Even using F9/FH would have been much cheaper than SLS. And F9/FH are proven, working technology.
The craven avoidance of in-space refueling begs the question of what kind of future is NASA imagining for humanity in space, if something as simple as transferring a fluid from one tank to another is too difficult.
FH could probably be the foundation of a lunar program but I don't know what it looks like.
Growing up in the 1980s reading the "science fact" columns in Analog magazine I got the idea that we got sold out when we decided to do Apollo the way we did and that instead of a stunt we could have had a much more capable program that would have led to a more durable presence on the moon.
Today though looking at large numbers of plans to get to the moon it's easy to come to the same conclusion von Braun did (from looking at large number of plans), that the Apollo architecture was much more feasible than any of the others. It wasn't just "get it done on Kennedy's timeline" but a matter of being able to do it at all.
It's not so hard to transfer fluids with gravity, still unprecedented to do it without. I studied theoretical physics so I didn't get too into it but I ran into a few situations in labs handling cryogenic fluids where a liquid wasn't a liquid when it got to the other end of a pipe!
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From a mission planning viewpoint also I'm not too impressed with Starship scenarios that involve refueling. That is, I've heard it takes anything from 12-20 Starships to fully top off a Starship to go to the Moon or Mars.
You could imagine one launchpad could launch 1500 tons of cargo to Mars a year (1 launch a day staging fully fueled Starships in a holding orbit to waiting for Earth and Mars to align every 2.5 year or so) but if you can launch 20x the cargo to a destination (as opposed to fuel) you could build a baby O'Neill colony in LEO and have one hell of a space tourism destination. It's not so much a shortcoming of Starship as much as it is the reality that Heinlein was wrong and LEO is much closer to the Earth than other destinations.
(For instance in the 1980s the US fielded an antisatellite weapon that could be launched from an F-15 and kill LEO satellites with just a 2.5 km/s delta-V. Try to shoot down a GPS satellite, however, and that's an entirely different problems)
The craven avoidance of in-space refueling begs the question of what kind of future is NASA imagining for humanity in space, if something as simple as transferring a fluid from one tank to another is too difficult.