NASA's Mars Rovers Set Surface Longevity Record

05.19.10

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
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› Interactive: Mars Exploration Rovers

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.

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

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

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

I am still crazy about Mars and the robots we have up there. It really is amazing what we have achieved up there. The http://www.nasa.gov/rovers is awesome -- go check it out!

@dmgerbino

Close Encounter with Mars

01.26.2010

January 26, 2010: It rises in the east at sunset, pumpkin-orange and brighter than a first magnitude star. You stare at it, unblinking. Unblinking, it stares right back.

It is Mars.

This week Earth and Mars are having a close encounter. On Jan. 27th, the Red Planet will be only 99 million kilometers away and look bigger through a telescope than at any time between 2008 and 2014. The planet's 14-arcsecond diameter will remain essentially unchanged for another week or so, setting the stage for some good observing.

"Mars is an excellent target for all backyard telescopes right now," reports amateur astronomer Joel Warren, who sends these pictures from his observatory in Amarillo, Texas:

"The planet's North Polar Cap was brilliant in my 11-inch reflector," he says.

And because summer is coming to the Martian north, the bright polar cap and its icy-blue clouds are shifting, sublimating and changing every night. It's a lively show for anyone with a mid-sized telescope and a digital camera.

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But a telescope is not required to enjoy the show. Mars is a pleasing sight even to the unaided eye. With a visual magnitude of -1.3, it is almost as bright as Sirius (magnitude -1.44), the brightest star in the sky.

Compare the two—Sirius vs. Mars. They are in the same patch of sky all week long. While Sirius is as blue as the tip of an acetylene torch, Mars looks more like the ruddy head of a lit match. The contrast is beautiful.

Another fun comparison: Sirius twinkles but Mars does not. Distant, pinprick stars are more disturbed in their appearance by tiny irregularities in Earth's atmosphere than nearby, disk-shaped planets. Compared to the dancing light of a star, Mars has a smooth, unblinking glow.

For visual observers, the best display comes on Friday, Jan. 29th, when the full Moon and Mars converge for a floodlamp-bright conjunction. On that night, Mars will be at opposition—i.e., directly opposite the sun. It will rise alongside the Moon at sunset and soar overhead at midnight, never straying more than about 6^o from the first full Moon of 2010. (Note: Contrary to "Mars Hoax" emails, Mars will not be as wide as the full Moon. To the unaided eye, Mars will resemble a bright orange star.)

Right: The full Moon and Mars converge in the constellation Cancer on Jan. 29th. Full-sized sky maps: Jan. 27, 28, 29.

Earth and Mars have close encounters approximately every 26 months. Some are closer than others, however. In 2003, the Earth-Mars distance was only 56 million kilometers, a sixty-thousand year minimum. The whole world stopped to watch as news reports trumpeted the event. This year's gulf is almost twice as wide, and professional astronomers do not consider it a particularly remarkable encounter.

Don't let that stop you. Mars is near. Take a look!

Author:james.a.phillips@earthlink.net"> Dr. Tony Phillips | Credit: Science@NASA

It is true, I am Mars crazy and this is the best month to be Mars crazy. All kidding aside, is it is clear out tonight, go outside and look up in the sky for Mars. If this Friday, January 29th, is a clear night for you. Go outside and look for Mars.

For further evidence that I am Mars crazy, look no further than my Twitter web page background. It is Mars' moon Phobos - http://twitter.com/dmgerbino

Spirit is Now a Stationary Science Platform

01.26.2010

January 26, 2010: After six years of unprecedented exploration of the Red Planet, NASA's Mars Exploration Rover Spirit is no longer a fully mobile robot. NASA has designated Spirit 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.

Above: Spirit's last tracks. This view from Spirit's navigation camera shows tracks left by the rover as it drove backward, dragging its inoperable right-front wheel, to the location where the rover became trapped in soft sand in April 2009. [more]

"We told the world last year that attempts to set the beloved robot free may not be successful," adds McCuistion. "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.

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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."

Right: Ashley Stroupe, a rover driver at JPL who has been involved in the efforts to free Spirit. [more]

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. (See , e.g., "Sandtrapped Rover Makes Big Discovery.")

"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.

Right: As a stationary platform, Spirit will help probe the core of Mars. [larger image]

"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 may have been stopped, but it hasn't stopped discovering the secrets of Mars. Stay tuned to Science@NASA for updates.

Editor:james.a.phillips@earthlink.net"> Dr. Tony Phillips | Credit: Science@NASA

It is disappointing that the Spirit team can not get the rover moving again. The good news is there is still more scientific work to be done. I can not wait to see what additional discoveries these amazing rover's will make.

Resumed Mars Orbiter Observations Yield Stunning Views

Dunes of sand-sized materials have been trapped on the floors of many Martian craters. This is one example, from a crater in Noachis Terra, west of the giant Hellas impact basin. Image Credit: NASA/JPL-Caltech/University of Arizona
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January 14, 2010

Dunes of sand-sized materials have been trapped on the floors of many Martian craters. This view shows dunes inside a crater in Noachis Terra, west of the giant Hellas impact basin in Mars' southern hemisphere.

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter captured this view on Dec. 28, 2009. The orbiter resumed making observations in mid-December following a three-month hiatus. A set of new images from the HiRISE camera is on the camera team's site, at http://hirise.lpl.arizona.edu/nea.php.

The dunes here are linear, thought to be due to shifting wind directions. In places, each dune is remarkably similar to adjacent dunes, including a reddish (or dust-colored) band on northeast-facing slopes. Large angular boulders litter the floor between dunes.

The most extensive linear dune fields known in the solar system are on Saturn's large moon Titan. Titan has a very different environment and composition, so at meter-scale resolution they probably are very different from Martian dunes.

The University of Arizona, Tucson, operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

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

Mars has always fascinated me. All through Jr. High, High School, and College, I made time to view Mars with my old 6 inch Newtonian telescope.