NASA rover celebrates eight years on the Martian surface today (Jan. 24), and the long-lived robot is still going strong.
http://www.space.com/14329-amazing-m...rm=Marleybonez
Despite an arthritic joint in Opportunity's robotic arm, the rover is in good health overall, Callas said. Still, the mission team isn't taking the aging robot's continued performance for granted.
"Every day is like a gift," Callas said. "We just keep charging ahead as if every day is our last day, and we want to maximize the science we can do with this vehicle."