US 11,939,938 B2
Liquid level equalization for propellant tanks
Claire Jocelyn Atkinson, Corvallis, OR (US); and John Michael Dixon, Renton, WA (US)
Assigned to BLUE ORIGIN, LLC, Kent, WA (US)
Filed by Blue Origin, LLC, Kent, WA (US)
Filed on Jun. 6, 2022, as Appl. No. 17/805,591.
Prior Publication US 2023/0392567 A1, Dec. 7, 2023
Int. Cl. F02K 9/56 (2006.01); F02K 9/42 (2006.01); F02K 9/60 (2006.01)
CPC F02K 9/566 (2013.01) [F02K 9/42 (2013.01); F02K 9/56 (2013.01); F02K 9/60 (2013.01); F02K 9/605 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for equalizing fluid levels of a propellant tank that stores a liquid propellant for a rocket engine of a rocket, the propellant tank having a vent line with a vent valve and an equalization valve, the method comprising:
after filling the propellant tank with the liquid propellant to a level above a height of the equalization valve within the propellant tank before launch of the rocket:
using one or more controllers to:
determine the level of the liquid propellant relative the height of the equalization valve within the propellant tank after the launch of the rocket;
in response to the level of the liquid propellant falling below the level of the equalization valve, open and close the vent valve to re-duce pressure of the propellant tank; and
in response to the level of the liquid propellant falling below the equalization valve during or after the launch of the rocket, close the equalization valve.