Contamination assessment of 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 these systems already orbit, characterizing their contamination potential a space environment becomes relevant. In this paper we discuss experiments on plume induced from novel propene/nitrous oxide bipropellant thruster, including high-speed imaging, SEM-EDS analysis, QCM measurements and in-situ mass spectrometry. Additional combustion chamber pressure complement overall characterization thruster performance high vacuum environment. The main findings exploratory study strong indications solid liquid phase particles being ejected nozzle, which will be investigated subsequent activity.