Martian Dust Devil Whirls into Opportunity's View

In its six-and-a-half years on Mars, NASA's Mars Exploration Rover Opportunity had never seen a dust devil before this month, despite some systematic searches in past years and the fact that its twin rover, Spirit, has seen dozens of dust devils at its location halfway around the planet.

A tall column of swirling dust appears in a routine image that Opportunity took with its panoramic camera on July 15. The rover took the image in the drive direction, east-southeastward, right after a drive of about 70 meters (230 feet). The image was taken for use in planning the next drive.

"This is the first dust devil seen by Opportunity," said Mark Lemmon of Texas A&M University, College Station, a member of the rover science team.

Spirit's area, inside Gusev Crater, is rougher in ground texture, and dustier, than the area where Opportunity is working in the Meridiani Planum region. Those factors at Gusev allow vortices of wind to form more readily and raise more dust, compared to conditions at Meridiani, Lemmon explained. Orbiters have photographed tracks left by dust devils near Opportunity, but the tracks are scarcer there than near Spirit. Swirling winds at Meridiani may be more common than visible signs of them, if the winds occur where there is no loose dust to disturb.

This is the first dust devil that NASA's Mars Exploration Rover Opportunity has observed in the rover's six-and-a-half years on Mars. Image credit: NASA/JPL-Caltech/Cornell University/Texas A&M

Just one day before Opportunity captured the dust devil image, wind cleaned some of the dust off the rover's solar array, increasing electricity output from the array by more than 10 percent.

"That might have just been a coincidence, but there could be a connection," Lemmon said. The team is resuming systematic checks for afternoon dust devils with Opportunity's navigation camera, for the first time in about three years.

Opportunity and Spirit arrived on Mars in January 2004 for missions designed to last for three months. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington. For more information about the project and images from the rovers, visit http://www.nasa.gov/rovers .

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100728.html

NASA Instrument Will Identify Clues to Martian Past

NASA's Curiosity rover, coming together for a late 2011 launch to Mars, has a newly installed component: a key onboard X-ray instrument for helping the mission achieve its goals.

Researchers will use Curiosity in an intriguing area of Mars to search for modern or ancient habitable environments, including any that may have also been favorable for preserving clues about life and environment.

The team assembling and testing Curiosity at NASA's Jet Propulsion Laboratory, Pasadena, Calif., fastened the Chemistry and Mineralogy (CheMin) instrument inside the rover body on June 15. CheMin will identify the minerals in samples of powdered rock or soil that the rover's robotic arm will deliver to an input funnel.

"Minerals give us a record of what the environment was like at the time they were formed," said the principal investigator for CheMin, David Blake of NASA's Ames Research Center, Moffett Field, Calif. Temperature, pressure, and the chemical ingredients present -- including water -- determine what minerals form and how they are altered.

The instrument uses X-ray diffraction, a first for a mission to Mars and a more definitive method for identifying minerals than any instrument on previous missions. It supplements the diffraction measurements with X-ray fluorescence capability to garner further details of composition.

X-ray diffraction works by directing an X-ray beam at a sample and recording how the X-rays are scattered by the sample's atoms. All minerals are crystalline, and in crystalline materials, atoms are arranged in an orderly, periodic structure, causing the X-rays to be scattered at predictable angles. From those angles, researchers can deduce the spacing between planes of atoms in the crystal.

Blake, of the NASA Ames Research Center, Moffett Field, Calif., is seen here collecting data from a CheMin cousin called Terra. The scene is from a NASA field test of technology for producing water and oxygen from soil, using the Hawaiian site as an analog for the moon. In such an application, Terra could analyze the starting soils as well as products from the extraction process. Image Credit: NASA

"You get a series of spacings and intensities for each mineral," Blake said. "It's more than a fingerprint because it not only provides definitive identification, but we know the reason for each pattern, right down to the atomic level."

NASA's Mars Science Laboratory mission will send Curiosity to a place on Mars where water-related minerals have been detected by Mars orbiters. The rover's 10 science instruments [link to http://msl-scicorner.jpl.nasa.gov/Instruments/ ] will examine the site's modern environment and geological clues to its past environments. NASA's multi-step strategy might include potential future missions for bringing Mars samples to Earth for detailed analysis. One key goal for the Mars Science Laboratory mission is to identify a good hunting ground for rocks that could hold biosignatures -- evidence of life -- though this mission itself will not seek evidence of life.

On Earth, life has thrived for more than 3 billion years, but preserving evidence of life from the geologically distant past requires specific, unusual conditions.

Fossil insects encased in amber or mastodon skeletons immersed in tar pits are examples of how specific environments can store a record of ancient life by isolating it from normal decomposition. But Mars won't have insects or mastodons; if Mars has had any life forms at all, they were likely microbes. Understanding what types of environments may have preserved evidence of microbial life from billions of years ago, even on Earth, is still an emerging field of study. Some factors good for life are bad for preserving biosignatures. For example, life needs water, but organic compounds, the carbon-chemical ingredients of life, generally oxidize to carbon dioxide gas if not protected from water.

Some minerals detectable by CheMin, such as phosphates, carbonates, sulfates and silica, can help preserve biosignatures. Clay minerals trap and preserve organic compounds under some conditions. Some minerals that form when salty water evaporates can encase and protect organics, too. Other minerals that CheMin could detect might also have implications about past conditions favorable to life and to preservation of biosignatures.

"We'll finally have the ability to conduct a wide-ranging inventory of the minerals for one part of Mars," said John Grotzinger of the California Institute of Technology in Pasadena, chief scientist for the Mars Science Laboratory. "This will be a big step forward. Whatever we learn about conditions for life, we'll also get a great benefit in learning about the early evolution of a planet."

Curiosity's 10 science instruments, with about 15 times more mass than the five-instrument science payload on either of the Mars rovers Spirit or Opportunity, provide complementary capabilities for meeting the mission's goals. Some will provide quicker evaluations of rocks when the rover drives to a new location, helping the science team choose which rocks to examine more thoroughly with CheMin and the Sample Analysis at Mars (SAM) experiment. SAM can identify organic compounds. Imaging information about the context and textures of rocks will augment information about the rocks' composition.

