Originally written by @Whitecat106, this mod introduces the idea of decaying orbits. Original thread here: https://forum.kerbalspaceprogram.com/index.php?/topic/116818-1
Adopted by @Papa_Joe, he compiled it for a later version of KSP (1.4), thread is here: https://forum.kerbalspaceprogram.com/index.php?/topic/175618-1
I've adopted it, fixed a lot of bugs (see list below), and am continuing it now.
What does it do?
On rails and off rails orbital decay for any vessel around