2000-hour endurance test of indium field emission electric propulsion microthruster cluster

Abstract

An indium field emission electric propulsion (In-FEEP) thruster was recently selected as a micropropulsion candidate for ESA's Gravity Field and Steady-State Ocean Circulation (GOCE) mission. Within a pre-verification phase, a cluster of two In-FEEP thrusters successfully completed a 24 h endurance test. This is the longest endurance test ever performed for field emission thrusters. Although the test did not include a neutralizer, the results show stable and good performance and suggest that lifetime is mostly limited by the propellant reservoir tank size. This information is very important for many upcoming missions that require ultraprecise drag-free control such as GOCE, LISA, Terrestrial, Planet Finder/Darwin or SMART-2.