NASA's Spirit Rover Completes Mission on Mars

Pasadena CA (JPL) May 26, 2011

NASA has ended operational planning activities for the Mars rover Spirit and transitioned the Mars Exploration Rover Project to a single-rover operation focused on Spirit's still-active twin, Opportunity. This marks the completion of one of the most successful missions of interplanetary exploration ever launched.

Spirit last communicated on March 22, 2010, as Martian winter approached and the rover's solar-energy supply declined. The rover operated for more than six years after landing in January 2004 for what was planned as a three-month mission.

NASA checked frequently in recent months for possible reawakening of Spirit as solar energy available to the rover increased during Martian spring. A series of additional re-contact attempts have ended, designed for various possible combinations of recoverable conditions.

"Our job was to wear these rovers out exploring, to leave no unutilized capability on the surface of Mars, and for Spirit, we have done that," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Spirit drove 4.8 miles (7.73 kilometers), more than 12 times the goal set for the mission. The drives crossed a plain to reach a distant range of hills that appeared as mere bumps on the horizon from the landing site; climbed slopes up to 30 degrees as Spirit became the first robot to summit a hill on another planet; and covered more than half a mile (nearly a kilometer) after Spirit's right-front wheel became immobile in 2006.

The rover returned more than 124,000 images. It ground the surfaces off 15 rock targets and scoured 92 targets with a brush to prepare the targets for inspection with spectrometers and a microscopic imager.

"What's really important is not only how long Spirit worked or how far Spirit drove, but also how much exploration and scientific discovery Spirit accomplished," Callas said.

One major finding came, ironically, from dragging the inoperable right-front wheel as the rover was driving backwards in 2007. That wheel plowed up bright white soil. Spirit's Alpha Particle X-ray Spectrometer and Miniature Thermal Emission Spectrometer revealed that the bright material was nearly pure silica.

"Spirit's unexpected discovery of concentrated silica deposits was one of the most important findings by either rover," said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for Spirit and Opportunity.

"It showed that there were once hot springs or steam vents at the Spirit site, which could have provided favorable conditions for microbial life."

The silica-rich soil neighbors a low plateau called Home Plate, which was Spirit's main destination after the historic climb up Husband Hill. "What Spirit showed us at Home Plate was that early Mars could be a violent place, with water and hot rock interacting to make what must have been spectacular volcanic explosions. It was a dramatically different world than the cold, dry Mars of today," said Squyres.

The trove of data from Spirit could still yield future science revelations. Years of analysis of some 2005 observations by the rover's Alpha Particle X-ray Spectrometer, Miniature Thermal Emission Spectrometer and Moessbauer Spectrometer produced a report last year that an outcrop on Husband Hill bears a high concentration of carbonate. This is evidence of a wet, non-acidic ancient environment that may have been favorable for microbial life.

"What's most remarkable to me about Spirit's mission is just how extensive her accomplishments became," said Squyres.

"What we initially conceived as a fairly simple geologic experiment on Mars ultimately turned into humanity's first real overland expedition across another planet. Spirit explored just as we would have, seeing a distant hill, climbing it, and showing us the vista from the summit. And she did it in a way that allowed everyone on Earth to be part of the adventure."

Source: Mars Daily.
Link: http://www.marsdaily.com/reports/NASA_Spirit_Rover_Completes_Mission_on_Mars_999.html.

Rover finds signs of buried Martian water

Trapped craft discovers evidence water trickled beneath Red Planet's surface

NASA's stuck Mars rover Spirit has found more evidence that water trickled beneath the Red Planet's surface in the past perhaps within the last few hundred thousand years.

The sandy spot where Spirit got bogged down last year harbors stratified layers of dirt with different compositions close to the surface, a new study reveals. Researchers suspect these layers were caused by seepage of thin films of water on Mars, perhaps from melting frost or snow.

