The Mars rover Spirit has been operational for 6 years, in spite of its 3 month projected lifespan (c.f. the Scotty Principle). However, it appears finally to be on its last leg.
Personally, I find this to be an amazing accomplishment, and it's a shame that the Mars rovers have lost their luster in the public consciousness. But while so many negative events may define the past decade, I like to think that the efforts of all the geeks at JPL and elsewhere have made a step, small as it may be, toward future extraterrestrial human existence.