The rovers Opportunity and Spirit were designed to function for only 90 days when they landed on Mars four years ago. They are still creaking along, but just barely. Engineers are using the space age version of baling wire and bubble gum to keep the little rovers functioning.
Both rovers have at least one defective wheel, which limits their maneuverability. Scientists have Spirit moving in reverse, dragging its useless wheel behind it. Both have problems with their robotic arms, and the two grinding tools still work only because of software patches and shortcuts implemented by the creative teams who maintain them.
I fully appreciate what the NASA scientists are having to do to keep their babies going. Over the years, I’ve had to perform similar gymnastics to keep my old cars running. Just a few more miles, a few more . . . . .