Boeing is to produce the upper stage of NASA's Ares I crew launch vehicle, giving the company a role in US space agency's Constellation exploration systems programme.

Boeing was selected over Alliant Techsystems to support NASA-led design of the upper stage then be responsible for production.

The almost $515 million cost-plus contract covers design support and manufacture of a ground test article, three flight-test units and six production upper stages to support NASA's Ares I flight manifest to the end of 2016.

Ares I upper stage

ATK, already under contract to develop and produce the first stage derived from the Space Shuttle solid rocket booster, led a team that included Lockheed Martin - prime contractor for the Orion crew exploration vehicle that will be launched by the Ares I. Its team also included Pratt & Whitney Rocketdyne, already under contract to develop the J-2X liquid oxygen/liquid hydrogen upper-stage engine.

Boeing's team includes Hamilton Sundstrand, Moog, Northrop Grumman, Orion Propulsion, Summa Technology, United Space Alliance and United Launch Alliance.

NASA is competing the Ares I avionics separately, with a contract award expected by year-end.

Boeing expects to produce from two to six upper stages a year to meet NASA launch requirements, and says it could build as many as 23 upper stages by the end of 2017 if all contract options are exercised.

Under the contract, Boeing says it will employ "several hundred technical support personnel" at NASA Marshall Space Flight Center in Alabama to assist with design of the upper stage, and "several hundred production support personnel" at NASA Michoud Assembly Facility in Louisiana where the upper stages will be assembled.