Is this Unrealistic? (Gravity in a space station)

[Battlehymn Republic]

I wrote a short story in which a bunch of bad guys take over a torus shaped orbital space station, and somehow stop the artificial gravity.

I then realized that the whole point of wheel-shaped Island Twos are to create artifical gravity through spinning.

So would it be impossible to stop a wheel-shaped space station from spinning?

[Kuroneko]

Impossible? No. Just put some torque on it, say by attaching rockets to the space station. To get rid of the angular momentum, you must give it to something else, and the rocket idea is probably the simplest one that wouldn't risk too much damage to the station.

[Gil Hamilton]

It depends on the construction of the space station. Is the entire space station itself spinning or does it have wheel sections that spin and a stable middle section.

As Kuroneko says, they probably could stop the station by way of a rocket to strip its rotation. A neat trick could be that they did it on the way in while boarding the spacestation, by docking with the space station and then gunning their drive section. Assuming the ship they got their doesn't break free of the docking moorings, it could potentially stop the rotation of the station on landing. It would be a pretty cool trick, since they could do their nefarious deeds under the cover of the chaos caused by the loss of gravity.

However, if it has a wheel and a counterweight system, rotation could be stopped by turning off / jamming /destroying the motor.

[Drooling Iguana]

However, if it has a wheel and a counterweight system, rotation could be stopped by turning off / jamming /destroying the motor.

That would reduce the gravity, but not stop it entirely. The thing would have the same angular momentum it always had, so jamming the motor would just cause the whole thing to start spinning at a reduced rate.

[Sriad]

If the pirates had an extremely good flywheel thingie (this is not unlikely in a setting where you have artificial gravity on space stations etc) they could attach it at the station's hub and steal all their rotational inertia. This could be done more sneakily than rockets all around the outside. (if the space station is built right)

An important question to answer in your story is why they would do such a thing, ie how is it better for them to have a 0-G space station.

[AMX]

However, if it has a wheel and a counterweight system, rotation could be stopped by turning off / jamming /destroying the motor.

That would reduce the gravity, but not stop it entirely. The thing would have the same angular momentum it always had, so jamming the motor would just cause the whole thing to start spinning at a reduced rate.

I'm pretty sure the counterweight is supposed to rotate in the opposite direction, keeping the total angular momentum close to zero.

[drachefly]

But why would they keep the flywheel on board when it's just a major shrapnel hazard one they've spun up? Unless they periodically spin down for maintenance or something... that would work.

[AMX]

But why would they keep the flywheel on board when it's just a major shrapnel hazard one they've spun up? Unless they periodically spin down for maintenance or something... that would work.

*think-a-think-a-think-a*

Maybe they have significant changes in the mass of the habitat ring, or the distribution of said mass (read: lots of stuff moving up and down); still being connected with the flywheel would probably simplify the task of keeping the rotation rate (nearly) constant (without resorting to thrusters, or always moving appropriate counterweights inside the station).

Or maybe they have a need to re-orient the station regularly (the torque from the habitat and the flywheel should cancel out, making it easier to turn the station's axis of rotation)

Or, as you said, maintainance. If, say, people have to crawl around at the outside of the station regularly, de-spinning it would be nice.

That's all I can come up with at the moment.

[Wyrm]

Another thing to consider is that, when a space station using a spinning habitation ring is oriented, even if you have a counterweight rotating to keep the total angular momentum close to zero, the spinning ring will still put non-trival stresses on the ring's bearings (that's why you can change the angular momentum of the ring itself; you apply torque on it through the bearings, and the same is true for the counterweight). In these cases it would be useful to spin down the ring to make the stresses more manageable.