Car commercials put their vehicles in the most improbable of places: sides of cliffs, tops of rock pillars, middles of deserts. But NASA is about to outdo them all. In 2010 it plans to land a Mini Cooper on Mars--or more precisely, a rover of about the same size and weight. And it plans to do so using a procedure never before seen in spaceflight: piloting the craft to its landing site using its entry capsule like a hypersonic flying wing, then hovering above the ground and lowering the buggy down on a long rope. "They have a very cool system," comments another rover builder, Jorge Vago of the European Space Agency.

Engineers were driven to their audacious--and not entirely uncontroversial--approach by the sheer size of the $1.5-billion Mars Science Laboratory (MSL). It outweighs by more than four times the go-cart-size Spirit and Opportunity rovers now prowling the Red Planet. Its enclosing capsule, measuring 4.5 meters across, will be bigger than even the Apollo command module was (at 3.9 meters). "We will be the biggest heat shield ever to enter an atmosphere," says Adam Steltzner of the Jet Propulsion Laboratory, who leads the team designing the entry, descent and landing sequence for the mission.