In-Orbit Performance of Hughes HS 376 Solar Arrays-Update

The synchronous orbit performance of the Hughes Aircraft Company HS 376 spacecraft solar arrays using the K7 solar cell is updated and compared with ground-based computer predictions for orbital durations greater than 8 years. A brief description of each solar array and the general methodology for predicting solar array performance are also presented. In addition, the ability to accurately predict solar array performance within telemetry accuracy is demonstrated. This capability combines the solar array electrical measurements in the as-built configuration, manufacturing consistency, and sound computer modeling techniques. The HS 376 spacecraft discussed herein are the Satellite Business Systems (SBS) F-1, F-2, and F-3 and the Telesat Canada Anik C-2, C-3, D-1, and D-2. The in-space performance data indicate forward solar array power degradation of 13.8% for SBS F-3 after 103 months in orbit, 15.1% for Anik C-3 after 79 months in orbit, and 13% for Anik D-1 after 82 months in orbit. The predicted solar array outputs are within 2% of the actual outputs as obtained through telemetry.