Nitrous Oxide Ethane Ethylene Engine

The Nitrous Oxide Ethane-Ethylene (NEE) engine is a proposed technology designed to provide spacecraft with non-toxic non-cryogenic high-performance propulsion. With the NEE engine, nitrous oxide is used as an autogenously pressurizing oxidizer, and a mixture of ethane and ethylene is used in the same manner as fuel. Initially, the ethane and ethylene mixture have the same vapor pressure as the nitrous oxide. By utilizing the autogenous pressurization capabilities of these propellants instead of an additional pressurization system greater system simplicity and reliability can be attained. Achievable specific impulse with pure N2O is about 315 s, which can be raised above 325 s by dissolving some O2 in the N2O. Catalytic ignition can be achieved by using a ruthenium reactor to exothermically dissociate N2O. Since both propellants can exist as a liquid in the same temperature range, no thermal separation is required, and the two propellants can be stored together in compact common bulkhead tanks, and freezing is not an issue down to -90C. Pioneer Astronautics has demonstrated monopropellant nitrous oxide thrusters with a specific impulse of 190 s. Using such nitrous oxide monopropellant engines for low thrust RCS together with the NEE for ??V and larger thrust reaction control propulsion, it will be possible to build spacecraft propulsion systems that are completely storable and non-toxic, with only two propellant fluids required. In the proposed program, we will demonstrate a NEE engine.