Members of NASA's Mars Science Laboratory team carefully steer the hoisted Chemistry and Mineralogy (CheMin) instrument during its June 15, 2010, installation into the mission's Mars rover, Curiosity. The main body of the rover, upside down, is in the left half of the image, behind the installers. Image Credit: NASA/JPL-Caltech

"CheMin will tell us the major minerals there without a lot of debate," said Jack Farmer of Arizona State University, Tempe, a member of the instrument's science team. "It won’t necessarily reveal anything definitive about biosignatures, but it will help us select the rocks to check for organics. X-ray diffraction is the gold standard for mineralogy. Anyone who wants to determine the minerals in a rock on Earth takes it to an X-ray diffraction lab."

Blake began working 21 years ago on a compact X-ray diffraction instrument for use in planetary missions. His work with colleagues has resulted in commercial portable instruments for use in geological field work on Earth, as well as the CheMin instrument. The spinoff instruments have found innovative applications in screening for counterfeit pharmaceuticals in developing nations and analyzing archaeological finds.

CheMin is roughly a cube 25 centimeters (10 inches) on each side, weighing about 10 kilograms (22 pounds). It generates X-rays by aiming high-energy electrons at a target of cobalt, then directing the X-rays into a narrow beam. The detector is a charge-coupled device like the ones in electronic cameras, but sensitive to X-ray wavelengths and cooled to minus 60 degrees Celsius (minus 76 degrees Fahrenheit).

A sample wheel mounted between the X-ray source and detector holds 32 disc-shaped sample cells, each about the diameter of a shirt button and thickness of a business card, with transparent plastic walls. Rotating the wheel can position any cell into the X-ray beam. Five cells hold reference samples from Earth to help calibrate the instrument. The other 27 are reusable holders for Martian samples. Samples of gritty powder delivered by the robotic arm to CheMin's inlet funnel will each contain about as much material as in a baby aspirin.

Each CheMin analysis of a sample requires up to 10 hours of accumulating data while X-rays are hitting the sample. The time may be split into two or more nights of operation.

Besides X-ray diffraction, CheMin records X-ray fluorescence data from the analyzed material. X-ray fluorescence works by recording the secondary X-rays generated when the atoms in the sample are excited by the primary X-ray source. Different elements, when excited, emit fluorescent X-rays at different and characteristic energies, so this information indicates which elements are present. This compositional information will supplement similar data collected by the Alpha Particle X-ray Spectrometer on Curiosity's arm.

CheMin's team of scientists combines expertise in mineralogy, petrology, materials science, astrobiology and soil science, with experience studying terrestrial, lunar and Martian rocks.

The launch period for the Mars Science Laboratory will begin on Nov. 25, 2011, for a landing on Mars in August 2012. Blake's wish for results from the Martian rock data he's already been anticipating for more than two decades: "I hope we find something unexpected, something surprising."

For more information visit http://www.nasa.gov/centers/ames/news/features/2010/CheMin.html

---

Next Mars Rover Sports a Set of New Wheels

PASADENA, Calif. – NASA's next Mars rover, Curiosity, is sitting pretty on a set of spiffy new wheels that would be the envy of any car show on Earth.

The wheels and a suspension system were added this week by spacecraft technicians and engineers. These new and important touches are a key step in assembling and testing the flight system in advance of a planned 2011 launch.

Mars rover Curiosity, the centerpiece of NASA's Mars Science Laboratory mission, is coming together for extensive testing prior to its late 2011 launch. Image Credit: NASA/JPL-Caltech

Curiosity, centerpiece of NASA's Mars Science Laboratory mission, is a six-wheeler and uses a rocker-bogie suspension system like its smaller predecessors: Spirit, Opportunity and Sojourner. Each wheel has its own drive motor, and the corner wheels also have independent steering motors. Unlike earlier Mars rovers, Curiosity will also use its mobility system as a landing gear when the mission's rocket-powered descent stage lowers the rover directly onto the Martian surface on a tether in August 2012.

In coming months at NASA's Jet Propulsion Laboratory, the mobility system will get functional testing and be part of environmental testing of the rover. The mobility system will now stay on Curiosity through launch unless testing identifies a need for rework that would require it to be disassembled.

With the wheels and suspension system already installed onto one side of NASA's Mars rover Curiosity the previous day, spacecraft engineers and technicians prepare the other side's mobility subsystem for installation on June 29, 2010. Image Credit: NASA/JPL-Caltech

The mission will launch from Florida during the period Nov. 25 to Dec. 18, 2011. Curiosity will examine an area of Mars for modern or ancient habitable environments, including any that may have also been favorable for preserving clues about life and environment, though this mission will not seek evidence of life. It will examine rocks, soil and atmosphere with a diverse payload of tools, including a laser to vaporize patches of rock from a distance and an instrument designed to test for organic compounds.

For more information visit http://www.nasa.gov/mission_pages/msl/msl20100701.html

Seventh Graders Find a Cave on Mars

Using the camera on NASA's Mars Odyssey orbiter, 16 seventh-graders at Evergreen Middle School in Cottonwood, Calif., found lava tubes with one pit that appears to be a skylight to a cave. Mars Odyssey has been orbiting the Red Planet since 2001, returning data and images of the Martian surface and providing relay communications service for Mars Rovers Spirit and Opportunity.

The students in Dennis Mitchell's science class were examining Martian lava tubes as their project in the Mars Student Imaging Program offered by NASA and Arizona State University. According to the university, the imaging program allows students in upper elementary grades through to college students to participate in Mars research by having them develop a geological question to answer. The students actually command a Mars-orbiting camera to take an image to answer their question. Since MSIP began in 2004, more than 50,000 students have participated.

"The students developed a research project focused on finding the most common locations of lava tubes on Mars," Mitchell said. "Do they occur most often near the summit of a volcano, on its flanks or the plains surrounding it?"

The feature, on the slope of an equatorial volcano named Pavonis Mons, appears to be a skylight in an underground lava tube. Similar 'cave skylight' features have been found elsewhere on Mars, but this is the first seen on this volcano.

Sixteen seventh-graders at Evergreen Middle School in Cottonwood, Calif., found the Martian pit feature at the center of the superimposed red square in this image. Image Credit: NASA/JPL-Caltech/ASU

The students subsequently submitted the site as a candidate for imaging by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. HiRISE can image the surface at about 30 centimeters (12 inches) per pixel, which may allow a look inside the hole in the ground.

"It gives the students a good understanding of the way research is conducted and how that research can be important for the scientific community. This has been a wonderful experience," Mitchell said."

