@PebMet1@Josh143574359 Actually NASA has an easier time. The hydrogen is stored and loaded at its normal boiling point.
In a normal boiling point system heat gain just means loss of propellant.
In the SpaceX sub-cooled system all heat gain leaves you with warmer propellant.
@KevinSwindell Definitely. It's not terribly difficult once you get the basics down. I'm lucky to have some good professors teaching that kind of thing.