Full Scale Oxygen Rich Combustion Thrust Cell for Ejector Ramjets

New air-breathing propulsion systems are being considered for space launch applications. A Rocket Based Combined Cycle engine with near term potential is the hydrocarbon fueled, subsonic combustion, Ejector-Ramjet (ERJ) using liquid oxygen and liquidmethane propellants. In this engine, one of the highest risk components is the ejector system. This program will develop a thrust cell for the ejector of this type of engine that will operate at 2,000 psia chamber pressure and at a mixture ratio of 9:1.The overall technical objectives of this program are to demonstrate the ability a thrust cell to achieve more than 100 cycles of life when operating at full thrust and with oxygen rich combustion gases. The program will also demonstrate the ability of thespecial exhaust mixing design to provide short mixing lengths by testing two thrust cells side by side. The successful demonstration of these objectives will demonstrate the feasibility and durability of the thrust cells. It will also form the basis ofsubsequent programs testing a complete ejector ring of thrust cells to verify the performance of a complete ejector ramjet engine. Successful completion of the program will form the basis of for development of a full scale ejector ramjet engine using hydrocarbon fuels. The successful completion of the program will also demonstrate the capability to operate high pressure rocketcombustion chambers at oxygen rich mixture ratios, providing the technology base to operate a rocket engine in multiple modes: oxygen rich at launch to maximize thrust and density specific impulse and fuel rich later in the rocket's trajectory to maximizespecific impulse for maximum payload.