For more information visit http://www.nasa.gov/topics/moonmars/features/kids_find_cave.html

---

NASA Rover Finds Clue to Mars' Past And Environment for Life

PASADENA, Calif. -- Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA's rovers have found other evidence of formerly wet Martian environments. However the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Lengthy detective work with data NASA's Mars Exploration Rover Spirit collected in late 2005 has confirmed that an outcrop called "Comanche" contains a mineral indicating that a past environment was wet and non-acidic, possibly favorable to life. Image credit: NASA/JPL-Caltech/Cornell University

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place. "

Spirit inspected rock outcrops, including one scientists called Comanche, along the rover's route from the top of Husband Hill to the vicinity of the Home Plate plateau which Spirit has studied since 2006. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

"We used detective work combining results from three spectrometers to lock this down," said Dick Morris, lead author of the report and a member of a rover science team at NASA's Johnson Space Center in Houston."The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is."

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.

It is important to determine where most of the carbon dioxide went. Some theorize it departed to space. Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Morris suspected iron-bearing carbonate at Comanche years ago from inspection of the rock with Spirit's Moessbauer Spectrometer, which provides information about iron-containing minerals. Confirming evidence from other instruments emerged slowly. The instrument with the best capability for detecting carbonates, the Miniature Thermal Emission Spectrometer, had its mirror contaminated with dust earlier in 2005, during a wind event that also cleaned Spirit's solar panels.

NASA's Mars Rover Spirit began its Mars exploration at its landing site in January 2004. Image credit: NASA/JPL-Caltech/UA/Cornell/NM Museum of Natural History and Science

"It was like looking through dirty glasses," said Steve Ruff of Arizona State University in Tempe, Ariz., another co-author of the report. "We could tell there was something very different about Comanche compared with other outcrops we had seen, but we couldn't tell what it was until we developed a correction method to account for the dust on the mirror."

Spirit's Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The rovers landed on Mars in January 2004 for missions originally planned to last three months. Spirit has been out of communication since March 22 and is in a low-power hibernation status during Martian winter. Opportunity is making steady progress toward a large crater, Endeavour, which is about seven miles away.

NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Exploration Rovers for the agency's Science Mission Directorate in Washington. For more information about the rovers, visit:

http://www.nasa.gov/rovers

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100603.html

Phoenix Mars Lander is Silent, New Image Shows Damage

PASADENA, Calif. -- NASA's Phoenix Mars Lander has ended operations after repeated attempts to contact the spacecraft were unsuccessful. A new image transmitted by NASA's Mars Reconnaissance Orbiter shows signs of severe ice damage to the lander's solar panels.

"The Phoenix spacecraft succeeded in its investigations and exceeded its planned lifetime," said Fuk Li, manager of the Mars Exploration Program at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Although its work is finished, analysis of information from Phoenix's science activities will continue for some time to come."

Last week, NASA's Mars Odyssey orbiter flew over the Phoenix landing site 61 times during a final attempt to communicate with the lander. No transmission from the lander was detected. Phoenix also did not communicate during 150 flights in three earlier listening campaigns this year.

This view of one of the Mars Phoenix Lander's solar panels is a composite of multiple exposures taken by the spacecraft's Surface Stereo Imager camera. Image credit: NASA/JPL-Caltech/University Arizona/Texas A&M University

Earth-based research continues on discoveries Phoenix made during summer conditions at the far-northern site where it landed May 25, 2008. The solar-powered lander completed its three-month mission and kept working until sunlight waned two months later.

Phoenix was not designed to survive the dark, cold, icy winter. However, the slim possibility Phoenix survived could not be eliminated without listening for the lander after abundant sunshine returned.

An image of Phoenix taken this month by the High Resolution Imaging Science Experiment, or HiRISE, camera on board the Mars Reconnaissance Orbiter suggests the lander no longer casts shadows the way it did during its working lifetime.

"Before and after images are dramatically different," said Michael Mellon of the University of Colorado in Boulder, a science team member for both Phoenix and HiRISE. "The lander looks smaller, and only a portion of the difference can be explained by accumulation of dust on the lander, which makes its surfaces less distinguishable from surrounding ground."

Apparent changes in the shadows cast by the lander are consistent with predictions of how Phoenix could be damaged by harsh winter conditions. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the lander's solar panels. Mellon calculated hundreds of pounds of ice probably coated the lander in mid-winter.

During its mission, Phoenix confirmed and examined patches of the widespread deposits of underground water ice detected by Odyssey and identified a mineral called calcium carbonate that suggested occasional presence of thawed water. The lander also found soil chemistry with significant implications for life and observed falling snow. The mission's biggest surprise was the discovery of perchlorate, an oxidizing chemical on Earth that is food for some microbes and potentially toxic for others.

Two images of the Phoenix Mars lander taken from Martian orbit in 2008 and 2010. The 2008 lander image shows two relatively blue spots on either side corresponding to the spacecraft's clean circular solar panels. In the 2010 image scientists see a dark shadow that could be the lander body and eastern solar panel, but no shadow from the western solar panel. Image credit: NASA/JPL-Caltech/University of Arizona

"We found that the soil above the ice can act like a sponge, with perchlorate scavenging water from the atmosphere and holding on to it," said Peter Smith, Phoenix principal investigator at the University of Arizona in Tucson. "You can have a thin film layer of water capable of being a habitable environment. A micro-world at the scale of grains of soil -- that's where the action is."

The perchlorate results are shaping subsequent astrobiology research, as scientists investigate the implications of its antifreeze properties and potential use as an energy source by microbes. Discovery of the ice in the uppermost soil by Odyssey pointed the way for Phoenix. More recently, the Mars Reconnaissance Orbiter detected numerous ice deposits in middle latitudes at greater depth using radar and exposed on the surface by fresh impact craters.

"Ice-rich environments are an even bigger part of the planet than we thought," Smith said. "Somewhere in that vast region there are going to be places that are more habitable than others."

The Mars Reconnaissance Orbiter reached the planet in 2006 to begin a two-year primary science mission. Its data show Mars had diverse wet environments at many locations for differing durations during the planet's history, and climate-change cycles persist into the present era. The mission has returned more planetary data than all other Mars missions combined.

Odyssey has been orbiting Mars since 2001. The mission also has played important roles by supporting the twin Mars rovers Spirit and Opportunity. The Phoenix mission was led by Smith at the University of Arizona, with project management at JPL and development partnership at Lockheed Martin in Denver. The University of Arizona operates the HiRISE camera, which was built by Ball Aerospace and Technologies Corp., in Boulder. Mars missions are managed by JPL for NASA's Mars Exploration Program at NASA Headquarters in Washington. JPL is a division of the California Institute of Technology in Pasadena.

