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

[Dave McGuire]

On Saturday, February 1, 2003, at 11:37 PM, Ido Dubrawsky wrote:
>>    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.
>>
> 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.

   Ummm...wow.  Ok, now you've got my undivided attention.  I've always 
known that you know what you're doing, but...I had no idea...

> 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.

   Thanks for the authoritative explanation.  I understand now why it 
wouldn't have been possible.

   Is there any way that ISS facilities could help in a situation like 
this, should they conclude that they can't safely land as planned?

           -Dave

--
Dave McGuire                 "Rubber duckies *are* important."
St. Petersburg, FL                            -Doc Shipley