Spirit, also known as
MER-A (
Mars Exploration Rover – A) or
MER-2, is a
robotic rover on Mars, active from 2004 to 2010. It was one of two
rovers of
NASA's ongoing
Mars Exploration Rover Mission. It landed successfully on
Mars at 04:35
Ground UTC on January 4, 2004, three weeks before its twin,
Opportunity (MER-B), landed on the other side of the planet. Its name was chosen through a NASA-sponsored student essay competition. The rover became stuck in late 2009, and its last communication with Earth was sent on March 22, 2010.