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Space Science

NASA Finds Critical Assembly Fault in Shuttle 383

Posted by michael from the lucked-out dept.
mzs writes "During corrosion inspection on Discovery, technicians noticed that one of the gears in a rudder actuator had been installed backwards. This particular actuator was the top-most of four that control the air brakes on the tail. As luck turns out, if it had been the bottom-most actuator, loss of the shuttle and crew would have been nearly inevitable. Plans are in place to have four spares by the time Shuttle missions resume next year."
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NASA Finds Critical Assembly Fault in Shuttle More

NASA Finds Critical Assembly Fault in Shuttle

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  • Simple solution, really. (Score:5, Funny)

    by grub ( 11606 ) <slashdot@grub.net> on Tuesday March 23, 2004 @01:29PM (#8646533) Homepage Journal

    Could they not stamp "THIS SIDE UP" or whatever on the components?

    • Re:Simple solution, really. (Score:5, Insightful)

      by Lattitude ( 123015 ) on Tuesday March 23, 2004 @01:34PM (#8646605)
      Even better, they are going to machine them so they mechanically impossible to put in backwards.

    • Re:Simple solution, really. (Score:5, Funny)

      by fbform ( 723771 ) on Tuesday March 23, 2004 @01:37PM (#8646660)

      Could they not stamp "THIS SIDE UP" or whatever on the components?

      They did something similar with the modified 747 that carries the shuttle orbiter back after landing. See this picture [purdue.edu]. This is supposed to be a sign on top of the 747, where the orbiter links to the top of the 747's fuselage. It reads "Place Orbiter Here...Black Side Down".

      If this is real, they have one hell of a sense of humor.
      • Reminds me of the black humour on a concrete lid on a nuclear ICBM tube. Allegedly it's painted like a pizza box- with the words:

        'Guaranteed delivery anywhere in world in 30 minutes'

        '- or the next one's free'

        :-)

        I also liked the story on slashdot a few years ago about a decommisioned secret RSA listening station with a huge smiley face painted on the parabolic radio receiver dish saying 'hi' to the russians...

        • Reminds me of the black humour on a concrete lid on a nuclear ICBM tube. Allegedly it's painted like a pizza box- with the words:
          'Guaranteed delivery anywhere in world in 30 minutes'

          '- or the next one's free'

          On my SSBN we had two signs over the firing console. The first said "Trident - When you care enough to send the very best", the other said "16 empty missile tubes, 16 mushroom clouds, It's Miller Time". Yes, strategic weaponeers have a black sense of humor.

    • Or, do what they do now for computer compoments:

      Colour code the connections.

      From the article:
      'The gear fits into the assembly both ways, but is slightly asymmetric so the teeth do not fit exactly if the gear is reversed.'

      So why not have the side its supposed to go in green, and the side where its not supposed to go in red?
      Simple visual solution that can be spotted quicker?

      NeoThermic
    • Crap, I wrote the same thing [slashdot.org] about 10 seconds after this story hit the front page but I already had a comment posted 47 seconds prior. Then I posted mine, now I'm going to look like a choad. :(

    • Re:Simple solution, really. (Score:5, Funny)

      by Kenja ( 541830 ) on Tuesday March 23, 2004 @01:42PM (#8646717)
      "Could they not stamp "THIS SIDE UP" or whatever on the components?"

      There is no "up" in space....

    • Re:Simple solution, really. (Score:5, Interesting)

      by s20451 ( 410424 ) on Tuesday March 23, 2004 @02:03PM (#8647004) Journal
      This is the original definition of Murphy's Law: If it is possible to do something in more than one way, and one of those ways leads to catastrophe, someone will inevitably do it the wrong way.

      In fact the original inspiration for Murphy's Law was a G-force meter that was installed backwards, thereby taking meaningless readings. (It probably didn't go below zero.)

      Another example is the 1969 gearbox fire on the Canadian navy ship, HMCS Kootenay. A gearbox bearing was installed backwards, which restricted its flow of lubrication oil (on a naval vessel, the gearbox is the size of a car and absorbs tremendous loads). Apparently it did say which way to install it, but the installation was made in a foreign shipyard where the workers could not read English. The poorly lubricated bearing overheated and caused an explosion during a full-power trial; nine sailors were killed and dozens injured.

      The moral of all these stories is: if it's important which way something is installed, make it asymmetric so that it's physically impossible to install it the wrong way. Labels are not enough.

