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Space Science

Probe Crash Due to Misdesigned Deceleration Sensor 374

Posted by michael
from the for-want-of-a-nail dept.
squirrelhack writes "Seems as though the Genesis spacecraft was able to launch from earth, travel through space, avoid aliens, and cruise back into the atmosphere to be caught by stunt pilots waiting patiently with their helicopters. Alas, the brakes didn't work because a sensor was designed upside down.
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Probe Crash Due to Misdesigned Deceleration Sensor

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  • by AKAImBatman (238306) * <akaimbatman@gmaiWELTYl.com minus author> on Friday October 15, 2004 @03:21PM (#10539299) Homepage Journal
    Look on the bright side. The craft was not a complete loss, and it was the first probe to successfully test the Interplanetary Superhighway [wikipedia.org]. (Article with pictures [nasa.gov]) Now that we know the IPSHwy works, we have the capability to launch cargo ANYWHERE in the solar system.

    The primary limitation is the maximum weight we can get to the Earth/Moon Lagrange points. Once at the L-points, the cargo pretty much travels one gravity slingshot to the next with nearly no fuel expenditure. This could be a massive boon for sending Interplanetary mission cargo, especially when staging manned missions!

    The only down side is that the IPSHwy is simply too slow for manned travel. Not too bad of a tradeoff, however, when you consider the amount of mass that can be more easily staged at Mars in advance! It's certainly reasonable that we could have a complete microsat network at Mars before a human ever sets foot there. Services that could be provided include:

    - Mars GPS system
    - Deep Space Network [wikipedia.org] Uplink
    - Satellite Radio Communicators for landing teams
    - Detailed mapping and emergency surveillance of problem areas

    In short, we could have a complete technological infrastructure on Mars before we risk anyone's life going there. It wouldn't have to be like the moon mission. We could go to stay.
  • It seems ... (Score:3, Insightful)

    by Sonic McTails (700139) on Friday October 15, 2004 @03:22PM (#10539303)
    ... that human error can happen even in the most expensive projects.
    • Re:It seems ... (Score:5, Insightful)

      by kfg (145172) on Friday October 15, 2004 @03:35PM (#10539473)
      ... that human error can happen even in the most expensive projects.

      Because no matter how much money you spend you can't buy perfect humans, and to err is human.

      To correct error is engineering.

      Once upon a time some 'wires' in my brain got crossed and I actually picked up a hot soldering iron from the wrong end. Have you ever had that experience where you realize you're about to do something terribly, terribly wrong, but the impulse has already been sent and you can't stop it?

      I hate when that happens.

      But I only did that once. Pain is a great teacher. One might almost come to the conclusion that that's what it's there for.

      So the next probe will have the sensor absolutely correct and working. They'll have to come up with brand new ways to mess things up.

      Just like I do.

      • Re:It seems ... (Score:5, Interesting)

        by lukewarmfusion (726141) on Friday October 15, 2004 @03:39PM (#10539529) Homepage Journal
        Have you ever made a mistake that hurt so much you knew you'd never make that mistake again? And when it came around next time, you made so much effort to not make that mistake that you ended up making a completely different mistake?

        Mistakes happen, as you say. As is commonly accepted my many software developers, software has bugs.

        The parent notes that mistakes happen in even the most expensive projects. I think it's more likely to happen in complex (and therefore expensive) projects.
      • by Martin Blank (154261) on Friday October 15, 2004 @04:04PM (#10539809) Journal
        Have you ever had that experience where you realize you're about to do something terribly, terribly wrong, but the impulse has already been sent and you can't stop it?

        Yeah. Every time I go to Slashdot.
    • Man, you are wasting your talent here on Slashdot. With such super-sleuthing abilities, no mystery would be too great for you!
  • by Amsterdam Vallon (639622) * <amsterdamvallon2003@yahoo.com> on Friday October 15, 2004 @03:22PM (#10539309) Homepage
    I wish POLITICIANS would stop judging accidents with NASA and spaceflight in general as "wastes".

