You guys seem to be in the know. I\'ve been starting to play, and I had a few questions. What gravity model does Kerbin have - similar to WGS84? Newtonian? Does Kerbin orbit Kerbol elliptically (same question for Mun and Kerbin)? Does KSP take into account center of gravity / center of mass differences for orbit attitude dynamics and control? What velocity does the speed indicator measure - is there an inertial frame of reference? Does everything lie in an 'ecliptic' or are there out of plane orbits for celestial bodies too? I personally think N-body physics would be cool for KSP - although extremely difficult. You can add Lissajous and Lyapunov orbits and many other 'cool' orbital mechanical phenomena. Some of you say there is no solution to the N-body problem as if it were impossible to work with. There exists simulations for specific circumstances of the n-body problem - solutions if you will. There just isn\'t a global solution like in the 2-body case -> elliptical orbits, patched conics. Lissajous orbits I don\'t seem to see it addressed, but for a 2-body problem the solutions are planar, yes. But for n-body (3+) problems you start to get non-planar behavior. When considering the Jacobi for your body you get key-hole behaviors which become important when you have limited propellant. http://svs.gsfc.nasa.gov/vis/a010000/a010600/a010636/ The artemis program took advantage of a lot of n-body problem dynamics to reach the moon from earth orbit on low propellant. As you can see - at the right distances the n-body solution differs dramatically from 'patched conics' simply because 2 bodies cannot give you the same behavior. You even start to get solutions where the orbits are 'pseudo periodic' in that a single velocity component returns to zero but the orbit never physically passes through the same point in space, it traverses a surface. I\'m not sure but the SAS seems to take care of much of the orbital stability (attitude-wise), but for a real body decays in attitude lead to decays in orbital behavior (the two are coupled behaviors). Has anyone played with attitude behaviors in KSP? Thanks for reading -Areyla