For Phoenix information and images, visit: http://www.nasa.gov/phoenix .

For more information visit http://www.nasa.gov/mission_pages/phoenix/news/phx20100524.html

NASA's Mars Rovers Set Surface Longevity Record

PASADENA, Calif. -- NASA's Mars Exploration Rover Project will pass a historic Martian longevity record on Thursday, May 20. The Opportunity rover will surpass the duration record set by NASA's Viking 1 Lander of six years and 116 days operating on the surface of Mars. The effects of favorable weather on the red planet could also help the rovers generate more power.

Opportunity's twin rover, Spirit, began working on Mars three weeks before Opportunity. However, Spirit has been out of communication since March 22. If it awakens from hibernation and resumes communication, that rover will attain the Martian surface longevity record.

Spirit's hibernation was anticipated, based on energy forecasts, as the amount of sunshine hitting the robot's solar panels declined during autumn on Mars' southern hemisphere. Unfortunately, mobility problems prevented rover operators from positioning Spirit with a favorable tilt toward the north, as during the first three winters it experienced. The rovers' fourth winter solstice, the day of the Martian year with the least sunshine at their locations, was Wednesday, May 12.

"Opportunity, and likely Spirit, surpassing the Viking Lander 1 longevity record is truly remarkable, considering these rovers were designed for only a 90-day mission on the surface of Mars," Callas said. "Passing the solstice means we're over the hump for the cold, dark, winter season." Unless dust interferes, which is unlikely in the coming months, the solar panels on both rovers should gradually generate more electricity. Operators hope that Spirit will recharge its batteries enough to awaken from hibernation, start communicating and resume science tasks.

Unlike recent operations, Opportunity will not have to rest to regain energy between driving days. The gradual increase in available sunshine will eventually improve the rate of Opportunity's progress across a vast plain toward its long-term destination, the Endeavour Crater.

NASA's Mars Exploration Rover Opportunity used its navigation camera for this northward view of tracks the rover left on a drive from one energy-favorable position on the northern end of a sand ripple to another. Image credit: NASA/JPL-Caltech

This month, some of Opportunity's drives have been planned to end at an energy-favorable tilt on the northern face of small Martian plain surface ripples. The positioning sacrifices some distance to regain energy sooner for the next drive. Opportunity's cameras can see a portion of the rim of Endeavour on the horizon, approximately eight miles away, across the plain's ripples of windblown sand.

"The ripples look like waves on the ocean, like we're out in the middle of the ocean with land on the horizon, our destination," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is the principal investigator for Opportunity and Spirit. "Even though we know we might never get there, Endeavour is the goal that drives our exploration."

The team chose Endeavour as a destination in mid-2008, after Opportunity finished two years examining the smaller Victoria Crater. Since then, the goal became even more alluring when orbital observations found clay minerals exposed at Endeavour. Clay minerals have been found extensively on Mars from orbit, but have not been examined on the surface. "Those minerals form under wet conditions more neutral than the wet, acidic environment that formed the sulfates we've found with Opportunity," said Squyres. "The clay minerals at Endeavour speak to a time when the chemistry was much friendlier to life than the environments that formed the minerals Opportunity has seen so far. We want to get there to learn their context. Was there flowing water? Were there steam vents? Hot springs? We want to find out."

Launched in 1975, Project Viking consisted of two orbiters, each carrying a stationary lander. Viking Lander 1 was the first successful mission to the surface of Mars, touching down on July 20, 1976. It operated until Nov. 13, 1982, more than two years longer than its twin lander or either of the Viking orbiters.

The record for longest working lifetime by a spacecraft at Mars belongs to a later orbiter: NASA's Mars Global Surveyor operated for more than 9 years after arriving in 1997. NASA's Mars Odyssey, in orbit since in 2001, has been working at Mars longer than any other current mission and is on track to take the Mars longevity record late this year. Science discoveries by the Mars Exploration Rover have included Opportunity finding the first mineralogical evidence that Mars had liquid water and Spirit finding evidence for hot springs or steam vents and a past environment of explosive volcanism.

JPL manages the Mars rovers for NASA's Science Mission Directorate in Washington. For more information about the rovers, visit:

http://www.nasa.gov/rovers

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100519.html

---

Spirit's Rear View After Parking for Fourth Winter

NASA's Mars Exploration Rover Spirit recorded this fisheye view with its rear hazard-avoidance camera after completing a drive during the 2,169th Martian day, or sol, of Spirit's mission on Mars (Feb. 8, 2010). The drive left Spirit in the position where the rover will stay parked during the upcoming Mars southern-hemisphere winter.

Spirit moved about 34 centimeters (13 inches) toward the south southeast in a series of drives beginning on Sol 2145 (Jan. 15, 2010). The left-rear wheel (on the right in this rear-facing view) moved out of a rut that it had dug in soft soil in April 2009. The drive motor for the right-rear wheel (on the left in this view) stopped working in late 2009, leaving the six-wheeled rover with only four functioning wheels. The top of the image shows the underside of Spirit's solar array.

The rover's solar array is tilted 9 degrees toward the south for the winter. In the three previous winters that Spirit has spent on Mars, its parked positions tilted toward northward, a better attitude for drawing energy from the sun in the northern sky. Engineers anticipate that, due to the unfavorable tilt for this fourth winter, Spirit will soon be out of communication with Earth for several months. A low-power hibernation mode will shut down almost all functions except keeping a master clock running and checking periodically on Spirit's power status until it has enough power to reawaken.

Image Credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/mer/images/mer20100211.html

---

President Barack Obama on NASA's Day of Remembrance

Message from the President on NASA's Day of Remembrance

For more than a half-century, NASA has explored our final frontier and transformed humankind's understanding of our planet and its place in the universe. These extraordinary achievements have required great sacrifice.

On this Day of Remembrance, we pause to reflect on the Apollo 1, Challenger and Columbia crews, as well as others who lost their lives supporting NASA’s mission of exploration and study of the earth, the planets and the stars. All of humanity has benefited from their courage and devotion.

We mourn their loss while celebrating their spirit of discovery. May their sacrifice be an inspiration as we continue our nation's work to explore our universe.

