Spacecraft charging anomaly on a low-altitude satellite in an aurora

On May 5, 1995, the microwave imager instrument aboard the Defense Meteorological Satellite Program F13 spacecraft experienced a lockup of its microprocessor unit. The anomaly is attributed to an electrical malfunction caused by an electrostatic discharge on the vehicle. It occurred during an intense energetic electron precipitation event within a region of very low plasma density in the auroral zone. Plasma measurements indicate that the spacecraft frame charged to a voltage near 459 V within a few seconds. Calculations of the capacitance of the ungrounded thermal blankets covering the surface of the spacecraft are consistent with a surface charging time of a few seconds to reach several kilovolts. Subsequent electrostatic discharge led to the lockup. (Author)