Observations of Differential Charging with Meteostat

Abstract : The behavior of the geosynchronous Meteosat spacecraft in the Earth's shadow throws new light on the topic of the influence of secondary electron emission on differential charging, which could assist understanding of these processes in more general situations. Meteosat F1, a geosynchronous meteorological satellite operated by the European Space Agency, suffered from a number of non-damaging operational anomalies that were attributed to electrostatic discharges caused by differential charging. The second flight model F2 was modified in several ways to reduce its susceptibility to arcing. In addition, two new sensors were included in the payload to monitor the plasma environment and to detect the electrical effects of discharges. Since launch in June 1981 the spacecraft has experienced only a few anomalies attributable to arcing and no electrostatic discharges have been detected by the monitor although that could be a matter of sensitivity. So far the only evidence for the spacecraft charging to significant potentials occurs during eclipse and comes from the plasma environment monitor.