We were talking about this Monday night at my book club. One person wanted to know why space ships used Navy terms when she felt they should be Air Force. I'll not go into our discussion but if it is going to be inter-orbital & inter-planetary a Space Force similar to the Air Force & a break off of the Air Force, makes sense to me. Like someone mentioned they would be a break off of the Air Force. Once we get into long term space flight it once more becomes more ship like with the personal living on it as if the were on a ship, thus the Navy terms..
Now if you are going to have something like the Marines going onto space stations you then need a transport. Depending on the size of the personal force & time it takes would indicate whether it would be a large transport flying machine or a ship like a Navy ship.
I don't know if that helps.
I'm partial to the Navy idea since I'm a Navy Vet.
