When the Spirit and Opportunity rovers landed on Mars in 2004, it was one of the most phenomenally successful space exploration missions ever [source: NASA]. The twin robots survived for years beyond their expected lifespan and gathered a treasure trove of knowledge, including evidence that liquid water may have existed fairly recently on the planet's surface [source: NASA]. Scientists hope that the Curiosity robotic rover, which is scheduled for launch in late November to mid-December 2011, will follow in its predecessors' illustrious tread marks.
At 10 feet (3 meters) in length, Curiosity is twice as big as the previous rovers, and it carries the most extensive array of scientific instruments ever sent to explore another planet's surface. Powered by an on-board nuclear generator, the six-wheeled robot is designed to roam between an eighth and a quarter of a mile each day. Its super-high resolution camera, which is capable of capturing details smaller than the width of a human hair, will take extreme close-up photos of rocks, soil and -- if it exists -- ice on the Martian surface. Another instrument, the ChemCam, will aim a laser beam at Martian rocks and turn them into hot gas, which then can be analyzed by other instruments to determine the rocks' chemical composition down to the atomic level. The rover's most important scientific mission is to search for conditions in which microbial life might possibly exist, but it will also measure radiation levels on Mars, a prerequisite for an eventual manned mission [source: NASA].