Columbia Myths? ( What if Apollo fire in orbit?

Derek Lyons wrote:

.

The fact is - we don't know whether there was a hole, or a crack, or
just a loose piece held in place by sheer force of will. The only
evidence we have, indirectly, is the 'flight day 2' object - which is
likely to be RCC, but the exact nature of which is unknown.



Whatever it was, it was big enough to show up on radar, and also
apparently on the AF Maui infrared views:
http://www.popularmechanics.com/scie...e/1282936.html
So it's not tiny in size- it's a few inches on a side at least.
Since the foam broke up on hitting the wing, that means whatever it was
came from the Shuttle itself.
Of course, you can see what everyone thought on detecting it- Ed White's
Glove Syndrome; something left by accident in the cargo bay before
launch that floated out during an RCS firing.

Pat

Jorge R. Frank wrote:

It's fairly doubtful that it would have been visible, considering that the
resolution of those photos appears to be in the 2 ft range (the RCS nozzles
are barely single pixels) while the suspected hole was in the 6-10 inch
range.



I was really surprised by the level of detail that is visible on them
though; you can see the Columbia's name on the wing top, for instance,
though it's not legible. One thing that could change the equation is
that the hole would appear darker than the medium dark gray RCC due to
shadows; and I still think that the infrared might show an effect
despite its lower resolution due to differential heating at the damage site.

BTW, why isn't the rear cargo bay door on the port side fully open?



There are no "forward" or "rear" cargo bay doors; the port and starboard
doors each move as one piece. What you're seeing is the port *forward*
radiator, which normally is flush with the door, in the deployed position
for extra cooling (the aft radiators are fixed to the inside of the doors).


I should have remembered that from my model: I didn't realize just how
far the doors opened on-orbit (they don't open that wide on the model)
and of course you are right; each door opens as a unit, not in
front/back halves.



Then, presuming you had a hose to do that with that you could
attach to the water dump vent, you'd have to get the patch
aerodynamically smooth, as otherwise the airflow over the wing
wouldn't be laminar during reentry and you'd end up with the same
sort of excessive heating that the hole led to, and still lose the
vehicle. That degree of smoothness needed for repairs has always been
the major bugaboo in any on-orbit repair scheme.



Correct. It's not just because of aerodynamic smoothness, either; it turns
out that RCC damage can propagate across the panel if the surface gets
delaminated. The extent of the problem was not fully appreciated until NASA
started doing arcjet tests on damaged RCC; the tolerances for allowable
damage turned out to be tighter than they thought. That's why everyone who
knows anything about RCC repair - including those who participated in the
in-flight options assessment in the CAIB report - now thinks that the
improvised repair described in that section was not just optimistic, but
that it flat-out would not have worked.


I remember just how critical smoothness was to laminar airflow due to
Columbia going non-laminer at velocities higher than the other Shuttles
on one side on earlier flights due to less precision in its tile smoothness.
I think the whole on-orbit repair option is about as likely to work as
having Australian aborigines do the "firefly" dance from "The Right Stuff".
Makes a nice story...but...
In reality, the story of the Columbia's loss is just a case of a lot of
little things going wrong that led up to something big going wrong;
problems in the whole thought process that went into continuing to
launch with known foam shedding problems, not realizing just how much
the RCC's strength had degraded over the years due to the zinc primer
run-off problem, and frankly, the inability to realize that something
very bad had occurred during ascent, and unfortunately you didn't have
any real way to check out the damage on-orbit.
If there is a villain here, it's that after Challenger this sort of
thing shouldn't have happened again; but that was a lot of years before
Columbia, and after Goldin's purge of the NASA Old Boys, a lot of the
Shuttle brain trust that lived through Challenger wouldn't have been
there anymore to raise the red flag as things started to fall into the
old bad habits again.

Pat

Craig Fink wrote:

And, anything to keep the plasma out of the wing for as long as possible
is better than nothing. Columbia's structure was 99.5% sound prior to
entry. The 0.5% being a hole in the heat shield. Aluminum is particularly
bad in a plasma environment. Fiberglass much, much better, higher melting
temperature, won't oxidize and burn, vary viscous when melted. Water is
great for cooling.



