I was just thinking about theoretical space craft. If a ship never left space, does it have a center of gravity when flying? For example, do the thrusters need to be in the middle rear of the ship, or could they be lopsided? If they were asymmetrical, would it rotate the ship or could it fly straight?
My understanding is that it wouldn't matter in a vacuum - the ship would accelerate in the opposite direction of the thrust, no matter where on the ship the thrust is coming from.