Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Shuttle engine failure on the pad
Message-ID: <1990Mar19.015743.6241@utzoo.uucp>
Organization: U of Toronto Zoology
References: <140@caslon.cs.arizona.edu> <231@puma.ge.com> <5564@bgsuvax.UUCP>
Date: Mon, 19 Mar 90 01:57:43 GMT

In article <5564@bgsuvax.UUCP> frazier@bgsuvax.UUCP (Paul Frazier) writes:
>I thought that they could "blow the lid" off of the SRBs, and thereby reduce 
>their thrust to zero.  Is this true? ...

No, it's a common misconception.  The destruct system on the SRBs uses a
linear shaped charge running up along the side to blow the casings open
like a pea pod.  This is sometimes known as a "thrust termination" system,
which is its purpose -- destruct systems are not meant to shred the
rocket, just to make sure it follows a predictable path and doesn't run
wild -- but it's not the sort of thing one would use on the pad.  There
is no provision for gentle, or even only mildly violent, SRB shutdown.
-- 
MSDOS, abbrev:  Maybe SomeDay |     Henry Spencer at U of Toronto Zoology
an Operating System.          | uunet!attcan!utzoo!henry henry@zoo.toronto.edu