Voltage Threshold and Power Degradation Rate for GPS Solar Array Arcing

Abstract

We present here an investigation of the arcing voltage threshold for GPS-like arrays performed in the Spacecraft Charging and Instrument Calibration Laboratory at the Air Force Research Laboratory’s Battlespace Environment Laboratory at Kirtland Air Force Base, New Mexico, USA. Our simulations were done under GPS-like plasma environments in a vacuum-plasma chamber. The arc voltage threshold found is compared with that predicted from the Los Alamos National Laboratory (LANL), detectors, and the question of to what degree were the indium tin oxide-coated cells on GPS properly grounded is discussed. It is shown through the current–voltage testing of the arrays pre- and postarcing that the anomalous power degradation seen on GPS satellites on orbit can be completely accounted for by arcing at the anomalous event rates seen by LANL radio frequency detectors onboard. Implications for arcing and contamination mitigation on future GPS satellites are presented.