But the main thing is the plan is projecting a whole 20 years into the future
This is what depresses me. It took only 12 years to go from mankind never having touched space to Armstrong and Aldrin walking on the moon. And that is using 50's and 60's technology...
We have better data and materials. It should be easier and faster.
Possibly one factor is how much safer it HAS to be now. You couldn't get away with a 50% moon-shot success prediction More like 99.5% these days. That said, it still amazes me how few astronauts the US lost up to the end of the Apollo programme.