The Atlas V 400 series launch vehicle incorporates a Common Core Booster stage and uses the Centaur upper stage and 4-meter diameter payload fairing developed for the Atlas II and Atlas III families. A dual-engine Centaur configuration provides additional performance capabilities for low to intermediate orbits. Performance of the 400 series vehicles can be tailored by incorporating up to three solid rocket boosters (SRB).

Characteristics
Total liftoff mass: 333,298 kg (734,800 lbm)
Total length: 58.3 m (191.3 ft) with extended length payload fairing

*Single Engine Centaur = SEC Dual Engine Centaur = DEC
The solid rocket boosters each have a fueled mass of approximately 46,494 kg (102,502 lb) and develop a thrust in excess of 1.36 MN (306,173 lb).

Launch Sequence
In a typical Atlas V 400 series launch, the vehicle's two RD-180 thrust chambers are ignited shortly before liftoff. Upon a successful verification of engine health, the RD-180 engine is throttled up to near 100% of rated thrust and the vehicle flight control system controls ascent through the atmosphere toward orbit. For the Atlas V 400 series employing solid rocket boosters, the SRBs are ignited at liftoff.

Just over 100 seconds into flight, as the booster propellants are consumed, the engine begins to throttle to limit acceleration to 5.5 g's. Booster engine cutoff occurs just over four minutes into flight and is followed by separation of Centaur from Atlas. The first Centaur burn lasts about eleven minutes (single engine configuration) after which the Centaur and its payload coast in a parking orbit.

Approximately 259 seconds into the flight, the payload fairing is jettisoned. The second Centaur ignition occurs about 22 to 25 minutes into the flight, depending on mission profile, and continues between four and six minutes. It is followed several minutes later by the separation of the spacecraft from Centaur.