🚀 go-pugleaf

	In response to the question "what is shuttle centaur and why did it
die?" I say this:
	The shuttle Centaur project was to be a high energy upper stage for
the space shuttle allowing deep space probes and *very* heavy clark orbit
satellites to be launched from the shuttle payload bay.  The vehicle was 
actually little more than an expanded centaur upper stage from the Atlas
ELV with dumping capabilities to ensure safe shuttle landing weights.  The
fuel was hydrazine and highly caustic.  Thus (in the event of aborted take-
off) the fuel would have had to be dumped over uninhabited areas at low 
altitudes to prevent possible serious damage to the environment.  Then the
Challenger was destroyed and crew safety ruled out the use of the upper stage
altogether.  This may be one of the decisions that limits the shuttle to
use as something very different than its original designs.  Deep space probes
must now use the Inertial Upper stage and take ridiculous time periods to get
where they need to go.