On Sunday May 22, 2011, the Tropical Rainfall Measuring Mission (TRMM) satellite captured an image of the rainfall rate in the supercell thunderstorm that generated the deadly twister that struck Joplin, Missouri.

TRMM is a satellite that is managed by both NASA and the Japanese Space Agency, and monitors rainfall rates in the tropics. It's often used for hurricane research, but also calculates rain rates in other weather systems. On May 22 at 2042 UTC (3:42 p.m. CDT), about two hours before the deadly tornado touched down in Joplin, Missouri, TRMM captured rainfall rates in a supercell thunderstorm that was approaching Joplin from the west. A supercell, also known as a rotating thunderstorm, is a thunderstorm with a deep, continuously-rotating updraft.

"This supercell contained a deadly tornado as it moved into southwestern Missouri a few hours later and hit Joplin, Missouri," said Hal Pierce, meteorologist on NASA's TRMM team who created images using TRMM rainfall imagery. TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) were used to create images that showed an analysis of rainfall in the vicinity of the storm. TRMM data revealed a large area of heavy rainfall, where rainfall rates were more than 2 inches (50 millimeters) per hour.

Two hours after the TRMM satellite captured that heavy rainfall, the tornado touched down in Joplin with winds up to 198 miles per hour, according to the National Weather Service. As of May 24, 117 people were reported killed, making the twister the most deadly in the U.S. in over 60 years.

Southwestern Missouri can't get a break from the severe weather as the recovery efforts continue today, May 24. The National Weather Service (NWS) in southwestern Missouri noted that "Multiple rounds of thunderstorms are expected over the region from this evening through at least Wednesday morning."

For more information visit http://www.nasa.gov/topics/earth/features/joplin_tornado-20110524.html

NASA is once again charting a new course to extend humanity's presence into the solar system, developing a new heavy lift rocket and crew capsule to take astronauts beyond low-Earth orbit.

This journey into the future has its foundations 50 years in the past, when President John F. Kennedy issued a challenge that transformed the tentative early steps of human spaceflight into a giant leap for mankind.

In just a short six weeks in the spring of 1961, a trio of dramatic events set the stage for our first journey to another world: Soviet Yuri Gagarin's first human spaceflight on April 12, was followed on May 5 by Alan Shepard's first American flight. Then, on May 25, 1961, President Kennedy went to Congress for an address on "Urgent National Needs."

Kennedy told Congress and the nation that "space is open to us now," and said that space exploration "may hold the key to our future here on Earth." Then he issued an audacious challenge to NASA that seemed unthinkable after just a single U.S. spaceflight:

NASA fulfilled Kennedy's goal on July 20, 1969, when Apollo 11's lunar module Eagle touched down in the Sea of Tranquility, with Neil Armstrong and Buzz Aldrin aboard (› Interactive Feature: Apollo 11). A dozen men would walk on the moon before the Apollo program ended in 1972.

Now, we stand at a moonshot moment once again, with 50 years of accomplishment to build on. NASA planners and engineers are already working new capabilities to take us farther into the solar system and help us learn even more about our place in it.

We will use the recently completed International Space Station as a test bed and stepping stone for the challenging journey ahead. We are changing the way we do business, fostering a commercial industry that will safely service low Earth orbit so we can focus our energy and resources on sending astronauts to an asteroid and eventually to Mars.

All the while, NASA continues to invest in science missions that study our earth, solar system and beyond, as well as aeronautics research focused on increased safety and reduced economic impact. We're also focused on educating the next generation of technology leaders and investing in high payoff, high-risk technology that industry cannot tackle today.

Later in his speech, President Kennedy said that "this nation will move forward, with the full speed of freedom, in the exciting adventure of space."

Fifty years later, NASA is moving forward at full speed.

A new NASA and university study of the March 11, 2011, Japan earthquake that included researchers from NASA’s Jet Propulsion Laboratory, Pasadena, Calif., provides the most comprehensive look to date at how Earth moved that day, unleashing widespread destruction and a devastating tsunami.

The study of the magnitude 9.0 Tohoku-Oki quake, led by researchers at the California Institute of Technology in Pasadena, and published online in the May 19 issue of Science Express, details the first large set of observational data from this rare megathrust earthquake event.