This seepage could have occurred during cyclical climate changes when Mars was tilted more on its axis, researchers said. The water may have moved down into the sand, carrying soluble minerals deeper than less-soluble ones, they added. [ Most Amazing Mars Rover Discoveries ]

The axis tilt of Mars varies over time scales of hundreds of thousands of years. The fact that Spirit found these layers in the dirt rather than locked away in rock further suggests the water was seeping relatively recently, rather than billions of years ago, researchers said.

"Once you freeze that evidence in a rock, it can stay there for a long time," said Bruce Banerdt, a project scientist for the Mars Exploration Rovers project at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But you don't expect to maintain evidence in loose dirt for long periods of time."

Buried water in Martian history
The relatively insoluble minerals near the surface include what is thought to be hematite, silica and gypsum, according to researchers. Iron-rich ferric sulfates, which are more soluble, appear to have been dissolved and carried down deeper by water, they added.

None of these minerals is exposed at the surface, which is covered by wind-blown sand and dust.

"The lack of exposures at the surface indicates the preferential dissolution of ferric sulfates must be a relatively recent and ongoing process since wind has been systematically stripping soil and altering landscapes in the region Spirit has been examining," rover deputy principal investigator Ray Arvidson of Washington University in St. Louis, explained in a statement.

The new study, which appears in the Journal of Geophysical Research, is based on observations made by Spirit before it stopped communicating with Earth in March of this year. The findings contribute to an accumulating set of evidence that Mars may harbor small amounts of liquid water at some periods during ongoing climate cycles.

Spirit, its rover twin Opportunity and other NASA Mars missions have found evidence of wet Martian environments billions of years ago that may have been favorable for life. Observations by the Phoenix Mars Lander in 2008 and various orbiters since 2002 have identified buried layers of water ice at high and middle latitudes and frozen water in polar ice caps.

Spirit still sleeping
The twin Mars rovers finished their three-month prime missions in April 2004, then kept exploring in bonus missions. One of Spirit's six wheels quit working in 2006.

In April 2009, Spirit's left wheels broke through a crust at a site called "Troy" and churned into soft sand. A second wheel stopped working seven months later. Spirit could not maneuver into a position slanting its solar panels toward the sun for the winter, as it had done for previous winters.

Engineers anticipated it would enter a low-power, silent hibernation mode, and the rover stopped communicating March 22 of this year. Spring begins next month at Spirit's site, and NASA is listening to see if the rover reawakens, officials said.

"Most of us have high hopes," Banerdt told SPACE.com. "Our models say she could start communicating any day now. But we also recognize that this is an extremely risky situation for Spirit, and there are so many unknowns that we just can't be sure."

Among those unknowns, according to Banerdt: how much dust blankets Spirit's solar panels, how cold the rover's interior got and the current surface conditions where it bogged down.

Researchers took advantage of Spirit's months at Troy last year to examine in great detail soil layers the wheels had exposed, along with neighboring surfaces. Spirit made 13 inches of progress in its last 10 backward drives before energy levels fell too low for further driving in February.

Those drives exposed a new area of soil for possible examination if Spirit does awaken and its robotic arm is still usable, researchers said.

"With insufficient solar energy during the winter, Spirit goes into a deep-sleep hibernation mode where all rover systems are turned off, including the radio and survival heaters," said rover project manager John Callas of JPL. "All available solar array energy goes into charging the batteries and keeping the mission clock running."

The rover is expected to have experienced temperatures colder than it ever has before, and it may not survive. If Spirit does get back to work, the top priority is a multi-month study that can be done without driving the rover, researchers said.

The study would measure the rotation of Mars through the Doppler signature of the stationary rover's radio signal with enough precision to gain new information about the planet's core. The rover Opportunity has been making steady progress toward a large crater, Endeavor, which is now approximately 5 miles away.

Source: MSNBC.
Link: http://www.msnbc.msn.com/id/39899649/ns/technology_and_science-space/.

End of the Road for NASA's Mars Rover 'Spirit'

The roving days are over for NASA's Mars rover Spirit after more than six years rolling across the Martian surface, the space agency announced Tuesday.

The roving days are over for NASA's Mars rover Spirit after more than six years rolling across the Martian surface, the space agency announced Tuesday.

