NASA Rovers Set New Record for Longest Mission on Mars

NASA's long-lived twin Mars rovers Spirit and Opportunity have set a new endurance record on Mars, with Opportunity hot on the heels of its sister robot for the title of longest-running mission on the Martian surface.

Opportunity today matched the Marsmission lifespan of NASA's iconic Viking 1 lander, which spent six yearsand 116 days (for a total of 2,245 days) working on the red planet in the mid 1970sand early 80s.

If Opportunity survives three weeks longer than its older robotic twinSpirit, which has been silent for weeks but may actually be hibernating, therover will take the all-time record for the longestmission on Mars. The two solar-powered rovers recently experienced theirfourth Martian winter solstice – the day with the least amount ofsunlight at their respective spots on Mars – on May 12.

"Opportunity, and likely Spirit, surpassing the Viking Lander 1longevity record is truly remarkable, considering these rovers were designedfor only a 90-day mission on the surface of Mars," said John Callas,NASA's rover mission project manager at the Jet Propulsion Laboratory inPasadena, Calif, in a statement. "Passing the solstice means we're overthe hump for the cold, dark, winter season."

Opportunityand Spirit were initially slated for only 90-day missions to explore thegeology and chemistry of their respective landing sites. But they blew pastthose deadlines and have continued their missions for far longer than NASAengineers ever thought possible.

In January of this year, they each celebrated their sixth anniversary onMars. That means right now both rovers are in the midst of their seventh Earthyear exploring the red planet.

Spirit touched down on the surface of Mars in January 2004, ahead ofOpportunity, but fell silent on March 22, when it skipped a plannedcommunications session with controllers on Earth.

The beleagueredSpirit rover has been out of communication for weeks after entering alow-power hibernation mode once winter sat in and temperatures dropped alongwith the sun dipping in the sky, leaving Spirit with insufficient power toproperly function.

The rover may wake up with the arrival of the Martian spring, and if so,will keep its hold on the record for the longest mission.

Spirit landed on Mars on Jan. 3, 2004 while Opportunity touched down on Jan.25 (Eastern Time) of that year. So Opportunity would have to survive at least22 days longer than its twin to take the Martian mission title.

But, because Spirit is out of contact, mission managers may not know forseveral weeks whether or not it has survived and was still in operation on itsrecord-setting day.

Opportunity, which is doing fine, is expected to breeze past Viking 1's2,245-day record today with no problems. The rover also hit anothermilestone in March, passing the 20-kilometer (12.43-mile) mark.

While Opportunity could swipe the Mars surface mission record from Spirit,it has a long way to go to take the title for longest mission in the Martianneighborhood.

The current record for any mission to Mars is nine years and is held byNASA's late Mars Global Surveyor, which studied the planet between 1997 and 2006.NASA's Mars Odyssey orbiter has been studying Mars since 2001 – longer thanany mission currently underway – and could take the longest-ever mantleaway from the Mars rovers later this year, NASA mission managers said.

Opportunity has been steadily roving toward a huge Mars crater calledEndeavour since mid-2008, when it finished its last crater pit stop VictoriaCrater. Photos from the rover show the rim of Endeavour in the distance withvast plains of Martian sand etched with ripple-like dunes.

"The ripples look like waves on the ocean, like we're out in the middleof the ocean with land on the horizon, our destination," said roverprincipal investigator Steve Squyres of Cornell University in Ithaca, N.Y. "Eventhough we know we might never get there, Endeavour is the goal that drives ourexploration."

Photos of Endeavour Crater from spacecraft orbiting Mars have revealed thetantalizing fact that clay minerals are exposed at the crater. Scientists havenot yet had a chance to examine such minerals on the surface in the more thansix years Opportunity and Spirit have been on Mars.

"Those minerals form under wet conditions more neutral than the wet,acidic environment that formed the sulfates we've found with Opportunity,"Squires said. "The clay minerals at Endeavour speak to a time when thechemistry was much friendlier to life than the environments that formed theminerals Opportunity has seen so far. We want to get there to learn theircontext. Was there flowing water? Were there steam vents? Hot springs? We wantto find out."

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