Space Forum / Shuttle / November 2003

I'll answer the easy bit - It was our very own Jim Oberg (thus it was all of
us).

As Dave said, that was Jim Oberg. The inspection EVA was possible. The
rescue shuttle... well, that's still open for debate. The prox ops were
certainly possible, but the rescue mission analysis was asked to use some
*very* optimistic assumptions for timing.

No, there is an airlock on every flight, in the event an EVA is required to
manually close the payload bay doors.

In most cases, yes.  In this case, the damage turned out to be close enough
to the payload bay doors that an EVA could have been staged from there.

See Appendix D.13 of the CAIB report for NASA's analysis of the
inspection/repair/rescue EVAs:

http://www.caib.us/news/report/pdf/vol2/part13.pdf

The inspection EVA is pictured in Figure 5.

Both. The shuttle was moving very fast (Mach 2.5), and the foam, being very
light and draggy, decelerated very quickly into the wing.

I think Story Musgrave is also on record saying this was possible.

There was an upward-facing EVA hatch in the tunnel between the Crew
Compartment and Spacehab.

Brian

The program gave the impression that a rescue would have been easy...."just"
send up another shuttle to rescue them, or "just" send up another rocket
with supplies until another shuttle could have been launched.

It also kept saying Columbia exploded........

The programme was quite good on its description of the cause of the
accident, but very poor in its facile analysis of the potential rescue
solutions.

As far as I can see the matter hinged on actually *knowing* that there was
potentially safety-critical damage to the airframe. It would seem that the
best available information suggested that any damage from the foam would not
be safety-critical. The consequences of foam hitting the RCC leading edge
panels were only fully understood AFTER the accident, and the firm belief
(however misleading) that it was substantially stronger than the wing skin
heat shields only compounded this unfortunate oversight.

Everything is obvious with 20-20 hindsight, but from the viewpoint of the
controllers and engineers at the time of the mission there was no striong
argument to justify the risks of an EVA inspection, especially since it is
more than likely that any damage may not have been especially visible. Quite
aside from the standard EVA risks I understand that there is a huge risk of
damage to the underskin heat shield material even if it just catches a waft
from a jetpack thruster, let alone physical contact. As far as I'm aware
none of the crew were experienced airframe structural surveyors, so they may
not have understood what they were looking at anyway. so in light of all
that was known at the time one can understand why the decision was strongly
influenced in the "no inspection" direction.

As for the suggested solutions, the idea of sending up additional supplies
(presumably food & CO2 scrubbers) to extend the mission to await a potential
rescue was glibbly mentioned as if it was something that could be thrown
together in a few hours. Even assuming the supplies existed in suitable
packaging (it something that would protect the items through the
acceleration of launch and the variety of temperature/pressue environments
between the pad and orbit) it would still be necessary to design and
manufacture something to allow these containers to be mounted into the
payload area of the available spacecraft. This isn't the sort of thing you
throw together overnight unless your surname is "Laforge". I would also
presume that there would be a limited range of viable launch solutions which
would place the supplies in a parking orbit close to the shuttle, so this
would add further constraints. Then factor in the possibility of launch
delays of the rescue shuttle due to weather, malfunction etc and this
solution looks dubious.

The programme stated that the crew could have "bailed out" from 40,000 feet,
but ignored the minor point that they never got down as low as 40,000 feet,
and diving down to that height at the time would have increased the thermal
and physical stresses and made a catastrophioc failure *more* likely. I'm
guessing, but I doubt the bail-out solution is available at Mach 18, so both
height AND speed needed to be shed. The craft was the wrong side of an
energy event horizon to use this option.

Other references to doing the re-entry with side-slip to "favour the good
wing" assume the exact nature of the damage was known AND that the data was
available to accurately model/simulate/predict the thermal profile of the
structure in un-balanced configurations. Unless this kind of manoeuver was a
previously identified recovery scenario it is unlikely the data could have
been developed in any useful timescale. In the real world such things are
not done by the seat-of-th-pants by the ace pilot with a cigar clenched in
huis teeth...

The final part of theprgramme seemed to be suggesting that the crew could
have been saved, but I would contend that this could not have been done with
any great degree of certainity given the knowledge available AT THE TIME.
This is surely the only test that can be fairly applied to judge the actions
of the people involved.

£0.02 supplied

PDR