back to article Hubble 'scope gyro drama: Hey, NASA, have you tried turning it off and on again? Oh, you did. And it worked? Cool

The classic “turn it off and turn it back on” strategy has worked once again for NASA, in that it may return the Hubble Space Telescope to active duty. On October 5, the venerable orbiting 'scope glitched out, and automatically put itself into hibernation to avoid any self-inflicted damage. Since then, its human controllers …

  1. TJ1
    Alien

    Someone left the ash tray open...

    ... in that SpaceX Tesla Roadster.

    It's all that space junk I tell ya!

  2. Mark 85 Silver badge

    Hammers in Space?

    We need either someone up there or maybe a robot arm attachment with a hammer for "fine tuning" these aging satellites.

  3. Spherical Cow

    Re: Hammers in Space?

    Up-voted for percussive maintenance.

    They'd still need to turn it off first, because STOP It's Hammertime!

  4. Evil Auditor Silver badge

    Re: Hammers in Space?

    Hammer. Or a healthy blast of pressurised air to get rid of all that star dust. Just imagine how it must look in Hubble's bowels...

    Lester's ventblockers

  5. phuzz Silver badge
    Thumb Up

    Re: Hammers in Space?

    If in doubt, give it a clout.

  6. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921

    That's very impressive and awesome work by NASA! Now if they could upgrade from the Pentium+AMD Overdrive...

  7. bombastic bob Silver badge
    Meh

    might I suggest...

    rotating the 'spare' units into service every few months, to keep something like this from happening again

    (that was standard operating procedure when I was in the Navy - get the spare out of the supply system, and rotate it in, taking the next unit out of service and putting it back into 'spares' in the supply system).

  8. Headley_Grange Silver badge

    Rotating

    Bob - I guess it depends what the dominant failure mode is. I assume space stuff is run-in before launch so they're not at the start of the bathtub, but if a component is more likely to fail when powering up then rotating is a bad strategy.

    When I was at uni my housemate had a knackered Mini which was always a pain to start and once it got going he didn't like to turn it off - e.g. nipping into shops. He once left it running in the student car park for about half an hour because he'd left something in the lab and was on his own.

  9. Kernel Silver badge

    Re: might I suggest...

    "rotating the 'spare' units into service every few months, to keep something like this from happening again"

    My experience with ringing generators suggests that this is an excellent way of ensuring all units fail due to the same mechanical wear within a few days of each other. We stopped swapping 'spares' into service after that, instead just doing a changeover to ensure the spare worked and then changing back again to the normally working unit.

  10. 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921

    A large, powerful vibrator in Hubble's design would have saved fuel

  11. Spazturtle Silver badge

    Hubble uses reaction wheels to turn, so no fuel used.

  12. jmch Silver badge

    "Hubble uses reaction wheels to turn, so no fuel used."

    Eh? Sorry, could you explain that to this rather coffee-deprived layman? Surely turning requires some change in velocity in the reaction wheels that would require some sort of energy expenditure? Or do you mean it uses electricity from solar panels and thus does not need to use propellant?

  13. Gene Cash Silver badge

    Yes, it uses electrical motors to spin, so the telescope rotates in the opposite direction.

    However, this eventually results in "saturation" where the reaction wheels can't spin faster to move the 'scope.

    "Desaturation" is usually done by firing rockets to hold it steady while the wheel is spun down... however this is an expensive telescope with very contamination sensitive optics, so you can't have rocket exhaust floating around. Instead they use magnetotorquers, which react against the Earth's magnetic field to to apply a small but steady torque.

    Well then why don't they use the magnetotorquers themselves to control the attitude? Because the force is very very small, and can't be used for quick pointing maneuvers in something as large as HST. "Going to the next star" would take weeks.

  14. ChrisC
    Coat

    "Well then why don't they use the magnetotorquers themselves to control the attitude? Because the force is very very small, and can't be used for quick pointing maneuvers in something as large as HST. "Going to the next star" would take weeks."

    Oh, that's a shame, not being able to tell Hubble to "use the force, look"...

  15. Juha Meriluoto

    Just shake it a bit, and it'll run all right... isn't that what we all do?

  16. jake Silver badge
    Pint

    Vacuum induced gimbal stiction ...

    ... is a hazard of the environment. Good to see they got it going again, at least for a while.

    This round's on me ... Job well done.

  17. Gene Cash Silver badge

    Re: Vacuum induced gimbal stiction ...

    Actually, it's not vacuum stiction... it may be pitting in the bearings caused by electrical arcing caused by static buildup from the solar wind. This is a new theory.

    http://esmats.eu/esmatspapers/pastpapers/pdfs/2017/bialke.pdf

    https://www.youtube.com/watch?v=KibT-PEMHUU

  18. jake Silver badge

    Re: Vacuum induced gimbal stiction ...

    Fair enough :-)

    Job well done anyway ... I'll get in another round when you bellow for it.

  19. I3N
    Boffin

    Hand of God or Superstition ...

    All for laying on the Touch ... VW Variant S - jumped up and down on back bumper until starter lined up to engage ... slamming the lid on the washer so that transmission would engage (later version so that lid lock switch would report closed.)

  20. arctic_haze Silver badge
    Pint

    Beer for everyone!

    This is the best news I've seen in a long time!

  21. JeffyPoooh Silver badge
    Pint

    I sure wish that they'd finish up that 'EM Thruster' gadget...

    Then they wouldn't need to use gyros on spacecraft. They could just lace the spacecraft with dozens of little EM Thrusters to have it point any which way you want, all solar powered and infinite lifespan.

    Come on kids, hurry up already.

    ;-)

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