Mars rover Mars rover A Mars rover is a motor vehicle that propels itself across the surface of the planet Mars upon arrival. Rovers have several advantages over stationary landers: they examine more territory, and they can be directed to interesting features, they can place themselves in sunny positions to weather winter months, and they can advance the knowledge of how to perform very remote robotic vehicle control. There have been four successful robotically operated Mars rovers. The Jet Propulsion Laboratory managed the "Sojourner" rover, the "Opportunity" rover, "Spirit" rover, and, now the "Curiosity" rover. On January 24, 2016 NASA reported that
Mars Surveyor 2001 Lander is identical to that of the Mars Polar Lander, which had been intended to be the first of a series of low-cost "Mars Surveyor" landers sent to Mars. Prior to mission cancellation, cost overruns and technical problems caused the Lander design to be rescoped, and the planned large Athena rover was replaced by a small rover duplicating the "Sojourner" which was a part of the Mars Pathfinder mission. (The Athena did later make it to Mars, however, with two such rovers making up the Mars Exploration Rover Mission of 2004. The second of these, MER-B "Opportunity", landed at Mars Surveyor