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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."
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.
Why slashdot? Why not?
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?
Lasers Controlled Games!
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.
I take drugs seriously.
A catastrophic failure rate of ~1% is not comparable to any other form of travel that I am aware of. Space travel is not a safe occupation. That being said, it is an important task and should be continued. I also hope we don't see any more fatalities, but this seems an unreasonable expectation in a young field.
...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.
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
Why wasn't Nasa demanding the government replace these flying Edsels' ? They didn't and there's your catastrophe.
Time to push for a new future nasa. Either go with more expensive x-33 or something more affordable. Just do it.
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.
## W.Finlay McWalter ## http://www.mcwalter.org ##
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.
Jeezus!?!?!?!? Really?
I'd pay any amount I could manage to fly on one! I'd sell off prized possessions, lose the car and walk/bike/public transit to work, go without sex (Oh wait, I'm married, that would be redundant), sever internet access, etc.... if it allowed me to ride the shuttle into space.
I think that would be the most fascinating thing I could ever do, and I simply can't fathom not wanting to go.
Of course, while I still think the shuttle is a pretty neat vehicle, I'd also be perfectly willing to go on any other vehicle that would send me into space.
Coming back safely would be nice too, but given the current state of the technology I'd accept the inherent risks.
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.
Everything in the world is controlled by a small, evil group to which, unfortunately, no one you know belongs.
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.
I did not design this game/I did not name the stakes/I just happen to like apples/And I am not afraid of snakes-AniD
4 Km/s... yeh it floated away
The object "floating" away from the space shuttle was moving at 4 Km/s. That indicates it absorbed momentum from a meteorite. The shuttle is susceptible to meteorites from 1-10 cm. Foam is being blamed because we can control the foam. The real story is that the 1-10cm meteorites are a risk we cannot control. Unfortunately, we will never be told what the probability of a meteorite hit will be.
...pulled out of the management's ass.
After Richard Feynman was asked to investigate the Challenger accident, he wrote up his experiences. They're published as the second half of his second autobiography.
He was stupified by the amount of fudge-factoring that went on at NASA. The MTBF for a component would be listed at 300 flight hours, and when he asked how they arrived at such a nice round figure, managers would retroactively come up with a listing where each sub-component had MTBFs listed to decimal places, 34.8712 hours, 29.1109 hours, ... and they all conveniently added up to exactly 300 hours.
Engineers were going nuts, but managers kept overriding the decisions. It was a fantastic "it looks nice on paper, therefore it works this way in real life, and fuck the laws of physics" mindset.
You cannot apply a technological solution to a sociological problem. (Edwards' Law)
My understanding is even if we had known the shuttle was doomed there was nothing we could do about it. Does this mean we would have been forced to watch the crew starve/asphyxiate in space? And given that, is it beyond reason to think they didn't even bother looking because of it?
Ever been hit in the head with a soaked Nerf ball fastball at the pool?
Try it at 800 mph.
DJ
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?
Put my fist through my alarm clock with its ding-dong death inside my ear. - The Blackjacks.
There was not enough fuel on the Shuttle to match orbits with the ISS. It's not just a difference in altitude, but in direction and velocity. They simply didn't have the means to get there. And it would not mattered if they did. There was no docking collar on the shuttle. And an emergency rescue launch was laso out of the question. It takes a minimum of 3 months to prep a shuttle for launch and there were no shuttles anywhere near launch status.
The bottom line with teh shuttle program is that if something goes wrong the astronaughts are screwed. But that has been true since the days of Project Mercury.
Boobies never hurt anyone. - Sherry Glaser.
I'm going from memory here but there are about 20 mission critical parts on the shuttle. If any one of these fails, there is no backup and a disaster will occur. Now remember, the shuttle is designed to a cost and the parts have something like 0.9999 reliability. Designing in more reliability would mean more cost so that wasn't going to happen. That means there is a roughly a 2% chance of catastrophic failure on any given mission. There have been 113 mission so the number of expected failures we should see is 2.26 (=(1-0.9999)* 113)).
This doesn't mean any given mission will fail, but we can be quite sure that we will lose one regularly no matter how careful NASA is. Thus because the shuttle was designed for a given level of reliability, we should expect to lose one roughly every 50 flights. Challenger was mission STS-51. Losing the Columbia should not surprise anyone. We should have expected to lose a shuttle around this time. Tragic but not surprising.