



You may want to put Hubble back in the payload bay for a reboost,
and you don't want to clip off the panels each time.

For the Gamma-Ray Observatory, one of the design requirements was that
there be no stored-energy mecahnisms (springs, explosive squibs, gas shocks,
etc.) used for deployment.  This was partially so that everything could
be reeled back in to put it back in the payload bay, and partially for
safety considerations.  (I've heard that the wings on a cruise missile
would cut you in half if you were standing in their swath when they opened.)

Back when the shuttle would be going up every other day with a cost to
orbit of $3.95 per pound :-), everybody designed things for easy servicing.
