Linguofreak
Well-known member
I'm sure I don't have to point out to people well-versed in orbital mechanics that it takes 3 days to get to the moon because if you want to cut that time, you have to waste fuel boosting to an orbit that loops well beyond the moon, then waste more fuel braking into lunar orbit... Even breaking it up into specialized chunks doesn't fix that. Personnel and cargo transfers in LEO and possibly LLO would ADD time...
Breaking it up into specialized chunks increases the available Delta-V by allowing each chunk to carry only the equipment necessary for its phase of flight. Lugging a heat shield all the way to the moon and back wastes propellant. Hauling that propellant all the way to the moon wastes more propellant. If you use an NTR for your LEO <-> LLO phase, it likely doesn't have the thrust to launch the stack from Earth itself, so it will need a chemical engine to lift off. Launching it from Earth for every Earth <-> Moon round trip will waste *more* propellant.
If you do it in chunks, you can take all the propellant otherwise wasted on lugging extra weight around, and use it for getting to the destination faster.