The Mars rover Opportunity is starting its 10th year on Mars today. This is remarkable, because it’s mission was supposed to be 90 days long. That’s Mars days, or sols, which translates into 24 hours, 39 minutes, and 35 some seconds. Opportunity is still going. That’s 39.4704637 times longer than originally planned, and designed for; I wish my car was built this way.
Opportunity’s twin, Spirit, was also well over warranty when it became stuck in soft soil. At that point its mission changed from mobile laboratory to stationary observer. It sent its last transmission on 22 March 2010. We salute you Spirit.
These rovers (including Pathfinder/Sojourner and Curiosity) have made great scientific observations, including that Mars once had liquid water on the surface.