, Nagano prefecture; and Akihiko Tago, Tsuyama-shi, Okayama prefecture.

Japanese amateur astronomers discovered Nova Cygni 2010 in an image taken at 19:08 UT on March 10 (4:08 a.m. Japan Standard Time, March 11). The erupting star (circled) was 10 times brighter than in an image taken several days earlier. The nova reached a peak brightness of magnitude 6.9, just below the threshold of naked-eye visibility. Credit: K. Nishiyama and F. Kabashima/H. Maehara, Kyoto Univ.

On March 13, Goddard's Davide Donato was on-duty as the LAT "flare advocate," a scientist who monitors the daily data downloads for sources of potential interest, when he noticed a significant detection in Cygnus. But linking this source to the nova would take several days, in part because key members of the Fermi team were in Paris for a meeting of the LAT scientific collaboration.

"This region is close to the galactic plane, which packs together many types of gamma-ray sources -- pulsars, supernova remnants, and others in our own galaxy, plus active galaxies beyond them," Donato said. "If the nova had occurred elsewhere in the sky, figuring out the connection would have been easier."

The LAT team began a concerted effort to identify the mystery source over the following days. On March 17, the researchers decided to obtain a "target-of-opportunity" observation using NASA's Swift satellite -- only to find that Swift was already observing the same spot.

"At that point, I knew Swift was targeting V407 Cyg, but I didn't know why," said Teddy Cheung, an astrophysicist at the Naval Research Laboratory (NRL) in Washington, D.C., and the lead author of the study. Examining the Swift data, Cheung saw no additional X-ray sources that could account for what Fermi's LAT was seeing.

V407 Cyg had to be it.

Half an hour later, Cheung learned from other members of the LAT team that the system had undergone a nova outburst, which was the reason the Swift observations had been triggered. "When we looked closer, we found that the LAT had detected the first gamma rays at about the same time as the nova's discovery," he said.

This image from Steve O'Connor in St. Georges, Bermuda, shows the nova (red star, center) on March 17, about a week into the eruption. Credit: Steve O'Connor

V407 Cyg lies 9,000 light-years away. The system is a so-called symbiotic binary containing a compact white dwarf and a red giant star about 500 times the size of the sun.

"The red giant is so swollen that its outermost atmosphere is just leaking away into space," said Adam Hill at Joseph Fourier University in Grenoble, France. The phenomenon is similar to the solar wind produced by the sun, but the flow is much stronger. "Each decade, the red giant sheds enough hydrogen gas to equal the mass of Earth," he added.

The white dwarf intercepts and captures some of this gas, which accumulates on its surface. As the gas piles on for decades to centuries, it eventually becomes hot and dense enough to fuse into helium. This energy-producing process triggers a runaway reaction that explodes the accumulated gas.

The white dwarf itself, however, remains intact.

The blast created a hot, dense expanding shell called a shock front, composed of high-speed particles, ionized gas and magnetic fields. According to an early spectrum obtained by Christian Buil at Castanet Tolosan Observatory, France, the nova's shock wave expanded at 7 million miles per hour -- or nearly 1 percent the speed of light.




Watch V407 Cyg go nova! Gamma rays (magenta) arise when accelerated particles in the explosion's shock wave crash into the red giant's stellar wind. Credit: NASA/Goddard Space Flight Center/ Conceptual Image Lab.


The magnetic fields trapped particles within the shell and whipped them up to tremendous energies. Before they could escape, the particles had reached velocities near the speed of light. Scientists say that the gamma rays likely resulted when these accelerated particles smashed into the red giant's wind.

"We know that the remnants of much more powerful supernova explosions can trap and accelerate particles like this, but no one suspected that the magnetic fields in novae were strong enough to do it as well," said NRL's Soebur Razzaque.

Supernovae remnants endure for 100,000 years and affect regions of space thousands of light-years across.

Kent Wood at NRL compares astronomical studies of supernova remnants to looking at static images in a photo album. "It takes thousands of years for supernova remnants to evolve, but with this nova we've watched the same kinds of changes over just a few days," he said. "We've gone from a photo album to a time-lapse movie."

For more information visit http://www.nasa.gov/mission_pages/GLAST/news/shocking-nova.html

Tuesday, August 10, 2010

WISE's View of a Wispy Cloud

This image captured by NASA's Wide-field Infrared Survey Explorer (WISE) highlights the Small Magellanic Cloud. Also known as NGC 292, the Small Magellanic Cloud is a small galaxy about 200,000 light-years away.

The Small Magellanic Cloud is named after the Portuguese explorer Fernando de Magellan who observed it on his voyage around the world in 1519. Since it is visible to the naked eye in dark-sky conditions, it is likely that people in the southern hemisphere observed the galaxy long before Magellan recorded it.

Located in the constellation Tucana, the Small Magellanic Cloud looks like a wispy cloud that circles the south celestial pole. Nearby, but not visible in this image, is the Large Magellanic Cloud, a sister galaxy to the Small Magellanic Cloud. Astronomers originally thought that both galaxies were orbiting our Milky Way galaxy. But recent research suggests that they might be moving too fast to be bound by the Milky Way's gravity and are passing by for the first time.

This WISE image illustrates why the SMC is considered an irregular galaxy. Galaxies are classified according to their shape, such as spiral or elliptical. Irregular galaxies don't fit into any of these categories -- they are unique in shape.

The two streaks seen in the upper half of the image are satellites orbiting Earth, which happened to pass in front of the Small Magellanic Cloud when WISE captured this view.

This mosaic image was made from all four infrared detectors aboard WISE. The color in this image represents different wavelengths of infrared light. Blue and cyan represent light at wavelengths of 3.4 and 4.6 microns mostly emitted from stars. Green and red represent light at 12 and 22 microns, which is mostly light from warm dust.

