Wing Seals Blamed in Columbia's Demise

MoonFacedAssassin writes "MSNBC has this article stating that a 'seal from Columbia's left wing was apparently the mystery object that floated away in orbit, and it was almost certainly struck by something - like a chunk of foam - before it came off, accident investigators said Tuesday.' The article also quoted Navy Rear Admiral Stephen Turcotte, a CAIB member, as having a confidence level 'up there near the 70s and 80s percent' about the T-seal."

Comments

Amazing...

[Anonymous Coward]

These shuttle disasters keep proving how important seals are in our lives, no matter how mundane or simple they appear to be.

The widespread practice of clubbing them, especially the baby ones, has got to stop.

Re:Amazing...

[GigsVT]

Don't worry, the recently passed RAVE act will put an end to all clubbing.

I read...

[crevette]

... Winged Seals responsible for Columbia's desmise.

You know, with all the flying pigs we've seen lately...

Re:I read...

[ackthpt]

... Winged Seals responsible for Columbia's desmise.

You know, with all the flying pigs we've seen lately...

and all the cow manure out of Washington lately, but that's beside the point. O-Rings, now T-Seals. There's an alphabetic trend here. I wonder if it was C-Foam.

Ever get the idea these things are built like models?

"Insert Seal (T) in Wing Assembly (A)"

Confidence Level

[therecaller]

So, if it's not 100%, they just give it another arbitrary number to feed to the media?

Re:Confidence Level

[GuyMannDude]

So, if it's not 100%, they just give it another arbitrary number to feed to the media?

Yeah, that was my reaction on reading the summary as well (god forbid I read the article). Just for once I'd love to see some members of the media really hold NASA's feet to the fire and ask some really tough questions in the press conference. Like "How did you come at that confidence value?" And if the NASA spokesperson hims and haws and doesn't give a solid reason, then the reporter ought to point out that if there is so much uncertainty in the accuracy of the confidence, maybe the answer itself isn't really 70-80% accurate.

The problem is that the media has settled in to a nice, comfortable role of transcribing press conferences mindlessly and reporting them verbatim to an equally mindless public. Where the hell has investigative reporting gone? Surely the cause of the disaster is beyond the ability of most news outlets to investigate for themselves but they should certainly be able to ask some tough questions and pass NASA's explanation through a sanity check.

I realize I'm going a bit off topic here, but I'm really getting sick of the crap in the media. The 'authorities' are just throwing out random numbers knowing that no one is going to bother to question them. The sad thing is that once those numbers are 'out there', they become accepted simply due to their familiarity.

GMD

What a suprise

[(54)T-Dub]

From the begining they said that at least two pieces of debris hit the wing during launch. It seemed pretty obvious to me that this caused the problem. I guess they didn't want to admit that they had been wrong when they gave the go ahead to re-enter.

Re:What a suprise

[Wyatt Earp]

"I guess they didn't want to admit that they had been wrong when they gave the go ahead to re-enter."

There was no other option than to re-enter.

On Columbia's mission there was no abort to ISS. Once it was up there, the only way for those astronauts to come home was to re-enter.

Re:What a suprise

[Exedore]

Well, I don't think that's exactly being fair to NASA. The foam hitting the wing on liftoff was a leading theory all along. What would you have them do? Declare from day one that the foam incident caused the disaster and then lose another shuttle down the road because they were wrong? No, I think the methodic approach is best in the long wrong.

Another point: regardless of what the exact cause is, something obviously went wrong and NASA would have to own up to it no matter what it is. So I don't think the pace of the investigation had anything to do with an attempt to dodge culpability.

Re:What a suprise

[Soft]

Well, there was no contingency plan. The Soyuz on the ISS has enough fuel for a complete deorbital burn; would that be enough to drop to LEO and the shuttle, and then reascend?

No. The ISS is in LEO (400km altitude; neither shuttle nor Soyuz can get much higher), it's a question of orbital inclination, which takes as much fuel to change as it took to get the spacecraft in orbit in the first place. (Well, roughly; I had calculated that 120-160tonnes were needed, the external tank at launch holds 2000, and the Soyuz less than1...)

But I imagine if you abandon the idea of a deorbital burn on the shuttle and instead use the fuel to get to a higher orbit

Not even close, I'm afraid.

I don't know if you could squeeze all seven astronauts into a three person capsule either.

Not for a return to Earth (the seats are form-fitting and the landing quite hard), otherwise possibly, but the more people aboard, the more fuel is required to get anywhere...

Maybe multiple trips would have been required. Can the shuttle and the Soyuz even dock?

No. And they don't use the same docking ports on the ISS either.

That might have required EVA's...in any event, I think that with all of those resources in orbit, something could have been worked out if NASA had committed to a solution.

