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 CulnGaSe 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 ofthe 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.