Storable Clean Ethane/ethylene Nitrous Engine (SCENE)

he Storable Clean Ethane-ethylene Nitrous Engine (SCENE) is a proposed technology designed to provide upper stages and spacecraft with non-toxic, liquid, non-cryogenic, high-performance propulsion with an Isp on the order of 300 seconds. The propellant components are stored as liquids under their saturated vapor pressures. With the SCENE, nitrous oxide is used as an autogenously pressurized oxidizer, and a mixture of ethane and ethylene is used in the same manner as fuel. Ethane-ethylene mixtures of about 50-50 have the same vapor pressure-temperature curve as nitrous oxide, allowing for lightweight common-bulkhead isothermal tanks. By utilizing the autogenous pressurization capabilities of these propellants instead of an additional pressurization system, greater system simplicity and reliability can be attained. The non-corrosive, stable characteristics of the proposed nitrous oxide and ethane-ethylene propellant components, along with their compatibility with military air transportation requirements, result in a high-performance, green propellant solution for air launch/air transportable liquid upper stages as well as orbit transfer vehicles. Approved for Public Release | 19-MDA-9932 (21 Feb 19)