For more information visit http://www.nasa.gov/topics/history/features/Obama_DoR2010.html

Curriculum Vitae

NAME: Spirit, Mars Exploration Rover A

ADDRESS:"Troy," 14.6 degrees South, 175.5 degrees East, Gusev Crater, Mars, 4th Rock from the Sun

PROFESSIONAL GOAL: To investigate the historical geology and climate of Mars, but would like to do less travel than in the past

EMPLOYMENT HISTORY: Geologist, meteorologist, chemist, photographer and mountain climber for NASA, working in the field since Jan. 3, 2004

TECHNICAL EXPERIENCE:

Image credit: NASA/JPL/Cornell University

• Trekked 7,730 meters (4.8 miles) across Gusev Crater, including driving backwards after the right front wheel stopped working in 2006
• Crossed the Columbia Hills, including scaling a 30.2 degree-incline at "West Spur" and reaching the 82-meter (269-foot) summit of "Husband Hill," the highest peak in the range
• Returned 27,000 raw images and 16 color, 360-degree panoramic mosaics
• Drilled into 15 rock targets and scoured 92 with my brush
• Survived three Martian winters despite low light and low energy for my solar panels

MAJOR SCIENTIFIC ACCOMPLISHMENTS:

• Unearthed a patch of nearly pure silica, the main ingredient of window glass, in 2007 while dragging my right front wheel. The silica patch, dubbed "Gertrude Weise," provided strong evidence that ancient Mars was much wetter than it is now because it was likely produced in an environment of hot springs or steam vents. It is my biggest scientific achievement to date.
• Found evidence of a long-ago explosion at a bright, low plateau called "Home Plate" in 2006. I saw coarse, bulbous grains overlaying finer material, which fits with the pattern of accumulation of material falling to the ground after a volcanic or impact explosion. These rocks, some of which had never been seen before on Mars, revealed the crater's violent history.
• Captured several movies of dust devils in motion in 2005, providing the best look of the wind effects on the Martian surface as they were happening.
• Churned up bright Martian soil in 2006 at a place named "Tyrone" that contained loads of sulfur and a trace of water. This material could be a volcanic deposit formed around ancient gas vents or could have been left behind by water that dissolved these minerals underground and evaporated when they came to the surface and evaporated.
• Discovered a surprising variety of bedrock in the Columbia Hills in 2004, showing a complex geological history for the region. Some of the rocks showed evidence of alteration by water.

EDUCATION: Built and trained at NASA's Jet Propulsion Laboratory in Pasadena, Calif. After reaching Mars, completed post-graduate courses online in autonomous processing with special attention to target tracking, hazard navigation and cloud recognition.

OTHER SKILLS:

• Extremely independent, but work well in teams
• Adapt well to challenging environments
• Nimble with new media, regularly updating my website, Twitter and Facebook

REFERENCE:
Steve Squyres, of Cornell University, Ithaca, N.Y., principal investigator for the Mars rovers' science instruments: "Spirit has been a wonderful workhorse. Because of Spirit's visit to the Columbia Hills, we know it was a violent place, a place churned by impacts and volcanic explosions. Spirit has shown us an ancient Mars that was very different from the Mars we see today."

AWARDS:
2004 Best of the Best - Software of the Year Award from NASA
2004 Best of What's New Grand Award from Popular Science
2005 Laureates Hall of Fame Award from Aviation Week and Space Technology
2007 Best Corporate/Team Achievement Award at the Sir Arthur Clarke Awards in England
2009 Thomas O. Paine Award for the Advancement of Human Exploration of Mars from the Planetary Society

For more information visit http://www.nasa.gov/mission_pages/mer/news/telecon/spiritCV-20100126.html

Now a Stationary Research Platform, NASA's Mars Rover Spirit Starts a New Chapter in Red Planet Scientific Studies

WASHINGTON -- After six years of unprecedented exploration of the Red Planet, NASA's Mars Exploration Rover Spirit no longer will be a fully mobile robot. NASA has designated the once-roving scientific explorer a stationary science platform after efforts during the past several months to free it from a sand trap have been unsuccessful.

The venerable robot's primary task in the next few weeks will be to position itself to combat the severe Martian winter. If Spirit survives, it will continue conducting significant new science from its final location. The rover's mission could continue for several months to years.

"Spirit is not dead; it has just entered another phase of its long life," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington. "We told the world last year that attempts to set the beloved robot free may not be successful. It looks like Spirit's current location on Mars will be its final resting place."

Ten months ago, as Spirit was driving south beside the western edge of a low plateau called Home Plate, its wheels broke through a crusty surface and churned into soft sand hidden underneath.

After Spirit became embedded, the rover team crafted plans for trying to get the six-wheeled vehicle free using its five functioning wheels – the sixth wheel quit working in 2006, limiting Spirit's mobility. The planning included experiments with a test rover in a sandbox at NASA's Jet Propulsion Laboratory in Pasadena, Calif., plus analysis, modeling and reviews. In November, another wheel quit working, making a difficult situation even worse.

Recent drives have yielded the best results since Spirit became embedded. However, the coming winter mandates a change in strategy. It is mid-autumn at the solar-powered robot's home on Mars. Winter will begin in May. Solar energy is declining and expected to become insufficient to power further driving by mid-February. The rover team plans to use those remaining potential drives for improving the rover's tilt. Spirit currently tilts slightly toward the south. The winter sun stays in the northern sky, so decreasing the southward tilt would boost the amount of sunshine on the rover's solar panels.

"We need to lift the rear of the rover, or the left side of the rover, or both," said Ashley Stroupe, a rover driver at JPL. "Lifting the rear wheels out of their ruts by driving backward and slightly uphill will help. If necessary, we can try to lower the front right of the rover by attempting to drop the right-front wheel into a rut or dig it into a hole."

This view from the front hazard-avoidance camera on NASA's Mars Exploration Rover Spirit shows the position of Spirit's front wheels following a backward drive during the 2,154th Martian day, or sol, of the rover's mission on Mars (Jan. 23, 2010). The view is toward the north. Image credit: NASA/JPL-Caltech

At its current angle, Spirit probably would not have enough power to keep communicating with Earth through the Martian winter. Even a few degrees of improvement in tilt might make enough difference to enable communication every few days.

"Getting through the winter will all come down to temperature and how cold the rover electronics will get," said John Callas, project manager at JPL for Spirit and its twin rover, Opportunity. "Every bit of energy produced by Spirit's solar arrays will go into keeping the rover's critical electronics warm, either by having the electronics on or by turning on essential heaters."

