A New Model for Plasma Interactions With High-Voltage Solar Arrays on the International Space Station

Recent data from the floating potential measurement unit (FPMU) on board the International Space Station have revealed floating potential transients that occur during certain high-voltage solar array operations. These transients are not well understood and are not predicted by the existing spacecraft-plasma interaction models. Herein, a new model is developed, which incorporates the important plasma interactions with dielectric surfaces that are believed to be the cause of these transients. The output of the preliminary model is compared to FPMU data, and parametric studies are performed in order to study the dependence of these transients on plasma characteristics and array operations. The model shows good agreement with FPMU data and indicates that the shape of the transient events is largely dependent on plasma density, temperature, array turn-ON time, and array orientation.