Composition measurements in a freely expanding green propellant thruster plume

Abstract

A number of propellant/thruster combinations are under development in recent years that aim to replace the prevailing hydrazine-driven reaction control thrusters with less hazardous substances (“green propellants”). With some of these systems already in orbit, characterizing their contamination potential in a space environment becomes relevant. In this paper we discuss experiments on plume induced contamination from a novel propene/N2O bipropellant thruster, including high-speed imaging and SEM-EDS analysis. Additional measurements of pitot probe and combustion chamber pressure complement the overall characterization of the thruster performance. The main findings of this exploratory study are strong indications of solid and liquid phase particles being ejected from the nozzle, which will be investigated in a subsequent phase of the activity.