Thursday, December 15, 2011

Cassini to Make a Double Play

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Cassini to Make a Double PlayIn an action-packed day and a half, NASA's Cassini spacecraft will be making its closest swoop over the surface of Saturn's moon Dione and scrutinizing the atmosphere of Titan, Saturn's largest moon.

The closest approach to Dione, about 61 miles (99 kilometers) above the surface, will take place at about 1:39 a.m. PST (4:39 a.m. EST) on Dec. 12. One of the questions Cassini scientists will be asking during this flyby is whether Dione's surface shows any signs of activity. Understanding Dione's internal structure will help address that question, so Cassini's radio science instrument will learn how highly structured the moon's interior is by measuring variations in the moon's gravitational tug on the spacecraft. The composite infrared spectrometer instrument will also look for heat emissions along fractures on the moon's surface.

Cassini will also be probing whether Dione, like another Saturnian moon, Rhea, has a tenuous atmosphere. Scientists expect a Dionean atmosphere – if there is one – to be much more ethereal than even Rhea's. Research published in journal Geophysical Research Letters and led by Sven Simon, a Cassini magnetometer team member at the University of Cologne, Germany, found magnetic field disturbances around Dione, hinting at a tenuous atmosphere. But scientists hope to get stronger confirmation by "tasting" the space around the moon with Cassini's ion and neutral mass spectrometer.

On Cassini's journey out from Dione toward Titan, the imaging science subsystem will turn back to look at Dione's distinctive, wispy fractures and a ridge called Janiculum Dorsa.

Cassini will approach within about 2,200 milles (3,600 kilometers) of the Titan surface, at about 12:11 p.m. PST (3:11 PM EST) on Dec. 13. At Titan, the composite infrared spectrometer will be making measurements to understand how the seasonal transition from spring to summer affects wind patterns in the atmosphere near Titan's north pole. It will also search for mist.

The visual and infrared mapping spectrometer and imaging science subsystem will be observing the same equatorial deserts where the imaging science subsystem saw sudden and dramatic surface changes last year, when Titan was experiencing early northern spring. One possibly theory is that rainstorms caused these changes. As Cassini recedes from Titan, the imaging cameras will also continue to observe the moon for another day to monitor any new weather systems. 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 mission for NASA's Science Mission Directorate, Washington.

Wednesday, November 9, 2011

The Global Water Cycle and NEWS

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The cycling of energy and water has obvious and significant implications for the health and prosperity of society. The availability and quantity of water is vital to life on earth and helps to tie together the Earth's lands, oceans and atmosphere into an integrated physical system. The global water cycle is driven by a multiplicity of complex processes and interactions at all time and space scales, many of which are inadequately understood and poorly represented in model predictions.

NASA is capable of and uniquely positioned to investigate the global climatic processes that govern precipitation and the replenishment of water resources. In 2003 NASA established the NASA Energy and Water cycle Study (NEWS), whose ultimate goal is a breakthrough improvement in the nation's energy and water cycle prediction capability. NEWS is expected to demonstrate advanced global observation, data assimilation, and improved representation of physical processes in climate models, better prediction systems that can be used to quantify the hydrologic consequences of climate change and produce useful seasonal and longer-range hydrologic predictions based on observed initial values and changing boundary conditions.

NEWS is therefore envisioned to be part of the broader NASA end-to-end Earth science program and thus includes the transition of research findings and new capabilities to academic/public education and to practical applications, through partnerships with the academic community-at-large, federal agencies.

Tuesday, October 25, 2011

Orion's Belt Lights Up Cassini's View Of Enceladus

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NASA's Cassini mission will take advantage of the position of two of the three stars in Orion's belt when the spacecraft flies by Saturn's moon Enceladus on Wed., Oct. 19. As the hot, bright stars pass behind the moon's icy jets, Cassini's ultraviolet imaging spectrograph will acquire a two-dimensional view of these dramatic plumes of water vapor and icy material erupting from the moon's southern polar region. This flyby is the mission's first-ever opportunity to probe the jets with two stars simultaneously, a dual stellar occultation.

From Cassini's viewpoint, the closest of Orion's stars will appear about 9 miles (15 kilometers) above the moon's limb, or outer edge. The second star will appear higher, about 19 miles (30 kilometers) from the limb. In the foreground will be Enceladus' icy plumes, which extend hundreds of miles into space.

As the spacecraft passes Enceladus, its infrared instruments, cameras and other instruments will also be monitoring activity on the moon. The orbiter will fly within about 765 miles (1,230 kilometers) of Enceladus' surface.

This flyby will provide researchers with new insight into the jets--their content, the speed at which they are travelling and how they vary. It will also provide new information on the famed "tiger stripes" from which the jets erupt. These fissures in Enceladus' surface are the "nozzles" from which the plumes are propelled at supersonic speeds. Knowing more about their structure may help unlock some of the secrets within Enceladus' interior, including the source of the water-rich plumes.

The Cassini mission celebrated the 14th anniversary of the spacecraft's launch last week. Having completed its four-year prime mission in 2008, the mission is now on its second extension, the Cassini Solstice Mission. One of the mission's goals is to provide further information on previous Cassini discoveries, such as lakes on Titan and plumes on Enceladus, first detected by Cassini in 2005.

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 mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL.

Wednesday, October 12, 2011

ESA To Collaborate with NASA on Solar Science Mission

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Solar Orbiter viewing the sun
On October 4, 2011, the European Space Agency announced it's two next science missions, including Solar Orbiter, a spacecraft geared to study the powerful influence of the sun. Solar Orbiter will be an ESA-led mission, with strong NASA contributions managed from Goddard Space Flight Center in Greenbelt, Md.

Solar Orbiter will venture closer to the Sun than any previous mission. The spacecraft will also carry advanced instrumentation that will help untangle how activity on the sun sends out radiation, particles and magnetic fields that can affect Earth's magnetic environment, causing aurora, or potentially damaging satellites, interfering with GPS communications or even Earth's electrical power grids.

"Solar Orbiter will use multiple gravity assists from Venus to tilt its orbit until it can see the poles of the Sun, and that's never been done before," said Chris St. Cyr, NASA's project scientist for Solar Orbiter at Goddard. "A full view of the solar poles will help us understand how the sun's magnetic poles reverse direction every 11 years, causing giant eruptions and flares, called space weather, that can affect the rest of the solar system."

Being so close to the sun also means that the Solar Orbiter will stay over a given area of the solar surface for a longer time, allowing the instruments to track the evolution of sunspots, active regions, coronal holes and other solar activity far longer than has been done before.

Solar Orbiter is also designed to make major breakthroughs in our understanding of how the sun generates and propels the flow of particles in which the planets are bathed, known as the solar wind. Solar activity and solar eruptions create strong perturbations in this wind, triggering spectacular auroral displays on Earth and other planets. Solar Orbiter will be close enough to the sun to both observe the details of how the solar wind is accelerated off the sun and to sample the wind shortly after it leaves the surface

The mission's launch is planned for 2017 from Cape Canaveral, Florida aboard a NASA-provided launch vehicle. Solar Orbiter will be placed into an elliptical orbit around the sun. Its closest approach will be near the orbit of Mercury, 75% of the distance between Earth and the sun – some 21,000,000 miles away from the sun's surface.


Tuesday, October 4, 2011

NASA's Dawn Spacecraft Begins New Vesta Mapping Orbit

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NASA's Dawn Spacecraft Begins New Vesta Mapping Orbit
NASA's Dawn spacecraft has completed a gentle spiral into its new science orbit for an even closer view of the giant asteroid Vesta. Dawn began sending science data on Sept. 29 from this new orbit, known as the high altitude mapping orbit (HAMO).

