SpaceX Super Heavy/Starship (BFR/BFS) - Earth to Deep Space / Re: SpaceX Starship : Texas Prototype(s) Thread 23 : Discussion« Last post by rsdavis9 on Today at 08:50 pm »
So the word has been that all the outer engines startup using GSE-supplied fluids. However, obviously there has to be a transition to vehicle-supplied propellants pretty darn quick as the vehicle lifts off.
It's possible that I'm lost, but "GSE-supplied fluids" to me means nitrogen, helium (whatever) for spin-up and other start neads but they always run on vehicle-supplied propellants.
I am not an authority. But I believe startup gases and electric from engine QD makes the most sense. Liquid from tank.