    • Re:Simple solution, really. (Score:5, Insightful)

      by chadjg ( 615827 ) <chadgessele2000.yahoo@com> on Tuesday March 23, 2004 @02:23PM (#8647258) Journal
      In some cases stamping lettering into a stressed rotating part can lead to sudden failure. Stamping can put odd stresses into the part, and makes a slightly weaker space in the part.

      I believe that the NTSB found a stamping on a rail car wheel caused a failure and derailment, but i'll be danged if I can find the incident. Maybe tonight...

      Moisture could collect in the little crevices of the letters leading to corrosion. i suspect that this is not really a concern.

      Silk screening or some creative powdercoating could totally avoid these issues. But what do I know. I managed to smoke my e-machine 500 last night. Nobody would hire me to be a shuttle engineer!

    • Re:Simple solution, really. (Score:5, Funny)

      by Stitch_626 ( 744380 ) on Tuesday March 23, 2004 @02:27PM (#8647306)
      They could stamp "If you can read this, turn gear around and install correctly" on one side and "There you go Einstein...you finally got it right" on the other.

      • Great idea, but the workers stamped the wrong side on some versions, and the part cannot be remade in time.

        This is a real problem in industry, you can put any sign on something, but then you gotta make sure the signs are right too. Indeed the wrong sign leads some workers to put it in backwards, even knowing the right way, while others will get in the habbit of putting it in with the lettering wrong, and not correct themselves when the next version is ships with the right parts.

    • Re:Simple solution, really. (Score:4, Interesting)

      by prisoner-of-enigma ( 535770 ) on Tuesday March 23, 2004 @03:35PM (#8648044) Homepage
      Ah, but this has been tried elsewhere. Look up the design history of the swing-wing pivots on the B-1 bomber. The pivots are two large hollow metal cylinders, slightly asymmetrical. One side is clearly marked "THIS SIDE UP."

      However, the manufacturer stamped the wrong side of the pivot, and it was dutifully installed upside-down. Murphy wins again no matter what you do.

  • How can a fault go unnoticed for so long? (Score:5, Interesting)

    by amigoro ( 761348 ) on Tuesday March 23, 2004 @01:31PM (#8646560) Homepage Journal
    Discovery flew safely 30 times with the defective actuator since its first launch August 30, 1984, and no one suspected a problem until the actuator was taken apart to check for corrosion.

    I thought they even checked Airplanes more thoroughly

    • They probably do check airplanes more thoroughly because airplanes are used much more frequently than space shuttles. No?
      • Speaking purely on a political level here, a shuttle disentegrating (sp?) over east texas does a lot more harm to the collective conscience of the nation than if a commuter jet goes down in the florida keys. Given that in mind, you would actually think NASA had the highest QA process in the world....but as we've seen...its horribly flawed.

        • Re:How can a fault go unnoticed for so long? (Score:4, Funny)

          by FatAlb3rt ( 533682 ) on Tuesday March 23, 2004 @02:05PM (#8647031) Homepage
          but as we've seen...its horribly flawed.

          Careful, jerking your knee so suddenly like that might result in an injury.

        • Re:How can a fault go unnoticed for so long? (Score:5, Insightful)

          by Ryan C. ( 159039 ) on Tuesday March 23, 2004 @02:47PM (#8647529)
          They found the problem before anything went wrong while checking for defects. I don't know what your definition of QA is, but that's pretty much the accepted definition.

          As for horribly flawed: Compared to whom? Spaceflight is dangerous. Minor oversights that in most industries would cause a misprint in a news article tend to blow up and kill people.

          Basically, until you land something off-planet, you have no room to talk. If you want to point to someone who is doing a better job of it, you pretty much have the Russians for comparison, and they have had even more problems.

          -Ryan C.
    • used 30 times to fly into space over 20 years without a problem ? Are they sure its deffective ?

      Yeah I know I know... but damn people you have to draw the line somewhere. I wish all things worked that well impropperly installed.

    • Re:How can a fault go unnoticed for so long? (Score:4, Funny)

      by Alkaiser ( 114022 ) on Tuesday March 23, 2004 @01:55PM (#8646896) Homepage
      The reason this went unnoticed for so long is simple...those guys at NASA...you know, they're not exactly rocket scientists...
    • Probably without a lot of difficulty. Evidentally, even with the gear installed backwards, the air brakes still functioned. The concern is that if a great deal of stress were ever placed on it (in an emergency landing after an aborted launch, the CNN article mentioned), it would fail. I don't know what kind of checks the shuttle is put through before it is allowed to fly, but if the rudder is doing what it is supposed to do, and the gears were not considered to be a a high-wear part, would they take ever

  • Instead of slamming NASA (Score:4, Interesting)

    by 0x0d0a ( 568518 ) on Tuesday March 23, 2004 @01:31PM (#8646564) Journal
    ...and I'm sure there will be lots of negative posts about NASA here...

