Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!dietz
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.space
Subject: Re: Condensed CANOPUS - December 1988
Message-ID: <1989Feb2.142632.15866@cs.rochester.edu>
Date: 2 Feb 89 19:26:32 GMT
References: <1226@cfa183.cfa250.harvard.edu>
Reply-To: dietz@cs.rochester.edu (Paul Dietz)
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 23

willner@cfa250.harvard.edu (Steve Willner P-316 x57123) writes:

>Here is the condensed CANOPUS for December 1988. 
...
>NASA is considering what to do with six flight sets of pre-
>Challenger boosters that it still has on hand. There is nothing
>physically wrong with them, other than having the two-O-ring design
>that allowed the Challenger accident to occur. NASA is trying to
>decide whether to use them or to burn off the propellant so the
>casings can be rebuilt to the triple-ring design. The can be flown so
>long as they are used in warm weather (as shown by the 24 flights
>that preceded Challenger); strip heaters can be added as a
>precaution. If that is done, however, it places NASA in the position
>of justifying the long standdown after the accident.

NO!  The 24 flights before Challenger do not show that the design is
safe in warm weather.  O-ring damage was found on many flights,
including one where the temperature at launch was 90 F.  As the Rogers
report stated, the O-ring design was flawed in many ways; the lack of
resilience of the rubber at low temperatures being only one problem.

	Paul F. Dietz
	dietz@cs.rochester.edu