The Mars rovers Spirit and Opportunity will celebrate five years of roaming around the red planet this month. Spirit landed on January 3, 2004 and Opportunity landed on January 24, 2004. The rovers were only supposed to last for three months, but, as with most of NASA’s probes, they have outlasted the official missions.
The rovers have lived through dust storms, sand traps, sliding down into craters, climbed a mountain and have collectively sent over 36 gigabytes of data back to Earth via the Mars Odyssey orbiter.
There is a nice write up about the rovers on the Astronomy Now web site.