Okay, first of all, I'm not very good at maths, so I will have to talk in programmer terms here. I have the following issue: A small rocket is moving in space, and I want it to move to and stay at a location in space, similar to a quadcopter. No as far as I see it, I have the following variables to consider: - Location - Target Location - Rotation / thrust vector - Maximum thrust - Gravity - time delta I want my function to output the thrust multiplier (0-1) and the change in rotation OR the optimal heading. I do NOT have information about: - How quickly I can change the rotation of the craft I can omit the following: - How quickly thrust changes. It changes instantly. - Air resistance Now, I'm aware that I can not expect a perfect calculation since I will have to approximate how rotational impulses will affect the craft, but I would like to have a good approximation. I can get a relatively good approximation for the altitude, but horizontal movement is giving me a headache.