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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."

11 of 302 comments (clear)

  1. just a spacewalk by qewl · · Score: 5, Interesting

    All they need to do is a spacewalk out and restart it.

    He stressed, however, "We're not dealing with a safety issue," and added it would take several weeks to determine when to schedule the spacewalk.

    There are two gyroscopes still functioning, and that is enough to stabilize the station, Suffredini said. If one of these remaining gyroscopes fails, the station will rely on thrusters to keep it steady.

    Too bad they can't do that for Hubble too.

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    1. Re:just a spacewalk by Derf+the · · Score: 4, Interesting

      Can anyone tell us why it takes 2 weeks to schedule the spacewalk?

      If it was an imminent emergency, how short a time before they could get out there? Minetes, hours, days?

      --
      No. You can't look at my Sig; it's mine, and I'm not showing you.
    2. Re:just a spacewalk by angusr · · Score: 5, Interesting
      "There are two gyroscopes still functioning, and that is enough to stabilize the station, Suffredini said. If one of these remaining gyroscopes fails, the station will rely on thrusters to keep it steady."

      Too bad they can't do that for Hubble too.

      No thrusters on Hubble, of course.

      It wouldn't work for Hubble anyway - thrusters are a fairly coarse method of control, resulting it lots of banging and vibration. While on the ISS that would be fine (although some mu-g experiments would probably be upset) on Hubble it would render it unusable until the vibrations have died down after every thrust. Plus, of course, while observations take place they couldn't use the thrusters - and hence the lack of control is going to make those observations pretty hopeless anyway.

      If the robot mission to attach a gyro pack to Hubble goes ahead (which I hope it does) then it is likely to have thrusters on it - however, I would suspect that they're not for day-to-day control but to control Hubble when it's re-entered.

  2. I shouldn't laugh... by John+Seminal · · Score: 4, Interesting
    "The gyroscope problem stemmed from an underlying failure in a circuit breaker.... At this time, the box that holds that particular circuit breaker ... is outside (the station)".

    I wonder why they would place the circuit breakers outside the space station. If those ciruit breakers are like anything in my house, they go out all the time. Or maybe it is just my power company with all the brown outs in the summer.

    I'm glad the story says this is not a critical system or a threat to the astronauts. Still, I wonder why the circuit breaker is not in a place easy to get to.

    This gives me another idea. I wonder if they have a special escape pod attached to the space station, so if some critical system goes, they can escape.

    --

    Rosco: "If brains were gunpowder, Enos couldn't blow his nose."

    1. Re:I shouldn't laugh... by DrMrLordX · · Score: 2, Interesting

      Well, the ISS is modular, isn't it? Something that is currently on the outside of the ISS might be inside later. They seem to imply that the position of that particular breaker is temporary(either that, or its status as being "outside" is temporary).

    2. Re:I shouldn't laugh... by arikol · · Score: 2, Interesting

      To answer the comment about the servos, complexity is avoided as possible, you would need wiring for each servo, a power source for the servos and probably a few other (probably needing more power conduits etc.) Another thing, Weight! The cost of sending 1 kg of payload into space is around u$5000 on the Soyuz system and around u$10.000 on the shuttle. I think that might also be the reason for not having a well stocked maintenance facility onboard.

    3. Re:I shouldn't laugh... by tiger99 · · Score: 4, Interesting
      And weight (of wiring etc) is probably one of the main reasons why the breakers are outside (might be to minimise the length between source and load), the other probably being that you would not want the wiring on the unprotected side of the breaker inside, because of what would happen if it shorted. At the very least, unpleasant smoke and fumes, possibly fire. Virtually every cable insulation will, given sufficient energy, burn or emit toxic fumes. The exceptions may be glass and ceramic, not really practicable.

      And before anyone mentions PTFE (Teflon), well it may be OK in a frying pan, but a wiring fault would result in the release of fluorine gas, which would resct with moisture in the air to give hydrofluoric acid. Not good. A frying pan fire could presumably be very serious if the temperature got too high, IIRC about 400 deg C. If you inhale hydrofluoric acid, or get a small amount on the skin, you usually die, fairly unpleasantly. Someone who went to school with me died that way, many years ago, age about 22, from a small skin splash of HF even though it was quickly washed off.

      Teflon has been, and probably still is, used in unmanned satellites, OK in the smaller ones where a total loss is not an absolute disaster, but I think it would be frowned upon in things which earn serious money and have to keep working, such as comms sattelites. There will be Teflon bits in the microwave equipment, and in some mechanisms, which can't otherwise be lubricated, but not necessarily on normal wiring.

      I don't know what kind of wire NASA currently use, the aerospace industry has been through a variety. At one time, Kapton seemed good, we now know that it is lethal in circuits which have sufficient energy to initiate arcing.

      BTW, Kapton and Teflon are OK where there is always insufficient energy available to seriously raise the temperature, in fact I like working with Teflon in particular, but only in the right place.

  3. Makes you wonder... by NivenMK1 · · Score: 2, Interesting

    This makes you wonder what specification of hardware gets used in spacefaring vehicles/structures.

    It seems that over history, the spacefaring versions of our technology are quite inferior to what we have planet-side. On typical space vehicles, this is because the vehicles were built so long ago. The ISS is a relatively new invention, and the number of bangs, bumps and hiccups seems to be more or less consistant with it's much older counterparts.

    On a sidenote, anyone know if it has enough mass to impact earth's surface if it should come down?

  4. How do these things work? by The+Fanta+Menace · · Score: 3, Interesting

    The article says that if another fails, they will have to use thrusters to keep the thing stable. So can someone perhaps explain to me what the gyroscopes physically do to keep it stable?

    --
    -- Even if a god did exist, why the fsck should I worship it?
  5. Re:Place your bets! by FireFury03 · · Score: 3, Interesting

    AFAIK, the only axis a gyro can't be used to control is it's spin axis, so you should only need 2 gyros to control all 3 axis - anyone know why hubble needs 3 to keep it stable?

    --
    http://blog.nexusuk.org
  6. gyroscope with no moving parts by peter303 · · Score: 3, Interesting

    JPL has been marketing a fiber optic "gyroscope". It using inferometry in long fiber loop. Motion will cause a loop of light to doppler shift out of phase. Four of these coils, each on the face of a tetrahedron, will measure any rotational motion. No parts to break or wear out.

    I presume NASA spacecraft are using mechanical gyros?