NASA began planning MSL's mission in 2003. Over the past eight years, scientists and engineers developed, built and tested Curiosity, a robotic behemoth that will take planetary exploration to a new level.
At 1 ton, Curiosity weighs five times more than each of its immediate Mars rover predecessors, the golf-cart-size twins Spirit and Opportunity, which landed on the Red Planet in January 2004 to search for signs of past water activity.
While Spirit and Opportunity each sported five scientific instruments, Curiosity boasts 10, as well as a drill that will allow it to access the interior of Red Planet rocks.
The huge rover will use all of this gear to gauge the past and present habitability of its Martian environs. It will look for carbon-containing compounds — the building blocks of life as we know it — and assess what the Red Planet was like long ago.
MSL is not a life-detection mission, but it will lay the foundation for future efforts that could hunt for evidence of microbial Martians, officials said.
"We bridge the gap from 'follow the water' to seeking the signs of life," said Doug McCuistion, head of NASA's Mars exploration program.