Thin Silicon Solar Cells for Large Flexible Arrays

Abstract

THE past year has witnessed increasing interest in solar-powered, electrical propulsion systems for spacecraft in both the United States and the United Kingdom. In the United States the main interest is in the use of electrical propulsion for missions to Mars and Jupiter, where there is a marked payload advantage over chemically powered spacecraft which are limited by their energy rather than by their power. The incentive for the United Kingdom to initiate development in this field was provided by Burt¹ who theoretically showed that it was possible to change independently all the elements of a spacecraft's orbit by means of small continuous thrusts from an electrical propulsion unit. In particular, he showed that the ability of the unit to change the inclination of an orbit made it possible for a communications satellite launched from a non-equatorial site to attain a geostationary orbit.