Orion Propulsion Inc. (OPI) of Huntsville, Alabama, successfully completed the first series of tests on a 445-newton oxygen/methane RCS thruster in September 2005. Orion designed, manufactured, and tested this thruster, which accommodated an OPI-developed acoustic igniter and spark igniter. Over 40 firings of this gas-gas propulsion system were performed with a total of 90 seconds testing time.

This engine offered many advantages over existing RCS thrusters, including flexibility, reusability, affordability, and high performance. The engine could also burn methane that was mined during Mars In-Situ missions, or stored on long-term orbit missions. OPI has begun planning for testing the thruster with a space nozzle. The company expected to qualify the engine to burn a variety of easily stored propellants, including propane/nitrous oxide, ethane/nitrous oxide, and hydrogen/oxygen.

Orion and HMX Inc. planned to jointly develop a product line based on this flexible engine design. The first application was to be the t/Space CXV human spaceflight vehicle for NASA. Orion performed the testing at its facility near Huntsville, Alabama.