Im currently trying to make Gravity with working Orbits, however finding these orbits is a pain.
Plugins exist such as this to help with things like this however its not on the roblox platform, but this is basicly what Im trying to find/create. 
If anyone could help we create something similar to this, or, just be able to get an orbit working without having to use trial and error process to find what works. Thanks to anyone who provides feedback I’ll try to stay updated on who responds and respond back.