Path: utzoo!news-server.csri.toronto.edu!rutgers!mcnc!uvaarpa!murdoch!helga4.acc.Virginia.EDU!rnm8s
From: rnm8s@helga4.acc.Virginia.EDU (Rory Neil Mcleod)
Newsgroups: sci.space.shuttle
Subject: Re: New (!?!?!?!) Shuttle Computers (and old parts)
Message-ID: <1991Mar11.004952@helga4.acc.Virginia.EDU>
Date: 11 Mar 91 05:49:52 GMT
References: <1991Mar7.142311.10412@vaxa.strath.ac.uk>
Sender: usenet@murdoch.acc.Virginia.EDU
Reply-To: rnm8s@helga4.acc.Virginia.EDU (Rory Neil Mcleod)
Organization: University of Virginia
Lines: 29


	Theora:  The computers on board the shuttle aren't the
only pieces of equipment that are out dated and used on the
shuttle or used to get the bird launched.  With notable exceptions,
the equipments used to launch the shuttle is the same as it was
designed in the late '70's.  There is of course, good reason for
this: each piece of equipment must be tested and all of its failure
modes well known.  Once a system is in place, and it works, it
is not likely to be replaced.

	It takes either failure or poor performance to get the
anyone interested in changing something.   The Environmental
Control System (ECS), of which most of the equipment is located
underneath the launch pad, is largley comprised of Apollo era
equipment.  It works, and, just as importantly, everyone who
works on the system knows ALOT about it.  Of course, the
Bureacracy tends to slow the rate at which changes are made,
but, the STS is a huge system, what may seem like a little 
change to one system may have a major impact someplace else.  
The checks and balances are there for a reason.  

	
Rory McLeod
Dept Mechanical and Aerospace Engineering
University of Virginia

Ex-NASA KSC
   ECS&PVD
   TV-MSD-13