Setup:
Have a ship with high move (to make it easier)
Have a ship (you want to duplicate in orbit of planet).
Tell ship with high move to move long distance.
Quickly go click on planet with ship to duplicate, and start clicking 'eject' to launch ship.
it does not 'launch' until they other ship finishes moving, but I have been able to get up to ten copies of my 'ship to duplicate' by clicking on the eject repeatedly.