[dmillar]

In-orbit refueling, etc. Those are Starships not SLS being counted: 29:45

Talking about methane, in situ refueling (not just spacex, but they've been the most vocal): 41:25

Complexity/redundancy: 46:28 (looong pause and laughter)

Comments on engine design: ~48:00 (you have to be aware of Raptor/SS booster design to get the criticism)

[avmich]

Raptors right now look very nightmarish if used for landing crew on anything - the Earth or the Moon alike. The most advanced liquid fuel engine with tons of feedback loops looks suspiciously like a catastrophe waiting to happen at a worst possible moment.

Landing on the Moon is supposed to use some other engines as well at the time, so that may help. As soon as we'll know more about design, we can say things more confidently.