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International Space Station Gyroscope Fails

Posted by CowboyNeal on from the tipsy-heavenly-bodies dept.

b00m3rang writes "Reuters reports that one of the three working gyroscopes that keep the international space station stable and in the right position stopped working, just hours after a new two-man crew moved in for a half-year stay."

8 of 302 comments (clear)

  1. Sensationalism... by Inominate · · Score: 5, Informative

    The article clearly states that ONE of three failed. The story posted makes it sound like the ISS is now starting to spin out of control.

    1. Re:Sensationalism... by Alter+Relationship · · Score: 5, Informative

      It's "one of the remaining three". There were 4 to begin with.
      (yes, I know, I must be new here cos' I RTFA :-)

    2. Re:Sensationalism... by Morham · · Score: 5, Informative
      The article clearly states that ONE of three failed. The story posted makes it sound like the ISS is now starting to spin out of control.
      The article clearly states.
      The station originally had four gyroscopes, but one of them failed two years ago. It was to have been repaired last year, but the shuttle Columbia accident grounded the three remaining shuttles and postponed that repair.
    3. Re:Sensationalism... by hasdikarlsam · · Score: 5, Informative

      ----
      The first gyroscope broke two years ago as a result of a bearing failure. Two more are still operating -- the minimum required -- but one has exhibited power surges and vibrations over the past year. If another gyroscope breaks, thrusters on the docked Russian capsule and the station would have to assume control over the massive orbiting structure for as long as a year.
      ----

      Rather, the thrusters *could* assume control over the ISS for up to a year; the repairs are in fact likely to be made a long time before that, never mind that there is currently no need for thrusters.

    4. Re:Sensationalism... by steve.m · · Score: 5, Informative

      No. If another one fails they switch over to thruster orientation by the Russian built modules (the FGB and SM). These consume fuel, but that's resupplied by progress flights.

  2. Re:How do these things work? by AlecC · · Score: 5, Informative

    Ever tried to twist a gyroscope? You can use them in two ways: if you don't try to push them, they stay oriented the same way so yo have a directional reference. But if you ty to move, they "push" back. This gives you something to "push against" in order to twist yourself in space. You don't need to spend expensive reaction mass hauled up from earth, you just use electricity from your solar cells, and you get a much smoother and more accurate control than thrusters.

    However, a single gyro can only handle positioning about two axes - you can rotate it about its spin axus as much as you like. So for three axis rotational stabilisation you need at least two gyros at 90 degrees to each other.

    --
    Consciousness is an illusion caused by an excess of self consciousness.
  3. If you're wondering how a gyroscope works by trystanu · · Score: 5, Informative

    If you're wondering how a gyroscope works and what it does:

    How stuff works has a nice article.

    Nasa's also got a page about how they're used in space shuttles

  4. Re:just a spacewalk by kzinti · · Score: 5, Informative

    Because you don't "just do" an EVA. Putting on a suit and going outside the station requires a lot of planning. You have to have the right time of the crew's daily cycle. You have to have the right ground personnel available to support the EVA. You have to schedule it for a time when you have sufficient TDRS (ground relay satellite) time available to cover the entire EVA. You maybe have to find a time when the station will be in the right attitude with respect to the Sun for the right amount of time, due to heating/cooling issues with the suit and perhaps (?) lighting issues with the area to be serviced. (And if the station has to be oriented a certain way, that might affect the amount of time the downlink antennas can be pointed in the general direction of the TDRS satellite.) Most importantly, the ground controllers have to draw up a complete step-by-step plan of the EVA, and the crew has to have time to study it. Take all that into account, and add the fact that the crew's every minute is planned days or
    weeks in advance, and you can see how it just takes some time to put together everything it takes to do an EVA. Going outside the vehicle is a risky activity. Extreme care is taken in its planning and execution, and rightly so.
    In a life-threatening emergency, like a sudden rapid depressurization, the plan probably calls for the crew to board the "rescue vehicle" (a Soyuz that stays docked at the station), undock, and deorbit.

    (Disclaimer: I don't work in the ISS program, but I have a general - read: vague - idea of how EVA works in the shuttle program. Consider the above to be an educated guess - but correct in spirit.)