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From: lmc@cisden.UUCP (Lyle McElhaney)
Newsgroups: net.columbia
Subject: Re: orbiter ascent attitude
Message-ID: <499@cisden.UUCP>
Date: Sun, 9-Feb-86 12:38:54 EST
Article-I.D.: cisden.499
Posted: Sun Feb  9 12:38:54 1986
Date-Received: Wed, 12-Feb-86 20:58:39 EST
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> > > Can anyone explain why during assent the orbiter flies upside-down?
> > 
> > As I understand it, it's simply so that the tank and SRB's don't block
> > line-of-sight for radio communications between the orbiter and the ground.
> 
> But, why the role?  Why doesn't it just fly straight onto its back?

The initial orientation of the shuttle (roll, or vertical axis) is defined
by the high radius turns in the lane from the VAB to the launch pad.
The crawlers cannot turn easily, and so straight-on approaches to the pad
are made, and the pads were designed with this in mind. Also, Kennedy
supports launch azimuths of from 35 degrees (northeast) to 120 degrees
(southeast), so some kind of roll manuever would be required in most
flights anyway before pitch over.

Lyle McElhaney
...hao!cisden!lmc