    It'd be nice to give some credit for the people that have put in layer upon layer upon layer of safeguards to check for exactly this sort of thing and the dilligent people that find this stuff. And caught it.

    The awful thing is that this is going to be just another reason for Congress to loot the NASA money bag.

    • Re:Instead of slamming NASA (Score:5, Informative)

      by molo ( 94384 ) on Tuesday March 23, 2004 @01:36PM (#8646641) Journal
      It'd be nice to give some credit for the people that have put in layer upon layer upon layer of safeguards to check for exactly this sort of thing and the dilligent people that find this stuff. And caught it.

      Maybe you missed the details, but this has been in place on the Discovery for over 20 years.

      -molo
    • >>> check for exactly this sort of thing and the dilligent people that find this stuff. And caught it.

      Yes, indeed. Their performance has been exemplary. However in the future, finding problems somewhat faster than 20 years after construction might be a good thing.
    • I wouldn't blame NASA for this but the subcontractor that made the part. They sould know to have a process in place to negate that.

      The sub should be punished for their lack of effort and watched closer in ongoing efforts.
    • That money bag is America's money bag, not NASA's, and using the funds elsewhere is not looting anyone. Profligate deficit spending is looting all Americans.
    • No, the credit should go to the engineers who designed something so rock solid that reasonable human error can occur without catastrophic failure.

  • Transparency. (Score:5, Interesting)

    by commo1 ( 709770 ) on Tuesday March 23, 2004 @01:31PM (#8646565)
    I'm quite surprised they're being quite so upfront about this. Kudos to them... On the other hand, I believe it to be a part of the healing process to convince the general public that they are, in fact taking the Columbia disaster extremely seriously, and want to show progress in the inspection and faliure-cathing procedures that obviously did not work for Columbia.

    It was, however, just a matter of time before a Columbia-type disaster occured. The suttle program has a remarkable safety record, Challenger and Columbia no matter.

    • On the other hand, I believe it to be a part of the healing process to convince the general public that they are, in fact taking the Columbia disaster extremely seriously, and want to show progress in the inspection and faliure-cathing procedures that obviously did not work for Columbia.

      Why didn't they do this after Challenger? Are they so thick they needed two disasters in order to get serious about safety?

      The suttle program has a remarkable safety record, Challenger and Columbia no matter.

      I have

      • I've got this multi-million pound bomb. Half a century ago, we couldn't get ANY of these off the ground without them exploding. But now we're 'pretty good' at it.

        Get real. At ANY point in technology, reaching orbit is a heck of a lot harder than getting from point A to point B over paved roads in a car. One gallon of gas, properly vaporized, is roughly equivalent to a stick of dynamite. So most of us strap ourselves in with 10-20 sticks of dynamite, daily. The Shuttle has millions of poinds of fuel and oxi

        • Re:Safety is relative (Score:4, Insightful)

          by Imperator ( 17614 ) <slashdot2 AT omershenker DOT net> on Tuesday March 23, 2004 @02:13PM (#8647121)

          Why does the modern Soyuz have a better safety record than the Shuttle? Why did our old ballistic missiles have a better safety record than the Shuttle? Even the enormous Saturn V rockets never had an accident in flight.[1]

          Why does the Shuttle have such a terrible safety record relative to other rockets that attain orbit?

          I'll tell you why: because it was over-ambitious. Congress was sold on the idea of a re-usable (read: cheap) launch vehicle that can do cool stuff like repair satellites. The truth of the matter is that if we had stuck with traditional launch vehicles (fire-once rockets), the money we saved over the long run would have allowed us to just replace failing satellites rather than repair them. (How many satellites have we repaired anyway?) We could even have built the space station for less. (Look at how we launched Skylab. Surely we could have repeated that a few times to get as large a space station as we wanted.) The legacy of the Shuttle is that of an overpriced, underperforming safety hazard.

          All manned spaceflight is dangerous. The Shuttle is just more dangerous that most.

