The Boeing 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 in 1996
- Mars Pathfinder in 1996
- Mars Climate Orbiter in 1998
- Mars Polar Lander in 1999
- Mars Odyssey in 2001
- Mars Exploration Rovers (MER-A and MER-B) in 2003
- Solid rocket motors: Used to increase engine thrust; 9 total, 6 of which are lit at liftoff, 3 a minute into flight
- Stage I: Fuel and oxygen tanks that feed an engine for the ascent
- 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 orient the third stage prior to it firing
- Stage III: Solid rocket motor provides the majority of the velocity change needed to leave Earth orbit and inject the spacecraft on a trajectory to Mars; connected to the spacecraft until done firing, then separates
- Payload fairing: Thin metal shroud or nose cone to protect the spacecraft during the ascent through Earth's atmosphere