I thought SS was going to do everything? Now they're talking about customized versions for specific environments???First off, SpaceX is working on a lunar version with neither fins nor heat shield, but including higher mounted engines for landing/ takeoff. So lunar surface to earth surface isn't a design constraint.
Have you done the math on landing and returning ~100 mT dry mass from the lunar surface to NRHO? You're going to need beefy engines to land successfully. To prevent debris from scattering into the skirt like in a recent SS test, they'll need to be high up. Are they going to be gaseous or liquid? In addition, round-tripping that much dry mass will require a bunch of propellant (we haven't even started talking about delivered payload!). How much propellant can be delivered to NRHO by a single fully-fueled SS tanker in LEO?
What's the schedule for launching up to a dozen tanker missions to complete one successful BEO mission? How much propellant will you lose to boil-off during that time?Why is required mass/ fuel load ugly? Fuel is the least expensive part of the entire endeavor (once all the other pieces are reusable). At two million dollars a launch (2019 Elon estinate) for a refueling run, even a dozen trips (if SS needed totally full tanks) is only $24 million. That is about the cost of four sets of F9 fairingsn about the cost of reused F9 launch ($50 million). Other than requiring more fuel, what's the problem?
I'd rather SpaceX spend their time and talent on designing innovative in-space craft that handle the Earth->Moon task.