          [1] The Apollo capsule had two serious accidents, one on the ground and one on the way to the moon.

          • Gee, where were you with your 20/20 hindsight vision when the Shuttle was being developed? It's very easy to make these kinds of statements now, 25 years after the fact. At the time though, there was a lot of pressure to make space flight cheap and prevalent and looking at that kind of volume a reuseable craft makes much more sense. Please don't treat the early shuttle designers as though they were money grubbing morons. There were many good reasons to do what they did, and there are many things, like H

      • Re:Transparency. (Score:3, Insightful)

        by afidel ( 530433 )
        Actually we are just about on schedule. The origional predicted failure rate for the Shuttle fleet was 1%. If you discount Challenger (which was a political failure not really mechanical, all of the people who knew anything told them not to launch at such low temperatures) we are right on track, one failure in 107 launches. Lauching a rocket into space isn't anywhere near as pedestrian as driving a car. Besides on a per mile basis I bet the shuttle is more safe than driving =)

  • I guess they... (Score:3, Funny)

    by Anonymous Coward on Tuesday March 23, 2004 @01:32PM (#8646568)
    Didn't get the memo. I'm gonna go ahead and get you another copy of that, mmmkay?

  • Geez... (Score:4, Funny)

    by Anonymous Coward on Tuesday March 23, 2004 @01:33PM (#8646588)
    Come on NASA, it's not rocket science! Oh wait...

    • Re:Geez... (Score:5, Interesting)

      by Hays ( 409837 ) on Tuesday March 23, 2004 @01:52PM (#8646861)
      Quoth John Carmack

      "I'm kind of at the top of my field [in gaming]," he said. "When I started reading about aerospace, I realized there was an incredible level of things to learn. ... There's this mytholigization of aerospace that it's the hardest thing you can do. That's just not true. In terms of actual difficulty, it's not that hard. Aerospace is plumbing with the volume turned up."

      • Re:Geez... (Score:4, Interesting)

        by pclminion ( 145572 ) on Tuesday March 23, 2004 @02:52PM (#8647588)
        The founder of my company has told me something similar. He used to design spy satellites (who knows exactly what he worked on -- 30 years later he still isn't allowed to talk about it), and he says that the day-to-day IT management problems he encounters now are far more difficult to solve than designing spacecraft.

        He blames it on the ten thousand different manufacturers you deal with in IT, ranging from motherboard suppliers, to RAM makers, to CPU makers, hard drives, UPSs, and of course, software. The pieces work, it's getting them to work together that's a bitch. With a satellite, you have maybe 20 or 30 people who, in combination, know everything about it and who can coordinate with each other.

        Think about that. Keeping a mid-size server farm up and running smoothly (all the while undergoing constant upgrades, new feature additions, etc.) is more difficult than designing and launching a satellite. Straight from the horse's mouth.

      • Re:Geez... (Score:5, Informative)

        by Unknown Kadath ( 685094 ) on Tuesday March 23, 2004 @03:00PM (#8647661)
        Like all high-tech endeavors, "rocket science" is a blend of many different fields. I happen to think that electrical engineering is far more difficult than aerospace engineering ever could be, but I have helped EE friends with their required mechanical engineering classes, and they got stuck on things I thought were simple and obvious. I'm sure they felt the same way when the time came to help me with my EE requirement. Ditto me and my CS friends. A lot of it is a matter of training and experience.

        I'm qualified to work on things like airframes and engines, and I can calculate a pretty mean orbit, if I do say so myself. But I'm lost when it comes to things like avionics or heat shield design. So "rocket science" is indeed complex and tricky, and a successful rocket design will require experts from many fields. But things like compressible flow, which seems to be what Carmack's talking about, aren't really outside the grasp of a dedicated student at all. And of course, all of this sounds like black magic to the nontechnical layman.

        Of course, we don't go around telling people this, or we wouldn't be able to look down our noses at everyone else. "I design jet engines, and I've done some work on the Mars program. Oh, you write computer games? Aw, that's cute." ;)

        -Carolyn
  • Is to add more Redundancies/bulk?

    Yep, thats a good plan, soon they'd be flying a bird full of gizzards and no egg. How about some consistant QC and management instead?

  • Why are heads not rolling? (Score:3, Interesting)

    by Anonymous Coward on Tuesday March 23, 2004 @01:34PM (#8646614)
    I cannot believe that such a fundamentally problematic organization goes about its business mishap after mishap, without some high-level heads rolling every once in a while. Organizations get sloppy when they are not held accountable. To think that so many billions of taxes go toward what is supposedly one of our most high-tech endeavors, and they can't even install the parts correctly? Someone high-up should get fired for not forcing NASA to get serious.

