Performance Characterization of Electrospray Thrusters with Energetic Ionic Liquid Monopropellant

Abstract

This work characterizes a passively fed porous electrospray thruster firing Advanced Spacecraft Energetic Non-Toxic propellant (ASCENT, formerly AF-M315E), an energetic ionic liquid monopropellant. Results on thruster current–voltage characteristics, angular beam divergence, plume energy spectra, plume mass spectra, direct thrust measurements, and long-duration testing are reported. The propulsive performance is assessed via indirect and direct methods across multiple units. ASCENT is found to provide a thrust-to-power ratio of [Formula: see text], a specific impulse of 600 s, and a total efficiency of 15%. The direct and indirect measurements of mass flow rate show significant disagreement, suggesting the presence of additional mass loss mechanisms. No failure modes, significant current decay, or degradation was observed over multiple thruster units up to [Formula: see text] firing time. These data can be used to advance the development of an ASCENT-fueled multimode chemical-electrospray propulsion system.