Setu

Why do I think I turned ninety degrees? Is it due to frame of reference? Possibly. I'm judging from the map. By eyeball I had a trajectory directly at Kerbin, and then suddenly I was in an orbit around Kerbin, 2/3rds of the way to Mun. Ok I can see that it is frame of reference phenomenon, thanks. Like trying to throw a ball into a bin from a moving car, you have throw it backwards more than sideways, so a trajectory from Mun towards Kerbin will miss it and go into orbit.

I'm new to Kerbal, just got first flight to the Mun. On the way back I got a nice trajectory towards the mother planet, but when I got in the SOI of the planet, my trajectory turned 90 degrees! I've tried to find out what happened, and I'm told this is because the three body physics is too hard to solve - but surely none is involved? Three body physics is where the path of body A is affected by B & C, but the path of B is affected by A &C, and the path of C is affected by A & B, so any tiny change in starting conditions rapidly changes the outcome, ( and even then that doesn't mean its incalculable, only that we cannot know the starting conditions accurately enough to calculate anything useful - which of course is not true in a simulation), anyway, the changes in the paths of the moons and planets is surely ignored in Kerbal, so this not a three body problem. Maybe the physics is harder than it looks, but reducing it to a series of one-body problems with a step change between zones, seems to me to be an over simplification? What other things are over simplified?