Honestly, I think you should see if anyone else has the same complaint before changing anything, since this would only matter if a lot of players care about physics making sense. To explain, a satellite suddenly not being affected by the gravity of a planet after being in a orbit wouldn't go directly away from the planet. It would go in the direction it was actually moving in, which after a perfect orbit would be perpendicular to the direction of the planet. The cannon idea would work to satisfy this because the cannon would be applying force in the direction it's aiming in to the object in question, with the rotation being more easily disregarded since the player doesn't know the internals of the cannon.