Multi-Mode Micropropulsion

This project will further development of a thruster capable of both chemical monopropellant and electrospray propulsion using a single "green" ionic liquid propellant. the thruster concept consists of an integrated microtube/electrospray thruster that shares all propulsion system hardware between electric and chemical thruster modes, i.e. one propellant, one propellant tank, one feed system, and one thruster. Thus, the thruster is not significantly more massive than a standalone state-of-the-art chemical or electric thruster, but capable of either thrust mode and selectable as mission needs arise. This has several benefits, including the optimization of trajectories using both chemical and electric thrust manuevers as well as a significantly increased mission design space for a single propulsion unit. The propulsion system is capable of both high impulse per unit volume and high thrust per unit volume as the total impulse per unit volume is 1500 N-s/U in the chemical thrust mode and 2750 N-s/U in the electric thrust mode, where either type of manuever could be selected on-the-fly. Operation and high performance in both modes has previously been demonstrated at the single emitter level. The specific objectives for this study are to design and build a cubesat sized multi-emitter thruster and test in both chemical and electrospray modes of operation. Two thrusters will be built and separate chemical and electric thrusters tested in parallel. Then, back-to-back operation of a single thruster will be demonstrated and indirect and direct performance measurements will be acquired. Additionally, the development of the multi-mode monopropellant will be furthered through material compatibility tests and hazard classification. Finally, system level items including PPU and and feed system components will be researched and selected and/or designed.