Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!uhccux!goldader
From: goldader@uhccux.uhcc.hawaii.edu (Jeff Goldader)
Newsgroups: sci.space.shuttle
Subject: Re: shuttle escape systems
Message-ID: <5151@uhccux.uhcc.hawaii.edu>
Date: 18 Oct 89 01:01:04 GMT
References: <538.252A3A3B@mamab.FIDONET.ORG> <34577@srcsip.UUCP> <126311@sun.Eng.Sun.COM> <1307@accuvax.nwu.edu> <15596@netnews.upenn.edu> <1321@accuvax.nwu.edu>
Reply-To: goldader@uhccux.UUCP (Jeff Goldader)
Organization: University of Hawaii
Lines: 44

In article <1321@accuvax.nwu.edu> phil@delta.eecs.nwu.edu (William LeFebvre) writes:
>In article <15596@netnews.upenn.edu> santerel@clarke.cis.upenn.edu.UUCP (Walter Santarelli) writes:
>>
>>[...]I'm still amazed that we launch people on the
>>current system at all. I believe the original concept called for a
>>re-usable liquid fueled booster. Liquid fueled boosters offer the
>>advantage that they can be throttled....
>
>And the disadvantage that they are much more volatile.  The actual
>explosion that broke up the Challenger was the nearly instantaneous
>combustion of the liquid fuel, NOT the solid fuel (and if you want to
>be picky, the solid fuel wasn't even the initial technical cause---the
>segmented booster construction was).  It's a matter of tradeoffs.

Well, if you want to be *real* picky, Challenger wasn't destroyed by any
"explosion" at all.  The shuttle was destroyed by the aerodynamic stresses
caused by the orbiter pitching violently into the airstream after the
breakup of the external tank.  The way I remember the Rogers Commission
report, the flame from the aft field joint sliced through the aft SRB
attach strut, which simultaneuosly destroyed the aft dome supports of the 
ET's hydrogen tank.  The SRB pitched around the forward attach strut, 
crushing the dome of the ET's LOX tank.  The hydrogen was already gushing
out of the ruined back of the tank, which gave a sudden thrust of some 
million pounds or so (can't remember exactly).  Since the ET wasn't made to
withstand this, and with the damaged forward section, it simply suffered
complete structural failure.  The orbiter found itself running through
the air upside-down at Mach 4 with no thrust, pitched nose-down, and
disintegrated.  The actual explosive combustion of the hydrox wasn't
all that bad; from what I remember, the orbiter could have survived
that, but the aerodynamics of the separation killed it.

Oh- correct me if I'm wrong, but wasn't the NASP funding killed altogether
in this budget?  Looks like we can forget about any shuttle replacement
before 2010 or so.

Jeff Goldader                        University of Hawaii
uhifa.ifa.hawaii.edu                 Institute for Astronomy

"So, Lonestar, now you see that Evil will always win- because Good is stupid."
-The Dark Lord Dark Helmet, _SPACEBALLS_ 

Disclaimer: The opinions expressed herein are my responsibility alone.  
The University of Hawaii and the Institute for Astronomy neither support 
nor are in *any way* responsible for these opinions.