Board reiterates foam's damage to shuttle

Washington Times ^ | Wednesday, June 25, 2003 | William Glanz

[JohnHuang2]

Accident investigators examining the disintegration of the Space Shuttle Columbia said more forcefully yesterday that foam insulation had shed from the orbiter's external fuel tank and pierced its left wing.

Investigators also said they will recommend that the National Aeronautics and Space Administration find better ways to guard against damage to thermal protection tiles from foam.

[JohnHuang2]

Wednesday, June 25, 2003

Quote of the Day by piasa

[The Duke]

No mention that this "foam" was the idea of the environmentalist Nazis during the Clinton regime.

[snopercod]

How did we get from a minor crack or a broken t-seal to "a hole 6-10" in diameter"?

[GodBlessRonaldReagan]

Thanks to Al Gore.

[Iris7]

How about cause and effect? The supersonic gas layer next to the shuttle is hotter that a cutting torch flame and moving about four times faster than a rifle bullet. The aluminum alloys making up the shuttle's structure mostly melt around a thousand degrees F. An eighth inch crack in the protective layer (especially on the leading edge) soon enough leads to a big hole. Then a bigger hole, then loss of half the wing, etc.

[Cold Heat]

Methinks they are using language that the general public will consume.

Obviously, at some point the hole was that large.(larger when the RCC detached)

I don't think these folks understand their own theory very well. They also do not understand that most folks were way ahead of them from the start.

On another note. I feel that their assumptions regarding the shuttle flying again within nine months is preposterous.

As I understand their recommendations and conclusions that are as yet forthcoming, the fixes needed will take well over a year, perhaps two.(and they still will have NOT fixed the cause!)

Call me a bit cynical, but I see nothing but a test flight or two within the next two years.

[snopercod]

How does your theory explain the object that floated away from the shuttle on orbit?

[NormsRevenge]

Thanks for the post.

The word 'pierced' as in pierced the left wing.. ouch. A large enough chunk embedded as part of the foam itself could leave a pretty good gouge and a large hole, at best, were it to hit the right spots of the wing.

Was it waste ice or a door or rcc panel spotted near the shuttle while in orbit?

sighhh....NASA has lost its lustre and it's way. Time to re-group...

[snopercod]

The radar signature of the "object" was consistent either with a t-seal, or a piece of RCC. Whatever it was had to have had a "bend" in it and an area of about 100 sq. in., IIRC.

If it was piece of RCC, then the attachment to the wing had to have failed - either the RCC part or the wing part.

It has not been demonstrated that the foam impact had enough energy to break the attachment. Maybe it's possible, or maybe the attachment was just defective somehow.

I doubt we'll ever know for sure.

[Iris7]

The investigation board ran an impact test on wing leading edge carbon-carbon heatshield and adjacent tiles using a piece of real fuel tank insulating foam and a large gas gun that gave the foam piece the correct velocity. The actual carbon-carbon heatshield components were not used because for this first test series it was decided to use glass fiber reinforced resin composite mock-up components that look like the real thing, pretty much, and have the same dimensions. These mock-up components came from early heatshield development and are surplus. These "fiber glass" components have very different mechanical characteristics than the carbon-carbon parts.

Analysis of the test results indicate fracture of carbon-carbon components was likely. One suspected piece is relatively long and thin, and a piece of it when tested on a radar range showed identical reflections to the object leaving COLUMBIA. The current theory is that this component did indeed fracture, and was observed by ground radar to leave COLUMBIA. This theory predicts that an opening in the order of 1/8" to 1/4" wide and perhaps twenty inches long occurred in the leading wing edge heat shield. Engineering analysis of the COLUMBIA debris is consistent with this theory. As I see the information, very consistent indeed.

This stuff comes from the investigation board and I read it on Yahoo! news over a period of some weeks.

Looks like least hypothesis to me.

[Iris7]

I watched the Shuttle debate and design with interest at the time. The unfortunate fact is that the Shuttle is not safe or cost effective due to it's design. Orbital insertion is much more cheaply achieved by other means, especially the Russian machines. The Shuttle cannot meet the promises made for it. A silk purse cannot be made from a sow's ear.

[Iris7]

My earlier to you was aimed poorly. I see you are probably more knowledgeable than I am. I believe the theory holds that what was observed was a part of the T-seal.

[snopercod]

I agree with what you say - it could have been a t-seal.

But there are a few "loose ends" with this theory. The most obvious one is that the board said earlier that the plasma got into the wing outboard of the t-seal. They determined this by the order in which the instrumentation failed, indicating which wire bundles burned through at what time. Maybe that opinion has been revised.