In this orbit, the average distance from the spacecraft to the Vesta surface is 420 miles (680 kilometers), which is four times closer than the previous survey orbit. The spacecraft will operate in the same basic manner as it did in the survey orbit. When Dawn is over Vesta's dayside, it will point its science instruments to the giant asteroid and acquire data, and when the spacecraft flies over the nightside, it will beam that data back to Earth.

Perhaps the most notable difference in the new orbit is the frequency with which Dawn circles Vesta. In survey orbit, it took Dawn three days to make its way around the asteroid. Now in HAMO, the spacecraft completes the same task in a little over 12 hours. HAMO is scheduled to last about 30 Earth days, during which Dawn will circle Vesta more than 60 times. For about 10 of those 30 days, Dawn will peer straight down at the exotic landscape below it during the dayside passages. For about 20 days, the spacecraft will view the surface at multiple angles.

Scientists will combine the pictures to create topographic maps, revealing the heights of mountains, the depths of craters and the slopes of plains. This will help scientists understand the geological processes that shaped Vesta.

HAMO, the most complex and intensive science campaign at Vesta, has three primary goals: to map Vesta's illuminated surface in color, provide stereo data, and acquire visible and infrared mapping spectrometer data. In addition, it will allow improved measurements of Vesta's gravity.

Dawn launched in September 2007 and arrived at Vesta in July 2011. Since beginning its first survey orbit in August, Dawn has been extensively imaging this intriguing world, sending back a bounty of images and other data. NASA-funded scientists and European scientists on the Dawn mission team will present a wealth of new findings at the joint meeting of the American Astronomical Society's Division for Planetary Sciences and the European Planetary Science Congress next week at La Cite Internationale des Congres Nantes Metropole, Nantes, France.

These findings about the giant asteroid Vesta will include information about the new coordinate system and official names of Vesta's prominent features.

Monday, September 26, 2011

Meteor Likely Cause of Southwest U.S. Light Show

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A meteor is the most probable cause of a bright, colorful fireball witnessed by people in a wide swath of the southwestern United States, according to Don Yeomans, manager of NASA's Near-Earth Object Program Office at JPL.

Residents from Southern California to Arizona to Las Vegas reported seeing a streak of light move rapidly from west to east around 7:45 p.m. PDT on Wednesday, Sept. 14.

"We're virtually certain this bright display was caused by a meteor, probably the size of a baseball or basketball, that burned up in Earth's atmosphere. It appeared much larger because of the heated and glowing atmosphere along its path," said Yeomans.

Many eyewitnesses described seeing brilliant colors of blue, green and orange. Yeomans said the blue or green colors indicate the meteor contained nickel or magnesium, while orange would mean the object was traveling relatively slowly for a meteor, but still moving a few miles per second.

A meteor is a small fragment of an asteroid. Yeomans said that similar fireballs from asteroids enter Earth's atmosphere every week or so, but they usually take place over the ocean or in a sparsely populated area.

This time, Yeomans says, "The fireball was very bright and provided a harmless but memorable light show for people in numerous cities and towns in the southwestern states."

Monday, August 29, 2011

Hurricane Season 2011: Hurricane Irene

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After pounding North Carolina and Virginia on Aug. 27, Hurricane Irene made a second landfall near Little Egg Inlet, N.J., early Sunday morning, Aug. 28, still as a category one hurricane with maximum sustained winds of 75 mph (120 kilometers per hour). It then weakened slightly before making a third landfall over Coney Island, N.Y. as a 65-mph (100-kilometer-per-hour) tropical storm. Irene's heavy rains, winds and storm surge are causing widespread problems throughout the U.S. mid-Atlantic and Northeast.

This infrared image of Irene was taken by the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft at 2:47 a.m. EDT on Aug. 27, a few hours before the storm's second landfall in New Jersey.

The AIRS data create an accurate 3-D map of atmospheric temperature, water vapor and clouds, data that are useful to forecasters. The image shows the temperature of Irene's cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation. The infrared signal of AIRS does not penetrate through clouds. Where there are no clouds, AIRS reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.

AIRS is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Thursday, August 4, 2011

Atlantis’ Final Mission Included Successful Kennedy-Developed Plant Experiment

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Atlantis carried many science and research experiments in its middeck during NASA’s last shuttle flight, STS-135, in July. Among these was a plant experiment developed at Kennedy Space Center’s Space Life Sciences Laboratory (SLSL) that could have an impact on long duration missions to the moon or Mars.

Principal Investigators Dr. Gary Stutte and Dr. Michael Roberts with QinetiQ NA, and NASA Project Scientist Dr. Howard Levine created the Biological Research in Canisters-Symbiotic Nodulation in a Reduced Gravity Environment (BRIC-SyNRGE). A first of its kind to fly on a space shuttle, the purpose of the experiment was to study the symbiotic relationship between plants similar to alfalfa, which is in the legume family, and specific nitrogen-reacting bacteria in microgravity.

According to Stutte, the bacteria were introduced to each plant sample’s root hairs in order to study the effect. What he and the SyNRGE team are hoping to find is that the plants have formed specialized nodules where the bacteria can convert atmospheric nitrogen into a form the plants can use to produce proteins.

Friday, July 15, 2011

Dark Fireworks on the Sun

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On June 7, 2011, Earth-orbiting satellites detected a flash of X-rays coming from the western edge of the solar disk. Registering only "M" (for medium) on the Richter scale of solar flares, the blast at first appeared to be a run-of-the-mill eruption--that is, until researchers looked at the movies.

"We'd never seen anything like it," says Alex Young, a solar physicist at the Goddard Space Flight Center. "Half of the sun appeared to be blowing itself to bits."

"In terms of raw power, this really was just a medium-sized eruption," says Young, "but it had a uniquely dramatic appearance caused by all the inky-dark material. We don't usually see that."

Solar physicist Angelos Vourlidas of the Naval Research Lab in Washington DC calls it a case of "dark fireworks."

"The blast was triggered by an unstable magnetic filament near the sun's surface," he explains. "That filament was loaded down with cool plasma, which exploded in a spray of dark blobs and streamers. "Cool" has a special meaning on the sun: The plasma blobs registered a temperature of 20,000 Kelvin or less. That is relatively cool. Most of the surrounding gas had temperatures between 40,000 K and 1,000,000 K.
The plasma blobs were as big as planets, many larger than Earth. They rose and fell ballistically, moving under the influence of the sun's gravity like balls tossed in the air, exploding "like bombs" when they hit the stellar surface.

Some blobs, however, were more like guided missiles. "In the movies we can see material 'grabbed' by magnetic fields and funneled toward sunspot groups hundreds of thousands of kilometers away," notes Young.

SDO also detected a shadowy shock wave issuing from the blast site. The 'solar tsunami' propagated more than halfway across the sun, visibly shaking filaments and loops of magnetism en route. [91 MB Quicktime] Long-range action has become a key theme of solar physics since SDO was launched in 2010. The observatory frequently sees explosions in one part of the sun affecting other parts. Sometimes one explosion will trigger another ... and another ... with a domino sequence of flares going off all around the star.

It's tempting to look at the movies and conclude that most of the exploded material fell back--but that wouldn't be true, according to Vourlidas. "The blast also propelled a significant coronal mass ejection (CME) out of the sun's atmosphere."

He estimates that the cloud massed about 4.5 x1015 grams, placing it in the top 5% of all CMEs recorded in the Space Age. For comparison, the most massive CME ever recorded was 1016 grams, only a factor of ~2 greater than the June 7th cloud. The amount of material that fell back to the sun on June 7 was approximately equal to the amount that flew away, Vourlidas says.

