-> Use the arrow keys to adjust orbit by thrusting up/down/left/right. -> Click Focus button to switch focus between Earth and your ship. -> Zoom slider to adjust the zoom. Zoom out to see the moon! -> Change the frame of reference when you are near the moon and try and get into lunar orbit! -> dt = timestep. Increase dt => faster simulation, less accurate -> thrust = rocket thrust The orbits are *not* stable! Probably never will be due to physics simulations being "hard to get right" :D This uses a very simple method, there are more accurate ones out there that I might try (although they might not run as fast...)