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Path: utzoo!watmath!clyde!burl!ulysses!bellcore!petrus!karn
From: karn@petrus.UUCP (Phil R. Karn)
Newsgroups: net.columbia,net.space
Subject: Re: SRB destruction
Message-ID: <21@petrus.UUCP>
Date: Wed, 5-Feb-86 15:22:47 EST
Article-I.D.: petrus.21
Posted: Wed Feb  5 15:22:47 1986
Date-Received: Fri, 7-Feb-86 20:24:32 EST
References: <463@mb2c.UUCP>
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Organization: Bell Communications Research, Inc
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Xref: watmath net.columbia:2091 net.space:5606

It is depressing to see the sheer volume of misinformation coming from
people who really ought to know better. Before you answer somebody's
question with an air of authority, check your references! Then quote
them.

This applies almost as much to the news media as it does to this group.
Two errors in particular come to mind:

1. Contrary to the New York Times, nitrogen tetroxide is NOT such an "exotic
material that it isn't listed in the Merck Index." The writer may have been
confused by the fact that what rocket engineers call "nitrogen tetroxide" is
actually a equilibrium mixture of N2O4 and NO2, nitrogen dioxide. The former
is colorless, the latter reddish-brown, and the proportions depend on
temperature.  Chemists are more likely to call it "nitrogen dioxide", which
definitely *is* in the Merck Index.

2. The range safety systems on the SRBs do NOT "blow the ends off".  A look
in any of the many detailed press kits given out by NASA and Rockwell would
reveal that the range safety system consists of a linear shaped charge
running almost the entire length of the SRB inside a cable duct. Detonating
this charge splits the case open lengthwise.  Linear shaped charges are
used in a number of places around the shuttle vehicle, not all of them
for destruct systems. For example, most of the SRB nozzle is routinely
cut off by a linear shaped charge before the booster hits the water
in order to reduce the impact loads.