No. The best bet, provided that the danger were known at the beginning of Columbia's mission, was to conserve power so as to last maybe an extra week or two in orbit, and rush Atlantis through launch preparations, bypassing a number of safety regulations to have it ready in less than a month. And only because it happend to be already sitting on the pad.

Sorry to sound rude like that, but I hear this kind of misconceptions so often...

This may all seem pointless, but it's not: at some point, we will encounter this situation again in some form. "Orbit to ISS" is not part of the any shuttle mission profile; perhaps it should be from now on.

It is said to be in the cards. Not that it would help (the ISS can't hold that many people for long), but no mission was planned elsewhere except for the last Hubble repair before its planned end of life, and all interesting places to go are out of the shuttle's reach anyway.

next problem

[ih8apple]

First it was the O-Ring in 1985
Then it was the T-Seal in 2003


Logically, the next problem will be with the Y-Tube in 2011.
Science and Logic Prevail!

Re:next problem

[John Harrison]

I realize your post was made in jest, but there are some serious differences that this brings up.

Remember how quickly and how harshly politicians jump on Thiokol after Challenger? They wanted to move all shuttle work to a different company. Now that some of the big boys might be at fault with Columbia nobody is up in arms. Why do you think that is?

And this is going to effect NASA how?

[confused philosopher]

There aren't going to be any great changes from this finding. We are still going to use the Shuttles. Only thing now is that we are going to "cross our legs and hope to fly," in the words of a great Canadian Prime Minister spoof.

more info

[pjgeer]

New Scientist also has the latest.

You mean there are seals that live on...

[kahei]

...oh, wait, I just realized that every other bored person on the entire face of the planet must be making the same joke.

Long Live the Shuttle ... now lets move on.

[Jedi Holocron]

The Shuttle is a wonderful experimental spacecraft. Let's all keep that in mind. Designed in the 1960's, built in the 1970's, finally flown in the 1980's on 20 year old technology. The world's first partially reusable launch vehicle. Kewl!

Okay, let's move on. Oh wait, we didn't. We floundered with National Space Plane projects. The X-33 was sacked. The Delta Skipper was sacked.

Hey, let's continue to rely soley on an outdated experimental concept vehicle can continue to stick roman candles up our kiesters as a way to get into "space". We'll live with the limited altitude (no micrometeorioid protection), limted power, limited duration, etc... etc...

Okay, sorry for the slight rant there. The shuttle rocked but it is time to move on. Why haven't we? If NASA had a budget that was maybe, at the least, equal to the increase in defense spending for 2003 we might be able to do this.

We are not. Maybe we just haven't found the reason to really want to go to space. I dunno. it is frustrating.

My graditude to everyone that has ever dared to travel to space. My thanks to those that have lost their lives in the endeavour.

transfer of kinetic energy

[lazira]

It had to be the result of some blunt-force trauma, the transfer of kinetic energy, somehow

I gotta remember that term. Like: "how about I transfer you some kinetic energy" or "Ouch! That transfer of kinetic energy was uncalled-for."

I know that a shuttle is different in many ways...

[WegianWarrior]

...from a fighter aircraft, but;

"he seals are made of reinforced carbon composite and fit between pairs of panels made of the same material that are designed to withstand temperatures of up to 3,000 degrees during re-entry. These seals and panels wrap around the leading edge of each wing." sure sounds like a badly thought out design to my ears.

At mach 2+, the airpreasure is high enought to rip an aircrafts structure apart - thus we make sure that no edges stick out of the airframe, and that no holes excist or can appear in such things as the leading edges of the wings, stabs or tail. At the speeds the shuttle has on reentry, this is even more important - even if you don't factor in the heatpulse. A design which, if it breaks, opens a gash into the interior structure is thus a flawed design - even if the designer didn't think it would ever fail! And remember fellow /.ers, NASA did more or less the same error when it came to the O-rings in the solid rocket boosters; the design was flawed from the start, but they choose to belive it wouldn't fail.

As far as I recall, the shuttle does not have leading egde flaps. Thus it shouldn't be a reason for a 'split' design like the article describes, a solid leading edge panel made of reinforced carbon should be both possible and perhapes even less expencive. It is certainly among the things NASA should consider to lessen the possibility of another disaster. Oh, and make sure the foam sticks to the tank as well, or at least find a better way to test it for flaws.

Re:Safety Record

[Waffle Iron]

Actually, it depends on how you measure it. If you go on a 10-day shuttle mission, you orbits traverse somewhere around 6.4 million miles. Driving a car that far would certainly carry a greater than 1% risk of a fatality.

But you have to ask: is it worth taking on the risk of traveling around the earth 160 times just so that you can tend to a zero-g ant farm?

Re:A chunk of foam?!

