According to NASA, Curiosity is twice as long and five times as heavy as earlier Mars rovers Spirit and Opportunity, which measured 5.2 feet long, 7.5 feet wide and 4.9 feet high. Curiosity is 7 feet tall. There are ten experiments on board, which weigh 15 times as much as its predecessors' experiments, NASA said.
The 1-ton rover is scheduled to land on Mars in August 2012. NASA plans to use it for about two years to examine the Gale crater in a target area with a size of 12.4 by 15.5 miles and "investigate whether environmental conditions ever have been favorable for development of microbial life and preserved evidence of those conditions."
NASA said that the mission is "challenging and risky." Other than its predecessors, Curiosity cannot land on Mars' surface with the aid of an air-cushion. Instead, the rover will use more sophisticated rocket-powered descent stage, which will lower the rover "on a tether like a kind of sky-crane." NASA's Spirit Mars rover was active between 2004 and 2010; Opportunity is still operational and has exceeded its originally planned lifetime of roughly 90 times more than 30 times.