Results of flight demonstration of terrestrial solar cells in space

Radiation resistance of six types of solar cells developed for terrestrial use has been demonstrated in space by the MDS‐1 Tsubasa satellite which flew in a geostationary transfer orbit where the radiation environment is severe. Open‐circuit voltage and short‐circuit current of the cells were monitored for duration of about 400 days after launch. Super radiation tolerance of the CuInGaSe 2 solar cell was demonstrated in actual space. Also, most of the cells were determined to have capability or applicability for space use. A comparison of the degradation trend of the flight data with that of ground irradiation test results using the displacement damage dose method demonstrated good agreement, indicating sufficient validity of ground‐test techniques and accuracy of the end‐of‐life prediction.