First space flight of InP solar cells

A large-scale, commercial process to produce high-efficiency diffused junction InP solar cells is developed. Proton irradiation effects on InP solar cells are also studied. Superior proton resistance of InP cells is confirmed by defect analysis. 1300 pieces of InP solar cells (2*1 cm/sup 2/), with efficiencies of 16-17%, were used as the power source for the lunar orbiter of the Japanese scientific satellite MUSES-A, launched in January 1990. The InP solar cells have been demonstrated to be stable in space.<
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