NASA engineers have decided to abandon efforts to rescue the Spirit rover from the deep Martian sand that snared it in May 2009. Instead, they are trying to prepare the rover to survive the harsh winter ahead in Mars' southern hemisphere. If the rover survives, it will serve as a fixed science outpost, mission managers said.

SLIDESHOW: Mars Rover Spirit's Best Photos

"This is not a day to mourn Spirit. This is not a day of loss," said Doug McCuistion, director of NASA's Mars exploration program, in a teleconference. "Its driving days are likely over, however its contribution will continue."

Spirit is stuck up to its wheel tops in Martian sand and slightly tilted back in a spot on Mars that scientists have named "Troy." The rover got stuck on May 6, when its wheels broke through a hard crust covering the soft sand and sunk into the sand trap.

"Spirit has encountered a golfer's worse nightmare," McCuistion said.

Engineers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., spent months working on ways to extract Spirit from its sandy predicament. Those efforts - which began in November - have been unsuccessful. Making matters worse, two of the rover's six wheels are broken, hampering its escape attempts.

Spirit and its robotic twin Opportunity have been exploring different parts of Mars since they landed in January 2004. Since then, the long-lived rovers have far outlasted their initial 90-day mission plans and discovered new insights into the history of water on Mars. Opportunity is currently working fine and is studying an odd rock called "Marquette Island" – which appears to have been ejected from deep inside Mars during an impact – as it heads toward a giant crater called Endeavour.

McCuistion called the Spirit's situation "inextractable." He didn't rule out that Spirit could free itself by accident, but that's not the goal anymore.

"Right now, our plan is to worry about getting through the winter," McCuistion said.

Recent attempts to drive Spirit backwards have made some improvement to its tilt toward the sun, which is vital for the rover's solar arrays to generate the power to stay alive.

During winters on Mars, the sun is low in the sky, so engineers try to perch Spirit and Opportunity on north-facing slopes to maximize the amount of sunlight their top-mounted solar panels can collect. NASA is hopeful that Spirit can be wiggled into a favorable position before the full brunt of winter arrives in a few months.

If successful, Spirit could continue to operate through the Martian winter, or possibly enter a hibernation-like mode until the season passes and springtime returns, bringing with it more favorable levels of sunlight.

"We have hope that Spirit will survive this cold, dark winter that we have ahead of us and be ready to do more science come springtime," said the rover mission's principal investigator Steven Squyres of Cornell University in Ithaca, New York.

Squyres said Spirit can still study the Mars dirt around Troy. There is also a tantalizing chance for scientists to determine if the core of Mars is liquid or solid iron. They could do that by using Spirit's radio signals to record the motion of Mars and deduce if the red planet's core is molten or not, he added.

"Totally new science," Squyres said.

But first, Spirit must survive the next winter on Mars.

Rover project manager John Callas of JPL said that, in the end, it will all come down to power. If Spirit does not find a good sunward tilt for the coming winter, it could experience a so-called "low-power fault" and shut down all non-essential systems.

"The rover will be like a polar bear, hibernating," Callas said. "It could be for many months...on the order of six months, that the rover will be in this state."

Unlike NASA's long-silent Phoenix lander in the Martian arctic, Spirit is designed to hibernate through winters on Mars and will experience temperatures of minus 45 degrees Celsius, Callas said. But Spirit is not a new rover, so its systems could be susceptible to damage due to age, he added.

"There's no guarantee that the rover will be able to survive these colder temperatures," Callas said.

It will likely be frustrating for NASA engineers as they await word from Spirit to determine if the rover survives the coming winter. After all, NASA has spent $900 million on the Mars rover mission, and typically spends $20 million a year to support Spirit and Opportunity during their extended treks on the red planet.

"That'll be challenging for the team, but it's just something we'll have to be disciplined about," Callas said.

Source: Fox News.
Link: http://www.foxnews.com/scitech/2010/01/26/end-road-nasas-mars-rover-spirit/.

Spirit remains trapped in Martian sand

PASADENA, Calif., Dec. 8 (UPI) -- NASA engineers attempting to free the Mars rover Spirit from loose Martian sand since April say the results of their attempts so far are not encouraging.

