A Sensor to Avoid Arcing Due to Grappling

New instrumentation might aid new ventures in space. Grappling missions are now being considered for geosynchronous Earth orbit. If spacecraft are at differing floating potentials, arcing during grappling might prove a hazard. In this paper, a device that might warn of arc-inducing conditions is described. The device is of a class of instruments that have been flown on many missions: curved plate electrostatic charged particle energy analyzers. However, the sensor is of a novel configuration that might enable the determination of very low absolute spacecraft floating potentials. Since very few spectra of the sort that the instrument would collect in space are available, estimates of its performance are necessarily uncertain. It is possible that such an instrument would prove useful on grappling missions.