Jorge:

To put this positively, if Node 2 is available and Node 3 is not, two
shuttles could dock at ISS at the same time.



"Jorge R. Frank" wrote in message ...
"Michael R. Grabois ... change $ to \"s\""
wrote in :

On 26 Oct 2003 18:03:38 GMT, (Hallerb) wrote:

No. There's no place to put the secondary docking mechanism (PMA-3)
that would allow positive clearance. For "safe haven", the first
(damaged) shuttle would be undocked unmanned, and deorbited
destructively, prior to the arrival of the second.

What about on the z-axis? Wasn't that where the shuttle docked when
they added the Lab and relocated PMA2?

Right, PMA-3 on the nadir (+Z) CBM. But with a shuttle already docked to
PMA-2, a tail-forward docking at PMA-3 (as was done for 4A and 5A) would
result in the two shuttles colliding. A nose-forward docking was never
possible due to collision with the FGB. A nose-out-of-plane docking isn't
possible due to collision with the Quest airlock.

It simply won't be possible to dock two shuttles to ISS until Nodes 2 and 3
are added. Then you could dock one shuttle to PMA-2 on Node 2, and another
to PMA-3 on Node 3, provided you "clock" PMA-3 for a nose-out-of-plane
docking. A nose-forward docking might also be possible at PMA-3 if the
Russian modules aren't added, but it's a constraint that one Russian module
*must* be added to FGB nadir prior to Node 3, else FGB nadir will no longer
be able to accommodate Soyuz.

Oh sure lets just throw away a multi billion dollar irreplaceable
asset........

Things like this should be planned for...

You *do* realize that the "safe haven" concept is for when the shuttle
cannot come home and survive but can still dock, right? Apparently
not.

And apparently he doesn't realize that ISS is only partially assembled, and
it is simply not possible to provide for *every* contingency scenario at
*every* stage of assembly.

Typical hallerb...