    It's NOT a waste. Research REQUIRES failure. SUCESS requires failure.

    One step at a time, my fellow scientists and engineers. One step at a time.
    • by turbotalon (592486) on Friday October 15, 2004 @03:40PM (#10539537) Homepage
      Yes, sucess requires failures, but not of this kind!! Imagine if in the early days of cars they had spent millions of dollars researching and designing the latest carburator, then installed it BACKWARD.

      We expect failures like "Hmm we didn't know there would be THAT much particulate matter in space, look at all those holes!", not "oops, got that backwards!!" or, "oops, forgot to convert to metric!"

      "It's always the little things that get me, I always get a fscking decimal point wrong or something!" --Michael, Office Space

      • Yes, sucess requires failures, but not of this kind!! Imagine if in the early days of cars they had spent millions of dollars researching and designing the latest carburator, then installed it BACKWARD.

        The carburator wouldn't work, it would be removed and replaced, and nobody would think anything untoward had happened.

        The problem here is that there's no way to test something like this on, say, a half-dozen demo models before it goes out the door. Every single thing has to work right the first time, with
        • by tftp (111690)
          The problem here is that there's no way to test something like this

          It is trivial to do 30G. You don't even have to drop the thing. If you can't rent a centrifuge, build one - it will cost peanuts in a project of this scope. And with that controlled acceleration you can test, non-destructively, all you want.

          What was missing there is the will to do things right.

    • by handorf (29768) on Friday October 15, 2004 @03:41PM (#10539551)
      But we know things like this already. Failure is fine if you learn from it.

      What did we learn? Um... accelerometers only work in one direction... if you install them backwards, things don't happen right!

      We tolerate mistakes if we have to make them, but this one (like all the recent Lockheed Martin screwups on work for NASA) appears to be stupidity.
      • What did we learn? Um... accelerometers only work in one direction... if you install them backwards, things don't happen right!

        Yes. But the real lesson here is that when you are designing something of this sort, don't design it so that it only works one way round. Make sure that it works in both directions, with the output only enabled for the correct direction...
    • by pclminion (145572) on Friday October 15, 2004 @04:07PM (#10539833)
      Research REQUIRES failure. SUCESS requires failure.

      This is very true, but this type of failure should be deemed unacceptable by any reasonable person. This is the NASA equivalent of accidentally filling your car with diesel instead of gasoline. Or doing an 'rm -rf *' in your home directory. It's completely boneheaded and shouldn't be accepted by anyone.

      I'm not a mean guy, and I don't hope that anyone at NASA loses their job over this, but I think a little bit of preventive ridicule is in order. I earned myself some nasty comments when I deleted a bunch of important (but thankfully, backed up) data with a braindead command, and I think I'm the better for it now.

  • by Average_Joe_Sixpack (534373) on Friday October 15, 2004 @03:22PM (#10539312)
    The scientists got their samples and the public got a cool crash video
    • Piper did say that quote, but only when nhe was being managed by the man who coined the phrase: Bobby "the Brain" Heenan

  • by freeze128 (544774) on Friday October 15, 2004 @03:23PM (#10539323)
    But it takes a rocket scientist to really screw things up.
  • by TykeClone (668449) <TykeClone@gmail.com> on Friday October 15, 2004 @03:24PM (#10539338) Homepage Journal
    They had the silly thing in reverse.
  • by Anonymous Coward
    ...and make some sort of Genesis joke but there just isn't anything funny at all about the damn group.

    When told about its demise, Peter Gabriel responded with "So?"

  • Enough! (Score:5, Funny)

    by Anonymous Coward on Friday October 15, 2004 @03:26PM (#10539367)
    Haven't we had enough stories about sensorship today?
  • by grunt107 (739510) on Friday October 15, 2004 @03:28PM (#10539393)
    You'd think the siseneG would have been a tip off!
  • Blame game... (Score:5, Interesting)

    by Jonah Hex (651948) <hexdotmsNO@SPAMgmail.com> on Friday October 15, 2004 @03:29PM (#10539408) Homepage Journal
    But the problem stemmed not from the installation but the design, by Lockheed Martin
    So what kind of trouble is LM going to get into over this one, like most big money contracts I'm sure there is some kind of penalty for such a screwup. I'm not talking about firing the engineer or some Q&A folks, I'm talking about money returned to NASA.