As remarkable as the June 7th eruption seems to be, Young says it might not be so rare. "In fact," he says, "it might be downright common."

Before SDO, space-based observatories observed the sun with relatively slow cadences and/or limited fields of view. They could have easily missed the majesty of such an explosion, catching only a single off-center snapshot at the beginning or end of the blast to hint at what actually happened.

Wednesday, July 6, 2011

NASA Dryden Flies New Supersonic Shockwave Probes

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NASA Dryden Flies
NASA’s Dryden Flight Research Center is flight testing two new supersonic shockwave probes to determine their viability as research tools.

The probes were designed by Eagle Aeronautics of Hampton, Va., under a NASA Research Announcement, and manufactured by Triumph Aerospace Systems of Newport News, Va. The probes were first tested in a wind tunnel at NASA's Langley Research Center, also in Hampton.

The new probes are being flown on NASA Dryden's F-15B research test bed aircraft.

Supersonic flight over land is severely restricted in the United States and elsewhere because the sonic booms created by the shock waves propagating from supersonic aircraft are an annoyance to many and can damage private property.

Sonic boom researchers hope the Eagle Aero probes will aid their understanding of supersonic shockwaves. The ultimate goal of NASA's sonic boom research is to find ways to control the shockwaves and lessen the noise, so that it may be possible for supersonic flight to become more routine.

"Using these probes can be a real benefit in understanding and modeling the generation of shock waves and their associated sonic booms," said Dryden research engineer Dan Banks. "They could allow us to accurately define the near-instantaneous flight conditions of the aircraft being probed, while defining that airplane's flow field. At the same time, the probes provide flight condition data on the host aircraft," Banks said.

The primary objective of the flight series is to determine the feasibility of using the Eagle probes for air-to-air shockwave probing. Additional objectives include determining the durability and robustness of the probes in flight, their sensitivity to flight conditions, and the accuracy of the software.

Tuesday, July 5, 2011

'Odd Couple' Binary Makes Dual Gamma-ray Flares

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'Odd Couple'
In December 2010, a pair of mismatched stars in the southern constellation Crux whisked past each other at a distance closer than Venus orbits the sun. The system possesses a so-far unique blend of a hot and massive star with a compact fast-spinning pulsar. The pair's closest encounters occur every 3.4 years and each is marked by a sharp increase in gamma rays, the most extreme form of light.

The unique combination of stars, the long wait between close approaches, and periods of intense gamma-ray emission make this system irresistible to astrophysicists. Now, a team using NASA's Fermi Gamma-ray Space Telescope to observe the 2010 encounter reports that the system displayed fascinating and unanticipated activity.
"Even though we were waiting for this event, it still surprised us," said Aous Abdo, a Research Assistant Professor at George Mason University in Fairfax, Va., and a leader of the research team.

Few pairings in astronomy are as peculiar as high-mass binaries, where a hot blue-white star many times the sun's mass and temperature is joined by a compact companion no bigger than Earth -- and likely much smaller. Depending on the system, this companion may be a burned-out star known as a white dwarf, a city-sized remnant called a neutron star (also known as a pulsar) or, most exotically, a black hole.

Just four of these "odd couple" binaries were known to produce gamma rays, but in only one of them did astronomers know the nature of the compact object. That binary consists of a pulsar designated PSR B1259-63 and a 10th-magnitude Be-type star known as LS 2883. The pair lies 8,000 light-years away.

The pulsar is a fast-spinning neutron star with a strong magnetic field. This combination powers a lighthouse-like beam of energy, which astronomers can easily locate if the beam happens to sweep toward Earth. The beam from PSR B1259-63 was discovered in 1989 by the Parkes radio telescope in Australia. The neutron star is about the size of Washington, D.C., weighs about twice the sun's mass, and spins almost 21 times a second.

The pulsar follows an eccentric and steeply inclined orbit around LS 2883, which weighs roughly 24 solar masses and spans about nine times its size. This hot blue star sits embedded in a disk of gas that flows out from its equatorial region.

At closest approach, the pulsar passes less than 63 million miles from its star -- so close that it skirts the gas disk around the star's middle. The pulsar punches through the disk on the inbound leg of its orbit. Then it swings around the star at closest approach and plunges through the disk again on the way out.

Friday, April 15, 2011

WISE Delivers Millions of Galaxies, Stars, Asteroids

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WISE DeliversAstronomers across the globe can now sift through hundreds of millions of galaxies, stars and asteroids collected in the first bundle of data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.

"Starting today thousands of new eyes will be looking at WISE data, and I expect many surprises," said Edward (Ned) Wright of UCLA, the mission's principal investigator.

WISE launched into space on Dec. 14, 2009 on a mission to map the entire sky in infrared light with greatly improved sensitivity and resolution over its predecessors. From its polar orbit, it scanned the skies about one-and-a-half times while collecting images taken at four infrared wavelengths of light. It took more than 2.7 million images over the course of its mission, capturing objects ranging from faraway galaxies to asteroids relatively close to Earth.

Like other infrared telescopes, WISE required coolant to chill its heat-sensitive detectors. When this frozen hydrogen coolant ran out, as expected, in early October, 2010, two of its four infrared channels were still operational. The survey was then extended for four more months, with the goal of finishing its sweep for asteroids and comets in the main asteroid belt of our solar system.

The mission's nearby discoveries included 20 comets, more than 33,000 asteroids between Mars and Jupiter, and 133 near-Earth objects (NEOs), which are those asteroids and comets with orbits that come within 28 million miles (about 45 million kilometers) of Earth's path around the sun. The satellite went into hibernation in early February of this year.

Today, WISE is taking the first major step in meeting its primary goal of delivering the mission's trove of objects to astronomers. Data from the first 57 percent of the sky surveyed is accessible through an online public archive. The complete survey, with improved data processing, will be made available in the spring of 2012. A predecessor to WISE, the Infrared Astronomical Satellite, served a similar role about 25 years ago, and those data are still valuable to astronomers today. Likewise, the WISE legacy is expected to endure for decades.

"We are excited that the preliminary data contain millions of newfound objects," said Fengchuan Liu, the project manager for WISE at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "But the mission is not yet over -- the real treasure is the final catalog available a year from now, which will have twice as many sources, covering the entire sky and reaching even deeper into the universe than today's release."
WISE Delivers

Astronomers will use WISE's infrared data to hunt for hidden oddities, and to study trends in large populations of known objects. Survey missions often result in the unexpected discoveries too, because they are looking everywhere in the sky rather than at known targets. Data from the mission are also critical for finding the best candidates for follow-up studies with other telescopes, including the European Space Agency's Herschel observatory, which has important NASA contributions.

"WISE is providing the newest-generation 'address book' of the infrared universe with the precise location and brightness of hundreds of millions of celestial objects," said Roc Cutri, lead scientist for WISE data processing at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, Calif. "WISE continues the long tradition of infrared sky surveys supported by Caltech, stretching back to the 1969 Two Micron Sky Survey."

Wednesday, April 13, 2011

Mars Rover's 'Gagarin' Moment Applauded Exploration

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Gagarin
A flat, light-toned rock on Mars visited by NASA's Mars Exploration Rover in 2005 informally bears the name of the first human in space, Yuri Gagarin, who rode into orbit in the Soviet Union's Vostok-1 spacecraft on April 12, 1961.

The team using Opportunity to explore the Meridiani Planum region of Mars since 2004 chose "Gagarin" for what they would call the rock that the rover examined beside "Vostok" crater. A target for close-up examination on Gagarin is called "Yuri."

To commemorate Gagarin's flight, a color image of the rock on Mars has been posted, here. The image combines frames taken through three different filters by Opportunity's panoramic camera.