Image Credit: NASA/JPL-Caltech/UCLA

For more information visit http://www.nasa.gov/mission_pages/WISE/multimedia/gallery/pia13124.html

Sunday, August 08, 2010

This Month in Exploration - August

From the early days of experimental airplanes to NASA’s soaring space shuttles, the evolution of flight has mirrored the evolution of society. The ongoing scientific discoveries that are part of aeronautics and space flight have improved life on Earth and allowed humans to begin investigating the secrets of the universe. “This Month in Exploration” presents the rich history of human flight, contextualizing where we’ve been and examining the exploration history NASA is making today.

100 Years Ago

August 31, 1910: Glenn Curtiss established a record for longest flight over water when he completed a course from Euclid beach in Cleveland, Ohio to Cedar Point in Sandusky, Ohio. Flying his biplane over Lake Erie parallel to the shore, Curtiss completed the trip in about an hour and fifteen minutes.

A Loening Amphibian aircraft similar to the three used on the MacMillan Arctic Expedition. Credit: NASA

85 Years Ago

August 1, 1925: Under the command of Lt. Cmdr. Richard E. Byrd, a U.S. Naval Air detail began aerial exploration of a 30,000-square-mile area near Etah, North Greenland using three Loening amphibian seaplanes introduced the previous year. The excursion was part of the MacMillan Arctic Expedition, the United States’ contribution to the global race to Earth’s last unexplored frontiers, the North and South Poles.

75 Years Ago

August 28, 1935: The Equipment Laboratory at Wright Field tested automatic radio-navigation equipment, called the Sperry automatic pilot, by mechanically linking it to a standard radio compass.

50 Years Ago

August 12, 1960: NASA launched its first communications satellite, the Echo 1, via a Thor- Delta rocket from Vandenberg Air Force Base. The satellite transmitted a radio message from President Dwight D. Eisenhower across the nation, demonstrating the feasibility of global radio communications via satellites. Echo 1 was the most visible and largest satellite launched at that time. Although the mission was successful, it was quickly superseded by active-repeater communications satellites such as Telstar.

A static inflation test of the 135 foot satellite Echo 1. Credit: NASA

45 Years Ago

August 21-29, 1965: NASA launched the Gemini-V via Titan-II rocket. Several records were set during this eight-day orbital flight, including the single longest manned spaceflight, total U.S. manned hours in space and a new altitude record for an American spacecraft. American astronaut Gordon Cooper was also the first man to make a second orbital flight and achieved the record for the most spaceflight time.

35 Years Ago

August 20, 1975: NASA launched Viking 1 from NASA’s Kennedy Space Center, Fla. It was the first of two spacecraft on the historic mission to the planet Mars. The primary objectives of the Viking mission were to return high-resolution images of the Martian surface, analyze the structure and composition of the atmosphere and surface and search for evidence of life on Mars.

25 Years Ago

August 27, 1985: NASA launched space shuttle Discovery (STS-51I) from NASA’s Kennedy Space Center, Fla. The shuttle deployed three communications satellites and retrieved, repaired and re-launched the TELSAT-1 Communications Satellite, Syncom IV-3.

10 Years Ago

August 9, 2000: The European Space Agency launched the second pair of Cluster II mission satellites, named Rumba and Tango, aboard a Soyuz-Fregat rocket from Russia’s Baikonur Cosmodrome. The Cluster mission used simultaneous measurements from four satellites to provide detailed analysis of the effects of solar wind on Earth’s magnetic field. The mission is still in effect today and has resulted in around 1000 scientific publications in peer-reviewed journals.

Astronaut Neil A. Armstrong in the Lunar Module during the Apollo 11 lunar landing mission. Credit: NASA

5 Years Ago

August 12, 2005: NASA launched the Mars Reconnaissance Orbiter (MRO) from NASA’s Kennedy Space Center, Fla. aboard the first Atlas V rocket used for an interplanetary mission. The ongoing mission was to map the physical features of Mars, including its atmosphere and its subterranean layering.

Present Day

August 5, 2010: Neil A. Armstrong turns 80 this year. Born in Wapakoneta, Ohio in 1930, Armstrong was the first person to walk on the moon. He is credited with the famous quote: "That's one small step for a man, one giant leap for mankind."

August 22, 2010: Science fiction writer Ray Bradbury was born 100 years ago on this day in Waukegan, Ill. He wrote “The Martian Chronicles” published in 1949. Among his poems is one inspired by a trip to NASA’s Kennedy Space Center, Fla. where he compared his tour of the Saturn hanger to “walking around inside Shakespeare’s head.”

For more information visit http://www.nasa.gov/exploration/thismonth/this_month_aug10.html

Wednesday, August 04, 2010

Fires in Eastern Siberia

Fires raged in eastern Siberia in late July 2010, sending a plume of thick smoke hundreds of kilometers wide over the Bering Sea. News sources attributed fires in the Russian Federation to drought, heat, and human activity.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on July 25, 2010. Red outlines indicate areas with unusually high surface temperatures associated with actively burning fires.

This image shows the region north of the Kamchatka Peninsula. The largest collection of fires is clustered around a river that feeds into the Penzhinskaya Guba, part of the Sea of Okhotsk. Smaller clusters of fires also burn in the northwest, northeast, and south. Most of the fires send their smoke toward the northeast, but east of the burning fires, winds carry the smoke toward the southeast. Off the coast, the smoke plume is thick enough to completely hide parts of the Bering Sea.

Credit: NASA image by Jeff Schmaltz, MODIS Rapid Response Team/ Caption by Michon Scott.

