In this February 17, 2009, image, NASA's Mars Science Laboratory rover is attached to the spacecraft's descent stage. The image was taken inside the Spacecraft Assembly Facility at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

This is the way the spacecraft will look after it comes out of its protective aeroshell and is descending to the Martian surface in 2012. Here, the descent stage sits on top of the rover, with its eight main engines straddling the rover structure. The rover is the big white box below the descent stage. At this point, the rover lacks its appendages (robotic arm, mast and most wheels), as these elements are still being assembled and were not needed for space-simulation testing of the spacecraft in late 2008.