
NASA originally projected that the Mars Exploration Rovers would last 90 days once on the surface of the red planet. Today, both rovers are still doing science five years after their arrival. Spirit is now driving on a plateau called Home Plate in the
Inner Basin valley, according to the Washington Post, while Opportunity has left
Victoria Crater on the other side of the planet, and is motoring toward
a much larger crater called
Endeavour.
Spirit, the less-healthy of the two, has a bunch of minor to moderate issues. They include a broken wheel, some flaky sensors and software, and enough dust on its solar panels to limit its power to 30 percent of normal, the report said. Each night, the two rovers sleep to conserve energy since there is little sunlight–but from April 9th to 11th, Spirit wouldn’t wake up. It’s working again, though scientists working on the program may never find out what happened.
That’s not necessarily a problem. When Spirit’s wheel broke three years ago, the other five wheels dragged the broken one across the surface, which gouged a trench along the way–revealing a silica that proved to be evidence of ancient hot springs, according to the article. “When life hands you lemons, you make lemonade,” said John Callas, project manager for the Mars rovers at the Jet Propulsion Laboratory in Pasadena, Calif., in the report.