For more information visit http://www.nasa.gov/mission_pages/fires/main/world/20100725_siberia.html

Tuesday, July 27, 2010

Cutting Into Arctic Sea Ice

"Over by the fish, below the soccer field," said ice scientist Bonnie Light, pointing at the Arctic sea ice from the bridge of the U.S. Coast Guard Cutter Healy earlier this month during NASA's ICESCAPE oceanographic mission.

Light, of University of Washington, and other ice scientists crowd around the windows on the bridge of the Healy describing shapes created by the melt ponds on the surface of the Arctic sea ice. They point out everything from unicorns to Volkswagons. But the imaginative morning ritual is serious business; the ice teams are discussing where on the ice to work and planning the logistics of the day’s field work.

Since 1979, satellites have tracked changes to Arctic sea ice extent, showing dramatic declines. On average the ice is losing about 13 percent of its summer coverage each decade and the record low was set in 2007. The decline raises two key questions: Why are these changes happening and what do they mean for Arctic ecosystems, particularly the ocean-dwelling plants -- phytoplankton -- that play an integral role in Earth's carbon cycle?

Chris Polashenski of Dartmouth College (left) and Benny Hopson from the Barrow (Alaska) Arctic Science Consortium bore a hole through sea ice in the Chukchi Sea on July 4. Credit: NASA/Kathryn Hansen

Exploring those questions since last month is the ICESCAPE mission onboard the Healy, which is studying the physics, chemistry and biology of the ocean and sea ice within a changing Arctic. On 12 days scattered throughout the five-week mission, the Healy "parked" amid an ice floe and teams of ice scientists stepped foot on the floating ice for a close up look.

After agreeing on a plan from the bridge, ice scientists on July 9, 2010, readied for work at ice station 10 in the Chukchi Sea. The ship's crane lowered sleds of scientific equipment over the side of the ship and then scientists descended down a steep ramp to the ice where they dispersed and set up equipment.

Coast Guard crew and scientists checked the ice for safety, and then guided a deafening drill through the ice and into the ocean. Researchers deployed instruments above, through and below the drill holes -- scattered strategically across the study site -- to characterize how much light is reflected, absorbed and transmitted by the ice.

The ICESCAPE mission is looking at how Arctic ecology is changing with the changes in ice cover. The Earth is undergoing a grand experiment and scientists want to understand those changes because some of those changes may affect our future.

Surprisingly, polar oceans are rich with life and play a major role in drawing down carbon from the atmosphere. But how will that capability change in an ice-free Arctic? How will the creatures in the sea themselves change? Understanding the connections between the ice and the phytoplankton -- the lower rungs on the food chain -- are key to understanding these changes.

Teams of scientists set up equipment on sea ice near the U.S. Coast Guard icebreaker Healy in the Chukchi Sea on July 4.Credit: NASA/Kathryn Hansen

"From a couple of optical measurements, a lot of thickness measurements, and some melt pond measurements, we can do some calculations and get a 2D map of how much light gets through at different wavelengths, and how much of that light is what's called 'photosynthetically available radiation,' which is the stuff the little algae really like," said Don Perovich of the Cold Regions Research and Engineering Laboratory.

To characterize the ice and its optical properties, researchers begin work on top of the ice. Here, pools of water, or "melt ponds," litter the surface, absorbing more sunlight -- both accelerating melt and passing more of that light along to the ocean below.

Chris Polashenski of Dartmouth College waded onto thin ice supporting a pond, drilled a hole, and measured the ice thickness. Just 30 centimeters of ice separated Polashenski from 150 feet of ocean. In contrast, surrounding ice measured in at an average thickness of 80 centimeters.

ICESCAPE scientists draw on the ship's bridge windows on July 9 as they plan a day of work on sea ice in the Arctic's Chukchi Sea. Credit: NASA/Kathryn Hansen

"The thickness distribution is one of the key parameters of sea ice," Perovich said. "In particular for this experiment it strongly governs how much light gets through into the ocean."

So how much light makes it through these ice thicknesses? To find out, Light worked with her team to collect optical measurements tracking the transmission of light above, inside, and just below the ice at the borehole sites.

Still other groups looked deeper, at both the life forms in the water column below the ice and the light that is sustains them. To gather these snapshots, Karen Frey of Clark University and colleagues dropped an optical sensor down 30 meters, while simultaneously collecting samples of water with Chief Scientist Kevin Arrigo’s group from Stanford University.

Back in the ship's onboard lab, Frey and Arrigo's groups looked at the life contained in the samples, while Sam Laney of Woods Hole Oceanographic Institution fed them under an microscope that automatically collects images of the tiny life forms.

Researchers are finding strong connections between the properties of the ice and the communities of microbes beneath them. For example, ponds were found to transmit between three and 10 times more light than bare ice.

"Algae are affected by what's above them," said Laney, who noted that algae communities photographed under melt pond ice were different compared to those that turned up under white ice.

For more information visit http://www.nasa.gov/topics/earth/features/icescape2010_arctic_ice.html

Wednesday, July 21, 2010

Arctic Voyage Illuminating Ocean Optics

During NASA's ICESCAPE voyage to the Arctic, scientists have been looking at the phytoplankton in the Arctic's Chukchi Sea -- how many, how big and at what depths they are found. But there are other ways of looking at these small life forms.

"We measure phytoplankton in terms of their pigments and light absorption properties," said Stan Hooker of NASA's Ocean Biology and Biogeochemistry Calibration and Validation Office at Goddard Space Flight Center, Greenbelt, Md. Hooker, Joaquin Chaves and Aimee Neeley, also of NASA, measure the color of the water. Anything in the water, plankton or not, can influence that color.

