Page 220 - Satellite Communications, Fourth Edition

200 Chapter Seven

Figure 7.1 The HS 376 satellite. (Courtesy of Hughes
Aircraft Company Space and Communications Group.)

manufactured by Hughes Space and Communications Company. The
spacecraft is 216 cm in diameter and 660 cm long when fully deployed
in orbit. During the launch sequence, the outer cylinder is telescoped
over the inner one, to reduce the overall length. Only the outer panel
generates electrical power during this phase. In 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. During eclipse, power
is provided by two nickel-cadmium (Ni-Cd) long-life batteries, which
will deliver 830 W. At the end of life, battery recharge time is less
than 16 h.
The HS 376 spacecraft is a spin-stabilized spacecraft (the gyroscopic
effect of the spin is used for mechanical orientational stability, as