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Space

Shuttle Surface More Vulnerable Than Suspected 55

Posted by michael from the fragile-handle-with-care dept.
Ant writes "The space shuttle's skin is turning out to be even more fragile than NASA engineers thought, its scientists and engineers say. Impact tests and analysis performed as part of the return-to-flight effort show that pieces of insulating foam that weigh less than half an ounce can cause small cracks and damage to the surface coating on the heat-resistant panels on the leading edge of the wing, agency officials said in interviews this week."
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Shuttle Surface More Vulnerable Than Suspected More

Shuttle Surface More Vulnerable Than Suspected

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  • Sounds like this could cause another nasty delay in getting the fleet back in orbit. Weren't they supposed to resume flights in the somewhat-near future?
    • That is a really bad thing.

      I've been interviewing for a position in the Neutral Buoyancy Lab [nasa.gov] at JSC, where for months they have been ramping up to perform mission training for astronauts. The NBL is where the space station and shuttle mockups are submerged under 6.5 million gallons of water to mimick the effects of zero-gravity in EVA, shuttle & station articulating arm, and escape scenarios. While I was there today, one excercise was running, with two astronauts ("suits") in the water. At least on
    • This is all just part of the big 'government funding' game, totally expected. Beaurocrats at Nasa are worried about one thing, maintaining the budget. If they lose another shuttle, the program will end, pure and simple, and that's the end of the vast majority of thier budget. Since the Columbia incident, they have realized an interesting detail, they can maintain the budget, without flying shuttles, and that's a zero risk proposition. The real issue now becomes one of risk management, the longer they go
  • Since the skin of the shuttle itself, the tiles, have undergone extensive testing in development, I wonder if this new finding is an original condition, or the result of aging?

    • Re:Aging? (Score:4, Informative)

      by ravenspear ( 756059 ) on Friday January 21, 2005 @04:45PM (#11435600)
      I don't think aging has much to do with it. As I recall, most of the surface components are replaced after each mission and everything is thoroughly inspected for defects/weaknesses.

      It sounds more like a design flaw. The foam issue is something NASA had known about for a while before the Columbia disaster, they just hadn't taken it seriously enough. Kind of the same thing as what happened with Challenger where they knew about the o-ring issue but didn't take it seriously enough either.

      • Re:Aging? (Score:5, Insightful)

        by Cecil ( 37810 ) on Friday January 21, 2005 @05:30PM (#11436092) Homepage
        I don't think aging has much to do with it. As I recall, most of the surface components are replaced after each mission and everything is thoroughly inspected for defects/weaknesses.

        My question would be whether the replacement tiles are actually new, or whether they've just been sitting in a warehouse for 40 years like most of the other shuttle spare parts.

        The foam issue is something NASA had known about for a while before the Columbia disaster, they just hadn't taken it seriously enough. Kind of the same thing as what happened with Challenger where they knew about the o-ring issue but didn't take it seriously enough either.

        It's easy to say in hindsight that they didn't take it seriously enough. But in reality, it's hard to tell which things need to be taken seriously and which are trivial. And you can't just assume everything is serious -- if you take everything seriously, you're never going to get *anything* done. NASA is and always was way, way, way on the 'better safe than sorry' end of the spectrum, even at the time of the O-ring and foam problems. But they have to draw the line at some point, due to the law of diminishing returns. I think they've gone beyond that line in the aftermath of Columbia, personally.

        • Re:Aging? (Score:4, Informative)

          by ComputerSlicer23 ( 516509 ) on Friday January 21, 2005 @05:57PM (#11436393)
          I don't know about the Columbia accident (it might be a freakish thing), but from the review I've read of the Challenger accident. Two things come to mind:

          Political pressure was put upon NASA to lauch a vehicle during this launch window. I forget the details behindwhat it was. If I remember right, there wasn't another window for several weeks if they missed this one.

