Full-scale models of three generations of NASA Mars rovers show the
increase in size from the Sojourner rover of the Mars Pathfinder project
that landed on Mars in 1997 (center), to the twin Mars Exploration Rovers
Spirit and Opportunity that landed in 2004 (left), to the Mars Science
Laboratory rover for a mission to land in 2010 (right).
The Mars Science Laboratory rover is about 9 feet wide, 10 feet long (not
counting its robotic arm) and 7 feet tall.
This image was taken in May 2008 at NASA's Jet Propulsion Laboratory,
Pasadena, Calif., which has built the real Mars rovers and managed the
rover missions for NASA's Science Mission Directorate, Washington. JPL is
a division of the California Institute of Technology.