Boeing will produce up to six upper stages per year during regular production, depending on NASA requirements. The initial phase of the contract calls for several flight-test production units. If all options of the cost-plus performance contract are exercised through 2017, Boeing could produce as many as 23 upper stages.
Ares I is an in-line, two-stage rocket that will carry to low Earth orbit the crew exploration vehicle Orion, which will succeed the space shuttle as NASA’s primary vehicle for human exploration in the next decade.
The Ares I upper stage, with an engine and an avionics unit procured separately, will provide the navigation, guidance, control and propulsion required for the second stage of the rocket’s ascent.
The Ares I first stage will consist of a five-segment solid rocket booster and motor similar to those used on the space shuttle.
The second, or upper, stage will consist of a J-2X main engine, a fuel tank for liquid oxygen and liquid hydrogen propellants, and associated avionics.