Early accomplishments in the Space Age inspired many of the researchers exploring other planets robotically today, who hope their work can, in turn, help inspire the next generation.

"The 50th anniversary of mankind's first fledgling foray into the cosmos should serve as an important reminder of the spirit of adventure and exploration that has propelled mankind throughout history," said Mars rover science team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md. "We are a species of explorers; it is encoded into our very DNA."

Rice continued, "Half a century ago Yuri Gagarin was lofted into a totally unknown, remote and hostile environment and in doing so opened up a new limitless frontier of possibilities for mankind. A mere 23 days later another brave human, Alan Shepard, climbed aboard a rocket and ventured into the starry abyss. Their courage and vision continue to inspire and lead us into the unknown. Hopefully, one day in the not too distant future it will lead humanity on a voyage to Mars."

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued in years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010. Opportunity remains active. This month, it has passed both the 27-kilometer and 17-mile marks in its total driving distance on Mars.

Tuesday, April 12, 2011

NASA Telescopes Join Forces to Observe Unprecedented Explosion

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NASA Telescopes Join Forces to Observe Unprecedented Explosion
NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location.

Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours.

Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its rotational axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction.

On March 28, Swift's Burst Alert Telescope discovered the source in the constellation Draco when it erupted with the first in a series of powerful X-ray blasts. The satellite determined a position for the explosion, now cataloged as gamma-ray burst (GRB) 110328A, and informed astronomers worldwide.

As dozens of telescopes turned to study the spot, astronomers quickly noticed that a small, distant galaxy appeared very near the Swift position. A deep image taken by Hubble on April 4 pinpoints the source of the explosion at the center of this galaxy, which lies 3.8 billion light-years away.

That same day, astronomers used NASA's Chandra X-ray Observatory to make a four-hour-long exposure of the puzzling source. The image, which locates the object 10 times more precisely than Swift can, shows that it lies at the center of the galaxy Hubble imaged.

"We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing now. This is truly extraordinary," said Andrew Fruchter at the Space Telescope Science Institute in Baltimore.

"We have been eagerly awaiting the Hubble observation," said Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Md. "The fact that the explosion occurred in the center of a galaxy tells us it is most likely associated with a massive black hole. This solves a key question about the mysterious event."

Monday, April 11, 2011

NASA Telescopes Join Forces to Observe Unprecedented Explosion

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NASA Telescopes
NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location.

Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours.

Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its rotational axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction.

On March 28, Swift's Burst Alert Telescope discovered the source in the constellation Draco when it erupted with the first in a series of powerful X-ray blasts. The satellite determined a position for the explosion, now cataloged as gamma-ray burst (GRB) 110328A, and informed astronomers worldwide.

As dozens of telescopes turned to study the spot, astronomers quickly noticed that a small, distant galaxy appeared very near the Swift position. A deep image taken by Hubble on April 4 pinpoints the source of the explosion at the center of this galaxy, which lies 3.8 billion light-years away.

That same day, astronomers used NASA's Chandra X-ray Observatory to make a four-hour-long exposure of the puzzling source. The image, which locates the object 10 times more precisely than Swift can, shows that it lies at the center of the galaxy Hubble imaged.

"We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing now. This is truly extraordinary," said Andrew Fruchter at the Space Telescope Science Institute in Baltimore.

"We have been eagerly awaiting the Hubble observation," said Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Md. "The fact that the explosion occurred in the center of a galaxy tells us it is most likely associated with a massive black hole. This solves a key question about the mysterious event."

Most galaxies, including our own, contain central black holes with millions of times the sun's mass; those in the largest galaxies can be a thousand times larger. The disrupted star probably succumbed to a black hole less massive than the Milky Way's, which has a mass four million times that of our sun

Astronomers previously have detected stars disrupted by supermassive black holes, but none have shown the X-ray brightness and variability seen in GRB 110328A. The source has repeatedly flared. Since April 3, for example, it has brightened by more than five times.

Scientists think that the X-rays may be coming from matter moving near the speed of light in a particle jet that forms as the star's gas falls toward the black hole.

"The best explanation at the moment is that we happen to be looking down the barrel of this jet," said Andrew Levan at the University of Warwick in the United Kingdom, who led the Chandra observations. "When we look straight down these jets, a brightness boost lets us view details we might otherwise miss."

This brightness increase, which is called relativistic beaming, occurs when matter moving close to the speed of light is viewed nearly head on.

Astronomers plan additional Hubble observations to see if the galaxy's core changes brightness.


Monday, April 4, 2011

NASA Lunar Reconnaissance Orbiter Delivers Treasure Trove of Data

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NASA Lunar Reconnaissance
NASA's Lunar Reconnaissance Orbiter (LRO) team released Tuesday the final set of data from the mission's exploration phase along with the first measurements from its new life as a science satellite.

With this fifth release of data, striking new images and maps have been added to the already comprehensive collection of raw lunar data and high-level products, including mosaic images, that LRO has made possible. The spacecraft's seven instruments delivered more than 192 terabytes of data with an unprecedented level of detail. It would take approximately 41,000 typical DVDs to hold the new LRO data set.

"The release of such a comprehensive and rich collection of data, maps and images reinforces the tremendous success we have had with LRO in the Exploration Systems Mission Directorate and with lunar science," said Michael Wargo, chief lunar scientist of the Exploration Systems Mission Directorate at NASA Headquarters in Washington.

Among the latest products is a global map with a resolution of 100 meters per pixel from the Lunar Reconnaissance Orbiter Camera (LROC). To enhance the topography of the moon, this map was made from images collected when the sun angle was low on the horizon. Armchair astronauts can zoom in to full resolution with any of the mosaics—quite a feat considering that each is 34,748 pixels by 34,748 pixels, or approximately 1.1 gigabytes

"Because the moon is so close and because we have a dedicated ground station, we are able to bring back as much data from LRO as from all the other planetary missions combined," said LRO Project Scientist Richard Vondrak of NASA's Goddard Space Flight Center in Greenbelt, Md.

LRO's Diviner Lunar Radiometer Experiment is providing new data relating to the moon's surface. These include maps of visual and infrared brightness, temperature, rock abundance, nighttime soil temperature and surface mineralogy. The data are in the form of more than 1700 digital maps at a range of resolutions that can be overlaid easily on other lunar data sets.


The Lyman-Alpha Mapping Project, which collects information to help identify surface water-ice deposits, especially in permanently-shadowed regions of the moon, also has new data. This release includes new maps of far-ultraviolet (FUV) brightness, albedo and water-ice data as well as instrument exposure, illumination and other conditions.

As a complement to the high-resolution digital elevation maps, representing 3.4 billion measurements already released by the Lunar Orbiter Laser Altimeter team, the group is delivering new maps of slope, roughness and illumination conditions. New maps from the Lunar Exploration Neutron Detector, and the latest data from the Cosmic Ray Telescope for the Effects of Radiation and the Miniature Radio Frequency instruments, also are featured.

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Saturday, April 2, 2011

A Race Against Time to Find Apollo 14's Lost Voyagers

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Apollo 14's Lost Voyagers
In communities all across the U.S., travelers that went to the moon and back with the Apollo 14 mission are living out their quiet lives. The whereabouts of more than 50 are known. Many, now aging, reside in prime retirement locales: Florida, Arizona and California. A few are in the Washington, D.C., area. Hundreds more are out there -- or at least, they were. And Dave Williams of NASA's Goddard Space Flight Center in Greenbelt, Md., wants to find them before it's too late.