The researchers used observations from a dense regional monitoring network that allows measurements of Earth movement to be gathered from GPS satellite data, along with globally distributed broadband seismographic networks and open-ocean tsunami data, to begin to construct models that describe how Earth moved due to the quake.

JPL researchers Susan Owen, Angelyn Moore and Frank Webb provided the GPS observations on which the study’s fault slip model was based. They analyzed the GPS data from Japan’s network and found the large horizontal and vertical movements that were used to determine where the earthquake ruptured the subduction zone fault.

Among the study’s findings:

* The length of fault that experienced significant slip during the quake was about 155 miles (250 kilometers), about half of what would be conventionally expected for an event of this magnitude. The area of greatest slip -- 98 feet (30 meters) or more -- happened within a 31- to 62-mile-long (50- to 100-kilometer-long) segment.
* High- and low-frequency seismic waves can come from different areas of a fault. The quake’s high-frequency seismic waves were generated much closer to the coast, away from the area of the fault slip, where low-frequency waves were observed.
* The amount of strain associated with the quake’s displacement was five to 10 times larger than normally seen in large megathrust earthquakes. Before now, it was generally believed that the relatively soft material of the seafloor near the Japan Trench could not support such a large amount of stress. Because of this local strengthening of the seafloor, the researchers believe the Pacific and Okhotsk tectonic plates had been pinned together for a long time, perhaps 500 to 1,000 years.
* The area just south of where the fault slipped in March, which is close to Tokyo, should be a focus area for researchers because they do not have data on the area and don’t know yet what it might do in the future.

The University of Michigan also participated in the study. The work was also funded by the Gordon and Betty Moore Foundation, National Science Foundation grants and the Southern California Earthquake Center.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-152

The Alpha Magnetic Spectrometer, or AMS, was carried into orbit on STS-134 on a mission to the International Space Station. While it may sound like just another instrument, in actuality it is the largest scientific collaboration to use the laboratory! This investigation is sponsored by the United States Department of Energy and made possible by funding from 16 different nations. Led by Nobel Laureate Professor Samuel Ting, more than 600 physicists from around the globe will be able to participate in the data generated from this particle physics detector.

According to Trent Martin, AMS project manager for NASA, "This type of collaboration is starting to become more common in the space science community, but AMS is by far the most diversely funded space based science detector ever built. This is the type of collaboration that NASA hopes the ISS National Laboratory will help foster in the space scientific community."

The mission, to seek out answers to the mysteries of antimatter, dark matter, and cosmic ray propagation in the universe, is only part of the story. To fully understand where the science is going, you have to look at where it came from. NASA efforts with AMS began in 1994, when NASA's Johnson Space Center in Houston, Texas, conducted a feasibility study to see if such a delicate instrument could even fly in space and still produce usable data.

Ken Bollweg, AMS deputy project manager for NASA, mentions the challenges that needed to be overcome for the hazardous environment of space. "The detectors used in these types of experiments are typically used in an underground environment where the temperature doesn’t change more than two degrees from winter to summer and the bedrock hasn't moved in millennia," comments Bollweg. "Reviews of the detectors and their operating requirements indicated that it would be very challenging to adapt this technology to space -- but possible nonetheless."

Work on AMS integration and interface hardware began in earnest upon approval in 1995. One of the first understandings NASA needed to reach with the AMS Collaboration was the limitations of mass, size and power. For instance, the AMS Collaboration considered the AMS permanent magnet lightweight at approximately 2 tons, given that similar electromagnets on Earth weigh about 10,000 tons.

Working together, NASA and the AMS Collaboration developed a two-part plan to enable the mass requirements. The Unique Support Structure or USS-01 completed in 1997 and was launched with STS-91 in June of 1998. It carried a 9,197 lb engineering evaluation version of AMS. With the successful STS-91 mission and some extra time, since it was clear that the station would not be ready to host AMS in 2001, the scientists decided to make a few improvements. Plans for the AMS grew to be more complex, including the upgrade to a more powerful cryogenic superconducting superfluid helium-cooled magnet. These changes increased the projected weight for AMS to 15,251 lb, making it necessary to test a second support structure, called USS-02.

