[net.space] shuttle turnaround?

SCHMIDT@SUMEX-AIM.ARPA (Christopher Schmidt) (02/06/86)

	As I understand it (probably incorrectly) we've been sending up
one shuttle per month instead of four because the turn-around time for
refurbishment has proved to be 4 months instead of the 4 weeks the 
shuttle was originally engineered for.  What takes so long?  I once
heard it was the main engines which suffered more wear than anticipated.
	Couldn't we increase shuttle launch rate by decreasing
turnaround time by maintaining 4 sets of engines (or whatever the critical
parts are) per shuttle?  I would imagine it would be cheaper (and more
timely) to build more engines/whatever than to build another shuttle.
	Or what's the key problem I'm overlooking?  thanks,
--Christopher
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