The voyagers in question are not astronauts. They're "moon trees" -- redwood, loblolly pine, sycamore, Douglas fir, and sweetgum trees sprouted from seeds that astronaut Stuart Roosa took to the moon and back 40 years ago.

"Hundreds of moon trees were distributed as seedlings," says Williams, "but we don't have systematic records showing where they all went."

And though some of the trees are long-lived species expected to live hundreds or thousands of years, others have started to succumb to the pressures of old age, severe weather and disease. At least a dozen have died, including the loblolly pine at the White House and a New Orleans pine that was damaged by Hurricane Katrina and later removed.

To capture the vanishing historical record, Williams, a curator at the National Space Science Data Center, has been tracking down the trees, dead or alive.

His sleuthing started in 1996, prompted by an email from a third-grade teacher, Joan Goble, asking about a tree at the Camp Koch Girl Scout Camp in Cannelton, Ind. A simple sign nearby read "moon tree."

"At the time, I had never heard of moon trees," Williams says. "The sign had a few clues, so I sent a message to the NASA history office and found more bits and pieces on the web. Then I got in touch with Stan Krugman and got more of the story."

Krugman had been the U.S. Department of Agriculture Forest Service's staff director for forest genetics research in 1971. He had given the seeds to Roosa, who stowed them in his personal gear for the Apollo 14 mission. The seeds were symbolic for Roosa because he had fought wildfires as a smoke jumper before becoming an Air Force test pilot and then an astronaut.

The seeds flew in the command module that Roosa piloted, orbiting the moon 34 times while astronauts Alan Shepard Jr. and Edgar Mitchell walked -- and in Shepard's case, played a little golf -- on the moon.

Back then, biologists weren't sure the seeds would germinate after such a trip. Few experiments of this kind had been done. A mishap during decontamination procedures made the fate of the seeds even less certain: the canister bearing the seeds was exposed to vacuum and burst, scattering its contents.

But the seeds did germinate, and the trees seemed to grow normally. At Forest Service facilities, the moon trees reproduced with regular trees, producing a second generation called half-moon trees.

By 1975, the trees were ready to leave the Forest Service nurseries. One was sent to Washington Square in Philadelphia to be the first moon tree planted as part of the United States Bicentennial celebrations; Roosa took part in that ceremony. Another tree went to the White House. Many more were planted at state capitals, historic locations and space- and forestry-related sites across the country. Gerald Ford, then the president, called the trees "living symbol[s] of our spectacular human and scientific achievements."

When Williams could find no detailed records of which trees went where, he created a webpage to collect as much information as possible. A flurry of emails came in from people who either knew of or came upon the trees.

Friday, April 1, 2011

NASA’s Kepler Mission Helps Reveal the Inner Secrets of Giant Stars for the First Time

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NASA’s Kepler
University of Sydney astrophysicists are behind a major breakthrough in the study of the senior citizens of our galaxy: stars known as Red Giants. Using high precision brightness measurements taken by the Kepler spacecraft, scientists have been able to distinguish profound differences inside the cores of stars that otherwise look the same on the surface.

The discovery, published in the latest edition of the journal Nature and made possible by observations using NASA's powerful Kepler space telescope, is shedding new light on the evolution of stars, including our own sun.

The paper's lead author, the University of Sydney's Professor Tim Bedding, explains, "Red giants are evolved stars that have exhausted the supply of hydrogen in their cores that powers nuclear fusion, and instead burn hydrogen in a surrounding shell. Towards the end of their lives, red giants begin burning the helium in their cores."

The Kepler space telescope has allowed Professor Bedding and colleagues to continuously study starlight from hundreds of red giants at an unprecedented level of precision for nearly a year, opening up a window into the stars' cores.
NASA’s Kepler
"The changes in brightness at a star's surface is a result of turbulent motions inside that cause continuous star-quakes, creating sound waves that travel down through the interior and back to the surface," Professor Bedding said.

"Under the right conditions, these waves interact with other waves trapped inside the star's helium core. It is these 'mixed' oscillation modes that are the key to understanding a star's particular life stage. By carefully measuring very subtle features of the oscillations in a star's brightness, we can see that some stars have run out of hydrogen in the center and are now burning helium, and are therefore at a later stage of life."

Astronomer Travis Metcalfe of the US National Center for Atmospheric Research, in a companion piece in the same Nature issue which highlights the discovery's significance, compares red giants to Hollywood stars, whose age is not always obvious from the surface. "During certain phases in a star's life, its size and brightness are remarkably constant, even while profound transformations are taking place deep inside."

Professor Bedding and his colleagues work in an expanding field called asteroseismology. "In the same way that geologists use earthquakes to explore Earth's interior, we use star quakes to explore the internal structure of stars," he explained.

Professor Bedding said: "We are very excited about the results. We had some idea from theoretical models that these subtle oscillation patterns would be there, but this confirms our models. It allows us to tell red giants apart, and we will be able to compare the fraction of stars that are at the different stages of evolution in a way that we couldn't before."

Wednesday, March 30, 2011

NASA Stardust Spacecraft Officially Ends Operations

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NASA Stardust Spacecraft
NASA's Stardust spacecraft sent its last transmission to Earth at 4:33 p.m. PDT (7:33 p.m. EDT) Thursday, March 24, shortly after depleting fuel and ceasing operations. During a 12-year period, the venerable spacecraft collected and returned comet material to Earth and was reused after the end of its prime mission in 2006 to observe and study another comet during February 2011.

The Stardust team performed the burn to depletion because the comet hunter was literally running on fumes. The depletion maneuver command was sent from the Stardust-NExT mission control area at Lockheed Martin Space Systems in Denver. The operation was designed to fire Stardust's rockets until no fuel remained in the tank or fuel lines. The spacecraft sent acknowledgment of its last command from approximately 312 million kilometers (194 million miles) away in space.

"This is the end of the spacecraft's operations, but really just the beginnings of what this spacecraft's accomplishments will give to planetary science," said Lindley Johnson, Stardust-NExT and Discovery program executive at NASA Headquarters in Washington. "The treasure-trove of science data and engineering information collected and returned by Stardust is invaluable for planning future deep space planetary missions."

After completion of the burn, mission personnel began comparing the computed amount of fuel consumed during the engine firing with the anticipated amount based on consumption models. The models are required to track fuel levels, because there are no fully reliable fuel gauges for spacecraft in the weightless environment of space. Mission planners use approximate fuel usage by reviewing the history of the vehicle's flight, how many times and how long its rocket motors fired.

"Stardust's motors burned for 146 seconds," said Allan Cheuvront, Lockheed Martin Space Systems Company program manager for Stardust-NExT in Denver. "We'll crunch the numbers and see how close the reality matches up with our projections. That will be a great data set to have in our back pocket when we plan for future missions."

Launched Feb. 7, 1999, Stardust flew past the asteroid named Annefrank and traveled halfway to Jupiter to collect the particle samples from the comet Wild 2. The spacecraft returned to Earth's vicinity to drop off a sample return capsule eagerly awaited by comet scientists.

NASA re-tasked the spacecraft as Stardust-NExT to perform a bonus mission and fly past comet Tempel 1, which was struck by the Deep Impact mission in 2005. The mission collected images and other scientific data to compare with images of that comet collected by the Deep Impact mission in 2005. Stardust traveled approximately 21 million kilometers (13 million miles) around the sun in the weeks after the successful Tempel 1 flyby. The Stardust-NExT mission met all mission goals, and the spacecraft was extremely successful during both missions. From launch until final rocket engine burn, Stardust travelled approximately 5.69 billion kilometers (3.54 billion miles).

After the mileage logged in space, the Stardust team knew the end was near for the spacecraft. With its fuel tank empty and final radio transmission concluded, history's most traveled comet hunter will move from NASA's active mission roster to retired.