    ---
    http://thewired.blogs.com/teotwawki
    The techno-mediated cultural conspiracy
    • Right. Because the head of NASA was on the assembly line 20 years ago when the parts were installed by some blue collar worker getting paid peanuts who is responsible but will never be held accountable. Makes sense.

    • Re:Why are heads not rolling? (Score:5, Insightful)

      by pz ( 113803 ) on Tuesday March 23, 2004 @02:48PM (#8647544) Journal
      When the Mars Climate Orbiter was lost [cnn.com] due to a mixup between NASA and Lockheed Martin concerning imperial vs. metric units, I recall Dan Goldin, the then-head of NASA, being asked by a reporter if heads would roll. He replied something like, "sure we could do that, but then we'd have to replace those engineers. Now we already hired the best ones we could find in the world, so where are we to get better ones?"

      The Shuttle is one of the (if not *the*) most complex bits of engineering we, as a world-wide society, have achieved. I would never expect any shuttle to be manufactured/assembled/flown/controlled/maintained perfectly without flaw. I would, however, expect it to be designed to work well in the face of such problems, as does seem to be the case here. Discovery had 30 successful flights despite a part on a major control surface being installed backwards? Everyone landed safely? Tons of good science, too? Doesn't mean the problem shouldn't be fixed, but kudos to NASA for what sounds to me like a job well done.

      • 30 succesful flights is not "a job well done" in this case. If the actuators had been installed on the other side a catastrophic failure would have been not only possible, but probable.

        What that is called is "dumb luck".

        It's sort of like winning at slots in a casino and being told that is "a job well done".

  • I'm betting... (Score:5, Funny)

    by Anonymous Coward on Tuesday March 23, 2004 @01:35PM (#8646621)
    ...I'll be running Duke Nukem: Forever on Microsoft Longhorn before the next shuttle launches.
  • So which inspectors found the fault? Was it one of NASA's inspectors or one that was outsourced to India? Can somebody post a copy of the article please?

  • Capsules (Score:2, Insightful)

    by Waffle Iron ( 339739 )
    This is yet another reason that manned missions should be using simple reusable capsules instead of winged orbiters. There are no rudders to jam.

  • A quote I remember .... (Score:4, Interesting)

    by airrage ( 514164 ) on Tuesday March 23, 2004 @01:36PM (#8646642) Homepage Journal
    I'm paraphrasing here but it went something like this:

    "When the most intelligent work on the most complex to build the the only prototype, inevitably the radio won't work."

    The point is that when working on very complex designs and prototypes installing something incorrectly doesn't seem odd because your brain is unable to "see" the mistake for what it is. In a car, if you install the brakes incorrectly, the scale is such that you understand the mistake simply from your gut, visually. Like looking at a crumpled front fender and understanding that's not correct.

  • time for a new one (Score:4, Interesting)

    by millahtime ( 710421 ) on Tuesday March 23, 2004 @01:37PM (#8646650) Homepage Journal
    With all the advances in vehicle health monitoring, diagnostics, prognostics and the like it might be better for them to either build a new vehicle with this technology or retrofit the shuttles with it. Then they could see when the gears are cracked or acting up.

  • Should have used Java (Score:5, Funny)

    by iamacat ( 583406 ) on Tuesday March 23, 2004 @01:37PM (#8646658)
    NASA Finds Critical Assembly Fault in Shuttle

    I know NASA is conservative with technology, but using assembly in this day and age is way backwards!
    • You should see the computers they use on the Shuttle, though. Not exactly state of the art in anything except radiation hardening.

    • Re:Should have used Java (Score:4, Insightful)

      by millahtime ( 710421 ) on Tuesday March 23, 2004 @01:45PM (#8646767) Homepage Journal
      "I know NASA is conservative with technology, but using assembly in this day and age is way backwards!"

      Bad Joke

      Actually Assembly is a great language if your worried about efficiency and/or space. A lot of controllers in aerospace are coded that way and there is good reason for that. You can never get away from machine language for everything. Many times it is the best route to code in.

