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From: dwg1@mhuxn.UUCP (GOULD)
Newsgroups: net.columbia
Subject: Re: Speculation
Message-ID: <234@mhuxn.UUCP>
Date: Fri, 31-Jan-86 13:44:51 EST
Article-I.D.: mhuxn.234
Posted: Fri Jan 31 13:44:51 1986
Date-Received: Sat, 1-Feb-86 06:46:33 EST
References: <1953@pur-phy.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 40

>What if ... moisture was inside some part of the connector
>where the umbilical joins the shuttle. If that moisture froze,
>it could damage the connector...
>... If there were a modest leak in the umbilical system ... as the
>shuttle begins to gain speed, the air stream would tend to draw the
>hydrogen towards the engines ... When the order to go full throttle
>was given, the flow from the tank almost doubled and the flow though
>the faulty connector increased in proportion... This would explain
>the flame seen at the base of the tank first, followed by the flash
>at the umbilical.
>	(Richard Piner @Purdue Univ.)

I had a similar guess after discussion with friends:
the umbilical connector probably failed.
The obvious question is: WHY?

Moisture induced pre-launch damage could be it, but

>While watching my VCR replay ... Using the fast scan ... Challenger
>seemed to be wobbling back and forth a little bit.
>	(Michael Ross @3M Company)
 
increased stress from improper movement of the airframe control
surfaces (e.g., elevators, rudder, etc.) could account for the
failure, as could mechanical wearout of the connector retention
system - Challenger has been re-used several times now ... (I
sure hope that wasn't the cause). I trust that NASA will
eventually tell us what happened...

>The best tribute we can pay to the memory of the Challenger
>crew is to perpetuate their own forward thinking.
>	(Steve Miller @Bell Communications Research Inc.)

Well Stated.

-----------------------------------------------------------------
Doug Gould @ AT&T Bell Laboratories, Murray Hill, NJ   mhuxn!dwg1

"The views expressed here are my own and do not represent 
 those of my employer"