Determining a way to communicate the data from AMS to the ground was another important element of the undertaking. A digital data recorder system was developed and used during the STS-91 mission to capture data for the AMS Collaboration. Even though this was a preliminary effort to the overall AMS goal, the resulting data led to improved measurement sensitivity.

Several years passed as engineers continued working on procedures, certification requirements, and entered into the testing phases of development. In December 2001 NASA flew a prototype synchrotron radiation detector with STS-108. This flight test clarified performance of the detector for the AMS. The enhanced complexity of the AMS also meant an increase in data channels from close to 70,000 to over 300,000. In response, NASA developed a new digital data recorder system, which launched on STS-133 in February 2011. This enabled a trial run of the recorder system in preparation for the actual launch of AMS with STS-134.

With the announcement that the space station would continue to operate through 2020, the AMS Collaboration swapped out the current cryogenic magnet with a permanent magnet, which would have an infinite life. The entire AMS was taken apart, the magnets exchanged, and put back together for testing. From concept to implementation, this only took seven months to extend the potential life of the AMS investigation.

Martin commends the efforts of the many NASA and contractor personnel who made significant contributions to the completion of the AMS investigation. These individuals will continue to support AMS while it is on its mission in orbit to gather valuable data. Martin notes in particular the support of NASA's Bill Gerstenmaier, associate administrator for space operations. "[He was] critical to AMS's success, especially while AMS was off the space shuttle and space station manifests after the Columbia accident," says Martin. "He saw to it that Advanced Projects Office personnel were able to continue with the integration and certification tasks and personally visited AMS at various stages of development and testing."

The AMS will be the most advanced charge particle detector flown in space, increasing global knowledge of antimatter and dark matter and providing a powerful tool to physicists. The investigation will enable the discipline of modern physics to grow as scientists seek answers to the origins of our universe.

For more information visit http://www.nasa.gov/mission_pages/station/research/news/ams.html

Paul G. Dembling, co-author of the legislation that founded NASA, died on Monday, May 16, in Florida. He was 91 years old.

As general counsel to NASA's precursor, the National Advisory Committee for Aeronautics (NACA), Dembling helped shape the agency's legislative charter, the National Aeronautics and Space Act of 1958. In a 1992 interview, Dembling described the process of drafting the bill.

"A lot of the policy aspects of it were done quickly," Dembling said. "But the functions and the authorities that were embodied in that piece of legislation were well thought out and very well considered."

Dembling was born in Rahway, N.J., on Jan. 11, 1920. He earned a bachelor's degree in economics in 1940 and a master's degree in 1942 from Rutgers University. He earned a J.D. from George Washington University Law School, where he served as an editor of the law review.

After NASA became operational, Dembling joined the staff, eventually becoming the agency's general counsel. He also managed the agency’s Legislative Affairs Office under Administrator James Webb, and served as a deputy associate administrator before retiring in December 1969.

"Of all the jobs I have had and things I have done, I am most pleased with the creation of the legislation for NASA," Dembling said in a 2002 interview.

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

Can't make it to this year's annual Open House at NASA's Jet Propulsion Laboratory? Not a problem! Join our virtual event live on Ustream.tv on Saturday, May 14. To participate, visit the "NASAJPL" channel at: http://www.ustream.tv/nasajpl2. The site will be available live on Saturday, May 14, starting at 9 a.m. PDT. The segments will also be archived for later viewing.

We will broadcast live from selected Open House JPL sites from 9 a.m. to noon PDT (noon to 3 p.m. EDT). Join the chat, get answers and meet other space enthusiasts.

On Twitter? You can follow what Open House visitors are saying on @NASAJPL, at www.twitter.com/NASAJPL. On May 14-15, use the hashtag #JPLOpen .

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-144

Engineers at NASA's Marshall Space Flight Center gave a key component of the J-2X engine a brisk workout to ensure it can withstand its extreme operating environment. The engine's fuel turbopump first stage nozzle passed the test, performing even better than expected.

