Old and Dusty - But Still Moving

Mars Rovers Spirit and Opportunity were expected to live for only three-months, but more than four years later they are still "moving." NASA is still using the rovers and conducting scientific discoveries with them. The Opportunity is unable to use its infrared spectrometer because dust has obscured the instrument. The computer that runs the RAT and the mechanism that clears dust out of the RAT has also been damaged by prolonged dust exposure. The Spirit's front wheel has a broken motor and is now forced to move in reverse. 

NASA has now set its sites on finding a way to fix these problems and prolong the rovers mission. If NASA can find the ingenuity to fix these problems while on the surface of Mars it will be a decent gauge of how ready they are to deal with problems on the future manned mission to the planets surface. Opportunity and Spirit may be very old...but they are still moving.