On 2020-05-23 8:41 AM, David Spain wrote:
There is a lot we don't
know here. 1) The configuration of the pressurization pipes vis-a-vis
the tanks, 2) presuming there is more than one engine performing tank
pressurization, how the pipes come together and the manifold and
regulator structure being used to join them, etc. I'll keep digging, see
what I can find for that. You can too.


So far the best pictorial I can come up with is he

https://i.stack.imgur.com/H4RtH.png

Which doesn't really show the pressurization plumbing as far as I can
see. Note the smaller tanks inside the larger tanks. As I understand it
these are NOT for pressurization, but to provide pressurized propellant
for the return trip. They can be smaller because you are not using as
much propellant for the return leg. Seems to be missing the first stage
(Super Heavy) LOX return tank, maybe because they did a cut out of the
base? You can clearly see them both in Starship.

Dave