For the SpaceX launches of the Falcon9 and Falcon Heavy, and also Blue Origin launch vehicles, the booster stage lands with a controlled decent and firing of main engines for retro-thrust.
During lift-off and rocket burn, inertial 'forces' keep the propellant at the valve end of the tank, but once this thrust stops, the tank is in free-fall. Gas thrusters then reorient the unit for retro-burn to de-orbit.
During this process, how are the propellant and LOX directed to the valves that direct the components to the engine nozzle?