    Jonah Hex
  • by handorf (29768) on Friday October 15, 2004 @03:31PM (#10539428)
    Seriously. Correct me if I'm wrong, but THEY're the ones who:
    Thought we still use Imperial for SPACE WORK (Mars Climate Orbiter IIRC?)
    Recently dropped a sat because it wasn't bolted down when they moved it.
    Now this.

    Can I get like a billion dollars to fail repeatedly? PLEASE?
    • References (Score:5, Informative)

      by handorf (29768) on Friday October 15, 2004 @03:34PM (#10539470)
      Lest I get a bunch of "What are you talking about?" responses:

      For them dropping the NOAA sat:
      http://www.space.com/spacenews/businessmonda y_0410 11.html
      (first link I found)

      Climate Orbiter:
      http://www.space.com/news/mco_report-b_9 91110.html
      • A great one for the NOAA sat is here:

        http://www.spaceref.com/news/viewsr.html?pid=102 99

        This one has the pictures that are enough to make anyone wince and shake their head sadly.
    • As I mentioned in another post, this project was one of the better-faster-cheaper ilk. I think BFC is not entirely without merit, but it was applied in precisely the wrong manner. Whose fault was that? NASA, not LM, and not even JPL. While it's easy to point the finger at LM (a subcontractor to JPL on this), JPL's job is to make sure the design and test were adequate. And NASA's job was to invest resources and conduct oversight. And Congress...

      When the final report comes out, we will presumably learn why t
  • Ass-umptions (Score:3, Insightful)

    by Mark of THE CITY (97325) on Friday October 15, 2004 @03:32PM (#10539441) Homepage
    All it takes is one ass-umption to make the great space systems contractor to look like an ass.

    Of course, they usually do get it right, in near-heroic fashion. But didn't it occur to anyone to try this out by, say, building a unit without the science part, bringing it along on a pre-scheduled Shuttle flight, and de-orbiting it? (IIRC, design and test pre-dated the Coulmbia accident). That way, they get a real re-entry at low (for NASA) cost.

  • by Scrameustache (459504) on Friday October 15, 2004 @03:34PM (#10539462) Homepage Journal
    Damn Australian scientists!
  • Hmm (Score:4, Funny)

    by rnelsonee (98732) on Friday October 15, 2004 @03:34PM (#10539463)
    From the article:
    The mission's Mishap Investigation Board will continue to investigate the problem.

    Oh, suuuure. MIB stands for "Mishap Investigation Board" now, huh? We're on to you, you governemnt spooks!

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

    by Anonymous Coward on Friday October 15, 2004 @03:35PM (#10539478)
    Isn't this the same situation that resulted in the creation of Murphy's Law. They were doing acceleration tests on humans but they installed the sensors backwards so the tests were useless.

    The original lesson they learned was: That if a design allows for a part to be installed incorrectly, then that part will be installed incorrectly (eventually, or maybe even the first time).

    Just a little bit of history repeating.
  • It's a good thing that the switch didn't attempt to detect acceleration as well (for some other purpose). It would could have been pretty disastrous (even more so?) to have the shoot fire during take off. :)
  • Alphaware ... (Score:5, Insightful)

    by dragondm (30289) on Friday October 15, 2004 @03:37PM (#10539498) Homepage

    These kind of mistakes make me wonder. WHY does NASA *HAVE* to re-design every freakin' thing on every freakin' mission from the ground up every freakin' time?

    We're flying alpha-test spacecraft.