The Arctic survey boat is lowered by crane for science excursions away from the main ship, which can mix water and cast a shadow. On July 2, NASA's Stan Hooker and Joaquin Chaves board the boat with Coast Guard crew to make first-of-a-kind measurements near the edge of Arctic sea ice. Credit: NASA/Kathryn Hansen

On July 2, a crane maneuvered a small boat halfway down the side of the U.S. Coast Guard Cutter Healy – the platform for the five-week ICESCAPE mission, NASA's first dedicated oceanographic field campaign, which is studying the physics, chemistry and biology of the ocean and sea ice within a changing Arctic.

Hooker, Chaves and Coast Guard crew boarded the small boat and readied for an expedition away from the stirred water and shadow of the 420-foot Healy. Lowered to the ocean surface, Hooker's team powered away, entering uncharted waters.

Maneuvering over smooth water and around chunks of sea ice, the small boat slowed to a stop near the edge of an ice floe.

Sensors on the Hydroscat 6 instrument measured optical properties of the Chukchi Sea at various depths. Some sensors emit light and measure how much is scattered back, while others measure the abundance of chlorophyll and dissolved organic matter. Credit: NASA/Kathryn Hansen

"This is new for us because we usually haven't been able to work this close to the ice before," Hooker said. "Satellites can't measure near the ice, so we do this to help specify the next generation of equipment, and to contribute to the science objectives."

First over the side was a small red instrument that the crew dropped on a line into the ocean and then reeled by hand, as if wrangling a fish. Sensors on the instrument measured the wavelengths of sunlight at different depths - both what's coming into the ocean and what's reflected back out which is similar to what is "seen" by satellites.

Next the crew lowered a second, larger package of instruments into the depths of the ocean. One pair of sensors emits light and measures how much is scattered back. Another pair measures the fluorescence of chlorophyll and colored dissolved organic matter, an important distinction as both appear green to satellites.

Last, the crew collected water samples to be returned to the Healy for analysis in the lab.

Crew from the Healy worked on the Arctic survey boat on July 2 reeling in an instrument from the Chukchi Sea that measures sunlight and how it interacts with the water. The measurements are similar to those made by ocean-observing satellites. Credit: NASA/Kathryn Hansen

"We can measure the changes in the color to find out what's happening with the ecology," said Greg Mitchell, a research biologist at Scripps Institution of Oceanography in San Diego, who analyzes the water samples. "We can relate color back to how much chlorophyll is in the ocean, how much algae biomass there is, and processes such as the rate of photosynthesis."

Similar, more frequent measurements are made from the Healy, which marked its one-hundredth ocean station of the mission on July 8. The small boat deploys less often -- almost daily -- but reaches more targeted regions.

"We do the measurements at sea in order to relate what's going on in the ocean with the optics," Mitchell said. "Then we apply those relationships to the optical data from the ocean color satellites and we can make estimates of processes and distributions globally."


Onboard the Healy to help scientists figure out where to sample is Bob Pickart, a physical oceanographer from Woods Hole Oceanographic Institution. Pickart can decipher water type and circulation to guide where to make measurements.

A great unknown, for example, is a picture of what's feeding the evolution of a "hotspot" in Barrow Canyon. Right now, winter water -- rich with nutrients -- has been carried across the shallow shelf where the Healy is surveying.

"This is a really interesting, important time of year," Pickart said. "As the ice recedes, productivity is starting and things are getting cranked up."

Chief scientist Kevin Arrigo (right) and physical oceanographer Bob Pickart analyze a map of the Chukchi and Beaufort seas on July 2, planning a route for the science mission. Pickart points to Barrow Canyon, the site of an ecological hotspot. Credit: NASA/Kathryn Hansen

But for how long will these hotspots thrive? While this is dictated by light and nutrients, the circulation near Barrow and Herald canyons -- two fissures that channel water off the shelf -- plays a vitally important role as well.

On July 12, after a night of cutting through sea ice, ICESCAPE scientists caught a glimpse of the hotspot. As an instrument lowered from the Healy descended through the water, real-time fluorescence information showed low levels of chlorophyll.

Scientists on the Healy will analyze the hotspot data and water samples, but whether a plankton bloom has come and gone, the region remains a hotspot for ground-dwelling communities, according to Karen Frey of Clark University. Feeding off plankton that sink to the seafloor, species here are diverse and large. A single sample retrieved from the ocean floor turned up a large crab, sponges and a sea star.

Meanwhile, samples returned from the near-ice survey July 2 on the small boat are turning up mixed results – sometimes indicating the presence of phytoplankton communities and sometimes not, according to Atsushi Matsuoka, of Laboratoire d'Oceanographie de Villefranche. To find out why, his group will look at trends after returning home from ICESCAPE.

For more information visit http://www.nasa.gov/topics/earth/features/icescape2010_arctic_optics.html

Monday, July 05, 2010

Saturn System Moves Oxygen From Enceladus to Titan

Complex interactions between Saturn and its satellites have led scientists using NASA's Cassini spacecraft to a comprehensive model that could explain how oxygen may end up on the surface of Saturn's icy moon Titan. The presence of these oxygen atoms could potentially provide the basis for pre-biological chemistry.

The interactions are captured in two papers, one led by John Cooper and another led by Edward Sittler, published in the journal Planetary and Space Science in late 2009. Cooper and Sittler are Cassini plasma spectrometer team scientists at NASA's Goddard Space Flight Center in Greenbelt, Md.

"Titan and Enceladus, another icy moon of Saturn, are chemically connected by the flow of material through the Saturn system," Cooper said.

