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Path: utzoo!linus!security!genrad!grkermit!masscomp!clyde!ihnp4!astrovax!ks
From: ks@astrovax.UUCP (Karl Stapelfeldt)
Newsgroups: net.columbia
Subject: Re: contrails? - (nf)
Message-ID: <152@astrovax.UUCP>
Date: Tue, 29-Nov-83 22:34:43 EST
Article-I.D.: astrovax.152
Posted: Tue Nov 29 22:34:43 1983
Date-Received: Thu, 1-Dec-83 20:40:49 EST
References: <4188@uiucdcs.UUCP>
Organization: Princeton Univ. Astrophysics
Lines: 7


     The effects that you saw on the nose of both SRB's during the STS-9
launch are due to the passage of the vehicle through Mach 1.  What you saw
was not smoke, but water vapor rapidly condensing out of the air in the
(complicated) shock wave structure around the SRB nose.  You can observe the
same kind of effect when supersonic aircraft pass through the "sound barrier".
The condensation should also be visible about the top of the external tank, if
you get a chance to see that video tape again.