Spirit and Opportunity were robots with wheels that allowed them to move around on the surface of Mars. The rovers performed experiments on the planet’s soil and rocks and took many photographs.
Spirit was the first of the two rovers to land on January 4, 2004, three weeks before its twin, Opportunity, landed on the other side of the planet.
Not everything has gone to plan. One of Spirits wheels stopped turning. It has since had to travel backwards dragging the bad wheel behind it. This has been actually a help as the trench it leaves behind itself has been useful for gathering samples.
On May 1, 2009 (5 years, 3 months, 27 Earth days after landing), Spirit became stuck in soft soil. For the following eight months NASA tested possible ways of freeing Spirit. These efforts continued until January 26, 2010 when they decided it could not be moved. It is now continuing its mission working from the position its got stuck in. However as of 22nd March 22 2010 nothing has been heard from Spirit. The rover team continues to listen for communication from Spirit and the hope is that when summer arrives on Mars the Rover might start working again.