Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!wasatch!utah-gr!uplherc!sp7040!obie!wes
From: wes@obie.UUCP (Barnacle Wes)
Newsgroups: sci.space.shuttle
Subject: Re: Discovery's launch: Am I imagining things?
Summary: Late flight profile of solid-fuel rocket motors...
Message-ID: <214@obie.UUCP>
Date: 7 Oct 88 05:27:40 GMT
References: <1104@cfa237.cfa250.harvard.edu> <4305@cadnetix.COM> <1925@cloud9.UUCP>
Organization: the Well of Souls
Lines: 20

In article <1925@cloud9.UUCP>, cme@cloud9.UUCP (Carl Ellison) writes:
> The flame I saw was from a very long distance telephoto shot, just
> before SRB separation.

One possible explanation for this phenomenon:
This is one of the more annoying "features" of large sold-fuel rocket
motors, especially those in which the fuel core has been "star-cut" to
provide more thrust.  The problem is that towards the end of the burn,
there are "sheets" of propellant that burn through and get thrown out
the cone before being completely burnt.  Once ejected, they "flash",
causing irregularities in the exhaust.  Solid-fuel motors are notorious
for having unsteady thrust towards the end of their burn also - it
becomes more and more difficult to control the burn surface as the
original core shapes disappear.

-- 
                     {hpda, uwmcsd1}!sp7040!obie!wes

         "How do you make the boat go when there's no wind?"
                                 -- Me --