    Re-usable modules anybody?? Heard of those? Standard designs? Sure, some parts are going to be different, namely the actual scientific instruments, but fer ghodssake an accelerometer?! WhyTF do we need to redesign that (its a weight, a spring and a switch, fer the love of pete) ?!!

    • You Forgot (Score:3, Funny)

      by Greyfox (87712)
      Freaking "This side up" sticker. It could have been a great alpha test if they'd just had a freaking "this side up" sticker.

      Of course, said sticker would have shown up on the invoice to NASA as "sund.explns" and carried a price of $42,000.

    • Re:Alphaware ... (Score:4, Informative)

      by wass (72082) on Friday October 15, 2004 @04:20PM (#10539981)
      Re-usable modules anybody?? Heard of those? Standard designs?

      I hate to tell you this, but NASA HAS been using proven parts in spacecraft, there is a strong push for COTS (Commercial Off-The-Shelf) Hardware, it's much cheaper than designing every op-amp from scratch. But this COTS stuff has to be beyond military spec, it has to be rad-hard, withstand severe thermal and vibrational stresses, etc. It's easy to make a reusable op-amp or logic gate in a desktop computer, but for a satellite they have to be MUCH more rugged.

      Regarding this accelerometer, not sure why it had to be different, but like I said before, it definitely needed to be rad-hard, endure strong vibrational and thermal extremes, and still function flawlessly upon re-entry. That's not easy to design, and there are 100000000 things to go wrong, one of which is that it's installed backward.

      Now as to the reason they don't re-use spacecraft designs is that every craft has different operating parameters. Some are very far from Sun and Earth, and need higher-gain antennas (ie, parabolic dishes that can retract) and RTG's (solar panels become inefficient beyond Jupiter). Some operate close to Earth orbit and use solar panels and smaller antennas. Some will never re-enter earth, some will burn up on re-entry when their use is finished, and some need to survive re-entry intact. Some craft close to the sun (eg SOHO) need special rad-hard thermally-shielding designs. The inclusion or exclusion of each of these items will drastically change the structure of the craft.

      So basically, each mission is so different that it's very unfeasible to come up with a reusable 'strawman' design from which to start all NASA craft. And this is just considering operating environment, power, and communications. That's not even including the scientific instruments, all of which need specialized heating or cooling or shielding or vibrational-isolation requirements, etc.

  • When the capsule - which blazed into the atmosphere at 11 kilometres per second - decelerated by three times the force of gravity (3 Gs), the sensors should have made contact with a spring."It's like smashing on the brakes in your car - you feel yourself being pushed forward," says NASA spokesperson Don Savage.

    Doesn't that mean that the parachutes should have deployed on take off? heh....

  • Hmmm... (Score:5, Funny)

    by katsiris (779774) on Friday October 15, 2004 @03:42PM (#10539562)
    I didn't realize that up and down were different in metric than the imperial system.
  • by GMFTatsujin (239569) on Friday October 15, 2004 @03:45PM (#10539589) Homepage
    You'd think they would have figured out that the braking switch was in backwards when they saw Genesis's airbags deploy at liftoff.

    3... 2... 1... *PFOOF*
    • Which of course didn't happen because there are known side vectors at launch and differing attitudes throughout flight, and so the sensors were activated only shortly before the descent was to begin.

      But I suspect you may have just been trying to be funny?
  • but this was when I playing 'Moonlander' and accidentally mapped Up to the down arrow key and Down to the up arrow key.

    Caused me many a lost mission and endless hours of frustration that night. These guys got lucky...

  • by shoppa (464619) on Friday October 15, 2004 @03:46PM (#10539608)
    Testing of the assembly would have shown up this problem immediately.

    Just like you should never write that code that cannot be tested (in the perfect world, every line would be executed during testing), you should never design a subassembly that cannot be tested.

    It's a organizational attitude adjustment that's needed to put this into effect.

