An investigation of the variation of leakage resistance of electrical insulating materials used on spacecraft power systems

Spacecraft power systems are subjected to extremely hostile environments, due to the action of space plasma, temperature cycling and atomic oxygen. Literature indicates that the resistivity is sensitive to ambient temperature and pressure. The resistivity is an index which can indicate the performance of space based electrical systems. Hence, there is a need for experiments to determine the variation of leakage resistance with temperature and pressure. The surface leakage resistance, and volume resistance of Kapton H and V and Mylar films of 2 mils and 5 mils thickness were determined. The leakage resistance measurements were made according to ASTM D257. The experiments were conducted in a vacuum chamber with electrode temperatures ranging from 27° Centigrade to 140° Centigrade, and pressures varying from atmospheric to 10 millitorr at a voltage of 500 V