Sacramento, Calif.-based Aerojet said Nov. 22 that it successfully completed vibration, shock and hot-fire design verification testing on its first MR-104G monopropellant thruster planned for use on NASA’s Orion Multi-Purpose Crew Vehicle (MPCV).

Twelve of the hydrazine-fueled, 160-pound thrust MR-104G engines are needed to provide primary and redundant control for Orion during atmospheric re-entry. The engines will be arranged in four single-engine pods and four dual-engine pods.

Doug Cosens, deputy for Aerojet’s space and launch systems business unit, said in a Nov. 23 interview that completion of the design verification testing keeps the company on track to deliver the flight-ready MR-104G pods to Orion prime contractor Lockheed Martin Space Systems by mid-2012 to support a 2014 unmanned test flight of the Orion crew module, which NASA recently announced would launch atop a United Launch Alliance Delta 4 Heavy rocket.

While the Orion MPCV will be equipped with its aft-mounted service module for the 2014 test flight, it will not carry any of the propulsion elements Aerojet is developing for it. Cosens said work on those propulsion elements, which include a 7,500-pound thrust main engine and numerous steering thrusters, has been put on the back burner as the Orion team focuses on the 2014 mission, dubbed the Exploration Flight Test-1.