Path: utzoo!mnetor!uunet!husc6!bloom-beacon!mit-eddie!killer!bigtex!james
From: james@bigtex.uucp (James Van Artsdalen)
Newsgroups: sci.space.shuttle
Subject: Re: Orbiter/SRB separation
Message-ID: <1869@bigtex.uucp>
Date: 10 May 88 01:19:20 GMT
References: <48048@ti-csl.CSNET>
Reply-To: james@bigtex.UUCP (James Van Artsdalen)
Organization: F.B.N. Software, Austin TX
Lines: 28

IN article <48048@ti-csl.CSNET>, kas@hp-pcd.hp.com (Ken Scofield) wrote:
> Why
> not just jettison the entire shuttle craft from the tank/booster assembly?
> [...]  Two arguments I've heard against
> this are:  The shuttle would break up due to aerodynamic forces, and/or it
> would be burned up in the departing booster's firetail.  Neither of these set
> well with me, because (a) the shuttle is designed to re-enter the atmosphere
> in excess of Mach 25, and (b) do so with skin temperatures of several thousand
> degrees.  So, what's the big problem?  You may post this one, too, if desired.

Shuttle is designed to re-enter at certain angles, with stress & temperature
in certain places.  Will not take large aerodynamic forces in wrong places,
and will NOT take heat in wrong places.  Heat shielding is by no means uniform
even along the front/bottom of orbiter.

Seems unlikely that (1) "aerodynamic" pressure within SRB exhaust is same as
re-entry aerodynamic pressure (momentum of SRB is likely much greater than that
of gases striking orbiter on re-entry) and (2) that shuttle could safely
maintain exact attitude in that exhaust.  If orbiter rotated or translated
just a little bit, surfaces exposed to exhaust would change.

Lastly, I'm not sure what if any provisions exist for steering SRB and
external tank away from orbiter after separation.  Center of mass moves
significantly, so SRB/tank may want to change course.  I don't believe
SRB nozzles can be gimbled.
-- 
James R. Van Artsdalen   ...!ut-sally!utastro!bigtex!james   "Live Free or Die"
Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746