The second thing is that the nitrogen-gun tests did not damage the t-seal at all. But suppose that they had. The t-seal would have been broken in only one place, near the leading edge, or a chunk would have been knocked out. That would have left two pieces still attached at the respective ends. It seems possible that the mach 2 airflow could have ripped off one or both of the remaining fragments, but then they wouldn't have "floated off" later on, would they?

I fear that NASA has just settled on the easiest thing to explain and fix.

I guess I just won't be satisfied until I find out about the leading edge modification that was done in Palmdale in 1999. I want to know what was done, why it was done, and see some verification that whatever was done was done properly.

I also want to see the rationale for rejecting the electrical discharge (blue lightning) theory. Having some knowledge of lightning effects on fiberglass and carbon fiber aircraft, I know that lightning can blow big chunks out of carbon material if it strikes.

At one time, there were "fault trees" open on both these theories. Were they properly evaluated and put to bed? Or just covered up?

[Cold Heat]

The Russian payload capability is totally insufficient for station construction or anything else we have planned.

As far as I am concerned the shuttle is it! (until the new gen bird is ready to fly.

The recent loss was caused by a impact. The debris came off the tank, which is the culprit.

Come to think of it, the tank was the culprit in the other total loss as well. The insulation was insufficient to protect itself from the faulty booster seal.

It seems that I have summarized both losses and not mentioned the shuttle once.

No, I do not think the shuttle airframe is faulty. It is too complicated, but not faulty. No airframe is designed to take a impact like that on the wing. None at all. My concern now is that the engineers will attempt to make the craft idiot proof and never fix the real problem.......

The tank.

[Cold Heat]

I gave some thought to the lightning theory and rejected it because there is absolutely no other information that points to it. I just cannot seem to be able to factor it in. As you mentioned, the fault tree ended with the report.

The floater has received much attention and everyone is trying to fit the floating object into the scenario via the T-seal.

Again, with no other information to ID the debris, I must leave it out and go with what we have.

The fact that the wings and TPS received many changes during the overhaul is a fact, (as we discussed previously).

The impact test is not definitive because the foam piece was rotating at a high rate and hence likely changed the force of impact dramatically. It could have damaged the T-seal mount and even the RCC fasteners. It likely punched a hole behind the RCC as well, allowing plasma to cut the mounts and critical structure.

But strengthening the RCC and related hdwe is not the answer without fixing the shedding foam problem that caused the damage. In fact, the shuttle should be fine. Unless, in a effort to reduce weight and increase payload they did some changes that we are unaware of.

If I were running things, I would be all over the Michoud facility with every resource I had to fix the damn tank.

During my years in plant maintenance I discovered a fact that always followed me from facility to facility. When ever a problem causes losses and loss of life the emphasis always shifts from fixing the cause to idiot proofing the machine so that It cannot happen again. That is what they are doing here.

If what they do helps with micro-meteorite impacts then it will be worth the effort, but if they try to make an indestructible tank out of it, then the flight characteristics issue will come up and that bird will never fly again. It needs to be lighter, not heavier..................................Just fix the tank please.

[Iris7]

As far as the Russian payload being too small for current programs, Jerry Pournelle points out that the Saturn V would get any job done better than the Shuttle. He points out that the last two Saturn Vs were not used but instead made into monuments. Pournelle believes NASA has destroyed the Saturn V blueprints and support documents.

To me the Shuttle is absurd especially because half of it's operating cost in terms of dollars per pound to orbit is lost in the Shuttle's own weight. Why put a hundred tons into orbit, or whatever the mass of the Shuttle is, when you are merely going to use the cost of doing so to return a few men to earth? Heartbreakingly stupid.

[bonesmccoy]

Q: How did we get from a minor crack or a broken t-seal to "a hole 6-10" in diameter"?

A: How did we get from minor blow-by to a hole in the SRM casing that lead to 51-L?

One hates to answer questions with another question, but this one is so patently obvious that... well... you'd have to be blind not to see the hole.

[bonesmccoy]

I doubt that the plans for the Saturn launch vehicles have been destroyed.

Nevertheless, the plans are somewhat irrelevant. No one working in NASA was around 40 years ago when the Saturn project occurred.

STS can be converted to a heavy lift system. These studies were published by Marshall in analyses called Shuttle-C or even Shuttle Z.

Shuttle Z extends the STS to lift 100,000+ pound payloads to higher orbits or even cislunar flight.

[snopercod]

Very sensible post. Thanks.

[snopercod]

Do we know that RCC erodes at high temperatures just like steel? I have not seen that demonstrated.