Temperature Effect on Primary Discharge Under Simulated Space Plasma Environment

Electrostatic discharge tests on solar array coupon of spacecraft were carried out to investigate the effect of temperature on the discharge frequency and threshold voltage of discharge inception. The tests were carried out under a plasma environment (low Earth orbit) and a high-energy electron beam environment (geosynchronous orbit). The discharge frequency increased with decreases of temperature, regardless of environment. The threshold voltage of discharge inception did not depend on the temperature, regardless of environment. These results show that we do not need to take into account the temperature effect on threshold voltage to estimate the number of discharges in orbit. However, the electrical material parameters, such as volume conductivity, change with the temperature. Therefore, we do need to monitor the temperature in the charging analysis.