Multimode space propulsion systems are being proposed that integrate high specific impulse electric propulsion and high thrust chemical propulsion. The most important attribute of this concept is a shared propellant capable of both modes of propulsion, which enables mission flexibility. One promising ap-proach is a catalytic monopropellant thruster paired with an electrospray electric thruster. Previous re-search has identified a green double-salt ionic liquid consisting of 41% wt. 1-ethyl-3-methylimidazolium ethyl sulfate and 59% wt. hydroxylammonium nitrate as a promising propellant candidate. In this work, the burn rate of this monopropellant is measured through pressure-based and high-speed imaging meth-ods in a fixed-volume chamber pressurized across a pressure range from 0.5 to 10 MPa. Its performance is benchmarked by 80% wt. hydroxylammonium nitrate-water and nitromethane propellants. The burn rate of the multimode monopropellant is found to follow an exponential law given by r(b) = -5 . 35 exp 1 . 11 P between 0.5 and 3 MPa and is approximately constant at 142 +/- 29 mm/s between 3 and 10 MPa. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.