If a space station has artificial gravity created by spinning, how can it best be spun up to speed? Little attitude rockets could do it, but they would use up fuel, and limit your ability to change the spin rate in future. What if you had an external wheel that you spin up very fast in the opposite direction? If you did this, would it cancel out the gyroscope effect because the total angular momentum of the whole would be zero, and make it easier to orient the station with respect to the Sun, spacecraft, etc.?