Even in a stationary state, Spirit continues scientific research.

"There's a class of science we can do only with a stationary vehicle that we had put off during the years of driving," said Steve Squyres, a researcher at Cornell University and principal investigator for Spirit and Opportunity. "Degraded mobility does not mean the mission ends abruptly. Instead, it lets us transition to stationary science."

One stationary experiment Spirit has begun studies tiny wobbles in the rotation of Mars to gain insight about the planet's core. This requires months of radio-tracking the motion of a point on the surface of Mars to calculate long-term motion with an accuracy of a few inches.

"If the final scientific feather in Spirit's cap is determining whether the core of Mars is liquid or solid, that would be wonderful -- it's so different from the other knowledge we've gained from Spirit," said Squyres.

Tools on Spirit's robotic arm can study variations in the composition of nearby soil, which has been affected by water. Stationary science also includes watching how wind moves soil particles and monitoring the Martian atmosphere.

Spirit and Opportunity landed on Mars in January 2004. They have been exploring for six years, far surpassing their original 90-day mission. Opportunity currently is driving toward a large crater called Endeavor and continues to make scientific discoveries. It has driven approximately 12 miles and returned more than 133,000 images.

JPL manages the rovers for NASA's Science Mission Directorate in Washington. For more information about Spirit and Opportunity, visit: http://www.nasa.gov/rovers .

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100126.html

Rover Gives NASA an "Opportunity" to View Interior of Mars

PASADENA, Calif. -- NASA's Mars exploration rover Opportunity is allowing scientists to get a glimpse deep inside Mars.

Perched on a rippled Martian plain, a dark rock not much bigger than a basketball was the target of interest for Opportunity during the past two months. Dubbed "Marquette Island," the rock is providing a better understanding of the mineral and chemical makeup of the Martian interior.

"Marquette Island is different in composition and character from any known rock on Mars or meteorite from Mars," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for Opportunity and its twin, Spirit. "It is one of the coolest things Opportunity has found in a very long time."

During six years of roving, Opportunity has found only one other rock of comparable size that scientists conclude was ejected from a distant crater. The rover studied the first such rock during its initial three-month mission. Called "Bounce Rock," that rock closely matched the composition of a meteorite from Mars found on Earth.

Marquette Island is a coarse-grained rock with a basalt composition. The coarseness indicates it cooled slowly from molten rock, allowing crystals time to grow. This composition suggests to geologists that it originated deep in the crust, not at the surface where it would cool quicker and have finer-grained texture.

"It is from deep in the crust and someplace far away on Mars, though exactly how deep and how far we can't yet estimate," said Squyres.

The composition of Marquette Island, as well as its texture, distinguishes it from other Martian basalt rocks that rovers and landers have examined. Scientists first thought the rock could be another in a series of meteorites that Opportunity has found. However, a much lower nickel content in Marquette Island indicates a Martian origin. The rock's interior contains more magnesium than in typical Martian basalt rocks Spirit has studied. Researchers are determining whether it might represent the precursor rock altered long ago by sulfuric acid to become the sulfate-rich sandstone bedrock that blankets the region of Mars that Opportunity is exploring.

"It's like having a fragment from another landing site," said Ralf Gellert of the University of Guelph, in Ontario, Canada. Gellert is lead scientist for the alpha particle X-ray spectrometer on Opportunity's robotic arm. "With analysis at an early stage, we're still working on some riddles about this rock."

This approximately true-color view of Marquette Island comes from combining three exposures that Opportunity's panoramic camera (Pancam) took through different filters during the rover's 2,117th Martian day, or sol, on Mars (Jan. 6, 2010). Image credit: NASA/JPL-Caltech/Cornell

The rover team used Opportunity's rock abrasion tool to grind away some of Marquette Island's weathered surface and expose the interior. This was the 38th rock target Opportunity has ground into, and one of the hardest. The tool was designed to grind into one Martian rock, and this rock may not be its last.

"We took a conservative approach on our target depth for this grind to ensure we will have enough of the bit left to grind the next hard rock that Opportunity comes across," said Joanna Cohen of Honeybee Robotics Spacecraft Mechanisms Corp., in New York, which built and operates the tool.

Opportunity currently is about 30 percent of the way on a 12-mile trek begun in mid-2008 from a crater it studied for two years. It is en route toward a much larger crater, Endeavour. The rover traveled 3.3 miles in 2009, farther than in any other year on Mars. Opportunity drove away from Marquette Island on Jan. 12.

"We're on the road again," said Mike Seibert, a rover mission manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The year ahead will include lots more driving, if all goes well. We'll keep pushing for Endeavour crater but watch for interesting targets along the way where we can stop and smell the roses."

Since landing on Mars in 2004, Opportunity has made numerous scientific discoveries, including the first mineralogical evidence that Mars had liquid water. After working 24 times longer than originally planned, Opportunity has driven more than 11 miles and returned more than 133,000 images. JPL manages the rovers for NASA's Science Mission Directorate in Washington.

For more information about the rovers, visit: http://www.nasa.gov/rovers

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100121.html

---

---

NASA's Mars Rover has Uncertain Future as Sixth Anniversary Nears

PASADENA, Calif. -- NASA's Mars rover Spirit will mark six years of unprecedented science exploration and inspiration for the American public on Sunday. However, the upcoming Martian winter could end the roving career of the beloved, scrappy robot.

Spirit successfully landed on the Red Planet at 8:35 p.m. PST on Jan. 3, 2004, and its twin Opportunity arrived at 9:05 p.m. Jan. 24, 2004. The rovers began missions intended to last for three months but which have lasted six Earth years, or 3.2 Mars years. During this time, Spirit has found evidence of a steamy and violent environment on ancient Mars that was quite different from the wet and acidic past documented by Opportunity, which has been operating successfully as it explores halfway around the planet.

A sand trap and balky wheels are challenges to Spirit's mobility that could prevent NASA's rover team from using a key survival strategy for the rover. The team may not be able to position the robot's solar panels to tilt toward the sun to collect power for heat to survive the severe Martian winter.

