The Spirit Rover was launched by NASA to start the Mars Exploration Rover mission

Description :

Spirit Rover was one of the two Mars rovers launched by NASA under the Mars Exploration Rover (MER) mission on June 10th, 2003. Spirit Rover arrived at Mars on January 3rd, 2004. Figuring out if life could ever have existed on Mars, learning about the Red Planet's current and past climate, and characterizing Martian geology are the tasks of Spirit Rover. 

The landing of Spirit Rover was like that of the Mars Pathfinder mission in 1997. But it was able to move much better than the Mars Pathfinder rover and the on-the-ground mission was very different from the Mars Pathfinder rover. 

The promised warranty duration of Spirit was 90 Martian days or sols. But it was activated more than 2,200 sols or 2,266 Earth days. Spirit Rover stopped its' communication with Earth on March 22nd, 2010 because it got stuck in a sand trap. But explorations of Spirit provided a remarkable glimpse into Mars' early and wet history to scientists. Under that, Spirit was founded evidence that Mars was once much wetter than it is today. Also, it helped scientists to get a better understanding of the Martian wind.