Pseudostew

I've programmed in physics. I added gravity using with an altitude Delta using this wiki https://en.wikipedia.org/wiki/Gravity_of_Earth#Altitude but it's not consistent. I then went to try Newton theory physics but the weight range is so large the i cant accurately calculate it within the range of variables. I was just wondering if anyone knew of a method to fake this like KSP?

Hi, I'm a student games programmer in my final year of University. I absolutely love KSP as it has given me a greater understanding of the difficulty and science behind real life space missions! I really want to make a simple 2D space sim game in order to buff out my portfolio (and for fun of course!). I've looked everywhere on the internet and forums for suggested methods of programming realistic gravity physics for orbiting etc. The problem is the methods I try are inconsistent or unrealistic... Looking at KSP it looks like they calculate trajectories and then put the ship on rails effectively so (relatively) wonky game engine physics don't change the orbit paths. I was just wondering if anyone knew how Squad achieved this, or if any developers who saw this could shed some light? Thank you very much, Jason.