In one paper, Cooper and colleagues provide an explanation for forces that could generate the Enceladus geysers that spew water vapor into space. In the other, published in the same issue, Sittler and colleagues describe a unique new process in which oxygen that circulates in the upper atmosphere of Titan can be carried all the way to the surface without further chemical contamination by being encased in carbon cages called fullerenes.

The work draws upon previous work by Sittler and others that model the dynamics of how particles, including water molecules, travel from Enceladus to Titan. At Enceladus the flow process begins with what they call the "Old Faithful" model, after the Old Faithful geyser in Yellowstone National Park. In this model, gas pressure slowly builds up inside Enceladus, then gets released occasionally in geyser-like eruptions.

Unlike terrestrial geysers, or even geyser-like forces on Jupiter's moon Io, the model proposed by Cooper shows that charged particle radiation raining down from Saturn’s magnetosphere can create the forces from below the surface that are required to eject gaseous jets.

Energetic particles raining down from Saturn's magnetosphere – at Enceladus, mostly electrons from Saturn's radiation belts -- can break up molecules within the surface. This process is called radiolysis. Like a process called photolysis, in which sunlight can break apart molecules in the atmosphere, energetic radiation from charged particles that hit an icy surface, like that of Enceladus, can cause damage to molecules within the ice. These damaged molecules can get buried deeper and deeper under the surface by the perpetual churning forces that can repave the icy surface. Meteorites constantly crashing into the surface and splashing out material might also be burying the molecules.

This annotated image collage features Saturn and the moons Titan, Enceladus, Dione, Rhea and Helene, which are being studied by the Cassini mission. Image credit: NASA/JPL/Space Science Institute

When chemically altered icy grains come into contact beneath the surface with icy contaminants such as ammonia, methane and other hydrocarbons, they can produce volatile gases that can explode outward. Such gases can create plumes of the size seen by Cassini. Cooper and colleagues call such icy volatile mechanics "cryovolcanism."

What's unique about the "Old Faithful" model is that it "is a model for cryovolcanism that is based on not only liquid water, but also requires the production of gases by the radiolytic chemistry observed at Enceladus," said Sittler.

The plumes that emanate from Enceladus' south polar region consist of water, ammonia and other compounds. Scientists have known since the 1980s that Saturn's magnetosphere is inexplicably filled with neutral particles. In the intervening decades, particularly since the discovery of plumes jetting out from the south pole of Enceladus, work has shown how some of the water molecules that escape from Enceladus get split up into neutral and charged particles and are transported throughout Saturn's magnetosphere.

Sittler's new model indicates that as these broken water molecules enter Titan's atmosphere, they may be captured by fullerenes—hollow, soccer-ball shaped shells made of carbon atoms. Although the heavy molecules Cassini has detected in the upper atmosphere of Titan may be other molecules, Sittler suggests they are likely fullerenes.

In Sittler's model, the fullerenes then condense into larger clusters that can attach to polycyclic aromatic hydrocarbons—chemical compounds also found on Earth in oil, coal and tar deposits, and as the byproducts of burning fossil fuels. The fullerene clusters form even larger aerosols that travel down to Titan's surface.

This process protects the trapped oxygen from Titan's atmosphere, which is saturated with hydrogen atoms and compounds that are capable of breaking down other molecules. Otherwise, the oxygen would combine with methane in Titan's atmosphere and form carbon monoxide or carbon dioxide. Until now, scientists have not been able to explain how oxygen fits into the picture of the dynamics and chemistry of Saturn and its moons.

As the oxygen-rich aerosols fall to Titan's surface, they are further bombarded by products of galactic cosmic ray interactions with Titan's atmosphere. Cosmic rays bombarding the oxygen-stuffed fullerenes could produce more complex organic materials, such as amino acids, in the carbon-rich and oxygen-loaded fullerenes. Amino acids are considered important for pre-biological chemistry.

Scientists have been able to couple the new models that describe the generation of plumes at Enceladus and oxygen ion capture in fullerenes near the top of Titan's atmosphere to existing theories of the transport of oxygen across the magnetosphere. Taken together, Sittler and Cooper suggest a chemical pathway that allows the oxygen to be introduced to Titan's surface chemistry.

"Cooper and Sittler's work helps us understand more about the potential for chemical interactions among Saturn's moons," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"The Saturn system is indeed a dynamic place, with the Enceladus plumes creating the E ring and loading the magnetosphere with water which interacts with Titan and the other moons," Spilker said.

The Cassini mission is a joint effort of NASA, the European Space Agency, and the Italian space agency Agenzia Spaziale Italiana. The mission is managed for NASA by the Jet Propulsion Laboratory, a division of the California Institute of Technology. Partners include the U.S. Air Force, Department of Energy, and academic and industrial participants from 19 countries.

For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/saturn20100701.html

Wednesday, June 30, 2010

NASA's TRMM Satellite Sees Heavy Rainfall in Hurricane Alex

Hurricane Alex is generating some very heavy rainfall, and the Tropical Rainfall Measuring Mission satellite known as TRMM has been calculating it from its orbit in space.

As predicted by the National Hurricane Center (NHC) in Miami, Florida, Alex intensified after entering the warm waters of the southwest Gulf of Mexico.

At NASA's Goddard Space Flight Center in Greenbelt, Md., scientists created an analysis of Alex's rainfall using data captured by the TRMM satellite on June 29, 2010 at 1350 UTC (9:50 a.m. EDT). At that time the sustained winds around Alex were estimated to be 60 knots (~69 mph). Alex continued to strengthen and was classified as a hurricane early on 30 June 2010. This made Alex the first hurricane in the 2010 Atlantic hurricane season.