          Second, the O-Ring was blantantly known. There's a reason the demonstration the NASA Engineer put on, where he pulled the O-Ring out of water and pulled on it was so blantantly bad. It's my understanding from reading Richard Feynmann's comments that he insisted be added as an appendix to the report, that essentially the right people in NASA knew it was going to blow up. However, they justified it, with "Well the O-Ring is three times as thick as it needs to be, so the problem it is showing where it has a 1/3rd erosion is not a problem". You can read up on it here

          Feynman essesstially accuses them of using previous success as a evidence that all future launches will be a success. That's not good science or good Engineering. I think Columbia was screwed from the moment they made orbit (they might have been able to abort pre-orbit, post foam collision. I'm not sure on that). However, Challenger, they KNEW, they had an important piece behaving oddly in a way they didn't understand, while launching under extreme conditions. That's not being particularly safe.

          While I agree with you on Columbia, I strongly disagree with your characterization of Challenger.

          Also, I'm absolutely positive those parts haven't been sitting in a warehouse since 1965. We were fairly busy with the Mecury and Gemini missions in that time frame. My guess is they got invented no earlier then 1975, and made no early then 1980 or so. I'd have to go look into the history, but I'm reasonable sure the drawing hadn't even been brought out before 1972 or 1973, screw making parts to a specification.

          Kirby

        • Re:Aging? (Score:2, Informative)

          by Odo ( 109839 )
          My question would be whether the replacement tiles are actually new, or whether they've just been sitting in a warehouse for 40 years like most of the other shuttle spare parts.

          Yes, they are new. One can't stock spare tiles since each is tile different. Not only are the tiles not interchangable, the orbiters don't have compatible tile layouts. So they are custom built as needed. Until recently they were manufactured by the original facility in Palmdale, California. This made sense since the shuttles

    • It's not the tiles that have this problem, it's the reinforced carbon-carbon (RCC) pieces on the leading edges of the wings.
  • Well, so much for that asteroid-womprat-bullseyeing mission they were planning for April, then...

  • Fly it anyway! (Score:2, Insightful)

    by FuturePastNow ( 836765 )
    I think it's time to get this shuttle show back on the road. NASA will never be able to fix all of the problems; there are just too many ways a shuttle can explode on launch or burn up on re-entry. Somehow, I don't think that's ever caused NASA any problems with recruiting new astronauts.

    Meanwhile, there's an unfinished space station up there, a dying orbital observatory, and a lot of scientific research that has been put on hold. The shuttle should be returned to flight ASAP and it should be used until
    • Meanwhile, there's an unfinished space station up there, a dying orbital observatory, and a lot of scientific research that has been put on hold. The shuttle should be returned to flight ASAP and it should be used until NASA or private industry can build an adequate replacement.

      We can do these things more safely and cheaply by buying Soyuz from the Russians. NASA has done quite enough damage to the idea of manned spaceflight. Let them go back to the drawing board and build something that isn't such a klu

  • Sounds like it's time to look for a better material for the wing edges. Something less brittle. Of course, I'm sure they haven't thought of that option already :)

    • Re:new materials (Score:2, Insightful)

      by Anonymous Coward
      How about slashdotter's skulls.

      Thicker and more resistant to external forces than most man-made materials.

  • Quick Physics Reminder (Score:3, Informative)

    by ReciprocityProject ( 668218 ) on Friday January 21, 2005 @05:20PM (#11435989) Homepage Journal
    Keep in mind that the space shuttle is kind-of tall, and that it accelerates at several Gs, that wind resistance is accelerating the insulation downward, and that this isn't necessarily your household pink-panther fiberglass insulation, and that these tiles are designed to resist heat and pressure, not impact, and that the shuttle is designed to be able to lose several tiles and survive reentry (we assume that Columbia lost more than that many tiles). So if the tiles seem remarkably fragile, just keep those facts in mind.


    Let me say again, this is NOTHING like dropping the pink-panther stuff out of your second story window and breaking a ceramic dinner plate that you left on the ground.

