Effects of environment on high voltage electrical/electronic circuits

Gas pressure inside a spacecraft decreases rapidly when continuum flow exists. During molecular flow the internal pressure decreases slowly due to the outgassing of the spacecraft structural, electrical and other materials. Non-pressurized, conformally coated high voltage circuits must be de-energized until the gas pressure is less than that which can support partial discharges and probable arc-over corona, as shown in Fig. 7.