Better change that to glass fiber, not Fiberglass. Fiberglass is a
composite, and I've seen it burn.

If NASA had seen the hole in the wing, the "Columbia Heatshield Repair
Contest" would have already been held at the JSC arc jet facility. And I
believe they would have come up with something better than what showed up
CAIB report, or discussed here.


Remember the time frame to get this all worked out before the Columbia's
consumables in regard to electricity and life support run out. You've
got a few weeks at most.

And it would have worked. Maybe everyone
in this newsgroup just has a much lower opinion of what the people who
work at NASA as a group would have been capable of come up with.


The reason those leading edge panels were made out of RCC was that was
one of the only things that could take the heat of reentry. You can be
as inventive as you want, but there actually is the no-win situation
lurking out there, that no amount of creativity and duct tape can get
you out of.

But, I
personally know and have worked with many of them in the past, and they're
a very smart group of people. Well, most of them. And I'm sure the
collective minds of all these people would have been working overtime on
the problem. Probably the collective minds of the entire nation. If they
had just assessed the damage, instead of doing a parametric study.



Of course given the fragility of the silica tiles and the lack of any
SAFERs our MMUs on the Columbia they thought that any EVA by the
astronauts that could see the area where they thought the damage was
liable to damage the TPS due to the need to keep them tethered.
So assume there isn't any tile damage, and the RCC held up to the
impact. And you send astronauts out on a EVA that damages the tiles in
such a way that you lose the Shuttle on reentry? That's not a good
decision, is it?

NASA did discuss putting bags of water in the void, along with a bunch of
other stuff. I just thought it would be better to put fiberglass in the
bags to slow the usage rate down, spread the cooling out, make it more
rigid. And possibly fiberglass around the bags. Maybe punch holes in some
of the bags afterwards and forcing the water out so that it can flash
evaporate and freezes the whole thing into a large chunk.



Again, you can't get this smooth enough from an airflow point of view to
work. Heating will occur at the ice RCC interface due to it's roughness,
and then the RCC panels on either side of the patch will fail during
reentry, and you'll have a big block of glass-reinforced ice wobbling
around inside the front of the wing. This would not be a good thing, as
it's going to stay in one big chunk due to the glass fibers, and if it
falls out it well wreak havoc on anything it strikes at the velocities
involved.




At that point you really can't ruin the odds, you can only improve them.



No kidding.



Can you make a smooth surface with ice/fiberglass, etc. almost 100% not.



Fiberglass/ice would quickly be self leveling, all the "high" spot would
quickly vaporize (water), fiberglass bend with the flow (if there was any
qbar), and probably melt from the heat before there was any significant
qbar.




That's not how it works; at those hypersonic velocities, any
irregularity will cause increased heating, and that increased heating
will cause the ice in that area to melt faster, which will create a
larger irregularity, which will lead to even faster melting, and pretty
soon everything will just go to hell. This was the fear in regards to
tile damage and the "Zipper Effect". One damaged or missing tile would
cause a spreading area of tile damage as increased temperatures led to
more tiles failing.



Could you create something that would have taken some of the heat load.
100% yes.

Would it have worked. 100% unknown.



And this is the "only" reason NASA rated it's chance of success as "low".
The CIAB members said it was probably much higher than low. NASA rating
it's chance as low is why I said I don't think they really considered it.
Many unknowns. NASA doesn't like unknowns. To painful to look at. In
denial.

Hindsight being 20/20, NASA really should test all the objects onboard in
their arc jet facility, post facto.



That include the crew? ;-)

Pat

Jorge R. Frank wrote:

That's not the only evidence. The aerothermal evidence also strongly
supports the scenario of a 6-10 inch breach in RCC panel 8L (cited in
several places in the CAIB report, but especially note pages 66 and 73).



Then there's just how early during the reentry objects shedding from the
Shuttle are noted (as those over California), despite the low dynamic
pressure at the time. I assume that these were probably individual tiles
just astern of the hole starting to peel off.
Is that the general consensus?