"This kind of feels like the end of one of those old western movies where you watch the hero ride his horse towards the distant setting sun -- and then the credits begin to roll," said Stardust-NExT project manager Tim Larson from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Only there's no setting sun in space."

Stardust and Stardust-NExT missions were managed by JPL for NASA's Science Mission Directorate in Washington. The missions were part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Joe Veverka of Cornell University was the Stardust-NExT principal investigator. Don Brownlee of the University of Washington in Seattle was the Stardust principal investigator. Lockheed Martin Space Systems built the spacecraft and managed day-to-day mission operations.

Tuesday, March 29, 2011

Work Stopped on Alternative Cameras for Mars Rover

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Work Stopped on Alternative Cameras for Mars Rover
The NASA rover to be launched to Mars this year will carry the Mast Camera (Mastcam) instrument already on the vehicle, providing the capability to meet the mission's science goals.

Work has stopped on an alternative version of the instrument, with a pair of zoom-lens cameras, which would have provided additional capabilities for improved three-dimensional video. The installed Mastcam on the Mars Science Laboratory mission's Curiosity rover uses two fixed-focal-length cameras: a telephoto for one eye and wider angle for the other. Malin Space Science Systems, San Diego, built the Mastcam and was funded by NASA last year to see whether a zoom version could be developed in time for testing on Curiosity.

"With the Mastcam that was installed last year and the rover's other instruments, Curiosity can accomplish its ambitious research goals," said Mars Science Laboratory Project Scientist John Grotzinger, of the California Institute of Technology, Pasadena. "Malin Space Science Systems has provided excellent, unprecedented science cameras for this mission. The possibility for a zoom-camera upgrade was very much worth pursuing, but time became too short for the levels of testing that would be needed for them to confidently replace the existing cameras. We applaud Malin Space Science Systems for their tremendous effort to deliver the zooms, and also the Mars Science Laboratory Project's investment in supporting this effort."

Malin Space Science Systems has also provided the Mars Hand Lens Imager and the Mars Descent Imager instruments on Curiosity. The company will continue to pursue development of the zoom system, both to prove out the design and to make the hardware available for possible use on future missions.

"While Curiosity won't benefit from the 3D motion imaging that the zooms enable, I'm certain that this technology will play an important role in future missions," said Mastcam Co-Investigator James Cameron. "In the meantime, we're certainly going to make the most of our cameras that are working so well on Curiosity right now."

Mastcam Principal Investigator Michael Malin said, "Although we are very disappointed that the zoom cameras will not fly, we expect the fixed-focal-length cameras to achieve all of the primary science objectives of the Mastcam investigation."

The rover and other parts of the Mars Science Laboratory spacecraft are in testing at NASA's Jet Propulsion Laboratory, Pasadena, Calif., which manages the project for the NASA Science Mission Directorate, Washington. The spacecraft will be delivered to NASA Kennedy Space Center in Florida in coming months for launch late this year. In August 2012, Curiosity will land on Mars for a two-year mission to examine whether conditions in the landing area have been favorable for microbial life and for preserving evidence about whether life has existed there.

Monday, March 28, 2011

Payload Installation Set to Wrap Up Saturday Morning

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NASA's Kennedy Space Center
Launch Pad 39A crews at NASA's Kennedy Space Center in Florida briefly delayed installing space shuttle Endeavour's STS-134 payload into its cargo bay today to evaluate the alignment of the Alpha Magnetic Spectrometer's remotely operated electrical umbilical, which provides heating and avionics power to the experiment. Installation now is expected to be completed Saturday morning.

During the 14-day mission to the International Space Station, Endeavour's six astronauts will deliver the Alpha Magnetic Spectrometer-2, a particle physics detector designed to search for various types of unusual matter by measuring cosmic rays and the Express Logistics Carrier-3, a platform that carries spare parts that will sustain station operations once the shuttles are retired later this year.

At NASA's Johnson Space Center, STS-134 Mission Specialists Michael Fincke and Greg Chamitoff are rehearsing techniques for the mission's fourth and final spacewalk today in the Neutral Buoyancy Laboratory.

Launch of Endeavour on the STS-134 mission to the International Space Station is targeted for 7:48 p.m. EDT April 19.

Friday, March 25, 2011

NASA's Successful 'Can Crush' Will Aid Heavy-Lift Rocket Design

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NASA's Successful 'Can Crush'
On March 23, NASA put the squeeze on a large rocket test section. Results from this structural strength test at NASA's Marshall Space Flight Center in Huntsville, Ala., will help future heavy-lift launch vehicles weigh less and reduce development costs.

This trailblazing project is examining the safety margins needed in the design of future, large launch vehicle structures. Test results will be used to develop and validate structural analysis models and generate new "shell-buckling knockdown factors" -- complex engineering design standards essential to launch vehicle design.

"This type of research is critical to NASA developing a new heavy-lift vehicle," said NASA Administrator Charlie Bolden. "The Authorization Act of 2010 gave us direction to take the nation beyond low-Earth orbit, but it is the work of our dedicated team of engineers and researchers that will make future NASA exploration missions a reality."

The aerospace industry's shell buckling knockdown factors date back to Apollo-era studies when current materials, manufacturing processes and high-fidelity computer modeling did not exist. These new analyses will update essential design factors and calculations that are a significant performance and safety driver in designing large structures like the main fuel tank of a future heavy-lift launch vehicle.

During the test, a massive 27.5-foot-diameter and 20-foot-tall aluminum-lithium test cylinder received almost one million pounds of force until it failed. More than 800 sensors measured strain and local deformations. In addition, advanced optical measurement techniques were used to monitor tiny deformations over the entire outer surface of the test article.

Wednesday, March 23, 2011

NASA Dryden Flies New Supersonic Shockwave Probes

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NASA Dryden Flies New Supersonic Shockwave Probes
NASA’s Dryden Flight Research Center is flight testing two new supersonic shockwave probes to determine their viability as research tools.

The probes were designed by Eagle Aeronautics of Hampton, Va., under a NASA Research Announcement, and manufactured by Triumph Aerospace Systems of Newport News, Va. The probes were first tested in a wind tunnel at NASA's Langley Research Center, also in Hampton.

The new probes are being flown on NASA Dryden's F-15B research test bed aircraft.

Supersonic flight over land is severely restricted in the United States and elsewhere because the sonic booms created by the shock waves propagating from supersonic aircraft are an annoyance to many and can damage private property.

Sonic boom researchers hope the Eagle Aero probes will aid their understanding of supersonic shockwaves. The ultimate goal of NASA's sonic boom research is to find ways to control the shockwaves and lessen the noise, so that it may be possible for supersonic flight to become more routine.NASA Dryden Flies New Supersonic Shockwave Probes

"Using these probes can be a real benefit in understanding and modeling the generation of shock waves and their associated sonic booms," said Dryden research engineer Dan Banks. "They could allow us to accurately define the near-instantaneous flight conditions of the aircraft being probed, while defining that airplane's flow field. At the same time, the probes provide flight condition data on the host aircraft," Banks said.

The primary objective of the flight series is to determine the feasibility of using the Eagle probes for air-to-air shockwave probing. Additional objectives include determining the durability and robustness of the probes in flight, their sensitivity to flight conditions, and the accuracy of the software.

During the initial flight test phase, the probes are attached to an adapter that hangs on the aircraft's centerline instrumented pylon, or CLIP. A large splitter plate separates the CLIP from the F-15B. This helps protect to the aircraft in the unlikely event of flutter, or damaging vibration, that might cause the probes to break off the CLIP.

