Advanced bipropellant engines are needed for ARES/ORION vehicle maneuvering and future deep space science missions. Currently, an iridium-lined rhenium combustion chamber is the state-of-the-art for in-space propulsion applications. An example of an in-space engine that incorporates an iridium-lined rhenium thruster is Aerojet's HiPAT apogee engine. This engine uses monomethyl-hydrazine (MMH, CH3N2H3) as fuel and nitrogen tetroxide (N2O4, specifically MON-3) as oxidizer. To increase performance of bipropellant engines, improved chamber materials are needed that will allow higher operating conditions (pressure and temperature) and better resistance to oxidation. Therefore, Plasma Processes, Inc. and its partner, Aerojet, propose to develop hafnium oxide-iridium lined rhenium combustion chambers that will simplify engine design and allow higher operating conditions. As a result, a lower cost, higher performance bipropellant space engine will be produced.