The spacecraft surfaces degradation and contamination caused by arcing in low density plasmas

Previous experience has shown that some surfaces of large spacecraft may have a high negative potential relative to the surrounding plasma. When this potential reaches a few hundred volts, electrical discharges (arcs) occur on the surface. One of the adverse consequences of arcing is the degradation of the thermal insulation and the contamination of local environment. To prevent the negative influence of these processes on the operation of spacecraft systems and scientific equipment, it seems necessary to determine the rate of degradation and plasma contamination vs. arc rate, amplitude of current, and the duration of arc. This report describes the results of experiments that have been done to study the rate of coating degradation, atomic composition of the material injected into the plasma, and the spatial distribution of the contaminating material.