The rainfall analysis used TRMM Precipitation Radar (PR) data and TRMM Microwave Imager (TMI) data. The TMI data showed that a heavy band of precipitation (some areas showed rain falling at more than 2 inches per hour) was spiraling into the center of Alex's intensifying circulation. The precipitation analysis was overlaid on visible and infrared data from TRMM's Visible Infrared Scanner (VIRS). In this image a Geostationary Operational Environmental Satellite (GOES East) visible image was used to fill in locations not viewed by the TRMM satellite.

The TRMM satellite's data on June 29, 2010 at 9:50 a.m. EDT showed some heavy rain (red) falling at up to 2 inches per hour, spiraling toward Hurricane Alex's center. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Credit: NASA, Hal Pierce

Alex is expected to continue to be a large rainmaker when it makes landfall. Rainfall accumulations are expected of between 6 and 12 inches, with isolated amounts of 20 inches.

Tropical Storm-force winds are expected to reach coastal areas in the warning areas this afternoon, while hurricane-force winds will reach the coast tonight. In addition, the National Hurricane Center noted "a dangerous storm surge will raise water levels by as much as 3 to 5 feet above ground level along the immediate coast to the north of where the center makes landfall."

By 11 a.m. EDT, Alex was still a category one hurricane with maximum sustained winds near 80 mph. Alex was located about 145 miles (235 km) east of La Pesca, Mexico and 190 miles (310 km) southeast of Brownsville, Texas. That makes Alex's center near 23.8 North and 95.5 West. Alex is moving northwest at 7 mph (11 km/hr), and has a minimum central pressure near 961 millibars.

Satellite data show that Alex is a large hurricane and the hurricane force winds extend outward up to 60 miles (95 km) from the center. Tropical storm force winds extend outward up to 200 miles (325 km) primarily to the northeast of the center.

The National Hurricane Center noted today that "Given such a low minimum pressure...the current satellite presentation and a favorable environment for intensification...the winds should increase today and Alex could reach category two before landfall."

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_alex.html

Monday, June 28, 2010

Oil Offshore of Alabama and Florida's Western Panhandle

The possibility of detecting oil slicks in photo-like satellite images depends on the slick being located in the sunglint region—the wide, washed-out strip where the mirror-like reflection of the Sun off the water is diffused by waves and currents. When the oil is located in that relatively narrow region of the scene, it can strongly influence how the water reflects light. Oil-covered water may look dramatically brighter or darker than adjacent, oil-free water.

In this image from Sunday, June 27, 2010, eastern areas of the slick are more visible than western areas, even though analysis from the National Oceanic and Atmospheric Administration indicates heavy concentrations of oil in the vicinity of the leaking well, which is about 75 kilometers (47 miles) southeast of the Mississippi Delta (beyond the left edge of the image). Ribbons of silvery-gray oil swirl in the waters off Alabama and Florida, while farther west—closer to the source of the leak—the reflection seems to be dominated by muddy water in the Mississippi River Delta.

Although the oil extent does change from day to day, the big difference in the appearance of oil in this image versus the previous day’s image is the location of the oil in relation to the sunglint region. In this view from June 27, the sunglint fell across an area farther east than it did in the image from June 26, and so the oil is more visible there. Image Credit: NASA MODIS Rapid Response Team

Text credit: Rebecca Lindsey/NASA's Earth Observatory/NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/topics/earth/features/oilspill/20100628_oil.html

Wednesday, June 23, 2010

'L2' Will be the James Webb Space Telescope's Home in Space

When you ask an astronomer about the James Webb Space Telescope's orbit, they'll tell you something that sounds like it came from a science-fiction novel. The Webb won't be orbiting the Earth –instead we will send it almost a million miles out into space to a place called "L2."

L2 is short-hand for the second Lagrange Point, a wonderful accident of gravity and orbital mechanics, and the perfect place to park the Webb telescope in space. There are five so-called "Lagrange Points" - areas where gravity from the sun and Earth balance the orbital motion of a satellite. Putting a spacecraft at any of these points allows it to stay in a fixed position relative to the Earth and sun with a minimal amount of energy needed for course correction.

The five Lagrangian points for the Sun-Earth system are shown in the diagram below. An object placed at any one of these 5 points will stay in place relative to the other two. Credit: NASA

The term L2 may sound futuristic and mysterious, but the name actually honors a Mathematician born in 1736. The Lagrange points were named after the Italian-born mathematician and astronomer Joseph-Louis Lagrange, who made important contributions to classical and celestial mechanics. Lagrange studied the "three-body problem" (so-called because three bodies are orbiting each other) for the Earth, sun, and moon in 1764, and by 1772 he had found the solution; there are five stable points at which you could put an object and have it stay fixed in place relative to the other two.

In the case of L2, this happens about 930,000 miles away from the Earth in the exact opposite direction from the sun. The Earth, as we know, orbits the sun once every year. Normally, an object almost a million miles farther out from the sun should move more slowly, taking more than a year to complete its orbit around the sun. However, at L2, exactly lined up with both the sun and Earth, the added gravity of the two large bodies pulling in the same direction gives a spacecraft an extra boost of energy, locking it into perfect unison with the Earth's yearly orbit. The Webb telescope will be placed slightly off the true balance point, in a gentle orbit around L2.

Why send the Webb telescope all the way out to L2? When astronomers began to think about where the Webb telescope should be placed in space, there were several considerations to keep in mind. To begin with, the Webb telescope will view the universe entirely in infrared light, what we commonly think of as heat radiation. To give the telescope the best chance of detecting distant, dim objects in space, the coldest temperatures possible are needed.

