Characterization of the T-series hollow cathode thrusters for all-electric spacecraft

This paper presents the Phase A study of the Solar Electric Propulsion subsystemselected for the ESA European Student Moon Orbiter enhanced microsatellite, performed atQinetiQ under ESA funding. To minimise mass, a so-called "all electric" approach isadopted based around the re-use of the GOCE T5 gridded ion engine and the introduction ofHollow Cathode Thrusters (HCTs) for attitude control functions. Three different subsystemarchitectures are considered and analyzed with reference to the mass, cost, risk and level ofintegration between the HCTs and the T5. The favoured system architecture that best meetsthe various requirements adopts a shared tank and gas flow controller between the HCTsand the T5, with power being supplied from two dedicated power processing units. Thepossibility of reducing the propellant requirement by using an engine gimbal mechanism isalso presented. The study also demonstrates how an increase in the T5 specific impulse tohigher values than used on GOCE does not offer substantial system-level mass savings inthis particular case