Nine months ago, Spirit's wheels broke through a crusty surface layer into loose sand hidden underneath. Efforts to escape this sand trap barely have budged the rover. The rover's inability to use all six wheels for driving has worsened the predicament. Spirit's right-front wheel quit working in 2006, and its right-rear wheel stalled a month ago. Surprisingly, the right-front wheel resumed working, though intermittently. Drives with four or five operating wheels have produced little progress toward escaping the sand trap. The latest attempts resulted in the rover sinking deeper in the soil.

"The highest priority for this mission right now is to stay mobile, if that's possible," said Steve Squyres of Cornell University in Ithaca, N.Y. He is principal investigator for the rovers.

If mobility is not possible, the next priority is to improve the rover's tilt, while Spirit is able to generate enough electricity to turn its wheels. Spirit is in the southern hemisphere of Mars, where it is autumn, and the amount of daily sunshine available for the solar-powered rover is declining. This could result in ceasing extraction activities as early as January, depending on the amount of remaining power. Spirit's tilt, nearly five degrees toward the south, is unfavorable because the winter sun crosses low in the northern sky.

Spirit attempted to turn all six wheels on Sol 2126 (Saturday, Dec. 26, 2009) to extricate itself from the sand trap known as "Troy," but stopped earlier than expected because of excessive sinkage. Image Credit: NASA/JPL-Caltech

Unless the tilt can be improved or luck with winds affects the gradual buildup of dust on the solar panels, the amount of sunshine available will continue to decline until May 2010. During May, or perhaps earlier, Spirit may not have enough power to remain in operation.

"At the current rate of dust accumulation, solar arrays at zero tilt would provide barely enough energy to run the survival heaters through the Mars winter solstice," said Jennifer Herman, a rover power engineer at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The team is evaluating strategies for improving the tilt even if Spirit cannot escape the sand trap, such as trying to dig in deeper with the wheels on the north side. In February, NASA will assess Mars missions, including Spirit, for their potential science versus costs to determine how to distribute limited resources. Meanwhile, the team is planning additional research about what a stationary Spirit could accomplish as power wanes.

"Spirit could continue significant research right where it is," said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the rovers. "We can study the interior of Mars, monitor the weather and continue examining the interesting deposits uncovered by Spirit's wheels."

A study of the planet's interior would use radio transmissions to measure wobble of the planet's axis of rotation, which is not feasible with a mobile rover. That experiment and others might provide more and different findings from a mission that has already far exceeded expectations.

"Long-term change in the spin direction could tell us about the diameter and density of the planet's core," said William Folkner of JPL. He has been developing plans for conducting this experiment with a future, stationary Mars lander. "Short-period changes could tell us whether the core is liquid or solid," he said.

In 2004, Opportunity discovered the first mineralogical evidence that Mars had liquid water. The rover recently finished a two-year investigation of a half-mile wide crater called Victoria and now is headed toward Endeavor crater, which is approximately seven miles from Victoria and nearly 14 miles across. Since landing, Opportunity has driven more than 11 miles and returned more than 132,000 images.

For more information about the rovers, visit:
http://www.nasa.gov/rovers

Read more: Road Trip Memories of Mars.


Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov

Guy Webster/Veronica McGregor
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-5011
guy.webster@jpl.nasa.gov, veronica.mcgregor@jpl.nasa.gov

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20091231.html

---

---

Right-Front and Right-Rear Wheels Sit Out Latest Drive - 12.22.09

Spirit's drive on Sol 2120 (Dec. 19, 2009) included commands for using all six wheels. However, the right-front wheel rotated less than 2 degrees and the right-rear wheel did not rotate at all. The other four wheels completed enough rotations to drive about 10 meters (33 feet), but produced no measurable forward motion by the rover.

An artist's concept portrays a NASA Mars Exploration Rover on the surface of Mars. Image credit: NASA/JPL/Cornell University

The rover team plans to command further driving this week while continuing to assess the possibility of getting more motion from the right-front wheel.

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

Rotations by Spirit's Right-Front Wheel, Sol 2117

This three-frame animation aids evaluation of performance of the right-front wheel on NASA's Mars Exploration Rover Spirit during a drive on the rover's 2,117th Martian day, or sol (Dec. 16, 2009). This wheel, on the right side of the images, had stopped operating in March 2006 and had not been used for driving since then. However, it revolved with apparently normal motion during the first three of four driving segments on Sol 2117. It completed about 10 rotations, then it stopped early in the fourth segment of the drive. Whether it will work again on future drives is uncertain.

The three wide-angle views shown one after the other in this animation come from Spirit's front hazard-avoidance camera. They were taken at different stages of the Sol 2117 drive. The most obvious change is in the position of shadows, a change unrelated to the wheel's movement during the drive. The frame with the rover arm's shadow farthest to the left is the first image in the sequence of three. The view is northward.

The rover team began commanding extrication drives in November after months of Earthbound testing and analysis to develop a strategy for attempting to drive Spirit out of this soft-soil site, called "Troy." The extrication drives are expected to make slow, if any, progress in coming weeks, and the probability of success in escaping from Troy is uncertain.

Image Credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/mer/images/mer20091217.html

Slight Movement by Spirit's Right-Front Wheel, Sol 2113

This blink comparison aids evaluation of a test of the right-front wheel of NASA's Mars Exploration Rover Spirit during the rover's 2,113th Martian day, or sol (Dec. 12, 2009). The test of electrical resistance in the wheel's drive motor, planned for comparison with results of tests on the right-rear wheel, surprisingly indicated normal resistance and produced a slight wheel movement of about one-fourth of one degree. Slight wheel movement is expected during a resistance test for an operating wheel actuator, but the right-front actuator (the combination of motor and gearbox) was expected to be non-operational because it had stopped working in April 2006.

The results of the resistance test do not enable a conclusion about whether the right-front wheel is usable for driving. Further tests are planned for both the right-front wheel and for the right-rear wheel, which has not moved since it stalled on Sol 2099 (nov. 28, 2009).

The two wide-angle views shown one after the other in this comparison come from Spirit's front hazard-avoidance camera, one taken before the resistance test and the other after the test. The most obvious change is in the position of shadows, a change unrelated to the wheel's movement during the drive. The shaded area gets smaller in the "after" image. The very small amount of wheel movement discernable -- and also indicated by telemetry from the rover -- is equivalent to about one full rotation of the drive motor at the wheel's gear ratio of about 1,500 motor rotations for each full wheel rotation.

The rover team began commanding extrication drives in November after months of Earthbound testing and analysis to develop a strategy for attempting to drive Spirit out of this soft-soil site, called "Troy." The extrication drives are expected to make slow, if any, progress in coming weeks, and the probability of success in escaping from Troy is uncertain.

