Monopropellant-Electrospray Multimode Thruster Testing Results: Electrospray Mode

Christopher T. Lyne, Joshua L. Rovey, Steven P. Berg

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Multimode propulsion is the combination of two or more propulsive modes into a system that shares a single propellant, providing more flexibility than traditional propulsion systems. We report for the first time the electrospray operation of a multimode microthruster that can be switched between chemical monopropellant and capillary electrospray modes. We also demonstrated for the first time that the multimode propellant FAM-110A (59% wt. HAN, 41% wt. [Emim][EtSO4], <1% H2O), which was specifically designed for multimode monopropellant-electrospray propulsion, can be stably electrosprayed from a multi-emitter capillary thruster. Using a six-emitter subset of the thruster, stable electrospray operation is demonstrated for 10+ hours using the conventional ionic liquid propellant Emi-Im, and for 4+ hours using multimode propellant FAM-110A. Retarding potential analysis of the Emi-Im plume shows that the energy profile is nearly identical to that of similarly-sized single capillary emitters in the literature, implying that the thruster is operating in the mixed ion-droplet regime. The effects of hydraulic impedance on electrospray operating regime are briefly discussed. A simple analysis of capillary electrospray thrusters in the literature suggests that an emitter hydraulic impedance of Z > 1016 Pa-s/m3 is required to reach sufficiently low flow rates to suppress droplet emission.

Original languageEnglish (US)
Title of host publicationAIAA Propulsion and Energy Forum, 2021
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624106118
StatePublished - 2021
EventAIAA Propulsion and Energy Forum, 2021 - Virtual, Online
Duration: Aug 9 2021Aug 11 2021

Publication series

NameAIAA Propulsion and Energy Forum, 2021


ConferenceAIAA Propulsion and Energy Forum, 2021
CityVirtual, Online

ASJC Scopus subject areas

  • Energy(all)
  • Aerospace Engineering
  • Control and Systems Engineering
  • Electrical and Electronic Engineering
  • Mechanical Engineering


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