Satellite Electrical Power Subsystem: Statistical Analysis of On-Orbit Anomalies and Failures

A statistical analysis of satellite Electrical Power Subsystem (EPS) failures is conducted in this paper, and of particular interest is the comparison of the failures between the EPS of LEO and GEO satellites. To investigate in more details the failure mechanisms of the EPS, we also analyze the failure data of four subsystems of the EPS: the Battery / Cell subsystem, the Electrical Distribution subsystem (ED), the Solar Array Deployment subsystem (SAD), and the Solar Array Operating subsystem (SAO). Also, we categorized the anomaly and failure events into three groups based on the severity of the events: Minor, Major, and Fatal. The results show, first, that the EPS of GEO satellites experienced significantly more anomaly and failure events than the ones in LEO satellites; second, that the SAO subsystem was responsible for the majority of the anomaly and failure events experienced by the EPS of GEO satellites, indicating the vulnerability of that subsystem in GEO satellites, whereas the anomaly and failure events were spread amongst the EPS subsystems of LEO satellites; and third, that events in the EPS of GEO satellites tend to be less severe than in the EPS of LEO satellites. We hope that the results presented here would be useful to the space industry, for example, in redesigning test and screening programs for subsystems, or providing an empirical basis for redundancy allocation.