Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucla-cs.ARPA Path: utzoo!linus!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!ucla-cs!wales From: wales@ucla-cs.UUCP Newsgroups: net.columbia Subject: SRB joints Message-ID: <8931@ucla-cs.ARPA> Date: Wed, 12-Feb-86 23:01:16 EST Article-I.D.: ucla-cs.8931 Posted: Wed Feb 12 23:01:16 1986 Date-Received: Fri, 14-Feb-86 07:21:26 EST Reply-To: wales@ucla-cs.UUCP (Rich Wales) Distribution: net Organization: UCLA Computer Science Department Lines: 34 I'm confused. In the first several days after the Challenger disaster, speculation focussed on the possibility that a crack in the solid fuel might have opened up a path to the inside surface of the SRB. Such a crack was thought to have resulted either from the low pre-launch temperatures, or else from imperfect mating of propellant surfaces between adjacent sections of the booster. Supposedly, it was critical that combustion not find its way to the SRB's inside surface -- and the mass of propel- lant was supposed to prevent this from happening. Now, though, people are talking about problems with the O-rings and putty used to seal the joints between the booster sections. Reportedly, the "primary" O-rings routinely showed signs of fire damage. This would seem to suggest that combustion heat was expected to make its way to the joints of the SRB -- but would be kept from burning clear through by the O-rings and putty. Some are speculating that the low temperatures might have affected the O-rings adversely. These two accounts would seem to contradict each other. If the import- ant point is that the propellant should insulate the body of the booster from the heat of combustion, then why the concern over the O-rings as a line of defense? And if the O-rings are liable to burn through before the SRB walls themselves, then why the great concern over cracks in the propellant? Can anyone clear this point up? I would, of course, vastly prefer to hear from someone with authoritative knowledge from some source other than the same mass media I've been trying to follow. -- Rich Wales // UCLA Computer Science Department // +1 213-825-5683 3531 Boelter Hall // Los Angeles, California 90024 // USA ARPA: wales@LOCUS.UCLA.EDU -or- wales@UCLA-LOCUS.ARPA UUCP: ...!(ucbvax,ihnp4)!ucla-cs!wales