Interaction of charged spacecraft with electric propulsion plume: On orbit data and ground test results

On-orbit observations and ground tests demonstrate interaction between charged spacecraft and electrothermal thruster-generated plasma. On-orbit measurements and test results are presented for plasma diagnostics and solar array performance during long-term exposure of flight solar panel. The long-term performance of a flight 70V 2m x 4 m GEO solar array exposed to a 2 kW arcjet plasma environment was studied.