The angular momentum can be transferred through the magnetic coupling. What I'm curious about is how this system deals with 'saturation' (at some point, you ca

The angular momentum can be transferred through the magnetic coupling. What I'm curious about is how this system deals with 'saturation' (at some point, you can't spin it any faster...). "Real" satellites do use scaled up versions of this, but they use it to save fuel, not volume, as you still need attitude control thrusters to "desaturate" the reaction wheels from time to time. Having both systems works fine on a large satellite bus, but I don't see it scaling down all that well.