[rescue] Re: rescue Digest, Vol 3, Issue 4

[Ido Dubrawsky]

On Sat, Feb 01, 2003 at 05:49:55PM -0600, rescue-request at sunhelp.org wrote:
> Date: Sat, 1 Feb 2003 18:28:58 -0500
> From: Dave McGuire <mcguire at neurotica.com>
> 
>    So they knew they had problems and just had to come down anyway?  I 
> don't buy it.  They could've gone to ISS and hung out there and awaited 
> another ride home.  Sure, a difficult proposition, but better than 
> losing the ship and crew.
> 
>           -Dave
> 
OK, so now I've got to answere.  A little on my background first:  I have
both a bachelors and a masters in Aerospace Engineering (in particular, 
in orbital mechanics and spaceflight).  I used to work for NASA JPL doing
trajectory and maneuver calculations for the Galileo project in another life.
To answer your question Dave they could not have gone to ISS.  I'm not saying
it's a dumb idea (actually it would have been a great idea if it was possible)
however the amount of fuel required -- and this would mean waiting until they 
caught up to it because the space station orbits at a slightly higher altitude
than the typical shuttle orbit -- would be more than what they have on board.
They only bring enough fuel for the trip and a small amount of "extra" fuel 
because every pound of fuel matters.  They could not have executed such a 
maneuver given the fuel that they did have.  So, the proposition, while 
logically making sense, is not possible given the way NASA manages fuel on
board the shuttles and the orbital trajectory changes and maneuvers required.
I wish it would have been possible though...seven lives lost (and the pain
their families feel).  I haven't felt this crappy since 9/11.

Ido
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Ido Dubrawsky               			E-mail:  ido at dubrawsky.org
Network Security Architect				idubraws at cisco.com
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