Michoud External Tanks May Hold Clue About Columbia Accident

Michoud, Michoud, Nichoud. You will learn that name like you did with Martin Marrietta as it relates to Challenger.

This can be a very confusing issue to undestand. If you have a question, I will be happy to answer it, but if you are confused about something I wrote, Please ask me about it, and I will clarify the context for you. Thanks.

I have been working on this since yesterday morning. I am just linking my discussions on other boards so that you can see what I have found. Others have contributed to these findings, so you have to be willing to follow the links and take a few hours to fully grasp its contents.

My original hypothesis was posted here: http://www.flightsimnetwork.com/dcforum/DCForumID2/4703.html

In it I wrote: My Own research of course. Follow Closely now. I am 100% Serious, and I am not trolling, so please don't flame me, as I believe I am on to something here.

I was involved in a thread on flightsim here: http://www.flightsimnetwork.com/dcforum/DCForumID2/4703.html

In that Thread, I screwed up and called the ET (External Tank) An External Tank Booster. I was promptly corrected and I fixed it.

Anyway, that led to further speculation on my part regarding the ET, which is Manufactured by Michoud, a Lockheed Martin Company. http://www.lockheedmartin.com/michoud/et/et_index.html

Anyway the ET used on this mission was an older model, called a LWT. The Newer ones started flying in 1998, and are 7500 Pounds Lighter and are designated SLWT. (The SLWT's weigh in 7500 lbs lighter than LWT's and 17,500 lbs. from the original.)

You can see the designation numbers here from Michouds website: http://www.lockheedmartin.com/michoud/et/shuttle_flight_info.pdf

And there are 8 other shuttle missions that used higher ET Numbers. You have to go back to STS-99, ET-92 for a prior flight which was launched on February 1, 2000.

Here is why this may be relevent. In the fs thread, we talked about the sprayed on insulation, and I was theorizing about it when thinking this ET was a newer, 7500 Pond Lighter SLWT.

I was wrong. But That is what NASA said in its Press Kit for this flight, which you can read here: http://www.shuttlepresskit.com/STS-107

They Replied back to me by email with this: "ET-93 was a LWT. It was delivered to NASA Nov. 2, 2000"

The Info matches the delivery dates of 11/2/2000, and the on-dock date of 12/20/2000.

I also have sent emails to NASA to inquire about this, along with my condolences.

1) Is the reported weights in the Shuttle Press Kit correct, or 7500 Pound too light, which is the difference in weight between the LWT and the SLWT.

2) Will the Insulation sprayed on the ET degrade over a period of 2 years such that it will break off on Launch. (Which it appears has happened)

4) If the insulation did not fall off the ET, It would not have damaged the Wing, hence potentially no disaster.

Folks, I am absolutely serious about this and have spent all morning researching this.

"The report said that a foam insulation patch about 7 inches by 30 inches in size popped off the fuel tank about 80 seconds after Columbia had left its launch pad, Readdy said. NASA engineers spotted the peeling insulation on high-speed cameras that recorded Columbia's launch."

That lead to other comments in that thread: Well, Ron Dittemore of NASA just said on the news conference, he is speculating the ET as the main cause.

He also stated they were comparing debris from STS-112. STS-112 had an ET number of ET-115, delivered 9/26/01, On-dock 12/19/01.

If the ET from STS-112 is a SLWT, He was trying to compare two different tanks. The press kit from STS-112 also says it was a SLWT.

One more note. I have every right to speculate as does NASA. It was an accident, yes, but there is something called accountability, and I I have a theory, so what.

Ron Dittemore basically said in the Press Conference right now he considers the ET the cause as well.

He also just said they had had debris fall from the Et on STS-50. That launched on June 25th, 1992, and had ET-50, delivered on 10/31/88, and on-dock on 1/27/1992.

And in this thread: http://www.flightsimnetwork.com/dcforum/DCForumID2/4703.html

Engineers did speculate a large gash had occured, and their memo was dismissed for reasons unknown.

