I've been playing with the concept of zero gravity in my mind for a bit and I think it's not as hard as they make it sound.
If we line up 4 unbalanced wheels, make NR 1 and 3 spin in one direction, NR 2 and 4 spin in the other. We have the final mass moving horizontally. Now we accelerate the wheel half of the spin and decelerate it the other half.
behold! Both the acceleration and deceleration create opposed reaction forces in the same direction!
momentum of the wheel
balancing gyro momentum
art of the apparatus
stay in the air
combine momentum change
discussionsuggested readinggabydewilde - gde wilde anti gravity
conversion to linear rotation