Image Credit: NASA/JPL-Caltech

For more information visit http://www.nasa.gov/mission_pages/mer/images/mer20091215.html

Rear Wheel Trouble Continues - 12.10.09

Results of diagnostic tests on Spirit's right-rear wheel on Sol 2109 (Dec. 8, 2009) continue to indicate a troubled wheel, which may leave the rover with only four operable wheels.

The Sol 2109 plan included a check of the grind motor of Spirit's rock abrasion tool (RAT) because it shares the same motor controller as the right-rear wheel. It also included rotor resistance tests on the right-rear motor at three temperatures using opposite voltage polarity from earlier tests, backward and forward commanded motion of the right-rear wheel, and a check of rotor resistance on all other operating wheels. The RAT motor appears okay, although a more exhaustive test will be tried later. The right-rear wheel rotor resistance tests continue to show very elevated resistance, although not as high as in previous tests, and exhibiting a curious voltage-dependent effect. No motion of the right-rear wheel occurred during the backward commanded motion. The forward motion was not executed since the initial backward motion did not occur. The rotor resistances on all the other operating wheels are nominal.

The plan ahead, still being developed, will likely include more rotor resistance tests, an attempt to apply higher voltage to the right-rear wheel to see if any movement will occur, and a check of the right-front wheel to confirm its status and to see if it may offer insight into the right-rear wheel's condition. Further ahead, steering tests will be considered to explore an external jam as a possible explanation.

Concurrent with this, the project is exploring whether any meaningful rover motion would be possible with only four operable wheels. Spirit lost the use of its right front wheel in 2006.

Because of the current rover tilt, the environmental conditions and dust accumulation on the solar arrays, Spirit is at risk of inadequate power for surviving through the next southern Mars winter, which reaches solstice on May 13, 2009. Even if extrication is not possible, some limited rover motion may be able to improve rover tilt and increase the chance of winter survival.

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

Orbiter Puts Itself Into Safe Standby

Mars Odyssey Mission Status Report

PASADENA, Calif. -- NASA's Mars Odyssey orbiter put itself into a safe standby mode on Saturday, Nov. 28, and the team operating the spacecraft has begun implementing careful steps designed to resume Odyssey's science and relay operations within about a week.

Engineers have diagnosed the cause of the Nov. 28 event as the spacecraft's proper response to a memory error with a known source. The likely cause is an upset in the orbiter's "memory error external bus," as was the case with a similar event in June 2008.

In safe mode over the weekend, Odyssey remained in communication with ground controllers and maintained healthy temperatures and power. To clear the memory error, the team commanded Odyssey today to perform a cold reboot of the orbiter's onboard computer. The spacecraft reported that the reboot had been completed successfully.

"This event is a type we have seen before, so we have a known and tested path to resuming normal operations," said Odyssey Project Manager Philip Varghese of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Artist concept of Mars Odyssey. Image credit: NASA/JPL

Odyssey has been orbiting Mars since 2001. In addition to its own major scientific discoveries and continuing studies of the planet, the Odyssey mission has played important roles in supporting the missions of the Mars rovers Spirit and Opportunity and the Phoenix Mars Lander.

Until Odyssey is available again as a communications relay, Spirit and Opportunity will be operating with direct communications to and from Earth.

JPL, a division of the California Institute of Technology in Pasadena, manages Mars Odyssey for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. Additional information about Odyssey is at http://www.nasa.gov/mission_pages/odyssey.

Media contact: Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

For more information visit http://www.nasa.gov/mission_pages/odyssey/odyssey-20091130.html

Another Stall of Right-Rear Wheel Ends Drive

Spirit's right-rear wheel stalled again on Sol 2099 (Nov. 28, 2009) during the first step of a two-step extrication maneuver. This stall is different in some characteristics from the stall on Sol 2092 (Nov. 21). The Sol 2099 stall occurred more quickly and the inferred rotor resistance was elevated at the end of the stall. Investigation of past stall events along with these characteristics suggest that this stall might not be result of the terrain, but might be internal to the right-rear wheel actuator. Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions. These diagnostics are not likely to be ready before Wednesday. Plans for future driving will depend on the results of the diagnostic tests.

This blink comparison aids evaluation of a drive by NASA's Mars Exploration Rover Spirit during the rover's 2,099th Martian day, or sol (Nov. 28, 2009). Image Credit: NASA/JPL-Caltech

Before the Sol 2099 drive ended, Spirit completed 1.4 meters of wheel spin and the rover's center moved 0.5 millimeters (0.02 inch) forward, 0.25 millimeters (0.01 inch) to the left and 0.5 millimeters (0.02 inch) downward. Since Spirit began extrication on Sol 2088, the rover has performed 9.5 meters (31 feet) of wheel spin and the rover's center, in total, has moved 16 millimeters (0.63 inch) forward, 10 millimeters (0.39 inch) to the left and 5 millimeters (0.20 inch) downward.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer-20091201.html

No Wheel Stall in Diagnostic Drive

On Sol 2095 (Tuesday, Nov. 24), Spirit performed a set of diagnostic actions related to a stall of the right-rear wheel on the previous drive, three days earlier. The diagnostics showed a fully functioning wheel free of obstruction. The rover was commanded forward with 1.5 meters (4.9 feet) of wheel spin. The rover moved 2.1 millimeters (0.08 inch) forward, 1.1 millimeters (0.04 inch) to the left, and 0.3 millimeters (0.01 inch) down.

The cumulative results from Sols 2088 to 2095 (Nov. 17 to 24) are 8.1 meters (27 feet) of commanded motion, 15.7 millimeters (0.6 inch) of forward progress, 9.9 millimeters (0.4 inch) of movement to the left, and 4.8 millimeters (0.2 inch) of sinkage.

This view from the navigation camera near the top of the mast on NASA's Mars Exploration Rover Spirit shows the tracks left by the rover as it drove southward and backward, dragging its inoperable right-front wheel, to the location where the rover broke through a crust in April 2009 and became embedded in soft sand.Image Credit: NASA/JPL-Caltech

The plan for a drive during the long holiday weekend is another two-step drive, with each step 2.5 meters (8.2 feet) of commanded wheel spin. All wheels will be straight and run at the same speed. Results of this commanded drive will be analyzed Monday, Nov. 30.

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer-20091125.html