Launch Vehicle
A launch vehicle provides the velocity needed by a spacecraft to escape Earth's gravity and set it on its course for Mars.Rovers Launched on Delta II Rockets
When mission planners are considering different launch vehicles, what they take into consideration is how much mass each launch vehicle can lift into space. The Boeing Delta II launch vehicle was selected for the Mars Exploration Rover mission because it has the right liftoff capability for the weight requirements and because it's extremely reliable.The Delta II family of launch vehicles has been in service for over 10 years and has successfully launched 90 projects including the last six NASA missions to Mars: Mars Global Surveyor and Mars Pathfinder in 1996, Mars Climate Orbiter in 1998, Mars Polar Lander in 1999, Mars Odyssey in 2001, and Phoenix Mars Lander in 2007.