Abstract: A liquid-vapor separation system for use in a zero gravity environment for transferring and storing fluids, and particularly fluids that are primarily liquid, such as propellants, reactants and coolants, among others, has a low supply tank pressure and low pressurant gas requirement, which results in maximized capacity, reduced system weight and reduced cost. The temperature of a container provided as part of the present invention is decreased below the freezing point of residual liquid within the container. Non-compressible gas is thereafter vented and the liquid raised to liquid temperature. Gaseous contaminants are thereby vented and subsequent filling of the container is thereby maximized.