Sometimes refuses to assist orbital launcher. Depends on where you build the orbital launcher I think. Might be a height range thing.
Obrital fabber should not be supportable by non-orbital launchers (non-orbital ones have too much buildpower/are too energy effective to properly balance that). Only if building is on the ground should non-orbital ones be able to help - by beign directly assigned to the building itself, rather then assiting the fabber.
