primary electrical power for operating the electronic equipment is obtained
from solar cells. Individual cells can generate only small amounts of power,
and therefore, arrays of cells in series-parallel connection are required.
shows the solar cell panels for the HS 376 satellite manufactured by Hughes
Space and Communications Company.
geostationary orbit the telescoped panel is fully extended so that both are
exposed to sun- light. At the beginning of life, the panels produce 940 W dc
power, which may drop to 760 W at the end of 10 years.
eclipse, power is provided by two nickel-cadmium (Ni-Cd) longlife batteries,
which will deliver 830 W. At the end of life, battery recharge time is less
than 16 h.
of cylindrical and solar-sail satellites, the cross-over point is esti- mated
to be about 2 kW, where the solar-sail type is more economical than the
cylindrical type (Hyndman, 1991).