An update on BUAA nitrous oxide micro-thruster research

Nitrous oxide (N₂O) has been suggested as a promising propellant for its storable, non-toxic, self-sustaining and multi-mode propulsion properties. The objective of the research at Beijing University of Aeronautics and Astronautics (BUAA) is to develop a sub-Newton-thrust micro propulsion system based on the monopropellant catalytic decomposition of N₂O for fine attitude control of small spacecraft. After the proof-of-the-concept study and preliminary design of the micro propulsion system, current research focused on the restartable N₂O catalytic thermal decomposition as well as the MEMS control valve to meet the system requirements in detail. For this purpose a new ground test stand facility, equipped with propellant feed system and data acquisition systems, was built at BUAA to test the N₂O micro-thruster. Experiments, simulations, and design optimizations upon the micro-thruster with catalyst bed and the MEMS valve were thus implemented and evaluated respectively to improve the achieved static performance, such as the high decomposition and self-sustaining temperature, the little opening time delay, and etc. The latest research results would be presented and discussed in this paper. Further research is suggested to lower the total propulsion system power mainly for the MEMS valve and the catalyst heater, as well as to conduct the operational test on the N₂O micro-thruster along with the control valve to achieve accurate impulse bits.