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