Two rovers, Spirit and Opportunity, landed on Mars in January 2003, and have been operating more than 15 times longer than originally planned.
What we've learned from these little guys about Mars has been indispensable. Now, the rover Spirit is battling time to get itself in position to survive the Martian winter.
Spirit has about two weeks left to reach a sun-facing slope on the northern edge of a plateau known as Home Plate in Gusev Crater. So much dust blankets its solar panels however, that the rover needs to spend a day charging its batteries just to crawl for an hour, project manager John Callas said during a briefing at the American Geophysical Union conference in San Francisco this week.
Global dust storms swept over the planet for two months earlier this year, blotting out 99.5 percent of the direct sunlight. The rovers survived the storms, but Spirit is so coated with debris that its solar power panels are operating at 42 percent of their original capacity.
"It's almost camouflaged. There's so much dust on the arrays," Callas said.
Even if Spirit reaches its winter resting spot, surviving its third Martian winter will be tough, Callas said. Engineers estimate Spirit's power levels will be reduced to 30 percent -- about what is needed just to keep its equipment from freezing.
Spirit had 50 percent power during the last winter and 70 percent during its first winter on Mars.No matter what Spirit's fate may be, there is no doubt, that when we finally get Man to Mars, the little guy will be dusted off, and will get its ride back home.
Hang tough bud.