ABSTRACT
At COMSAT Laboratories in 1967, the Spacecraft Laboratory studied
all non-communications aspects of the communications satellites;
that is, everything related to the satellite itself including structure,
thermal attitude, power, etc. In my case, I was responsible for
primary power development in the Electric Power Department of
the Spacecraft Laboratory. In 1967, all satellites were powered by
silicon solar cells. We examined every major type of solar cell
that was available in manufacture or under development including,
silicon, cadmium sulfide, and cadmium telluride cells. We rapidly
concluded that only silicon solar cells were a viable option at that
time since the other devices were neither stable enough nor had
good radiation properties. We thereupon characterized every silicon
solar cell under manufacture that we could purchase doing all a
full battery of tests to determine how well they would perform
in a space environment. We also tested every type of transparent
or translucent solar cell shielding material available that could be
used to protect the solar cells from radiation in space including
fused silica, Microsheet, Kapton and other plastics and even spray
on coatings. At that time, the best material was fused silica. Finally,
we also tested the various adhesives that were used to bond the
shielding materials to the cells, both for stability and performance
under radiation. From this data we predicted what solar cells,
adhesives and shielding materials performed the best under space
conditions. Finally, taking all of the data and recommendations we
made predictions of how solar cell arrays of silicon solar cells with
various shielding materials would perform in space over time.
