Center of mass control of liquid tanks for spacecraft use

Abstract

A rigid structure propellant management device (PMD) liquid storage tank includes an outer shell and internal structures inside the outer shell that include a plurality of vertical columns each made up of a stack of individual storage cells. Each of the storage cells has solid vertical sidewalls and top and bottom capillary windows that allow vertical liquid transfer between adjacent cells in a vertical column. The top and bottom capillary windows in each of the storage cells have permeabilities that result in a selected direction of liquid flow in each column. A piping and valve system may be connected to the top capillary window of a top storage cell and to the bottom capillary window of a bottom storage cell of each vertical column, configured to allow controlled liquid transfer between adjacent vertical columns so that locations of empty cells in the tank as liquid is drawn from the tank achieves a selected column by column drainage sequence and controls a center of mass of the tank.

Dependencies are inferred from the claim text.