  • by Tablizer (95088) on Friday October 15, 2004 @03:47PM (#10539611) Journal
    I remember reading about an Apollo moon car issue where a core-sample clamp would not work because it was installed upside down. It ended up wasting about an hour of astronaut time. Parts designers should avoid symmetrical designs where things fit, or semi-fit, if misoriented. Design them with things sticking out so that it would not fit *at all* if put in wrong.
  • The experiment was good because it test a lot of novel space flight theories so it wasn't completely a waste. However, the part failure that compromised the mission was old, established tech and should not have failed. Get rid of the contractors! They suck.
  • Redundant logic (Score:5, Interesting)

    by Scorillo47 (752445) on Friday October 15, 2004 @03:48PM (#10539625)
    A while back, one of the main things I admired NASA for was the redundant design concept. You just have a backup path for everything.

    But recently it looks like they kind of dropped this concept, at least partially. Probably as a cost-cutting measure. The success of the whole mission now depends on the reliability of several single components, like the sensor in discussion.

    BTW, did you know that a Mars Rover has a single CPU that carries out all the computation? I found this puzzling. Today, you add redundance in every piece of equipment - even in web blades.
    • The success of the whole mission now depends on the reliability of several single components, like the sensor in discussion.

      That's what faster, cheaper, better is all about. Higher-risk, lower-cost missions. They're also considered a way to give younger people experience in running a mission (since not everybody can run, say, Cassini, and you'd like to have a way for them to build experience first), which means careers are getting torpedoed by not having the funding to do something completely redundant.


  • I must have put a sensor the wrong place or something. Shit, I always do that, I always mess up some mundane detail.

    Michael B.
    Satellite Design Group
    Lockheed Martin
  • The Origins of Murphy's Law had a similar start:

    "it became apparent that they had been installed incorrectly, with each sensor wired backwards. It was at this point that Murphy made his pronouncement."

    read about the whole story: http://en.wikipedia.org/wiki/Murphy's_law [wikipedia.org]

    (note that the sensors were wired backwards as opposed to installed backwards)

  • Murphy's law was a quote (people can argue about who said it first) directly related to accelerometers/strain guages and whether or not they could be connected backwards ...

  • by Tablizer (95088) on Friday October 15, 2004 @04:02PM (#10539792) Journal
    After that capsule crashed, I saw the following headline:

    Saucer From Space Crashes In Utah Desert!

    My first thought was, "what bullshit!". But then I realized it was 100% true. (Well, okay, it was kind of an obese saucer shape.)
  • i seem to recall a series of stories on slashdot about the origination of the ubiquitous Murphy's Law. they centered around the first experiments of excessive gee forces on humans, and the phrase was first used in conjunction with a set of accelerometers wired backwards.

    here's the link to the story: http://www.improb.com/airchives/paperair/volume9/v 9i5/murphy/murphy0.html
    (remove the fnords... er.. slashdot inserted spaces)

  • by AvantLegion (595806) on Friday October 15, 2004 @04:10PM (#10539868) Journal
    There is only negative acceleration.
  • by monoi (811392) on Friday October 15, 2004 @04:14PM (#10539913)
    We've all made mistakes like this, I think. Somehow, you just get things backwards in your head once, and then fix it as a `definite truth' which you don't bother to look at again.

    Usually, I find these kinds of mistake in my own work when someone else, who hasn't been tainted in the same way, points it out to me. I wonder why this kind of peer review didn't happen here?
  • by mhesseltine (541806) on Friday October 15, 2004 @04:50PM (#10540279) Homepage Journal

    One of the principles that has come about from continuous improvement, kanban, Toyota manufacturing is the idea of poke-a-yoke, or poka-yoke engineering.

    The idea is, you design something so that it can only be used one way, so that errors in installation are eliminated. For example, if this switch/sensor/whatever needed to be installed from one side, you put a bump/notch on the opposite side that would prevent the part from being installed wrong.

    For another example of this, if you have an N64 gaming system, take apart one of the controllers and look at the button design. Every button has slots that it fits in, so that you can only install a button in one location. There's no worrying about "Did I swap the A and B buttons?" because it's not possible.

Nothing succeeds like success. -- Alexandre Dumas