@modrobert In practice it has been known for a long time but never done for one simple fact: It only works for relatively large (wide) ships. Since we struggle to get even small ships into space it becomes a limiting factor. We simply cant build a ship big enough for it to be doable without being impractical.

There are other issues to though, specifically manuverability. Things that are rotating oppose any attempt to turn them. So providing thrusters in a position where a spaceship could change its course without wasting energy int the process is also an added difficulty.