In article ,
says...
Stuf4 wrote:
The Air Force has a program called "ABDR" that teaches how to do
such repairs. They will cut things like soda cans and flatten
them out and then duct tape them onto holes on a jet's wing or
fuselage as a viable patch.

You're talking about temporary repairs to bullet holes in flat pieces
of non-critical structure merely in order to smooth airflow, which is
just a little bit different than trying to replace a high temperature
piece of the TPS with a bit of tin can and speed tape. You can't fix
leading edge damage on ordinary aircraft like that, so you certainly
can't fix hypersonics with it.


So for doing a MacGyver-style Aircraft Battle Damage Repair of
Columbia's wing leading edge, you scour the crew cabin for some
flat bendable piece of metal. Maybe use clipboards. Whatever.
Then go out and tape it over the gaping hole. On day of Entry,
hope it holds long enough to get you home.


It won't. The first heat pulse will make it go away as if it wasn't
even there. When the experts started looking for a way to deal with
this type of damage after the accident, they came to the conclusion
that there was no way to implement an on-orbit repair.


As for detecting the damage, they could either have used NRO spy
sats, or simply get out and look. Such an EVA could have been
done on Flight Day 2.


They wouldn't have been looking in the right place for the right
thing. They were looking for TPS tile damage near the leading edge,
which is why they thought it was an acceptable risk. Nobody believed
that a piece of foam would be a sufficient impact to damage the RCC.



Fred is spot on with every point. And do keep in mind that after
Columbia the engineers had essentially unlimited time to come up with a
"glove" to bolt over leading wing edge damage. Even with the "right"
materials, it really wasn't possible to make such a repair without
wrecking the leading edge aerodynamics. If memory serves, during
reentry this would create hot spots which would likely burn through
which kind of defeats the purpose of a repair.

For tile damage (not RCC damage), a repair kit was developed (reference
below). But, the best NASA could do for wing leading edge damage like
Columbia had would have been to leave the crew to "shelter" on ISS for
rescue by another shuttle.

For the damaged orbiter, the astronauts would install "jumper wires" on
the badly damaged orbiter so it could be flown remotely towards a
landing (in the case where the damage could be repaired) or towards a
destructive reentry in the case where the damage was too great to repair
(i.e. RCC damage). The "jumper wires" were required because the orbiter
design included a few buttons which an astronaut had to physically push
and it therefore could not be flown remotely from deorbit to landing.
Reference:

http://www.space.com/2560-shuttle-ca...emote-control-
landing.html

For the last Hubble repair mission, I believe they had another shuttle
nearly ready to launch a rescue mission since "sheltering" at ISS
wouldn't have been an option. Searching... Yep, here's a reference:

https://www.wired.com/2014/12/sts-125-hubble-mission/

From above article:

Shuttle flights resumed in 2005, with the requirement that every
shuttle have its heat shields checked at the International Space
Station before reentry. But that wasn't an option for STS-125.
The orbit needed to rendezvous with Hubble wouldn't allow a visit
to the space station.

Instead, Endeavour was placed on standby, ready to launch should
Atlantis be unable to return. And the crew would have to inspect
its own ship. NASA had a plan for that, too?the Orbiter Boom
Sensor System, a 100-foot arm fitted with a camera, a laser and
other equipment. It was first deployed on STS-114, the inaugural
flight after Columbia. Once STS-125 was in orbit, mission
commander Scott Altman would deploy it to check Atlantis for
launch-related damage to the heat shields.

Stuf4, all of these details were covered by the "space media" and is
available online thanks to the magic of the Internet. You just have to
do a few Google searches to find it. It's all quite fascinating history
at this point (since the shuttles are quite literally museum pieces).

Jeff
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