  • Just goes to show.. (Score:5, Interesting)

    by iswm ( 727826 ) on Tuesday March 23, 2004 @01:37PM (#8646663) Homepage
    They should really do some double checking on this stuff. It's hard to imagine mistakes like this happen when dealing with something that holds the fate of a handfull of people's lives; not to mention all the millions of dollars put into these projects that would go down the drain. When dealing with people's lives and huge sums of money it's worth it to go over _everything_, and put in for better training so these thing don't happen again. They caught it this time, but if they don't take enough precaution, they might not be so lucky in the future.

    • This stuff happens all the time (Score:5, Interesting)

      by Unknown Kadath ( 685094 ) on Tuesday March 23, 2004 @02:15PM (#8647144)
      I work in New England, contracting for a jet engine manufacturer (and you can get it in two if you know the aero industry). Things like this happen frequently in manufacturing, especially with development hardware, before the kinks have been worked out of the assembly process and parts are ready to go to production. Assembly mistakes range from things that are easy to do but also easy to fix, like cut or cracked O-rings and tool knicks on non-critical parts, to things that are real screw-ups and result in major headaches, like parts left out entirely or vital parts being installed incorrectly and badly damaged because of it. You could consider the entire shuttle program to still be development-phase engineering, since only a few shuttles were ever built.

      An example: a while back, we had a test engine spewing fuel all over the test cell for no readily apparent reason, prompting a panic that an entire compartment of the engine would have to be redesigned from scratch--until one of the test engineers found a fuel line seal that had not been reinstalled in the engine after the last teardown and reassembly. How do you miss something like this when there's a careful set of instructions to follow for every step of the assembly? I don't know, but I do know that humans are fallible, so we are constantly dealing with a stream of lost, damaged, and defective parts. Anyway, they put the seal back in, and the engine worked fine. (I have an NDA, so this is not what actually happened, but it is analogous.)

      When I was in school, the more I learned about the environment the shuttle operates in, the more I was impressed by the fact that it worked at all, and now that I'm learning more about manufacturing engineering (not what I studied for; stupid job market), I'm surprised that the shuttles have as few problems as they do.

      -Carolyn

  • Twice?! (Score:5, Interesting)

    by 2marcus ( 704338 ) on Tuesday March 23, 2004 @01:37PM (#8646664)
    And if you read the article, you realize that NASA installed defective actuators not once, but twice! The first being the one that was successfully flown 30 times, and the second in the spare actuators.

    Given the complexity of a system like the shuttle, it is not surprising that out of 1000s of components there could be a mistake in one of them (and given some redundancy and robustness, it is not surprising that the shuttle could fly 30 times with one or more poorly installed components, though one would not normally want to bet on that...).

    However, two errors out of 8 actuators checked implies some serious quality control issues.

    -Marcus
    • I'd imagine that the first person to put them on incorrectly followed the instructions, and the people to replace them installed the replacements just as they were :)

      It will be amusing if we discover later that the parts were put on backwards deliberately, to compensate for some engineering flaw. Well, not so amusing for the astronauts falling out of the sky on fire.

    • Re:Twice?! (Score:3, Insightful)

      by Smidge204 ( 605297 )
      I think it's more of a design problem than an inspection problem. Either the gear should have been designed to be perfectly symmetrical, or to not fit at all if someone tried to install it incorrectly.

      =Smidge=

  • When is a problem a problem? (Score:4, Insightful)

    by stecoop ( 759508 ) on Tuesday March 23, 2004 @01:38PM (#8646669) Journal
    Discovery flew safely 30 times with the defective actuator

    When does a defect become a problem? I wonder if this was really a Critical problem because shouldn't some indication have already been seen by now?

    I mean since they have fixed this problem will two other problems surface that are more critical and maybe they should have left it alone?

  • Quothe NASA: (Score:2, Funny)

    by Luveno ( 575425 )
    "whoops!"

  • Murphy's Law (Score:3, Informative)

    by OldBus ( 596183 ) on Tuesday March 23, 2004 @01:40PM (#8646700)
    Is anyone else reminded of the story of how Murphy's Law came into being (where something could be connected up the wrong way round and was)? I'm sure NASA has tightened up its procedures since Challenger/Columbia, but given that these things could be fitted either way it was an accident waiting to happen - thankfully it never did.

  • NASA Finds Critical Assembly Fault in Shuttle (Score:3, Funny)

    by Anonymous Coward on Tuesday March 23, 2004 @01:41PM (#8646713)
    Isn't it about time they switched from assembly to C ?
  • technicians noticed that one of the gears in a rudder actuator had been installed backwards.