The J-2X is a highly efficient and versatile upper stage rocket engine that can stop and restart in space to support a variety of mission requirements. Full-scale testing begins later this summer but before then, engineers examined the longevity and durability of the engine's fuel turbopump first stage nozzle. The nozzle directs hot gas flow onto the turbine blades.

The entire engine operates at extremes, but the fuel turbopump's first stage nozzle really takes a beating. Drastic thermal changes, being super chilled and then immediately super heated, stresses the metal nozzle causing it to rapidly expand and contract which eventually causes it to crack. During engine operations, this turbine nozzle is exposed to cryogenic hydrogen at -422 degrees Fahrenheit and less than two seconds after the start sequence it is hit with hot gases at 1000 degrees Fahrenheit.

Apollo-era rocket scientists studied this same issue on the original J-2 engine. After a battery of tests, Apollo engineers discovered the fuel turbopump first stage nozzle cracked after dozens of starts and stops. While the part cracked, additional tests proved the engine performance and safety were not compromised.

Modeling and simulation for the J-2X suggested the same issue would emerge, so designers selected a new type of nickel metal alloy for the turbopump nozzle which is less brittle and was predicted to hold up better under extreme temperature fluctuations.

"We did a lot of design and analysis work on this issue to show required part life before we finalized design," said Gary Genge, J-2X turbomachinery manager at NASA's Marshall Space Flight Center in Huntsville, Ala. "We looked at making dramatic design alterations but changing the geometry of the part would have had a downstream effect we wanted to avoid. Also, the historic data hinted that wiith the improved material and minor changes, the new design might be acceptable."

In total, 43 tests were conducted which simulated the actual engine start and shutdown environment. Non-destructive evaluations were performed at the beginning of every test day and no detrimental condition was ever found.

"By taxing the same part over and over and carefully inspecting frequently, we know with confidence the part is very durable," said Genge. "This knowledge will save time and money in the long run because we can't inspect this area on the actual J-2X engines without disassembling the engine. This thorough test series shows we should be safe throughout the planned test series and we now have a better understanding of its longevity and structural integrity."

Assembly of J-2X Engine 10001, the first engine off the production line, is in full swing at NASA's Stennis Space Center. Full-scale engine testing will begin in June.

The J-2X is designed and built by Pratt & Whitney Rocketdyne of Canoga Park, Calif., for NASA's Marshall Space Flight Center in Huntsville, Ala.

For more information visit http://www.nasa.gov/mission_pages/j2x/j2x_test.html

NASA's Dawn spacecraft has obtained its first image of the giant asteroid Vesta, which will help fine-tune navigation during its approach. Dawn is expected to achieve orbit around Vesta on July 16, when the asteroid is about 188 million kilometers (117 million miles) from Earth.

The image from Dawn's framing cameras was taken on May 3 when the spacecraft began its approach and was approximately 1.21 million kilometers (752,000 miles) from Vesta. The asteroid appears as a small, bright pearl against a background of stars. Vesta is also known as a protoplanet, because it is a large body that almost formed into a planet.

"After plying the seas of space for more than a billion miles, the Dawn team finally spotted its target," said Carol Raymond, Dawn's deputy principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This first image hints of detailed portraits to come from Dawn's upcoming visit."

Vesta is 530 kilometers (330 miles) in diameter and the second most massive object in the asteroid belt. Ground- and space-based telescopes obtained images of the bright orb for about two centuries, but with little surface detail.

Mission managers expect Vesta's gravity to capture Dawn in orbit on July 16. To enter orbit, Dawn must match the asteroid's path around the sun, which requires very precise knowledge of the body's location and speed. By analyzing where Vesta appears relative to stars in framing camera images, navigators will pin down its location and enable engineers to refine the spacecraft's trajectory.

Dawn will start collecting science data in early August at an altitude of approximately 1,700 miles (2,700 kilometers) above the asteroid's surface. As the spacecraft gets closer, it will snap multi-angle images, allowing scientists to produce topographic maps. Dawn will later orbit at approximately 200 kilometers (120 miles) to perform other measurements and obtain closer shots of parts of the surface. Dawn will remain in orbit around Vesta for one year. After another long cruise phase, Dawn will arrive in 2015 at its second destination, Ceres, an even more massive body in the asteroid belt.

