A compact electrostatic charging monitor for spacecraft

A new instrument for monitoring both surface and internal charging effects on-board a spacecraft is described. The aim of the instrument is to provide a reliable diagnostic tool that can be flown on long-life operational satellites where severe mass, power and accommodation restrictions usually prevent the installation of more complex devices. A brief review of the charging hazard to spacecraft is provided followed by a description of the instrument's basic design in which electrical analogues of the charging of insulating materials are set up. Ultra-high-value resistors (up to 10/sup 14/ /spl Omega/) are employed in order to simulate the properties of a dielectric. Results from electron beam charging tests are provided which demonstrate the validity of the approach.