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Juno Marches On

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Juno Marches On
NASA's Juno spacecraft has completed its thermal vacuum chamber testing. The two-week-long test, which concluded on March 13, 2011, is the longest the spacecraft will undergo prior to launch.

In the image, a technician is attaching the lifting equipment in preparation for hoisting the 1,588-kilogram (3,500-pound) spacecraft out of the chamber. Prominent in the photo is one of three large, black, square solar array simulators, which reproduced the thermal properties of Juno's large solar arrays.

The actual solar arrays Juno will use to power the spacecraft during its voyage to, and its exploration of, Jupiter have already been shipped to NASA's Kennedy Space Center in Florida. The main body of the Juno spacecraft, including its suite of science instruments, is scheduled to ship to Kennedy in early April, where it will undergo final preparations and launch.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute at San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, is building the spacecraft. The Italian Space Agency in Rome is contributing an infrared spectrometer instrument and a portion of the radio science experiment. JPL is a division of the California Institute of Technology in Pasadena.

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Monday, March 21, 2011

Observing Clouds for NASA Becomes a Class Tradition

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Observing Clouds for NASA Becomes a Class Tradition
Attending homecoming games, purchasing class rings, and wearing school colors are a few common traditions students pass down. A not-so-common class tradition? Validating NASA satellites.

For over 10 years, Gary Popiolkowski's seventh grade students at Chartiers-Houston Jr./Sr. High School in Houston, Pa. have carried on the tradition of sending cloud observations to NASA to help scientists make sure satellites are identifying clouds correctly

Popiolkowski's seventh graders are participants in Students' Cloud Observations On-Line (S'COOL), a program based out of NASA's Langley Research Center in Hampton, Va., that allows students from around the world to coordinate their observations with the time a NASA satellite will be observing clouds over their school.

"After doing this for so many years, my students have really bought into being diligent observers and pass that tradition on from year to year," says Popiolkowski.

So diligent that S'COOL recently named this class the top observers for the program, completing 63 observations that match a satellite overpass during a one-month period.

"Gary's class is achieving really remarkable feats," says Lin Chambers, a research scientist at NASA Langley who runs the S'COOL program. "Given that there are four opportunities in a 24-hour period, some of which are in the middle of the night, they observed for more than half of them."

The four satellites students can use to complete cloud observations are Terra, which usually passes over a given area in the morning, and Aqua, CloudSat and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations), which generally come by in the afternoon.

Popiolkowski explains that students voluntarily record cloud observations after school in the evenings, and they also take turns signing up to observe clouds over the weekend.
"Students have to make their observations within 15 minutes of a satellite overpass, because clouds change on the timescale of minutes," explains Chambers.

According to Popiolkowski, the quick changes in clouds and the process of cloud formation are some of the local standards of learning with which the S'COOL program aligns.

"S'COOL also reinforces information on the water cycle, forecasting, and how scientists use data and dichotomous keys," says Popiolkowski. One of those keys is a tool on the S'COOL site developed to help students classify clouds when they are making their observations. Once students have identified the clouds in their area, they upload their data to the S'COOL website.

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Friday, March 18, 2011

NASA Makes Use of Historic Test Site for New Robotic Lander Prototype Tests

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Today, engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., began the first phase of integrated system tests on a new robotic lander prototype at Redstone Test Center’s propulsion test facility on the U.S. Army Redstone Arsenal, also in Huntsville. These tests will aid in the design and development of a new generation of small, smart, versatile robotic landers capable of performing science and exploration research on the surface of the moon or other airless bodies, including near-Earth asteroids.

This initial test phase, or strapdown testing, allows the engineering team to fully check out the integrated lander prototype before moving to more complex free flight tests. The team secures, or straps down, the prototype during hot fire tests to validate the propulsion system's response to the flight guidance, navigation and control algorithms and flight software prior to autonomous free flight testing

"Moving the robotic lander tests to the Redstone Test Center facility is a good example of intergovernmental collaboration at its best," said Larry Hill, Robotic Lunar Lander Development Project Manager Test Director, at the Marshall Center. "Engineers and technicians from NASA, the Army and our Huntsville-based support contractor, Teledyne Brown Engineering, have worked tirelessly over the last month to modify the historic test facility formerly used for missile testing to accommodate NASA's lander test in record time, saving NASA time and money."

"Our team has been on a record paced design and development schedule to deliver the robotic lander prototype to the test site," said Julie Bassler, Robotic Lunar Lander Development Project Manager. "We have succeeded in designing, building and testing this new lander prototype in a short 17 months with an in-house NASA Marshall team in collaboration with the our partners" -- Johns Hopkins Applied Physics Laboratory of Laurel, Md., and the Von Braun Center for Science and Innovation in Huntsville.

The flight test program includes three phases of testing culminating in free flight testing for periods up to sixty seconds scheduled for summer 2011. The prototype provides a platform to develop and test algorithms, sensors, avionics, software, landing legs, and integrated system elements to support autonomous landings on airless bodies, where aero-braking and parachutes are not options. The test program furthers NASA’s capability to conduct science and exploration activities on airless bodies in the solar system.

Development and integration of the lander prototype is a cooperative endeavor led by the Robotic Lunar Lander Development Project at the Marshall Center, Johns Hopkins Applied Physics Laboratory and the Von Braun Center for Science and Innovation, which includes the Science Applications International Corporation, Dynetics Corp., Teledyne Brown Engineering Inc., and Millennium Engineering and Integration Company, all of Huntsville.


Thursday, March 17, 2011

Japan Quake May Have Shortened Earth Days, Moved Axis

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Japan Quake May Have Shortened Earth Days, Moved Axis
The March 11, magnitude 9.0 earthquake in Japan may have shortened the length of each Earth day and shifted its axis. But don't worry—you won't notice the difference.

Using a United States Geological Survey estimate for how the fault responsible for the earthquake slipped, research scientist Richard Gross of NASA's Jet Propulsion Laboratory, Pasadena, Calif., applied a complex model to perform a preliminary theoretical calculation of how the Japan earthquake—the fifth largest since 1900—affected Earth's rotation. His calculations indicate that by changing the distribution of Earth's mass, the Japanese earthquake should have caused Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds (a microsecond is one millionth of a second).

The calculations also show the Japan quake should have shifted the position of Earth's figure axis (the axis about which Earth's mass is balanced) by about 17 centimeters (6.5 inches), towards 133 degrees east longitude. Earth's figure axis should not be confused with its north-south axis; they are offset by about 10 meters (about 33 feet). This shift in Earth's figure axis will cause Earth to wobble a bit differently as it rotates, but it will not cause a shift of Earth's axis in space—only external forces such as the gravitational attraction of the sun, moon and planets can do that.

Both calculations will likely change as data on the quake are further refined.
In comparison, following last year's magnitude 8.8 earthquake in Chile, Gross estimated the Chile quake should have shortened the length of day by about 1.26 microseconds and shifted Earth's figure axis by about 8 centimeters (3 inches). A similar calculation performed after the 2004 magnitude 9.1 Sumatran earthquake revealed it should have shortened the length of day by 6.8 microseconds and shifted Earth's figure axis by about 7 centimeters, or 2.76 inches. How an individual earthquake affects Earth's rotation depends on its size (magnitude), location and the details of how the fault slipped.

Gross said that, in theory, anything that redistributes Earth's mass will change Earth's rotation.

"Earth's rotation changes all the time as a result of not only earthquakes, but also the much larger effects of changes in atmospheric winds and oceanic currents," he said. "Over the course of a year, the length of the day increases and decreases by about a millisecond, or about 550 times larger than the change caused by the Japanese earthquake. The position of Earth's figure axis also changes all the time, by about 1 meter (3.3 feet) over the course of a year, or about six times more than the change that should have been caused by the Japan quake."

