Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Challenger tragedy
Message-ID: <1988Aug3.150925.8434@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1001@scicom.alphacdc.com> <5827@dasys1.UUCP> <14876@shemp.CS.UCLA.EDU> <6081@ihlpl.ATT.COM>
Date: Wed, 3 Aug 88 15:09:25 GMT

In article <6081@ihlpl.ATT.COM> knudsen@ihlpl.ATT.COM (Knudsen) writes:
>As I remember, one of the things that helped the Apollo Project
>catch up to schedule after the tragic fire,
>was the combining of lower and upper stage tests.
>Originally the first few 1st stage tests were to be launched
>with dummy upper stages (tanks full of water).
>Instead these firings were made with the complete 3-stage
>rocket, thus getting 3 tests for the price of one.

I don't recall the details of the timing, but I think Von Braun was talked
into "all-up testing" well before the fire.  It was not just a time issue
(although he later admitted that, in retrospect, they could not possibly
have made the Kennedy deadline with the traditional approach); there was
also a problem with dummy stages in that they are not representative of
real upper stages for characteristics like structural vibration.  The only
way to do a first-stage test with a fully realistic environment was to use
real, loaded upper stages, and then one might as well try to test them too,
if the first stage worked.

>I think there was one malfunction where we even got a freebie
>checkout of the escape tower rockets that pull the CM away
>from the stack.

Not on a Saturn, that I recall, but there was such a malfunction with one
of the Little Joe II rockets used for testing the CM and its escape system.

>I'm still impressed that no Saturn stage EVER screwed up in
>a crewed launch! ...

Well, actually there were some minor screwups in the upper stages once or
twice, but nothing disastrous.
-- 
MSDOS is not dead, it just     |     Henry Spencer at U of Toronto Zoology
smells that way.               | uunet!mnetor!utzoo!henry henry@zoo.toronto.edu