A series of diagnostic tests conducted on Spirit's right-rear wheel last week were designed to investigate stalls that occurred Nov. 28 and earlier. Those diagnostics, the space agency said, included rotor-resistance tests at three temperatures and a one-radian (about 57 degrees) forward motion test.

"The plan ahead is to explore a set of hypotheses: possible motor failure, possible internal gearbox jam, possible external jam (e.g., a rock in the wheel)," NASA said in a statement. "Commands being developed for Spirit's activities (Tuesday and Wednesday) will include more diagnostics to explore these hypotheses."

NASA fails again in attempt to free Spirit

PASADENA, Calif., Dec. 2 (UPI) -- NASA is again reporting failure in the latest of its attempts to free the stuck Mars rover Spirit from a sand trap on the surface of the Red Planet.

Scientists at the space agency's Jet Propulsion Laboratory said Spirit's right-rear wheel stalled Nov. 28 during the first step of a two-step extrication maneuver. But officials said the stall is different in some characteristics from a Nov. 21 stall. NASA said the most recent event occurred more quickly and the inferred rotor resistance was elevated at the end of the stall.

Investigation of past stall events, along with the new characteristics, suggest the latest stall might not be result of the terrain, but might be internal to the right-rear wheel actuator, NASA said.

"Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions," the space agency said, noting plans for future driving will depend on the results of the diagnostic tests.

The space agency said earlier its attempt to extract Spirit from the martian sand trap is expected to take weeks or even months, with uncertain probability of success.

Spirit has been stuck in loose martian sand since April 23.

NASA's Mars Rover Might Be Stuck For Good

By SPACE.com Staff

Efforts to free the stuck Spirit rover on Mars have been dragging on since May and today a NASA official said the robot may never get free.

"We are proceeding very cautiously and exploring all reasonable options," said John Callas, NASA project manager for Spirit and its twin, Opportunity. "There is a very real possibility that Spirit may not be able to get out, and we want to give Spirit the very best chance."

Callas and colleagues at the Jet Propulsion Laboratory have been testing ideas on a twin of Spirit at the California facility, in a pit designed to simulate the surface of Mars. It's tricky though, because of the difference in gravity of the two planets. The rover team is also refining a detailed computer model of rover mobility, calibrated with results from testing and measurements from Mars.

"The computer modeling will allow us to connect the results from tests performed in Earth gravity with what to expect from the rover in Mars gravity," Callas said in a statement Monday.

Spirit has certainly outlived expectations. It became embedded in soft soil at a site called Troy in early May, more than five years into a mission on Mars that was originally scheduled to last for three months. The rover team suspended further driving attempts with Spirit while evaluating how to free it.

The engineers are trying to figure out how to move Spirit while avoiding putting the rover's center of gravity directly over a rock that is touching or nearly touching the machine's underbelly. Other added tests are using a lighter-weight test rover than the one used for most of the testing this summer. A complete "dress rehearsal" test of the extrication strategy judged to hold the best chance of success is planned in the test setup at JPL before the team commands Spirit to begin driving. That test and subsequent review of its results are expected to take several weeks.

Moves by Spirit will not begin before October, according to current plans.

A dust storm that had reduced the electrical output from Spirit's solar panels by nearly half during late August still has some lingering effects on the skies above Spirit, NASA said.

Spirit lifted by Martian winds

By Mary O’Keefe

As the Mars rovers deal with advanced age, broken appendages and memory lapses, good news comes from Jet Propulsion Laboratory: the rover named Spirit had a little power boost, thanks to a Martian wind.

Solar panels convert the Sun’s rays into power for the rovers. The more dust that covers the panels, the less power gets through. A Martian wind this month has blown away some of the dust that had accumulated on the panels, giving Spirit a very important uptick in electrical output.

That boosts Spirit’s energy by about 10%, according to John Callas, rover program manager.

“We welcome that extra energy,” Callas said.