    As Edward A. Murphy, jr. said it: [geocities.com]

    "If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it."

    Nothing like seeing a faithful replication of the impetus for Murphy's observation...

    • Re:Murphy's Law (Score:4, Insightful)

      by AlterTick ( 665659 ) on Tuesday March 23, 2004 @01:50PM (#8646828)
      "If there are two or more ways to do something, and one of those ways can result in a catastrophe, then someone will do it."

      The important lesson here is about the design of critical parts. Nothing important should be made asymetrical and reversable. Even labeling it "THIS SIDE UP" on one side and "WRONG! DANGER! WRONG!" on the other isn't good enough. The part should either be symetrical, so it doesn't matter which way it goes, or non-reversable, so it wont fit upside down/backwards. Important thing to remember in mechanical engineering (gears|levers|*) or even eletrical parts specifications (connectors should be keyed to mate only one way: the right way).

  • Outsourcing (Score:3, Funny)

    by ever vigilant ( 749135 ) on Tuesday March 23, 2004 @01:43PM (#8646734)
    NASA needs to start outsourcing to India, I hear they do great work for their pay.

  • I always thought there were 5 of everything to keep surfaces working even after a double failure. With only 4 actuators, if 2 fail, and start working against the other 2, the working pair can't overpower the non-working pair and the surface is useless. With 5 actuators, it takes a triple failure before the surface won't work.

  • Slightly asymmetric? (Score:3, Interesting)

    by spellraiser ( 764337 ) on Tuesday March 23, 2004 @01:44PM (#8646749) Journal

    The mistake dates back to the actuator's assembly at Hamilton Sundstrand in Rockford, Illinois, and is not easy to spot. The gear fits into the assembly both ways, but is slightly asymmetric so the teeth do not fit exactly if the gear is reversed.

    Show me a man who can find a slightly asymmetric shape, and I'll show you a man who can find a slightly tritriangular number.

    Or a slightly odd one ... hey wait, that's me. Except I am not a number, I am a free man!

    • ...I remember as much from "Engine parts" that depending on load, you'd like the teeth of the gear to NOT be symmetric. This would give you better interconnection in one direction (the "right" way) and worse in the other (the "wrong" way).

      Ever see a winch? The teeth on the gear there is an extreme of that sort - only designed to pull load in. So it's not done to be mean - it's probably done as to fit the spec.

      Kjella

  • Engineering practices (Score:4, Insightful)

    by n3xup ( 411763 ) on Tuesday March 23, 2004 @01:47PM (#8646795)
    In engineering, it's usually good practice to design somthing that only assembles one way. That way, whoever is assembling it (no matter how intelligent they are) can only install the component the way it was meant to be.

    It's strange and somewhat disconcerting that this was not the case for this shuttle component, but I haven't seen the part in question.

  • New backwards moniker for NASA! (Score:3, Funny)

    by Jedi Holocron ( 225191 ) on Tuesday March 23, 2004 @01:50PM (#8646835) Homepage Journal
    ASANine

    This whole thing is despicable.

  • This happens: See the F-111 program (Score:4, Interesting)

    by dougermouse ( 581787 ) on Tuesday March 23, 2004 @01:56PM (#8646900)
    The same basic thing happened with the F-111 program in the 60s. The drawing had a piece that was installed upside down, but the technician installing them said, this ALWAYS goes right side up and installed it that way. A couple crashes and the grounding of the whole F-111 fleet later, and the trouble was found. I don't know what happened to the installer, but I can't imagine it was any good. Check twice, install once :)

  • Same Story - Different Article (Score:4, Informative)

    by H8X55 ( 650339 ) <jason...r...thomas@@@gmail...com> on Tuesday March 23, 2004 @01:57PM (#8646913) Homepage Journal
    NASA Finds Hidden Shuttle Danger [discovery.com] Same story, different article, in case the posted one gets /.'ed.

  • Stuff happens; learn from it. (Score:5, Interesting)

    by Kozar_The_Malignant ( 738483 ) on Tuesday March 23, 2004 @01:59PM (#8646949)
    In this case nobody died and several lessons were learned, including something about fault-tolerance in actuators. I think two of the most valuable space flights from this point of view were Apollo 13 and the Mir mission that caught fire.

    Things will go wrong. Learning how to cope when the evil wind blows is critical. In this case, we now know that the thing can be flown with one actuator in upside down. If the bottom one malfs, swap it out in orbit with the top one, and you still might get home. People are going to get killed doing this. People got killed learning to sail the Mediterranean. It's still worth doing.

