Atlas V

Lockheed Martin * United Space Alliance * International Launch Services

In order to meet commercial and U.S. government launch service requirements in the next century, Lockheed Martin is developing the Atlas V series of launch vehicles. The Atlas V will use the RD-180 first stage engine and the Centaur design from Atlas III, in conjunction with a new first-stage design called the common core booster (CCB). three basic varieties of the Atlas V will be available.
The Atlas V 400 version use the same 4-m diameter class fairing as the Atlas III. The Atlas V 500 versions have a new 5-m diameter payload fairing, and can have up to 5 solid strap-on boosters for increased performance. The Atlas V HLV (Heavy-lift Launch Vehicle) uses two additional CCBs like the first stage as liquid strap-on boosters. The Atlas V 500 and HLV will have the capability to deliver payloads directly into GEO.

Nomenclature Atlas V:
    first digit         Approximate payload fairing diameter in meters
    second digit   Number of strap-on boosters
    third digit        Number of engines on Centaur upper stage

The Atlas V variants have the following payload capabilities (*up to now used):

The Atlas V first-stage structure will be completely redesigned. In the CCB the stainless steel pressure-stabilized tanks are replaced by structurally stable aluminum isogrid tanks with a larger diameter of 3.8 m (12.5 ft.). The total stage length is increased, and instead of sharing a common bulkhead the tanks are independent. Two interstage assemblies are added to the top of the CCB, with different configurations depending on the payload fairing size. For the Atlas V 400, a conical 0.450 t graphite-epoxy interstage adapter provides the interface between the larger diameter first stage and the smaller diameter Centaur. A 0.375 t aluminum-lithium Centaur interstage adapter on the top of the CCB supports the upper stage. To interface with the larger fairing of the Atlas V 500 series, a short cylindrical 0.270 t booster interstage adapter is used. This is topped by a 1.30 t composite-sandwich Centaur interstage adapter.
When used inside the 5-m payload fairing of the Atlas V 500 or HLV, the upper stage Centaur can be modified to support injection directly into GEO. The short and medium length fairing (20.7/23.4 m) are available for the Atlas V 500, while the long fairing (26.4 m) is designed for the Atlas HLV.
The Atlas V 500 strap-on solid rocket motor is a new design produced by Aerojet. Atlas V 500 can fly with zero to five of strap-on boosters. All boosters are ignited at liftoff and are jettisoned in pairs after burnout.