Michoud External Tanks May Hold Clue About Columbia Accident

Nasa, Michoud ^ | 2/4/2003 | Joseph Ranos

[GovernmentShrinker]

ping

[GovernmentShrinker]

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)

Have you established when and where this insulation is foamed on? I.e., does the fact that the tank was shipped to NASA in 2000 actually establish that the foam had been sitting on it all this time?

[Sonar5]

You Said:
'Have you established when and where this insulation is foamed on? I.e., does the fact that the tank was shipped to NASA in 2000 actually establish that the foam had been sitting on it all this time?"


Good Question. It is my understanding it is applied at the manufacturing facility in Louisiana. I have come across nothing that conflicts with that.

Regards,
Joe

[GovernmentShrinker]

Next question (since nobody else seems to be peppering you with questions):

Can you create a table starting with STS-86 (first mission where the new "environmentally friendly" foam was used) which shows: 1) tank class (LWT/SLWT), 2) foam type (old/new), 3) degree of tile damage (e.g. STS-87 & STS 107 "severe" (at least presumed so for STS-107)/"moderate"/"negligible"), and 4) possible other contributing factors to moderate or severe tile damage (e.g. STS-87 was first mission to perform the "roll to heads up" maneuver). I'm interested in how many missions have had the combination of new foam and old LWT tank.

[Sonar5]

Ok, I'm working on it.

[SirAllen]

There is no such thing as a tile repair kit. So even if they had the "jetpacks" what good would have it done? The only thing that'd come from it is "we're going to die." And each of the 30,000 tiles on the shuttle are uniquely shaped, so unless they stocked all 30,000 of them in the shuttle bay which wouldn't leave them enough room to even get out on that spacewalk, nothing could have even been done beforehand. Not to mention the impossibility of gluing them back on in the void of space with huge temperature variances and no atmosphere.

[GovernmentShrinker]

Good. Remember, no rest for the weary. All work and no play makes Sonar5 a Freeper Extraordinaire :)

BTW, somebody ought to watch the next NASA press conference, and see if some smarty-pants reporter asks about the tank type discrepancy, as if s/he was the first to notice it.

[GovernmentShrinker]

Good. Remember, no rest for the weary. All work and no play makes Sonar5 a Freeper Extraordinaire :)

BTW, somebody ought to watch the next NASA press conference, and see if some smarty-pants reporter asks about the tank type discrepancy, as if s/he was the first to notice it.

[Sonar5]

Valid Points Sir Allen.

The External tank is the Cause, and the Tile damage is the effect, IMHO.

Fix the External Tank so it does not lose debris, and we can get back to space.

The Shuttle is a sound design, IMHO.

Regards,
Joe

[Cold Heat]

Yup sonar, I found all this stuff last night, but I did not need to look hard.

The fact that the heavier tank was used is that it fit into the weight allowances. According to the initial NASA briefing after the accident, it was one of only two left in inventory. They have been using the ulta light sue to the heavy payloads going to the ISS. The heavier tank fit the profile because they had removed a great deal of weight from the Columbia during re-fit.

Unfortunately they did not have any issues at the time with the insulation because they assumed the problem was fixed. They had sanded down certain areas of the insulation and done a number of other things to mitigate the insuation loss problem.

Apparently it was not enough.

BTW, Michoud is my old stomping grounds. It is pronouced "Meeshooo".

[expatpat]

What on earth is this rambling about. Can you give a succinct summary of your "theory", so we can understand what you are talking about? (and what has you single-engine license got to do with it?)

[Cold Heat]

Fix the External Tank so it does not lose debris, and we can get back to space

Unfortunately, my take on this is a bit more conservative.

I believe that the insulation strike did in fact contribute to the loss of Columbia, but it was not the sole cause.

The investigation should reveal this and Iam content to be patient.

What I am saying, is that if another shuttle, not Columbia had made this flight with the same tank, the results may very well have been different.

There is more to this IMHO!

[GovernmentShrinker]

Old model tank used on this mission. Hadn't been used for a long time (more recent missions used newer, lighter model). NASA current press kit misidentifies this mission's tank as being the newer model. Sonar5's direct communication with someone at Michoud confirmed it was actually the older model.

[Cold Heat]

He found the data that the tank was a old model with previous problems and connected the dots.

The only thing that I disagree with is the inference that NASA did not state which tank was used. Fortunately I heard them admit this during the initial briefing. The engineer stated that the older heavier tank was used. "One of two left in inventory", he said.

On the NASA site is the story of STS-87 and 86 which had insulation problems with this same tank in 1997.

[ASOC]

Uh, Dude
SLWT is used for ISS missions, the LWT is used for non-ISS misions. The difference in weight is a big deal for final orbit. Non-ISS mission = use old tank from stock.

This was covered in some depth in a press conference BTW.

Sorry you had to waste your morning.

Have fun.

[Denver Ditdat]

Look at the miracle of Apollo 13, and what they did to bring those heroes home.

Miracle is exactly right. Had the cryo tank explosion occured at almost any other time in the mission, Lovell, Haise, and Swigert would be dead. Earlier in the misison and there would not have been enough consumables. Slow death. Later, and the LM "lifeboat" would be left behind on the lunar surface. Quick death. Fatal either way, and all the wishing, hoping, and speculating in the world could do nothing about it.

As regrettable as it is, life isn't a Star Trek movie plot in which the heroes always narrowly escape and fatalities are suffered only by the expendable "no name" red shirts.

Sorry. I wish it were otherwise, too, but this time we fell outside the narrow margins of skill and good fortune.

[Cold Heat]

As a addendum to the above, I must say that the tank problem had been mitigated after 1997, and they honestly thought they had fixed it.

[GovernmentShrinker]

But if the old tank had problems associated with it other than greater weight, it wouldn't be a great idea to use it on any mission. It appears that this MAY be the case.

[Sonar5]

From the press conference Right NOW.

The guy on the press conference right now just said it is only the third occurence of debris hitting it.

Incorrect. At least Five that I am aware of.

STS-50
STS-86
STS-87
STS-112
STS-107

That is at least 5 debris reports from official sources in my links.

[Cold Heat]

They performed a number of mods on the tank and it was deemed safe and had not repeated the events of the past.

This tank unfortunately did. I cannot bring myself to be critical of the decision to use it.

In retrospect, sure! It was a bad idea, but who could have contemplated the accident and who could have made the decision to scrap this multi-million dollar hardware with no evidence except old historical records that have no relationship to the modified and repaired tank.

It is possible that time had caused the adhesive to fail and the shelf life of the tank was mis-interpreted.

Bear in mind that the insulation loss was really minimal compared to the initial difficulties. Bear in mind that this loose insulation had to act in a very peculiar way to cause the required damage, (assuming it is the cause) and that luck, fate and something else likely played a part in this.