  • manual (Score:5, Interesting)

    by Johnny Mnemonic ( 176043 ) <mdinsmore&gmail,com> on Tuesday March 23, 2004 @02:00PM (#8646959) Homepage Journal

    I can imagine the guy that noticed this first. Probably went something like: looks at actuators. looks at diagram of how they're to be installed. looks at diagram again. looks at actuators. turns diagram around; notices that the legend is now upside down, so concludes that can't be it. checks other pages of diagram to see if this page is unusual--different view, maybe. finds that it isn't. checks back for errata. finds none.

    Looks around. "Hey Bob, what do you make of this?" Thinks about all the work that day that isn't going to get done, because now management and, if he's lucky, congressional inspectors are going to crawl up his ass. At least he knows that he didn't *install* the things.

  • Fail Safe (Score:2, Interesting)

    by 3gm ( 718785 )
    The gears were in an actuator that is, itself, a failsafe. It's apparently not used except in an emergency. That's it didn't fail in use; it was never used! The gears apparently are made to fit in either a right side or left side actuator but need to be installed with the proper orientation. Makes sense to use the same gear for both sides only flip it over. If its orientation is critical though, you'd better have some really good assembly instructions. Maybe like those that come with that high quality

  • The ONLY way to guarantee that... (Score:2, Funny)

    by Anonymous Coward
    ...this sort of thing no longer happens (for NASA or Microsoft) is to put punitivie punchiments on the engineer/developer's heads if these things happen agaion.

    If the USA is to become the empire it plans to be, we need more draconian measures to keep the incompitentes out of the way. Something like this would suffice:

    From: Microsoft Corporate
    Subject: Trusted Computing Initiative 2

    In an effort to better secure computing for our customers, we are implementing new measures in our code revision system. The

  • Maybe (Score:3, Funny)

    by Salsaman ( 141471 ) on Tuesday March 23, 2004 @02:10PM (#8647078) Homepage
    maybe one part of NASA was using radians, and another degrees.

  • Nasa Haters... (Score:4, Interesting)

    by bobej1977 ( 580278 ) <rejamison&yahoo,com> on Tuesday March 23, 2004 @02:24PM (#8647276) Homepage Journal
    I think it's worth saying that very few of us would be capable of the high standards [nasa.gov] that go into the design, fabrication and assembly of these crafts. Quoth Nasa:
    "...[Discovery is] assembled from more than 2.5 million parts, 230 miles of wire, 1,060 valves, and 1,440 circuit breakers..."
    I for one stand amazed at what Nasa accomplishes every single day. Could they do better? Certainly. Would we do better? Almost certainly not.

    On a side-note, the reason Nasa is stuck in the proverbial hard-place between multi-billion dollar budgets and missions that nobody cares about is that we've all started over-valuing human-life. It's ridiculous that space exploration all but stopped because of the 2 shuttle disasters. Certainly, the loss of those crews was tragic, but the best way to honor those crews is to relentlessly pursue the dream that they died for, not hamstring ourselves being overly cautious.

    Call me old-fashioned, but I still believe there are things more important than one or a dozen human lives. IMO, exploring the universe is one of them.

  • the most complex engineered system ever (Score:4, Informative)

    by orn ( 34773 ) on Tuesday March 23, 2004 @02:53PM (#8647598)
    The shuttle is the most complex system ever engineered by people... by orders of magnitude.

    It's not suprising that there are flaws in the system - disasters lying dormant until the moment when they cause the destruction of the entire system.

    This is one of the biggest arguements for a Vertical Takoff / Vertical Landing vehicle - it simplifies the system because it eliminates specialized components for landing.

    Here's the mantra: fault tolerant systems. Things will fail. Can your space shuttle deal with those failures gracefully?

  • Remember the Hubble Telescope's mirror flaw [uoguelph.ca]? It was in all the papers at the time...
    Perkin-Elmer had done the rough grinding of the mirror in 1978, and had finished the final polishing in 1981. As the telescope's 2.4 meter primary mirror was being polished, an unrecognized 1.308 millimeter error in the structure of a device used to monitor the process caused technicians to give the mirror an exquisitely smooth surface with a grossly inaccurate shape. The result is the "spherical aberration" that now bathes the stars in fuzz whenever Hubble tries to look at them. The culprit device was called the reflective null corrector.

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