jerry@oliveb.UUCP (Jerry Aguirre) (05/08/84)
The fuses are not there to protect the module. They are there to
protect the power supply! The idea is that if module X shorts out it
can drain the battery dead. Module X might have a minor function or
even have a redundant backup in module X2. But if the space craft
loses power then thats the whole ball of wax. The telemetry and
control radio link is lost and all other modules stop functioning. And
of course it might be possible for the overload to overheat the
surrounding modules.
Given a real short circuit and no fuses they would never have been able
to cancel the tumble from ground control and the repair mission would
have failed!
Resettable fuses are a nice idea but would weigh and cost more. It's a
trade off with including a larger experiment package or bigger battery/solar
cells. Also they would have their own reliability factor.
Jerry Aguirre
{hplabs|fortune|ios|tolerant|allegra|tymix}!oliveb!jerry