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Upside-Down Sensors Caused Proton-M Rocket Crash

Posted by Unknown on from the someone's-getting-fired dept.

Michi writes "According to Anatoly Zak, the crash of the Russion Proton rocket on 1 July was apparently caused by several angular velocity sensors having been installed upside down. From the source: 'Each of those sensors had an arrow that was supposed to point toward the top of the vehicle, however multiple sensors on the failed rocket were pointing downward instead.' It seems amazing that something as fundamental as this was not caught during quality control. Even more amazing is that the design of the sensors permits them to be installed in the wrong orientation in the first place. Even the simplest of mechanical interlocks (such as a notch at one end that must be matched with a corresponding projection) could have prevented the accident." A review of the quality control procedures used by the contractors responsible is underway.

7 of 323 comments (clear)

  1. Re:QA is not the problem by TheCarp · · Score: 5, Informative

    Amusingly, when someone actually attempted to track down who murphy was, and where the law came from.... http://en.wikipedia.org/wiki/Murphys_law

    Edward Murphy proposed using electronic strain gauges attached to the restraining clamps of Stapp's harness to measure the force exerted on them by his rapid deceleration. Murphy was engaged in supporting similar research using high speed centrifuges to generate g-forces. Murphy's assistant wired the harness, and a trial was run using a chimpanzee.

    The sensors provided a zero reading; however, it became apparent that they had been installed incorrectly, with each sensor wired backwards. It was at this point that a disgusted Murphy made his pronouncement

    So this is potentially, very much related to the original usage.

    --
    "I opened my eyes, and everything went dark again"
  2. Re:The quality conrol problems... by PetiePooo · · Score: 5, Informative

    ...aren't so amazing when you look at the track record of Russian manufacturing.

    Before we Americans point too many fingers, let's not forget NASA is not immune to similar mistakes.

  3. Re:(The Real) Murphy's Law strikes again! by PetiePooo · · Score: 5, Informative

    My favorite is Cole's Law...

  4. Re:QA is not the problem by Baloroth · · Score: 5, Informative

    What seems more amazing is that a simple software check pre-launch (i.e. "do all the sensors think they are pointed up?") was not part of the SOP. Given that their exact function is orientation detection, skipping the opportunity for self-test via that function is somewhat baffling.

    Obligatory: It's not rocket science!

    The sensors in question were for angular velocity. Given that pre-launch the craft doesn't have any (peculiar) angular velocity, the sensors would return the correct results (zero) no matter how they were installed.

    --
    "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
  5. Re:The quality conrol problems... by Hognoxious · · Score: 1, Informative

    Communism(n) [also commernussum, comianizzem] - Anything that we don't do in the USA, such as believing that the Earth is more than 6,000 years old.

    --
    Confucius say, "Find worm in apple - bad. Find half a worm - worse."
  6. Re:QA is not the problem by smellsofbikes · · Score: 3, Informative

    Amusingly, when someone actually attempted to track down who murphy was, and where the law came from.... http://en.wikipedia.org/wiki/Murphys_law

    Edward Murphy proposed using electronic strain gauges attached to the restraining clamps of Stapp's harness to measure the force exerted on them by his rapid deceleration. Murphy was engaged in supporting similar research using high speed centrifuges to generate g-forces. Murphy's assistant wired the harness, and a trial was run using a chimpanzee.

    The sensors provided a zero reading; however, it became apparent that they had been installed incorrectly, with each sensor wired backwards. It was at this point that a disgusted Murphy made his pronouncement

    So this is potentially, very much related to the original usage.

    If I remember right, the way a wheatstone strain gauge is set up, there are four ways to connect it. One is right, two are wrong but give you half the resolution you expected -- so you get data, just lousy data -- and one is completely wrong and you get no data whatsoever. It was hooked up in the completely wrong configuration. That was what made him so mad: there was only a 25% chance it would get hooked up in the completely worthless configuration, but that's what happened.

    --
    Nostalgia's not what it used to be.
  7. From the same people that brought you Chernobyl... by Chas · · Score: 2, Informative

    And the K19.
    And the K141 (The Kursk)
    Soyuz 1
    Soyuz 11
    And about half a dozen other fatal accidents involving shoddy workmanship.

    --


    Chas - The one, the only.
    THANK GOD!!!