The James Webb Space Telescope (identified as "JWST" here) relative to the Hubble telescope's orbit around the Earth. Credit: NASA

"A huge advantage of deep space (like L2) when compared to Earth orbit is that we can radiate the heat away," said Jonathan P. Gardner, the Deputy Senior Project Scientist on the Webb Telescope mission and Chief of the Observational Cosmology Laboratory at NASA's Goddard Space Flight Center in Greenbelt, Md. "Webb works in the infrared, which is heat radiation. To see the infrared light from distant stars and galaxies, the telescope has to be cold. Webb's large sunshield will protect it from both Sunlight and Earthlight, allowing it to cool to 225 degrees below zero Celsius (minus 370 Fahrenheit)." For the sunshield to be effective, Webb will need to be an orbit where the sun and Earth are in about the same direction.

With the sun and the Earth in the same part of the sky, the Webb telescope will enjoy an open, unimpeded view of the universe. In comparison, the Hubble Space Telescope is in low-Earth orbit where it goes in and out of the Earth's shadow every 90 minutes. Hubble's view is blocked by the Earth for part of each orbit, limiting where the telescope can look at any given time.

The Spitzer Space Telescope, another infrared telescope, is in orbit around the sun and drifting away from the Earth. Spitzer is already more than 100 million kilometers (60 million miles) away from the Earth, and eventually its path will take it to the other side of the sun. Once we can no longer communicate with Spitzer that means it is at the end of its mission life.

This animation shows the Webb Telescope spacecraft orbiting far from the Earth. Credit: NASA/Chris Meaney (HTSI)

In contrast, a major perk of parking at L2 is the ease of communications. Essentially, the Webb telescope will always be at the same point in space. "We can have continuous communications with Webb through the Deep Space Network (DSN)," Gardner said. "During routine operations, we will uplink command sequences and downlink data up to twice per day, through the DSN. The observatory can perform a sequence of commands (pointing and observations) autonomously. Typically, we will upload a full week's worth of commands at a time, and make updates daily as needed."

Even before the Webb telescope, L2 has been known to astronomers as a good spot for space-based observatories. There are already several satellites in the L2 orbit, including the Wilkinson Microwave Anisotropy Probe, and the Herschel and Planck space observatories. But there's plenty of room for another neighbor, and the Webb telescope will be heading out to L2 in the near future.

The Webb telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

For more information visit http://www.nasa.gov/topics/universe/features/webb-l2.html

Monday, June 21, 2010

NASA's ICESCAPE Journeys Into the Arctic Circle

66° 33’ N, 179° 85’ W, June 18 — Friday night, the following pipe reverberated throughout the Healy: “Now attention all hands. The cutter Healy has crossed into the Arctic Circle — the cold, icy waters of King Neptune. Welcome home, Polar Bears. All Blue Noses beware! That is all.”

"Polar Bears" are those who have already crossed the Arctic Circle and gone through initiation. "Blue Noses," on the other hand, have some surprises waiting for them. Everyone’s wondering what the secret initiation will be, including Blue Nose chief scientist Kevin Arrigo.

Immediately after the announcement, a crowd of scientists and Coasties gathered at the bow as the Healy passed through a belt of sea ice and herds of walruses. For many, it was the first sighting of both — a truly surreal night to remember.

“This is what I’ve been waiting for!” said Cedric Fichot, a graduate student at the University of South Carolina. (Photo by Haley Smith Kingsland)

The walrus’ scientific name, Odobenus rosmarus, means “tooth-walking sea horse” in Latin. Walrus tusks are really extended upper canine teeth that lengthen with age— up to three feet during a walrus’ lifetime. Walruses live on the sea ice edge over shallow continental shelves, and use their tusks to hoist themselves onto the ice and bore holes in it. Males also employ their tusks to threaten rivals. Walrus’ whiskers, or vibrissae, help them nuzzle and forage for shellfish on the shallow sea floor. How will climate change affect these gargantuan creatures? As Arctic sea ice melts and retreats from shallow continental shelves, walruses lose their habitat to water that’s too deep for them to dive for less abundant food. So instead they “haul out” to rest on coastal lands, and over-congregation leads to stampedes and trampling of young calves as well as stiff competition for limited resources. (Photo by Haley Smith Kingsland)


United States Geological Survey scientists have been tracking walruses with satellite radio-tags in order to trace their movements in the changing sea ice habitat. You can follow animations of the walrus’ paths in both the Chukchi and Bering Seas at . (Photo by Haley Smith Kingsland)

For more information visit http://blogs.nasa.gov/cm/newui/blog/viewpostlist.jsp?blogname=icescape


Thursday, June 17, 2010

Deputy Administrator Garver Reaffirms in Europe the Importance of International Cooperation as Part of the President's Proposed Course for NASA

NASA Deputy Administrator Lori Garver returned June 15 from a week-long, three-city trip to Europe that included addressing the United Nations Committee on the Peaceful Uses of Outer Space and signing a cooperative agreement to extend the mission of an Earth science satellite.

Garver’s visit also included discussions with key European space agency heads and senior-level officials in the German and French governments. The focus of her travel was to explain the administration’s new plans for space exploration and make clear that expanded international collaboration will be a cornerstone of NASA’s future activities.

“NASA has a long history of international cooperation,” Garver said. “Indeed, international cooperation was envisioned as a key element in the U.S. legislation that formally established NASA. We intend to broaden and deepen those relationships as we seek to implement the president’s new U.S. space exploration enterprise.”

In Germany, Garver visited the Reichstag in Berlin to meet with key members of the Air and Space Group of the Bundestag, which is the parliament of the Federal Republic of Germany. Garver also had an opportunity to review NASA’s ongoing and planned cooperation with Germany with the U.S. ambassador there, Phillip Murphy.

