Lunar SmallSat Missions with Chemical-Electrospray Multimode Propulsion

Abstract

Multimode spacecraft propulsion combines two or more propulsive modes into a single system using a single propellant. In this study, a multimode system combining a monopropellant chemical decomposition mode with an electric electrospray mode is considered for specific NASA-relevant lunar small satellite missions. This multimode concept is compared to all-chemical and all-electric approaches for four design reference missions (DRMs) in terms of feasibility, propellant mass consumed, and transfer time. Point solution trajectories are developed using NASA’s General Mission Analysis Tool for each propulsion system. This is the first study to consider this multimode concept for specific missions with high-fidelity force modeling. The results demonstrate the multimode approach can complete three of the four DRMs within the allotted propellant budget, while the all-chemical approach fails to complete two DRMs and the all-electric system fails to complete one DRM. Across the three feasible DRMs, the multimode approach completes the mission in 11–55% less time than the all-electric approach while consuming up to 33% less propellant than the all-chemical approach. The number of switching events and the minimum required mode switching time are quantified for the first time, with the latter having values between nearly instantaneous and 112.5 days, depending on the mission.