An unmanned Atlas 5 rocket carrying a $2.5 billion NASA Mars probe lifted off from Cape Canaveral Air Force Station on Saturday, Reuters reported. The Mars Science Laboratory, a nuclear-powered rover as big as a compact car and nicknamed Curiosity, is scheduled to touch down on the 'Red Planet' on Aug. 6, 2012, and will search for signs of whether it is or ever was suitable for life. -- SPA