[athakur999]

The foam is quite a bit more rigid than nerf ball material :) It's more like hard foam some bicycle helmets and knee pads have in them... I used to intern at the place that makes the external tanks and had a chunk of the foam at my desk.

seals considered harmful

[wfmcwalter]

I remember reading a thing about Adm. Hyman Rickover, the father of the US nuclear submarine program. He was considering the means by which motive power would be extracted from the nuclear reactors. The scheme had turbine blades inside the reactor vessel, turning a shaft that (eventually) turned the boat's screws. This mean the shaft had to pass through the wall of the reactor vessel. He was worried that the seals around this opening wouldn't be perfectly reliable, and naturally if they ever failed this would allow radioactive fluid into the boat's compartments, irradiating the crew. The seal manufacturers assured him they could make a seal that was perfect, that would withstand all that could be thrown at it. Rickover wasn't sure, wondering if a magnetic interlock (where the reactor vessel is intact, and magnets on either side cause one shaft to move its counterpart).

Rickover took the seal guys aside, and asked them - if your son was on this boat, would you still want seals, or would you opt for the magnetic method? The seal guys thought for a while, and sheepishly replied that they'd go with the magnets. To this day, all US naval reactors have magnetic interlocks, not seals.

Fact is - seals are hard. Hard to make, hard to maintain, and hard to check. They're almost always the first thing to fail, and rarely gracefully.

So, rather than the next gen spaceplane being some slicko streamline hitech composite fibre whatnot, it should be a windowless monocoque made from thick polymerised concrete. The astronauts will need a stihlsaw to go EVA, but then a concrete spaceship needs no maintainance, so they won't have to.

Re:seals considered harmful

[seanmeister]

Where did you read that?? Last time I was in a naval reactor plant (1991, USS Theodore Roosevelt), the reactors heated water that was then circulated through a steam generator which created steam that was then carried outside of the reactor compartment to (among other things) turn a steam turbine that turned a main engine that moved the ship. That's pretty much how naval reactors work.

Support for Space

[JASP2]

Yo... latest polls show that 86% of Amercans feel the human risk is worth continuting Space exploration. That's pretty cool. I wonder why Politicians are so scared of approving NASA's budget ?

THe problem with the budget is not so much the small ammount they get, but the fact that the budget/mission changes every 2 years due to new officials in the house and senate and oval office. We need politicians to lock in a 15 year plan and write in riders to ensure the budget can't be changed. Then Nasa can focus on a long-term mission without worrying about next years budget cuts.

just my two-pence... and I work at the University of Colorado's Aerospace Department.

Re:brilliant way to disagree...

[WegianWarrior]

He is an expert. He is expected to say this sort of things, in fact, it is what he is paid for. And in some ways, it make a lot of sence; if the hole / gash hadn't opened up further, the ingress of hot gas may not have caused enought damage to the structure to cause a failure.

To take another example I know more intimatly; We (the RNoAF) lost a F-16AM during Operation Enduring Freedom this winter, when both main landing gear tensionstuts collaped on landing. Now, at the surface, we lost it because the struts broke. Dvelving deeper into it however, showed us that the struts broke because the jetjockey slammed a fully loaded, newly refuled (from a tanker aircraft) into the runway with a sinkspeed three times the limit.

Sometimes what you think causes the failuer is but the start in the chain of events, sometimes it is the last bit of it.

Re:I know that a shuttle is different in many ways

[lindsayt]

This is almost exactly the same point that Richard Feynman made in regard to the first shuttle accident: they calculate failure statistics wrong and don't properly reinforce to guarantee against disaster. I believe his example went something like this:

If a suspension bridge is expected to handle 40,000 pounds of traffic on a daily basis without failing, but small cracks begin to appear after a month of usage at that weight, the bridge has failed. It is architecturally flawed, regardless of the fact that the bridge has not collapsed. If an O-ring is 1 inch thick and cracks 0.25 inches thick routinely appear in said O-ring, there is not a 75% margin of error; the O-ring has failed. A disaster has not occured, but the structural integrity has been compromised, even if it is well below the point of a catastrophic failure.

His point was that NASA had virtually ignored all non-catastrophic failures, instead seeing how far they were from being catastrophic and calling that difference the margin of error. The problem is, the design had failed, since those non-catastrophic failures were not supposed to have happened. Hence, depending upon a device which has already shown a tendency for non-catastrophic failures is no margin of error at all.

I'm probably doing injustice to his argument since he was a genius and I'm merely a Systems Administrator, but I think it's relevant.

Upside Down?

[pz]

There's probably a really good reason, but from a naive viewpoint, the proximal cause for any chunks of foam coming off the main fuel tank being able to damage the shuttle is that during primary burn, the shuttle is slung below the tank. If the vehicle were lifted to orbit in shuttle-above-tank configuration (rotated 180 degrees along the longitudinal axis from the standard configuration), the Columbia accident might not have happened.

Anyone know why the current method (shuttle-below-tank) is used?