Gathering information about these two icons of the asteroid belt will help scientists unlock the secrets of our solar system's early history. The mission will compare and contrast the two giant bodies shaped by different forces. Dawn's science instruments will measure surface composition, topography and texture. Dawn will also measure the tug of gravity from Vesta and Ceres to learn more about their internal structures. The spacecraft's full odyssey will take it on a 5-billion-kilometer (3-billion-mile) journey, which began with its launch in September 2007.

Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala.

The University of California in Los Angeles is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research in Katlenburg-Lindau in Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research in Berlin and in coordination with the Institute of Computer and Communication Network Engineering in Braunschweig. The framing camera project is funded by NASA, the Max Planck Society and DLR.

For more information visit http://www.nasa.gov/mission_pages/dawn/news/dawn20110511.html

Karol "Bo" Bobko and Susan Helms joined the Hall of Fame during a ceremony at the Kennedy Space Center Visitor Complex at NASA's Kennedy Space Center in Florida. The celebration came two days after NASA marked the 50th anniversary of Alan Shepard's flight in 1961 that made him the first American in space.

Bobko flew as the pilot on STS-6, the first flight of space shuttle Challenger, in April 1983. Two years later, he commanded Discovery on STS-51D and landed the shuttle safely despite a blown main gear tire. Six months later, Bobko commanded Atlantis on its maiden flight, STS-51J.

"My wife said whenever I was given a chance, I chose the career path toward space," Bobko said. "All spaceflight is beautiful and inspiring."

The astronaut thought he would go into space a lot sooner. The Air Force chose him for its own astronaut corps in 1966 to crew the Manned Orbiting Laboratory, or MOL, a project the Air Force later canceled. Like STS-1 Pilot Bob Crippen and five others who were in the MOL program, Bobko joined NASA. He worked on the Apollo-Soyuz Test Project as a support team member before flying as a chase pilot on the shuttle prototype Enterprise landing tests.

"Bo loved spaceflight and he wanted everyone working with him to enjoy it as much as he did," said Bobko's presenter, former astronaut Jeff Hoffman. "He enjoyed flying so much that his family said they could judge how close he was getting to a flight because the smile on his face kept getting bigger and bigger and bigger."

Helms, an Air Force veteran like Bobko, flew five times on the shuttle beginning with STS-54 in January 1993. Her spaceflight career included flights on Endeavour, Discovery, Columbia, Atlantis and the International Space Station. She spent more than 5,000 hours in space, with 163 days of that on the station.

"It was one of the most amazing things that I've ever had the chance to do, which was be part of a space outpost" Helms said. "That truly was a human adventure that has no equal."

Working from Discovery, Helms performed a world-record spacewalk lasting eight hours and 56 minutes.

Endurance was kind of a trademark of Helms, said her presenter, NASA Administrator and former astronaut Charlie Bolden. She went for a jog on one occasion with her dog, Radar, and when she and the dog got back, she said the jog had gone fine. But Radar went and laid down on the bed for two days.

"She outran the dog," Bolden said.

Bobko and Helms join a group that includes the legends of Mercury, Gemini and Apollo, along with the astronauts who flew the space shuttle on some of its most noted missions.

For more information visit http://www.nasa.gov/centers/kennedy/news/ahof2011.html

You may have heard the news: Comet Elenin is coming to the inner-solar system this fall. Comet Elenin (also known by its astronomical name C/2010 X1), was first detected on Dec. 10, 2010 by Leonid Elenin, an observer in Lyubertsy, Russia, who made the discovery "remotely" using the ISON-NM observatory near Mayhill, New Mexico. At the time of the discovery, the comet was about 647 million kilometers (401 million miles) from Earth. Over the past four-and-a-half months, the comet has – as comets do – closed the distance to Earth's vicinity as it makes its way closer to perihelion (its closest point to the sun). As of May 4, Elenin's distance is about 274 million kilometers (170 million miles).

"That is what happens with these long-period comets that come in from way outside our planetary system," said Don Yeomans of NASA's Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "They make these long, majestic, speedy arcs through our solar system, and sometimes they put on a great show. But not Elenin. Right now that comet looks kind of wimpy."