  • This would imply over 80 missions have been flown without informaton as to what extent impacts to the tiles would damage them?
    I know the shuttle flies with the engines facing prograde while on orbit to minimise the risk of orbital debris, so you would expect the chance of impact to be small. Still I would have thought if there is a chance an analysis would have been done.
    Come on! You're NASA for Christ's sake! You're the ones who come up with this shit! Why I bet you have a bunch of guys sitting around so

  • Another reason it should be scrapped. (Score:1, Interesting)

    by Anonymous Coward
    Materials science, airframe design, computational testing and avionics have come a very long way since the shuttles were first conceived, designed and flown (the shuttle program was started in 1972, and it first flew in 1981). And then it was designed by commitee - it had so many goals that it didn't hit any of them. If I remember correctly: NASA wanted it to carry cargo to space stations (practical and forward-thinking), the government wanted it to carry people (manned space travel is glamorous), the milit

  • Public Choice raises its ugly head. (Score:3, Interesting)

    by Bob_Robertson ( 454888 ) on Friday January 21, 2005 @09:11PM (#11438012) Homepage
    This is a kluge, made by the lowest bidder that would build facilities in favored politicians districts, hamstrung by bureaucrats and inane regulation at every turn. The design was loaded with "everything for everyone" until it was a miracle that if flew at all.

    I admire the individual scientists and engineers that could make progress in this environment. No wonder they burn out at such a rate.

    Scrap the entire system, sell off NASA to the highest bidders, and have done with it. Putting more lives at risk on those craft is pointless. Any private effort wouldn't be able to afford the liability insurance for craft like those, aren't you glad it's your tax money being spent to kill people instead?

    If there is overwhelming support for such efforts, there is no need for taxes to taken at gun point to fund them. If the programs do not have such public support, there is no mandate for government to be doing it in the first place.

    Bob-

    • Sure the shuttle needs to be retired, but not because it was built cheaply. That's because it *wasn't* built cheaply.

      Do you know for a fact that the sole selection criteria for the contract was lowest price? Or are you just embellishing the punchline for an old joke?

      If anything, the shuttle needs to retired not because it's cheap, but because it's too expensive. NASA on the other hand needs more money. More money from taxpayers. Public money, in bucketloads, for NASA, is what I will vote for.
      • You are more than welcome to give all your money to NASA if that is what you want to do.

        I resent that you think it's ok to hold a gun to my head, taking my money to pay for something merely because you approve of it. Were I to do the same, you would object and call it "theft". Hypocrite.

        Taxation is a perfect example of the ends justifying the means.

        Bob-

        • Most of your wealth that you have you owe to others. I resent that you take from the public pool, use public services, and don't want to pay for them. Yes, that's you. Pay for what you use. If you're thinking that you're not using, then you need to look a little harder.

          • I owe NOTHING to others. I carry no debt. Your argument is one of greed and averace for things that others produce that you want. Envy.

            Freedom also means that no one is required to trade with me. They choose to buy what I sell, and sell to me what I wish to buy. I neither demand that they give me something just because I want it, nor does anyone (except leaches like you) demand that I give to them merely because they want it.

            Rather than deligate the act to others, you try going to people and robbing them
  • Wouldn't painting the main fuel tank (like they used to do) create a smoother surface and make it less likely for ice to stick to the craft in the first place? If you have less ice falling on the craft it's probably healthier.

    I know, the paint weights 600 pounds... but at least it survives. Spray it down with lard, even, if that works better, something to smooth and hydrophob the surface.
    • I used to have a professor who was an ex-NASA engineer. When the paint thing came up in class one day he gave us this explanation:

      The reason why the paint was scrapped was not because it was 600lbs lighter, but beccause NASA came under pressure from environmental agencies to reduce the amount of toxic chemicals in the air as the rocket went into orbit and also when it blissfully burns up in the atmosphere.

  • Limiting foam piece size does not seem to be a solution: micrometeor collisions happen quite often, there said to be several occurences with Mir station. Probably systems like shuttle should be tolerant to a single pointary fail or damage.

    Also this part was quite funny:

    NASA has been firing pieces of foam from a nitrogen-powered cannon into reinforced carbon carbon.

    In fact, Dr. Curry said, NASA has not been able to conduct impact tests on pieces of foam lighter than six-hundredths of a pound, because the


  • - what is Aerogel [nasa.gov]

    - where is the foam used and why. Is evacuated perlite used in the annular space for the cryo tanks?

    Basic ignorant questions, I'm just asking.

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