While the Spirit and Opportunity rovers wheel themselves into the history books of Mars exploration, get ready for the next giant leap in rolling across the red planet. The Mars Science Laboratory is an all-terrain, all-purpose machine, akin to an extraterrestrial Sport Utility Vehicle. To be rocketed toward Mars in 2009, this long-range, long-duration robot is a trend setter. It will scope out Mars like never before to assess that puzzling planet as a potential habitat for life — past or present — and help verify if human explorers could exist there in the future.