I'm sorry. They knew or should have known if the engineer group last Thursday concluded it was a problem, they should have told the crew.

If they didn't tell the crew, many heads will roll, and that was wrong. They had 2 days to inform them. I hope it turns out they did tell them.

That Shuttle Commander is exactly that. Pilot in Command. He had a right to know and NASA has let us down again, IMHO.

Do Accidents happen. Yes. But when the engineers acknowledge a problem in an investigation they were charged with carrying out as is this case, whoever stopped that memo or refuted it has some responsibility, IMHO. It should have been investigated, and the landing postponed. They have postponed landings before, and they do have contingent procedures for that as well.

Next up, get rid of that Insulation, or find a way to reduce or eliminate that ice, and then we can fly again.

It wasn't the design of the shuttle, IMHO. It was a defect in design on the External Tank (ET) that I feel is complicit at this point.

EDIT: I was wrong, I called the ET The External Main Booster, which Ned pointed out to me. Thanks Ned. It is The External Tank

Here is the link for the ET http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/et.html End Edit:

I saw an astronaut on FOX showing how easily those tiles could be chipped away once the perimeter has been breached. It chips away quite easily.

Furthermore, that damage may have a causal effect in the induced drag that NASA has acknowledged on the left wing. This may have forced the Shuttle into a path not conducent to a proper landing trajectory which may also have contributed.

IMHO, the pieces are already falling into place, and while other events may turn up something different, I feel my and others theories similar to mine are sound and logical.

I have confidence in the program even after this event. Someone dropped the ball here. The engineers felt differently than you stated, and that will be released soon enough.

The current tank system has been used since STS-91 in 1998. The Liquid Hydrogen Tank and The Liquid Oxygen Tank are made of Aluminum Lithium, which according to NASA is 30% Stronger and 5% less dense than the prior metal alloy.

I am going to do some more research on the ET and see what the MFG says about the sprayed on insulation compared to the prior ET. The new ET is 7500 pounds lighter and thus allows heavier payloads to be delivered to the ISS. I would be interested to see how the Ice formed is either less or more in similar weather conditions.

Your point about Humidity is valid. Maybe we should look at another location for launches. Maybe Edwards would be better, who knows. Good Question though, as I have not looked at that yet.

You Said: "there weren't contingencies to rescue the crew on orbit. There was nothing that could be done."

I disagree. They saved Apollo 13's astronauts. I think if we had to retrive in orbit, someone would have designed a plan. Would it have worked. Who Knows.

But the important thing is that all of these questions, yours, mine and others need to be asked.

Guess who has the decisions on all of the Abort Contingencies currently in place. Not The Ground.

It is the Flight Crew that determines the abort procedure carried out once launched. They should have been told. Period.

As to the Insulation, I did say: "Next up, get rid of that Insulation, or find a way to reduce or eliminate that ice, and then we can fly again."

That is still valid. If they find a way to eliminate that Ice, or that Insulation from the outside of the ET, there would not have been contact with the shuttle wing. That is what I should have said above.

The only thing I can think of right now, is the Double Hull Theory currently used on Oil Tankers.

If the ET Had a double shell with the insulation sprayed on the inner shell and then the outer shell may be protected from the ice. It is a thought. The question is, how can we eliminate the sprayed on insulation. Well, how about moving it to the inside shell. Just an Idea.

******************************** You Said: "-This ET was not one of the new Super Lightweight tanks, it was one of the last two Lightweight tanks (that have been flown since very early in the STS program)."

Please cite your official source on that, as mine states that it was a SLWT. And then I will post Mine.

The Weldalite on the ET is less than a Half Inch Thick. Yes they are on version #3, which has saved a total of 17,500 pounds from the original.

I just shot off an email to an official source, so I'll let you know what I get back.

I do wonder why they used an older model since they have been flying the SLWT's since 1998. Seems kind of Odd.

I got my Info from a NASA Press Kit, Page 142, which was obviously wrong, and on Page 18 where it states:

NASA has some more explaining to do. That is a major error in my book. Did they get the weights wrong, or is this just a Grammattical Error?

