Spaceplane Hangars

Spaceplane Hangars include all stock Cargo Bays and the full-featured heavy Mk3 Hangar.

Cargo Bays have Free launch positioning and limited functionality: only a single vessel can be stored in each bay and only at construction time; resources cannot be transferred, but the crew can.

Mk3 Hangar, on the other hand, is a full-featured rover hangar with Strict launch positioning. It has a large stack node at the front and another small one at the top (for docking port or such). It is meant to be used as a complete fuselage of a plane. Its single aft door is used as a ramp for rovers to drive in and out. The important thing about that ramp-door is that you can always set how far it is opened with the Open Gates slider.