ENVIRONMENTALLY-INDUCED DISCHARGES ON SOLAR-ARRAYS IN GEOSYNCHRONOUS ORBIT

An analysis into the conditions necessary for environmentally-induced inverted voltage gradient discharges in geosynchronous satellite solar arrays is conducted. This analysis shows that fused silica coverglass arrays can discharge in encounters with high current density, moderate energy substorms. Discharges can also occur in a relaxation phase of a standard design substorm environment. After six months in space, when the Kapton thermal blankets photodegrade to become quasi-conductive, only a very severe substorm environment encounter will produce the conditions necessary to trigger discharges, Analysis based on lumped element modelling Of the spacecraft indicates that the structure ringing persists longer than the discharge pulse. Ceria doped coverglass arrays discharge only after Kapton thermal blankets age.