Gross said that while we can measure the effects of the atmosphere and ocean on Earth's rotation, the effects of earthquakes, at least up until now, have been too small to measure. The computed change in the length of day caused by earthquakes is much smaller than the accuracy with which scientists can currently measure changes in the length of the day. However, since the position of the figure axis can be measured to an accuracy of about 5 centimeters (2 inches), the estimated 17-centimeter shift in the figure axis from the Japan quake may actually be large enough to observe if scientists can adequately remove the larger effects of the atmosphere and ocean from the Earth rotation measurements. He and other scientists will be investigating this as more data become available.


Wednesday, March 16, 2011

NASA Satellite Sees Area Affected by Japan Tsunami

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Area Affected by Japan Tsunami
A new before-and-after image pair from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft shows a region of Japan's northeastern coast, northeast of the city of Sendai, which was affected by the March 11, 2011 tsunami.

The images show the coastal cities of Ofunato and Kesennuma, located about 90 kilometers (55 miles) northeast of Sendai. Ofunato has a population of about 42,000, while the population of Kesennuma is about 73,000. Areas covered by vegetation are shown in red, while cities and unvegetated areas are shown in shades of blue-gray. The image on the left was acquired on March 14, 2011; the image on the right was acquired in August 2008. When compared closely, vegetation is no longer visible in many coastal areas in the new image, particularly around Kesennuma. Scientists believe this is most likely due to the effects of the tsunami.

The images show an area located at 39.4 degrees north latitude, 141.9 degrees east longitude, and cover an area of 28 by 46 kilometers (17 by 27 miles).

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Monday, March 14, 2011

Speed Demon Creates a Shock

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Speed Demon Creates a Shock
Just as some drivers obey the speed limit while others treat every road as if it were the Autobahn, some stars move through space faster than others. NASA's Wide-field Infrared Survey Explorer, or WISE, captured this image of the star Alpha Camelopardalis, or Alpha Cam, in astronomer-speak, speeding through the sky like a motorcyclist zipping through rush-hour traffic. The supergiant star Alpha Cam is the bright star in the middle of this image, surrounded on one side by an arc-shaped cloud of dust and gas -- a bow shock -- which is colored red in this infrared view.

Such fast-moving stars are called runaway stars. The distance and speed of Alpha Cam is somewhat uncertain. It is probably somewhere between 1,600 and 6,900 light-years away and moving at an astonishing rate of somewhere between 680 and 4,200 kilometers per second (between 1.5 and 9.4 million mph). It turns out that WISE is particularly adept at imaging bow shocks from runaway stars. Previous examples can be seen around Zeta Ophiuchi , AE Aurigae, and Menkhib. But Alpha Cam revs things up into a different gear. To put its speed into perspective, if Alpha Cam were a car driving across the United States at 4,200 kilometers per second, it would take less than one second to travel from San Francisco to New York City!

Astronomers believe runaway stars are set into motion either through the supernova explosion of a companion star or through gravitational interactions with other stars in a cluster. Because Alpha Cam is a supergiant star, it gives off a very strong wind. The speed of the wind is boosted in the forward direction the star is moving in space. When this fast-moving wind slams into the slower-moving interstellar material, a bow shock is created, similar to the wake in front of the bow of a ship in water. The stellar wind compresses the interstellar gas and dust, causing it to heat up and glow in infrared. Alpha Cam's bow shock cannot be seen in visible light, but WISE's infrared detectors show us the graceful arc of heated gas and dust around the star.

JPL manages and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

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Friday, March 11, 2011

NASA Finds Polar Ice Adding More To Rising Seas

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NASA Finds Polar Ice Adding More To Rising Seas
The Greenland and Antarctic ice sheets are losing mass at an accelerating pace, according to a new NASA-funded satellite study. The findings of the study -- the longest to date of changes in polar ice sheet mass -- suggest these ice sheets are overtaking ice loss from Earth's mountain glaciers and ice caps to become the dominant contributor to global sea level rise, much sooner than model forecasts have predicted.

The nearly 20-year study reveals that in 2006, a year in which comparable results for mass loss in mountain glaciers and ice caps are available from a separate study conducted using other methods, the Greenland and Antarctic ice sheets lost a combined mass of 475 gigatonnes a year on average. That's enough to raise global sea level by an average of 1.3 millimeters (.05 inches) a year. (A gigatonne is one billion metric tons, or more than 2.2 trillion pounds.)

The pace at which the polar ice sheets are losing mass was found to be accelerating rapidly. Each year over the course of the study, the two ice sheets lost a combined average of 36.3 gigatonnes more than they did the year before. In comparison, the 2006 study of mountain glaciers and ice caps estimated their loss at 402 gigatonnes a year on average, with a year-over-year acceleration rate three times smaller than that of the ice sheets.

"That ice sheets will dominate future sea level rise is not surprising -- they hold a lot more ice mass than mountain glaciers," said lead author Eric Rignot, jointly of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of California, Irvine. "What is surprising is this increased contribution by the ice sheets is already happening. If present trends continue, sea level is likely to be significantly higher than levels projected by the United Nations Intergovernmental Panel on Climate Change in 2007. Our study helps reduce uncertainties in near-term projections of sea level rise."

Rignot's team combined nearly two decades (1992-2009) of monthly satellite measurements with advanced regional atmospheric climate model data to examine changes in ice sheet mass and trends in acceleration of ice loss.

The study compared two independent measurement techniques. The first characterized the difference between two sets of data: interferometric synthetic aperture radar data from European, Canadian and Japanese satellites and radio echo soundings, which were used to measure ice exiting the ice sheets; and regional atmospheric climate model data from Utrecht University, The Netherlands, used to quantify ice being added to the ice sheets. The other technique used eight years of data from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) satellites, which track minute changes in Earth's gravity field due to changes in Earth's mass distribution, including ice movement.

The team reconciled the differences between techniques and found them to be in agreement, both for total amount and rate of mass loss, over their data sets' eight-year overlapping period. This validated the data sets, establishing a consistent record of ice mass changes since 1992.

The team found that for each year over the 18-year study, the Greenland ice sheet lost mass faster than it did the year before, by an average of 21.9 gigatonnes a year. In Antarctica, the year-over-year speedup in ice mass lost averaged 14.5 gigatonnes.

"These are two totally independent techniques, so it is a major achievement that the results agree so well," said co-author Isabella Velicogna, also jointly with JPL and UC Irvine. "It demonstrates the tremendous progress that's being made in estimating how much ice the ice sheets are gaining and losing, and in analyzing Grace's time-variable gravity data."

The authors conclude that, if current ice sheet melting rates continue for the next four decades, their cumulative loss could raise sea level by 15 centimeters (5.9 inches) by 2050. When this is added to the predicted sea level contribution of 8 centimeters (3.1 inches) from glacial ice caps and 9 centimeters (3.5 inches) from ocean thermal expansion, total sea level rise could reach 32 centimeters (12.6 inches). While this provides one indication of the potential contribution ice sheets could make to sea level in the coming century, the authors caution that considerable uncertainties remain in estimating future ice loss acceleration.

Study results are published this month in Geophysical Research Letters. Other participating institutions include the Institute for Marine and Atmospheric Research, Utrecht University, The Netherlands; and the National Center for Atmospheric Research, Boulder, Colo.

JPL developed Grace and manages the mission for NASA. The University of Texas Center for Space Research in Austin has overall mission responsibility. GeoForschungsZentrum Potsdam (GFZ), Potsdam, Germany, is responsible for German mission elements.
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