Pat

On Tue, 25 Jul 2006 19:37:03 -0500, Jorge R. Frank wrote:

Pat Flannery wrote in
:

What's really tragic is that the Air Force infrared telescope at Maui,
Hawaii got fairly clear images of the Shuttle:
http://www.popularmechanics.com/scie...e/1282936.html
If the shuttle had been belly down as it came over the cameras, you
might well have been able to see the damage at this resolution due to
the different heat signatures of the damage and TPS. In this visual
spectrum Maui photo:
http://www.romfart.no/eRomfart/Bilde...iaAMOSsynlig.j
pg Significant detail is visible, but again it's not from the angle one
needs to see the damage.

It's fairly doubtful that it would have been visible, considering that
the resolution of those photos appears to be in the 2 ft range (the RCS
nozzles are barely single pixels) while the suspected hole was in the
6-10 inch range.

BTW, why isn't the rear cargo bay door on the port side fully open?

There are no "forward" or "rear" cargo bay doors; the port and starboard
doors each move as one piece. What you're seeing is the port *forward*
radiator, which normally is flush with the door, in the deployed
position for extra cooling (the aft radiators are fixed to the inside of
the doors).

Then, presuming you had a hose to do that with that you could attach to
the water dump vent, you'd have to get the patch aerodynamically
smooth, as otherwise the airflow over the wing wouldn't be laminar
during reentry and you'd end up with the same sort of excessive heating
that the hole led to, and still lose the vehicle. That degree of
smoothness needed for repairs has always been the major bugaboo in any
on-orbit repair scheme.

Correct. It's not just because of aerodynamic smoothness, either; it
turns out that RCC damage can propagate across the panel if the surface
gets delaminated. The extent of the problem was not fully appreciated
until NASA started doing arcjet tests on damaged RCC; the tolerances for
allowable damage turned out to be tighter than they thought. That's why
everyone who knows anything about RCC repair - including those who
participated in the in-flight options assessment in the CAIB report -
now thinks that the improvised repair described in that section was not
just optimistic, but that it flat-out would not have worked.

The participates in the post-flight assessment in the CAIB report who
rated the repair option "low" only because they just don't know. Due to
their own ignorance? I really haven't read anything about any
post-disaster testing conducted in the arc jet facility at JSC. I'm kind
of ignorant on the subject right now, does anybody have any references on
the subject of Columbia materials tested for an improvised repair of
Columbia's heatshield? How many different repair options were tested? What
was the "best" Columbia repair option tested? Who would have won the
"Columbia Heatshield Repair Contest" at NASA? If it hasn't been done yet,
then a "Columbia Memorial Heatshield Repair Contest" would be fun.

Did you see the cool video with the thermal camera of the RCC delaminated
test samples on-orbit. Reminds me of my senior project. It was really
clear the size of delaminated area. The exterior layer quickly changing
temperature, while the inner layer lagging behind as conduction is no
longer occurring between the two layers. The exterior layer changing
temperature much more quickly as the thermal mass in that area was
reduced, compared to the non-delaminated RCC. Expansion and contraction
rates between the delaminated layers vastly increased between the layers.
It's understandable how thermally induced stress caused by the
differential expansion/contraction between the layers can cause the
charcoal binder of the graphite/charcoal RCC composite to fail were the
stress is highest. The edge or transition from laminated to delaminated.
Charcoal just doesn't stretch or bend to very well.

Relieving the thermally induced stress would probably be a good idea, to
keep the delamination from propagating. Breaking, cracking, or cutting
one of the layers of the delamination might do it. Or, even grinding off
one of the layers before repairing it. I'm sure they are probably looking
at it.

From the perspective of building a better RCC panel, getting rid of the
lamination layers would be a good thing. Instead of gluing layer upon
layer of graphite cloth, weave the graphite into one variable thickness,
proper thickness layer, put it in the mold, add the binder and turn it
into charcoal. Or, cut all the layers to size, lay them in the mold, and
hand stitch a whole lot of graphite thread to bind the layers together.
Then add the binder and turn it into charcoal.


--
Craig Fink
Courtesy E-Mail Welcome @

On Wed, 26 Jul 2006 04:32:41 -0500, Pat Flannery wrote:


Then there's just how early during the reentry objects shedding from the
Shuttle are noted (as those over California), despite the low dynamic
pressure at the time. I assume that these were probably individual tiles
just astern of the hole starting to peel off.
Is that the general consensus?

