Electrostatic Charging of Mirrors in Space: A Plausible Cause of Solar Panel Anomalies on Satellites

摘要

The entire fleet of Boeing Model 702 geosynchronous satellites has suffered from a similar fate: degradation of the solar cell panels. Minors flank both sides of the solar cell panels. Degradation sometimes sudden and stepwise, shortens the lifetime of the solar cells. We suggest that space environment effects play an important role in damaging the solar cells. As a cornerstone in this idea, we expound a theorem that high reflectivity reduces photoemission. With little or no photoemission, mirrors often charge to minus kilovolts in eclipse as well as in sunlight, whenever the space plasma is hot enough. Since the rest of the solar panel does not have this mirror property, differential charging between the mirrors and the rest of the solar panel occurs during eclipse exits. We show the charging data obtained during an eclipse exit on LANL-97A satellite for supporting the idea of differential charging. Finally, we recommend this important mirror charging property to be taken in account in future solar panel designs and in commercial products of spacecraft charging computer codes.