Aerospatiale solar arrays, in orbit performance

Correlation between on-ground prediction and in-orbit mechanical and electrical behavior for Telecom-1, ARABSAT, and SPOT solar arrays is shown. When recorded during the deployment phases, the current growth curves allow a good correlation between mechanical models and flight data. Flight data and the performance predictions are well correlated, within the measurement and model accuracies after adjustment of the cell data with ground flasher test results. For geostationary (GEO) missions, transfer orbit degradation may be due to an equivalent radiation dosage lower than usually computed (5 El3 e/sq cm). If so, mismatch and calibration losses may be neglected at BOL, for a nominal power output prediction, this being confirmed by SPOT 1 data analysis. Solar cell degradation due to radiation as observed at the beginning of missions seems to be compatible with an annual equivalent radiation dosage of 5 El3 e/sq cm for GEO missions, and very low for low orbits.