Oh, and a quick non-political followup: Falcon 9 looks like another iteration of DC-X done with dense fuels in mind as per Mitchell Burnside Clapp's papers back in the 90's. I did a quick search but all that turned up was this. [1]
I don't know what this says regarding the possibility of further success for SpaceX; they've moved to a less dense fuel in hopes that it'll allow them to have self pressurizing tankage. While SpaceX has had increadible success I find myself wishing there was a way of wedding Elon's money and drive with the people who built DC-X in hopes that they could maybe, MAYBE, get more than one or two flights out of each test vehicle.
IF you could get cheap RL-10's for the price that the DC-X project was buying them for in the 90's, I'd suggest using them, suitably modified to burn methane, _just_ as a braking/landing engine. [2]
(But that was way back in the 90's, when the MIC was still sometimes running assembly lines instead of building each single engine by hand).
(Oh, and I found a slightly better ref. on RL-10's: [3])
[1] https://yarchive.net/space/rocket/fuels/hydrogen_deltav.html
[2] https://forum.nasaspaceflight.com/index.php?topic=11020.0
[3] https://yarchive.net/space/rocket/rl10.html