Here is a Link for the Press Kit last updated 12/8/2002, Page 9: http://www.shuttlepresskit.com/STS-107/

I also sent a request to NASA for addtional Clarification on the Press Kit Discrepancies.

And: Ok the closest comparison would have to be with STS-50, which was also Columbia, and took off in June of 1992.

Same Shuttle, although it does not state whether it used a LWT, it most likely did.

Columbia last flew in March of 2002 (STS-109) with a SLWT, menaing it had 7500 lbs. less of an External Tank, thus allowing more payload. That mission was a Hubble Maintenance Mission.

The comparison of STS-112 Atlantis (The debris comparison by NASA) Should not have been done as this was a different lighter shuttle, and a Lighter External tank. (A newer SLWT).

Can you compare a tire going flat on a Michelin to a Goodyear. Two totally different designs.

Now, it still has to be ascertained whether the sprayed on insulation process is different, and Michoud says it is, and different amounts are sprayed on the tanks at a different thickness.

Folks, all I am saying as this. NASA has been very forthcoming, but come to your own conclusions as well.

Their press conferences have already made mistakes in accuracy, and the Press is giving them passes, maybe because they don't realize this.

Their Press kit is wrong, and the press may be relying on some of that info as well.

Braun over at Avsim posted this: http://ftp.avsim.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=1422&forum=DCForumID6

During the STS-87 mission, there was a change made on the external tank. Because of NASA's goal to use environmentally friendly roducts, a new method of "foaming" the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter. Foam cause damage to a ceramic tile?! That seems unlikely, however, when that foam is combined with a flight velocity between speeds of MACH two to MACH four, it becomes a projectile with incredible damage potential. The big question? At what phase of the flight did it happen and what changes need to be made to correct this for future missions? I will explain the entire process.

basically what I have learned is they spray a different thickness on different parts of the ET's.

STS-87 had an ET-89 which Had a delivery date of 6/26/1997 and an on-dock date of 7/15/1997.

STS-87 flew on 11/19/1997, which was alos Columbia and it sustained extensive tile damage during launch according to Michoud.

Also: MOST IMPORTANT Discovery Yet. Someone pointed it out to me. This NASA Engineer Knew.

Look at what this guy said: Greg Katnik 12/1997 (Engineer at Kennedy Space Center) " The tiles do a fantastic job of repelling heat, however they are very fragile and susceptible to impact damage."

Now the big question -- why? The evidence of this conclusion has now been forwarded to Marshall Space Flight Center (MSFC) because this is the design center for the external tank. MSFC will pursue the cause of damage. Here are some descriptions of some of the possible causes:

POSSIBILITY 1 The primer that bonds the tank foam to the metal sub-stream was defective and did not set properly. This was eliminated as a cause because the photography indicated that the areas of foam loss (divots) did not protrude all the way down to the primer.

POSSIBILITY 3 The STS-86 mission revealed a similar damage pattern but to a much lesser degree than STS-87. The STS-86 tile damage was accepted ruled as an unexplained anomaly because it was a night launch and did not provide the opportunity for the photographic evidence the STS-87 mission did. A review of the records of the STS-86 records revealed that a change to the type of foam was used on the external tank. This event is significant because the pattern of damage on this flight was similar to STS-87 but to a much lesser degree. The reason for the change in the type of foam is due to the desire of NASA to use "environmentally friendly" materials in the space program. Freon was used in the production of the previous foam. This method was eliminated in favor of foam that did not require freon for its production. MSFC is investigating the consideration that some characteristics of the new foam may not be known for the ascent environment.

POSSIBILITY 4 Another consideration is cryogenic loading, specifically hydrogen (-423 degrees Fahrenheit) and oxygen (-297 degrees Fahrenheit). These extreme temperatures cause the external tank to shrink up to six (6) linear inches while it is on the pad prior to launch. Even though this may not seem much when compared to the circumference of the external tank, six inches of shrinkage is significant.

