In article ,
says...
Launch Orion uncrewed on Delta IV Heavy. Launch the crew in a Dragon 2
or Starliner and have them dock with Orion before heading off to the
moon. This eliminates the need to crew rate Delta IV Heavy or Falcon
Heavy.


So now you need 3-4 launches and on-orbit assembly to get the job
done.

You need docking, that's routine.


It's worth noting that Falcon Heavy can't (easily) launch Orion anyway
due to the fact that Orion has to be vertically integrated.


I don't see why this would be a problem.

It surely could be solved, with enough money. The devil is in the
details though. I've been told Orion and its service module can't be
horizontally integrated. Doubly so for the monster of an escape tower
(which wouldn't be needed if you launch Orion uncrewed).


You'd have
to come up with a way to stack Orion on top of Falcon Heavy on the pad,
which I doubt SpaceX is set up to do. That and ULA has said they can
build more Delta IV Heavies, if given the cash, of course. Keeping ULA
part of this builds political support anyway, even if they cost more.


I suspect the big driver of using Delta IV Heavy is to make the cost
comparison to SLS look 'better' (from NASA's perspective).

Sure. Also political since SpaceX isn't a good name to utter around
traditional contractors (many of whom either own part of ULA or some
other outfit that is trying to build a large launch vehicle of their
own).

Jeff

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