Initial results of BUAA nitrous oxide micro-thruster research

This paper presents some initial results of the research at Beijing University of Aeronautics and Astronautics (BUAA), P. R. China, promoting development of micro-thruster using nitrous oxide as monopropellant for application onboard small spacecraft. In the first phase of the research, preliminary scheme and primary design parameters were described for a sub-Newton-thrust micro propulsion system based on the monopropellant catalytic decomposition of nitrous oxide. The numerical simulation was used to analyze the decomposition product thermodynamic properties, the flow field of inner nozzle for the thruster in vacuum, and its vacuum plume, respectively. On the other hand, experiments of nitrous oxide catalytic decomposition and self-sustaining were conducted. Complete thermal dissociation of nitrous oxide was observed at catalyst preheat temperatures of about 523 K. The effect factors of the micro-thruster performance were thus discussed based on the experimental results. Although the results are not conclusive because of the small initial test set, preliminary numbers suggest the feasibility of the proposed concept of nitrous oxide monopropellant micro-thruster, and the future design will greatly benefit from the experiences as well.