Orion Propulsion, Inc. proposes to develop an Oxygen and Methane RCS Thruster to advance the technology of alternate fuels. A successful Oxygen/CH4 RCS Thruster will also be new reaction control engine that integrates readily with integrates readily with primary propulsion by using the same propellants. Orion has a developed a preliminary design of an Oxygen / Methane (O/M) RCS Thruster, and our purpose is to contribute to NASA Space Exploration goals by increasing the technology readiness of oxygen/methane rocket systems. Orion has demonstrated the current development status of our thruster with some 40 firings at sea level. The objective of the Phase 1 R&D would be to improve credibility of its design by testing another prototype test article, which is equipped with a flight type nozzle and propellant valves. These tests would be performed in a environmental chamber at reduced pressure to simulate space vacuum conditions. Although, the O/M Thruster test article would be constructed of stainless steel, its interior would be coated with a refractory metal alloy. This treatment enables the test article to sustain higher temperatures and enables longer tests. The expected result of a Phase 2 effort would be a flight-ready prototype thruster for delivery to NASA.