Atlas V 500 Series
The Atlas V 500 series launch vehicle extends the capability of the Atlas V with the addition of a 5-meter diameter (4.57-meter usable diameter) payload fairing (with three length options) and solid rocket boosters. A dual-engine Centaur configuration provides additional performance capabilities for low to intermediate orbits. Performance of the 500 series vehicles can be tailored by incorporating up to five solid rocket boosters.
Characteristics
Total liftoff mass: 333,298 kg (734,800 lbm)
Total length: 59.7 m (195.9 ft) with short Contraves payload fairing
|
Atlas |
Centaur |
| Length |
32.46 m (106.5 ft) |
12.68 m (41.6 ft) |
| Diameter |
3.81 m (12.5 ft) |
3.05 m (10 ft) |
| Propulsion |
One RD-180 (two chambers) |
One or Two RL10A-4-2 |
| Thrust |
3.82 MN (860 klb) - 100% SL |
99.2 kN (SEC)* 198.4 kN (DEC) |
| Inert Mass |
21,173 kg (46,678 lb) |
1,914 kg (4,220 lb) (SEC) 2,106 kg (4,693m lb (DEC) |
| Propellant Mass |
284,089 kg (626,309 lb) |
20,830 kg (45,920 lb) |
*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 500 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. All solid rocket boosters are ignited at liftoff. The vehicle flight control system controls ascent and manages RD-180 throttle settings through the atmosphere toward orbit.
The engine throttles down for the transition through Max Q, and then returns to full thrust. Just over 100 seconds into flight, as the booster propellants are consumed, the engine begins to throttle to limit acceleration to 4.6 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 ten minutes (single engine configuration) after which the Centaur and its payload coast in a parking orbit.
The payload fairing is jettisoned during booster operation, approximately 210 seconds into the flight. The second Centaur ignition occurs about 23 minutes into the flight, continues for about five minutes, and is followed several minutes later by the separation of the spacecraft from Centaur.
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