This is where the investigation stands at this point in time. As you can imagine, this investigative process has required many hours and the skills of many men and women dedicated to the safety of the shuttle program. The key point I want to emphasize is the PROCESS OF INVESTIGATION, which is coordinated amongst many people and considers all possibilities. This investigation has used photography, telemetry, radar coverage during the launch, aerodynamic modeling, laboratory analysis and many more technical areas of expertise.

As this investigation continues, I am very comfortable that the questions will be answered and the solutions applied. In fact, some of the solutions are already in progress. At present the foam on the sides of the tank is being sanded down to the nominal minimum thickness. This removes the outer surface, which is tougher than the foam core, and lessens the amount of foam that can separate and hit the orbiter.

Good for NASA, but it didn't work, IMHO, whatever changes they made still continued to occurr.

We are darn lucky that other shuttles have not crashed before this. This is a very serious issue.

I am convinced that Michoud's name will be learned as well as Martin Marrietta was in relation to Challenger.

Fix the ET's and we can get back where we belong. I have taken an enormous amount of grief over this, but that is ok. I'm used to it.

BBC Shuttle News Video: http://www.flightsimnetwork.com/dcforum/DCForumID2/4711.html

http://ftp.avsim.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=1420&forum=DCForumID6

http://ftp.avsim.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=1422&forum=DCForumID6

Yah, I like and suggested the same idea some time last night, (can't remember)

It could be designed like a Stanley thermos bottle, but the weight would sure be higher, unless a titanium shell would work. You could use vacuum in place of insulation to keep things at temperature.

BTW, these engineers who think a gash was created that was 22cm x 80cm, could be right, but the debris would have had to hit it just right and be launched by the turbulence into the tiles at the right angle.

It could happen and I believe that is what that were saying, a worst case scenario.

But, what was that large object seen coming of the shuttle over Nevada? Some say it was the wheel well door.

Only NASA would know the stresses on the shuttle prior to that point and if it was sufficient for a burn through from the debris damage. It was at over 200 thousand when it broke up. It was much higher over Nevada.

I still am looking for more factors here.

Some fluke of nature or as yet unknown sequence of events occurred, or the object did something while it was behind the wing that we could not see.

Just asked bonesmccoy if it was possible the "ice" plowed a channel in the underwing tile up to and under the landing gear door ?

Speaking of humidity, does anyone know the answers to these questions?

1. Could the humidity fluctuations have caused any number of shrink/swell cycles in the foam insulation while the ET was in storage, thus weakening the overall strength of the adherance of foam to tank?

2. Does the foam insulation retain moisture? If so, then wouldn't the foam insulation have been frozen solid at the time it broke free from the ET during launch, making it essentially a block of ice with some foam mixed in?

Sure, they would have gotten to say goodbye and we would have had a world wide drama and horror played out over multiple days that would have been much more painful. I don't know, if I was faced with the choice of knowing 4 days before I die that I was going to die, or not know, I'd choose not know. Also I think you assume too much that the families would like to have had that extra time. Again, if it was me I wouldn't have wanted that extra time. I couldn't handle the drama and emotion, it'd just make the inevitable worse.

Your choice - but not necessarily everyone else's.

It's their decision - by regulation and by right.

The Mission Commander and the crew deserve the right to at least make that decision.

This is all moot, however. I don't seriously think that NASA had a real clue what had happened or that there was a serious danger.

If they did, and chose to keep it a secret - heads will roll, and rightly so.

Sonar5, I want to commend you.

You have done work I would love to have had time to do after Saturday.

It would be interesting to have SOMEONE in the Press Corp simply ask whether the age and materials used on 107's ET contributed to the "popcorning" that may have proven eventually fatal to Columbia.

On another issue, I used to watch Dental Labs mill crowns on demand. Perhaps such a mill, based on such technology, could be added to standard equipment to punch out a limited number of critical tile replacements on orbit, using the coding unique to each tile.

But, I think I get it. ET=CAUSE / TILE=AFFECT

Thanks Again...

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