Satellite gravity awareness and thrust managment

I'm trying to write code to make my satellite aware to the gravity well (that it may be inside of).
I've been reading few of the posts here about doing that and on how to rotate a ship which is inside gravity well,
however I did not understand enough as of how it works.
Basically I'm trying to make gravity stabilizer so the satellite will keep the position it is on and rotation of the satellite, so down facing thrusters will keep facing the right way and it won't fall from the sky because of...

Satellite gravity awareness and thrust managment