SPACE PHOTOVOLTAICS – History, PROGRESS AND PROMISE

Abstract

The first space solar array was carried aloft on Vanguard I on March 17, 1958. Vanguard I was the second satellite successfully launched by the U.S. space program following the launch of Sputnik I by the (then) USSR on October 4, 1957. The array on Vanguard I consisted of six photovoltaic panels mounted on the outer surface of the satellite. The array produced about one watt of power for over six years. The cells on that first array were single crystal silicon, each 2 cm ×0.5 cm in size, and about 10% efficient at 28C. Solar arrays are now the primary source of power for all earth-orbiting satellites. Space solar arrays and power systems have grown in size and complexity since 1958. This paper will provide an overview of a typical satellite power system along with the current status of solar cell technology development in the U.S.