How does a NASA scientist define cometary wimpiness?

"We're talking about how a comet looks as it safely flies past us," said Yeomans. "Some cometary visitors arriving from beyond the planetary region – like Hale-Bopp in 1997 -- have really lit up the night sky where you can see them easily with the naked eye as they safely transit the inner-solar system. But Elenin is trending toward the other end of the spectrum. You'll probably need a good pair of binoculars, clear skies, and a dark, secluded location to see it even on its brightest night."

Comet Elenin should be at its brightest shortly before the time of its closest approach to Earth on Oct. 16 of this year. At its closest point, it will be 35 million kilometers (22 million miles) from us. Can this icy interloper influence us from where it is, or where it will be in the future? What about this celestial object inspiring some shifting of the tides or even tectonic plates here on Earth? There have been some incorrect Internet speculations that external forces could cause comet Elenin to come closer.

"Comet Elenin will not encounter any dark bodies that could perturb its orbit, nor will it influence us in any way here on Earth," said Yeomans. "It will get no closer to Earth than 35 million kilometers [about 22 million miles]. "

"Comet Elenin will not only be far away, it is also on the small side for comets," said Yeomans. "And comets are not the most densely-packed objects out there. They usually have the density of something akin to loosely packed icy dirt.

"So you've got a modest-sized icy dirtball that is getting no closer than 35 million kilometers," said Yeomans. "It will have an immeasurably miniscule influence on our planet. By comparison, my subcompact automobile exerts a greater influence on the ocean's tides than comet Elenin ever will."

Yeomans did have one final thought on comet Elenin.

"This comet may not put on a great show. Just as certainly, it will not cause any disruptions here on Earth. But there is a cause to marvel," said Yeomans. "This intrepid little traveler will offer astronomers a chance to study a relatively young comet that came here from well beyond our solar system's planetary region. After a short while, it will be headed back out again, and we will not see or hear from Elenin for thousands of years. That's pretty cool."

NASA detects, tracks and characterizes asteroids and comets passing relatively close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and predicts their paths to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington, DC. JPL is a division of the California Institute of Technology in Pasadena.

For more information visit http://www.nasa.gov/topics/solarsystem/features/comet20110504.html

NASA Administrator Charles Bolden visited NASA's Jupiter-bound Juno spacecraft on Thursday, May 5, 2011, at the Astrotech payload processing facility in Titusville, Fla. The solar-powered Juno spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere.

Juno will be carried into space aboard a United Launch Alliance Atlas V rocket, lifting off from Launch Complex-41 at the Cape Canaveral Air Force Station in Florida. The launch period opens Aug. 5, 2011, and extends through Aug. 26. For an Aug. 5 liftoff, the launch window opens at 8:39 a.m. PDT (11:39 am EDT) and remains open through 9:39 a.m. PDT (12:39 p.m. EDT).

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, built the spacecraft. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. JPL is a division of the California Institute of Technology in Pasadena.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-137

The team exploring Mars via NASA's Opportunity rover for the past seven years has informally named a Martian crater for the Mercury spacecraft that astronaut Alan Shepard christened Freedom 7. On May 5, 1961, Shepard piloted Freedom 7 in America's first human spaceflight.

The team is using Opportunity this week to acquire images covering a cluster of small, relatively young craters along the rover's route toward a long-term destination. The cluster's largest crater, spanning about 25 meters (82 feet), is the one called "Freedom 7." The diameter of Freedom 7 crater, about 25 meters (82 feet), happens to be equivalent to the height of the Redstone rocket that launched Shepard's flight.

"Many of the people currently involved with the robotic investigations of Mars were first inspired by the astronauts of the Mercury Project who paved the way for the exploration of our solar system," said Scott McLennan of the State University of New York at Stony Brook, who is this week's long-term planning leader for the rover science team. Shepard's flight was the first of six Project Mercury missions piloted by solo astronauts.

An image of Freedom 7 crater taken this week is online at: http://www.nasa.gov/mission_pages/mer/multimedia/gallery/pia13988.html.

