> Most spacecraft use chemical thrusters to desaturate momentum wheels; LightSail 2 relies on electromagnetic torque rods, which orient the spacecraft by pushin

> Most spacecraft use chemical thrusters to desaturate momentum wheels; LightSail 2 relies on electromagnetic torque rods, which orient the spacecraft by pushing against Earth's magnetic field. I'm trying to visualise what this process might look like. Having read a bit about momentum wheels it seems like it's probably not a one way street in terms of the direction of torque so the wheel at times might speed up and other times slow down so to avoid saturation. Clearly this is not always possible so an external energy source is used to provide a balancing torque so the wheels can be slowed down without turning the craft (too much). For the lightsail 2 it uses magnetic torque rods, which from https://en.m.wikipedia.org/wiki/Magnetorquer https://en.m.wikipedia.org/wiki/Magnetorquer are electromagnets so the energy comes from turning them on for a while. Can anyone guess a bit more or explain where in the orbit the saturation might occur and what this desatiration process would look like in terms of the motion of the craft?