The energy will allow Spirit to do more during the day. “We are trying to climb Home Plate,” he said.

Home Plate is a low plateau where Spirit has been parked during the winter months. Now that spring is almost over and the Martian summer is about to begin, engineers will be driving Spirit onto it.

“We want to climb up and drive across [Home Plate] south to our [new] destination,” he said.

With its extra power boost Spirit is expected to continue its quest to drive across Home Plate.

In late January, Spirit had a problem recalling its daily activity. It appeared to have thought it had driven somewhere but in actuality hadn’t moved. Callas said that a leading hypothesis to the memory loss was due to a cosmic ray event. This would explain why Spirit did not record its daily activities into a memory drive that erases when the rover shuts down.

Opportunity, Spirit’s sister rover, is rolling along on the other side of the planet.

“It is doing great,” Callas said.

He added that engineers have noticed an elevated current in Opportunity’s right front wheel that they will be watching. For now they feel it is a lubrication problem and are driving the rover backwards in an effort to correct it.

“We can’t drive as far going backwards,” he said. “It’s like backing up your car you can see [much easier] what is in front of you when you are driving forward.”

For right now engineers are taking it slow with Opportunity, and grateful for any extra Spirit power.

“We can expect some impulsive [sand storm] activities,” he said. “We will keep vigilante for dust storms but for now it has given us a good cleaning and we are happy with that.”

Spirit and Opportunity rovers mark five years on Mars

WASHINGTON (AFP) – The US space agency's Mars rovers Spirit and Opportunity this month mark their fifth anniversary on the Red Planet, where they have endured harsh conditions and revealed a deluge of information.

The twin robots, which landed on Mars three weeks apart in January 2004, were initially expected to have just 90-day missions, but have since sent back to Earth a quarter-million images, toured mountains and craters and survived violent dust storms.

"The American taxpayer was told three months for each rover was the prime mission plan. The twins have worked almost 20 times that long," said NASA assistant administrator Ed Weiler in a statement.

"That's an extraordinary return of investment in these challenging budgetary times."

The rovers, which along with 250,000 images have sent back to Earth some 36 gigabytes of data, have greatly advanced NASA's understanding of Mars' geology, including peeks into the planet's wet and habitable past.

Analysts say the wealth of information data will keep scientists busy for years as they further unravel the vast banks of data.

Since 2004 the machines have covered 21 kilometers (13 miles) of Mars' characteristic red rock desert, driving inch by inch to avoid chasms and rocky obstacles, picking up samples and snapping images to beam back to mission control on Earth.

"These rovers are incredibly resilient considering the extreme environment the hardware experiences every day," said John Callas, project manager for Spirit and Opportunity.

"We realize that a major rover component on either vehicle could fail at any time and end a mission with no advance notice, but on the other hand, we could accomplish the equivalent duration of four more prime missions on each rover in the year ahead."

While the machines have had relatively balmy 20 degree Celsius (68 degree Fahrenheit) summers, they have had to endure frigid extremes, where temperatures of minus-100 degrees Celsius (minus-148 degrees Fahrenheit) in winter are common.

Harsh Martian winds, however, have provided an occasional cleaning job to the rovers' solar panels -- critical instruments to power the machines.

This unconventional aid, however, has not be reliable, with the Spirit machine's panels hardly clear enough to survive its third southern hemisphere winter, which ended in December.

Although the 820-million-dollar project's mission began as scientific, the it has become something much larger, according to Steve Squyres of Cornell University, the rover mission's principal investigator.

The journeys "have led to something else important," he said. "This has turned into humanity's first overland expedition on another planet.

"When people look back on this period of Mars exploration decades from now, Spirit and Opportunity may be considered most significant not for the science they accomplished, but for the first time we truly went exploring across the surface of Mars."

The continuing wealth of data provided by the rovers is a welcome hold-over for the US space agency, which was forced to delay a landmark mission to Mars by 26 months last month.

The 2.3- billion-dollar Mars Science Laboratory (MSL) is now expected to be launched in 2011.

Launch opportunities for Mars come only every 26 months, when the planets are in right alignment.