At the Berlin Air Show, Garver and German Aerospace Center (DLR) Executive Board Chairman Johann-Dietrich Wörner signed an agreement June 10 to extend the Gravity Recovery and Climate Change (GRACE) mission through the end of its on-orbit life, which is expected in 2015.

NASA Deputy Administrator Lori Garver poses with members of the German Bundestag and NASA representatives at the Reichstag in Berlin. Credit: NASA

GRACE tracks changes in Earth’s gravity field by noting small variations in gravitational pull from local changes in Earth’s mass. Data from the GRACE mission have been used for such diverse purposes as measuring the amount of water lost in recent years from the aquifers for California's primary agricultural region and recording losses from Greenland's ice sheet.

NASA and DLR signed the original agreement in 1998. The two agencies jointly developed the GRACE mission and have cooperated on operations since the spacecraft’s launch in March 2002.

In Paris, Garver met with several representatives from the French president’s office who had an interest in science and technology activities. She also had meetings with the director general of the European Space Agency and president of the French space agency to discuss NASA’s future plans and opportunities for potential future cooperation.

After the meetings in Berlin and Paris, Garver traveled to Vienna, Austria, where she addressed the 53rd session of the United Nations’ Committee on the Peaceful Uses of Outer Space on June 14. She explained NASA’s new plans to the gathering of international representatives.

“President Obama has laid out a bold new path for NASA to become an engine of innovation, with ambitious new programs that I believe will inspire people from around the world,” Garver said. “Under the president’s direction, the United States will pursue a more meaningful and sustainable approach to human space exploration through the development of transformative technologies and systems.”

Garver’s trip also included meetings with officials from the National Space Agency of Ukraine.

“NASA’s level of international cooperation is increasing each year,” said Al Condes, deputy associate administrator of NASA’s Office of International and Interagency Relations, who accompanied Garver on the trip. “The deputy administrator’s travel to Europe provided an excellent opportunity to meet with our key partners to discuss NASA’s future plans and reaffirm our strong commitment to working collaboratively on a wide variety of programs.”

For more information on NASA’s Office of International and Interagency Relations visit: http://oiir.hq.nasa.gov/index.html.

News media representatives seeking additional information on the trip should contact Michael Cabbage in NASA’s Office of Communication at mcabbage@nasa.gov or 202-358-1600.

For more information visit http://www.nasa.gov/topics/people/features/garver_europe_2010.html

Monday, June 14, 2010

GOES-15 Solar X-Ray Imager's Miraculous First Light

The Solar X-Ray Imager instrument aboard the GOES-15 satellite has just provided its first light image of the sun, but it required a lot of experts to make it happen.

Scientists and engineers from NASA and the National Oceanic and Atmospheric Administration (NOAA) have been working to bring the Solar X-Ray Imager (SXI) instrument to full functionality since the Geostationary Operational Environmental Satellite (GOES)-15, formerly known as the GOES-P satellite achieved orbit.

GOES-15 launched on March 4, 2010 from Cape Canaveral, Fla. On April 6, 2010, GOES-15 captured its first visible image of Earth and on April 26, GOES-15 took its first full-disk infrared image.

"Since the early checkout of GOES 15 (P) and the anomalous turn on of the Solar X-Ray Imager, the team has been aggressively pursuing all avenues to recover the instrument," said Andre' Dress, GOES N-P Deputy Project Manager at NASA's Goddard Space Flight Center in Greenbelt, Md." Frankly, we were down to our last straw when all the teams' hard work and efforts finally paid off. We now believe we have a full recovery of the instrument's functionality! It's an incredible story and a true testament of our NASA/contractor teams expertise, hard work and determination."

On June 3, the GOES 15 Solar X-Ray Imager finally came on-line. Scientists and engineers had subjected SXI to a series of long duration turn on tests in the hopes of clearing the short. About 16 hours into the testing, the instrument voltages returned to normal values and SXI now appears to be functioning properly.

This first image of the sun from the GOES-15 SXI instrument from June 2, 2010 was a cause for celebration. Credit: NASA/NOAA/ Lockheed Martin

"We were facing a tough problem when we first attempted to bring SXI on line," said George Koerner, SXI program manager at the Lockheed Martin Space Systems Company (LMSSC) Advanced Technology Center (ATC) in Palo Alto, Calif. where the Solar X-ray Imager was designed and built. "But because of our ability to bring together subject matter experts from both government and industry, to move forward step by step, and to work as a team patiently and persistently, together we achieved mission success. This is an enormously satisfying outcome."

Since its recovery, several test solar images have also been subsequently taken successfully. The GOES team continue to assess the health of the instrument. This new round of testing will assess SXI's total functionality. That functionality means the team will capture images of the sun with the camera to assess whether the camera is properly processing image data.

"I don't think most people realize how important these space weather instruments are in our everyday life," Dress said. "This data is used by the U.S. Department of Defense, NOAA, NASA, and the Federal Aviation Administration (FAA) in protecting our space assets, land based assets and directing flight paths for the FAA."

GOES-15 will join three other NOAA operational GOES spacecraft that help the agency's forecasters track life-threatening weather and solar activity that can impact the satellite-based electronics and communications industry. NASA's testing of the spacecraft and its instruments will continue through the entire post launch test period expected to end in late August 2010. This will be followed by a series of NOAA Science Tests. The GOES series of U.S. satellites are developed by a joint NASA-NOAA-Industry partnership, launched by NASA (with industry partners), and operated by NOAA.

For more information about the GOES-P mission and program on the Web, visit:
www.nasa.gov/goes-p

For more information visit http://www.nasa.gov/mission_pages/GOES-P/news/xray_imager.html