The charging of spacecraft components by high energy radiation can result in spontaneous pulsed discharges, The pulses can interrupt normal operations of spacecraft electronics. The 20-year history of ground studies and spacecraft studies of this phenomenon are reviewed, The data from space are not sufficient to unambiguously point to a few specific solutions. The ground based data continue to find more problem areas the longer one looks, As spacecraft become more complex and carry less radiation shielding, the charging and discharging of insulators is becoming a more critical problem area. Ground experiments indicate that solutions for spacecraft are multiple and diverse, and many technical details are reviewed or introduced here.
