Electric propulsion interactive effects with spacecraft science payloads.

Interactive effects between electric thruster units and a Solar Electric Pioneer (SEP) spacecraft science payload are investigated. Studied effects include magnetic contamination (steady state), electric contamination (steady state and time varying) and particle contamination of regions in and around the spacecraft. Conducted electromagnetic interference is measured for thrusters powered with prototype power processing units and radio frequency interference effects between the thruster and the omnidirectional low gain antenna are determined. Material deposition and transport of thruster propellant ions and atoms and charge exchange metal ions and atoms are also experimentally determined. Large scale environmental effects between the plasma thrust beam and the particles and fields in interplanetary space are discussed. Contaminant reduction techniques are proposed, and both laboratory and in-space interactive effects tests are suggested.