Ground-Based Experiment of Arcing on Spacecraft Surfaces in Ambient Plasma Environments

Abstract

In the future, LEO spacecraft will be larger and higher powered. Because of the balance of currents through ambient space plasma, their main conductive body will have a higher negative potential without plasma contactor operation. When spacecraft operate with a higher voltage, more intensive arcing is suspected to occur on their surface. In this study, ground-based experiment was carried out to understand the arcing phenomenon and to examine influences of ambient space plasma on the arcing process. Simulating plasmas were generated by electron cyclotron resonance discharge. When arcing occurred on anodized aluminum sample (AAS) plates negatively biased by a capacitor in the plasma environment, the time variations in arc current and bias voltage were measured. Arc spot diameter was also measured. The experimental results showed that both the peak arc current and the total charge emitted by arcing increased with initial charging voltage and neutral particle number density. The diameter of arc spots increased with initial charging voltage although it was almost constant regardless of neutral particle density. Accordingly, high voltage operation of LEO spacecraft might bring drastic degradation of AAS by arcing depending on ambient plasma conditions.