Electric Propulsion Characterization for a Stand-Alone Mars CubeSat

Abstract

Stand-alone CubeSat missions to Mars that escape Earth and experience a deep-space cruise require robust primary propulsion systems for orbit manoeuvring and precise trajectory control. Combined chemical{electric propulsion systems enable a hybrid high-thrust{ low-thrust transfer from a high energy Earth orbit to Mars. High-thrust chemical propulsion is used for Earth escape and the low-thrust electric propulsion is used in deep-space cruise, ballisitic capture, and final circularization to an operational orbit about Mars. This work focuses on the performance and design characterization of an iodine-propelled electric propulsion system, concomitant with low-thrust trajectory optimization of the heliocentric transfer and ballistic capture at Mars for a 16U stand-alone CubeSat. A performance model of an inductively coupled miniature ion thruster is implemented to calculate thrust, speci_c impulse, and e_ciencies. A power-constrained low-thrust optimal control problem utilizing the thruster performance is solved to calculate the trajectory, ight time, _V , and the propellant consumption for time-optimal and fuel-optimal strategies.