XENON RESISTOJETS AS SECONDARY PROPULSION ON EP SPACECRAFTS AND PERFORMANCE RESULTS OF RESISTOJETS USING XENON

Solar electric propulsion based on Xenon propellant (ion or plasma thrusters) is being adopted as the main propulsion system for an important number of ESA scientific missions. Secondary propulsion systems such as resistojets commonly use different propellants such as methane, ammonia, and hydrazine, but since the total momentum required for attitude control by these missions is in general relatively low, important mass savings could be achieved by eliminating independent tanks for the secondary propulsion system. This paper will discuss the potential of this technology, showing how realistic performances would allow it to be competitive in the AOCS (Attitude and Orbital Control System) trade-offs of current, future and candidate ESA missions like SMART-1, Bepi-Colombo and Mars Exobiology. This paper also presents performance test results of two existing SSTL resistojet thrusters using Xenon as propellant, performed in the ESA Electric Propulsion Laboratory.