I would think the first thing to come off would be any dangling pieces of
RCC panel. The tiles would not have come of until some time after the
aluminum bulkhead had been pierced. After the plasma created a hole in the
aluminum bulkhead, it would have heated the skin of the wing from the
inside, melting the aluminum skin and letting the tiles go. Unzipping.

--
Craig Fink
Courtesy E-Mail Welcome @

On Wed, 26 Jul 2006 07:49:41 -0500, Craig Fink wrote
(in article ):


I would think the first thing to come off would be any dangling pieces of RCC

panel. The tiles would not have come of until some time after the aluminum
bulkhead had been pierced. After the plasma created a hole in the aluminum
bulkhead, it would have heated the skin of the wing from the inside, melting
the aluminum skin and letting the tiles go. Unzipping.

You really need to go back and re-read the CAIB report.

--
Herb

"Everything is controlled by a small evil group to which,
unfortunately, no one we know belongs."
~Anonymous

"OM" wrote in message
...
On Tue, 25 Jul 2006 10:35:43 -0400, "Jeff Findley"
wrote:

Exactly how do you stuff this insulation inside the void and get ice to
form
there considering you're in vaccuum?

...Actually, ice will form, Jeff. Remember the problems they had with
the Cosmic Space Turds?

True, but getting it to distribute uniformly in the insulation stuffed
inside would be fun. Plus it will start to sublimate once frozen, so you'd
want to start your deorbit burn a.s.a.p. after EVA.

As a last ditch effort, it would be better than nothing, but I wouldn't give
it much of a shot at working. Too many variables, plus no time to do a
proper analysis on the fix.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

"Greg D. Moore (Strider)" wrote in message
nk.net...
But again, the assumption (hindsight 20/20 of course) is "we know there's
a
hole and it's fatal"

At that point you really can't ruin the odds, you can only improve them.

Can you make a smooth surface with ice/fiberglass, etc. almost 100% not.

Could you create something that would have taken some of the heat load.
100%
yes.

Would it have worked. 100% unknown.

Agreed. It's a last ditch effort to stay alive.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

Pat Flannery wrote in
:

If there is a villain here, it's that after Challenger this sort of
thing shouldn't have happened again; but that was a lot of years
before Columbia, and after Goldin's purge of the NASA Old Boys, a lot
of the Shuttle brain trust that lived through Challenger wouldn't have
been there anymore to raise the red flag as things started to fall
into the old bad habits again.

It goes deeper than that, Pat. The external tanks have been shedding foam
since STS-1, and no one - the NASA Old Boys included - thought it was
enough of a safety hazard to put a high priority on fixing it. They put
*some* priority on fixing it - there have been efforts to tweak the foam
since STS-1 - but it was treated as a maintenance issue, not a safety-of-
flight issue.

This is one area where I take issue with the CAIB report. It wasn't an
issue of not learning the lessons of Challenger, or learning them and then
institutionally "forgetting" them due to personnel turnover. Since
Challenger, shuttle program management has repeatedly grounded the fleet
when they thought a safety hazard existed - hydrogen leaks in 1990, wiring
in 1999, MPS flowliner cracks in 2002, and a whole bunch more that I can't
remember off the top of my head right now.

It wasn't really an issue of schedule pressure, either: the flowliner
cracks were discovered during a period of schedule pressure that was just
as bad as it was for STS-107 a few months later, and NASA *still* grounded
the fleet for months to fix it.

The failure was one of imagination: it's easy to imagine how a hydrogen
leak, or a shorted electrical bus, or a piece of flowliner ingested into a
high-pressure turbopump, can ruin your whole day. It's not so easy to
imagine that with foam, especially when all the NASA Old Boys who were
program manager before you had all come to the same mistaken conclusion
about it.

If there had been a poll on sci.space.* on January 31, 2003 on the top ten
safety hazards in the shuttle program, I guarantee you foam wouldn't have
made the list. Anyone who says otherwise is seriously fooling themselves.

--
JRF

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