Electrical design and performance of the British Satellite Broadcast Spacecraft

The synchronous orbit performance of the Hughes Aircraft Company-built British Satellite Broadcast Spacecraft (BSB) solar cell array, utilizing large-area (6 cm×6.2 cm) solar cells is presented, and on-orbit performance is compared with ground-based computer predictions for orbital durations during the first year. The BSB satellite is a spin-stabilized spacecraft, designed to operate for ten years in synchronous orbit. The primary source of power during sunlight operation is provided by two concentric cylindrical solar panels. During transfer orbit, the deployable solar panel is stored over the fixed solar panel and provides power to the satellite and batteries. In synchronous orbit, the deployable panel is telescoped to its fully deployed position and power is provided by both panels. The resultant structure, less antenna, is 4.47 m tall by 2.1 m in diameter and provides an end-of-life power of 943 W. Performance measurements indicate the electrical power system meets all requirements and will perform successfully, over the ten-year mission life