I don't know if this was intended in the game but it is an exploit I've used. When in a system you have a ship on the one side of the system of five habitable planets and you need it to get to the other side in one turn and you don't have enough engine power to get you there. you have the ship launch next to the nearest planet. then move the ship into orbit of the next planet. Launch the same ship on the other side of said planet closest to the next closest planet C. Move ship into orbit. Again launch ship on opposite side. and then if needed goto planet D. This exploit allows one to move a ship potentially several spaces more than it could at its own accord.
Sorry to all others that have used this exploit if this was not attended. If it is great. I just didn't know if it was or wasn't.