A launch vehicle provides the velocity needed by a spacecraft to escape Earth's gravity and set it on its course for Mars.

Mars Science Laboratory Will Launch on an Atlas V 541

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 Atlas V 541 vehicle was selected for the Mars Science Laboratory mission because it has the right liftoff capability for the heavy weight requirements and rockets in the same family have successfully lifted NASA's Mars Reconnaissance Orbiter and New Horizons missions.

Details on the Launch Vehicle

Atlas V rockets are expendable launch vehicles (ELVs), which means they are only used once.

The major elements of the Atlas Rocket that will be used for the MSL mission are:

Stage I: Fuel and oxygen tanks that feed an engine for the ascent; powers spacecraft into Earth orbit

Solid Rocket Motors: Used to increase engine thrust; 4 total

Stage II: Fuel and oxidizer and the vehicle's "brains"; fires twice, once to insert the vehicle-spacecraft stack into low Earth orbit and then again to accelerate the spacecraft out of Earth orbit and on its way towards Mars

Payload Fairing: Thin metal shroud or nose cone to protect the spacecraft during the ascent through Earth's atmosphere