Spirit, also known as MER-A (Mars Exploration Rover – A) or MER-2, was a roboticrover that was active on Mars from 2004 to 2010. It was part of the Mars Exploration Rover program, and the rover's twin, Opportunity (also known as MER-B), was launched to the other side of the planet. Sprit got stuck in a sand trap, and, due to freezing temperatures, the rover made its last communication with NASA on March 22, 2010. ytvkg