>>11109781You mean one exactly to specs in the image from that book? Hopefully, never. Those are improperly designed and will just irradiate your people and be generally shitty. If you mean a space station colony that is properly designed, holds the same number of residents, and performs the same functions, as the O'Neill cylinder in that image then the answer is a question, "How long does anything take to build when we don't know anything about who is building it or their methods?" Your question is quite a bit ignorant.
I mean, you can just take it one step further and say that, "assuming you already have a mature industrial presence in space on the Moon and in orbit," means you have gigantic 3D printers that can make a station in a week and spit them out like Pez dispenser. See the inherent problems here?
