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From: cater%mcchi2@MCC.ARPA (John P. Cater)
Newsgroups: net.space
Subject: Re: Did the Challenger Wobble?
Message-ID: <8602202058.AA00624@mcchi-proteus>
Date: Thu, 20-Feb-86 15:58:17 EST
Article-I.D.: mcchi-pr.8602202058.AA00624
Posted: Thu Feb 20 15:58:17 1986
Date-Received: Sun, 23-Feb-86 18:55:18 EST
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It's my guess that what you see on your tape, when speeded up, is nothing
more than the normal course and alignment corrections produced by the
steerable rocket engines.  These adjustable jets make the orbiter-
SRB system fly slightly like a bicycle rides (a constant wobbling motion) to
maintain positional stability.  Remember, that system in not in a 
maximally stable position when flying vertical and being pushed from the 
rear (try balancing a pencil on your fingertip -- the only possible
way to do it is to wobble your finger back and forth to maintain
vertical stability).  So I think you are seeing a normal artifact of the
guidance control. I may be wrong, but my bet's on normal guidance wobble.
 
				John Cater
				(cater@mcc)
Disclaimer:
(These are my opinions, and everyone's entitled to them!)