Rover team member James Rice of NASA Goddard Space Flight Center, Greenbelt, Md., said, "The first 50 years of American manned spaceflight have been built upon immeasurable courage, dedication, sacrifice, vision, patriotism, teamwork and good old-fashioned hard work, all terms that embody and define the United States and her people. Alan Shepard's brave and historic 15-minute flight in Freedom 7 put America in space, and then a scant eight years later, Americans were standing upon the surface of the moon." Shepard himself would later walk on the moon when he commanded the Apollo 14 mission in early 1971, less than 10 years after his Freedom 7 flight. He died on July 21, 1998.

By taking advantage of seeing many craters of diverse ages during drives toward major destinations, the Opportunity mission is documenting how impact craters change with time. The cluster that includes Freedom 7 crater formed after sand ripples in the area last migrated, which is estimated to be about 200,000 years ago.

"This cluster has about eight craters, and they're all the same age," said Matt Golombek, rover team member at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "They're from an impactor that broke up in the atmosphere, which is quite common."

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued for 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. It has driven 28.6 kilometers (17.8 miles) total on Mars, including 1.9 kilometers (1.2 miles) since leaving "Santa Maria" crater on March 24, 2011, after studying that crater for three months.

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20110504.html

Professional and amateur space aficionados are in for a treat with the new Space Images Version 2 app, created by NASA's Jet Propulsion Laboratory, Pasadena Calif. The free app is now optimized for iPad, iPhone, iPod Touch and Android, and is also available online.

The app's higher-resolution images and improved user interface allow galactic admirers to zoom in on and rate their favorite images and share photos from NASA/JPL spacecraft with their friends on Facebook and Twitter.

The Space Images app uses an intuitive category-selection tool. People can see the initial batch of images, showing galaxies, stars, the sun and planets – including Earth and dwarf planets –as well as videos and editor picks. In the videos tab, users can see footage compiled by active NASA/JPL spacecraft and watch movies about astronomy and various space missions. Additional images will be added in coming months.

The app release is coupled with the launch of a Space Images website, which pulls in ratings from the app and allows users to create an account and photo albums, as well as download wallpapers. The website also includes an extensive collection of images in an easy-to-browse and interactive format.

After its release in January 2010, the original version of Space Images was selected as an iTunes "Staff Favorite," became a top app in the App Store's Education category, and reached over half a million downloads. The app has been praised for its extensive and stunning image collection and for its educational uses.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-132

Tornado tracks from last week's powerful tornado outbreak are visible in data from NASA's Aqua satellite and the Landsat satellite.

Among the more than 150 tornadoes reported on April 27 and 28, 2011, was a rare EF-5 storm. Such a storm has the capacity to collapse a concrete building. The tornado hit Smithville, Mississippi, where it killed at least 14 people, and moved northeast nearly 3 miles toward the Alabama border. It is the first EF5 tornado to occur in Mississippi since 1966, according to the National Weather Service.

An image captured by NASA's Aqua satellite shows the path of exposed ground left in the tornado’s wake. The trail left by the EF5 tornado in Mississippi is much shorter than a similar trail that cuts across northwestern Alabama. The National Weather Service rated this tornado at EF4, with winds around 175 miles per hour, said local news reports. The track was about 12 miles long, and the tornado caused more than 20 deaths.

The image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 28. The image was compared to an earlier image taken on April 12, 2011 and the tracks were not present.

Another satellite revealed the track from a tornado that touched down near Griffin, Georgia. In a Landsat image from April 28, 2011, a pale green swath indicated the path of a tornado outside of Griffin, Georgia. The tornado was on the ground between 12:03 and 12:28 a.m. local time on April 28, hours before the image was taken. By the time the funnel cloud lifted, the tornado had covered about 20 miles with a path about half a mile wide, said the National Weather Service. The tornado was an EF3 tornado with winds of about 140 miles per hour.

The Landsat satellite image showed that the tornado moved across lightly populated farmland. Bright-colored spots that appear in the image are buildings, and some were close to storm’s path. The town of Griffin is the nearest community to the storm track in this area. Landsat data was provided by the United States Geological Survey.

The large storm system that generated the tornadoes was the deadliest to hit the United States since 1974.

For more information visit http://www.nasa.gov/topics/earth/features/tornado-tracks.html