Oxygen liquefaction and zero-loss storage system

This paper presents an alternative concept that employs existing technologies and off-the-shelf components to liquefy gaseous oxygen from an in-situ propellant production (ISPP) unit and to store the liquid oxygen without boil-off loss. A primary goal is to minimize active components with a secondary goal of designing the active component in a protected or failure-free environment. The resulting design requires only one active component, a compressor operating in a closed and consequently more protected system. The design avoids pumps as active components by employing cryopumping for gaseous oxygen (GOX) and gravity transfer for liquid oxygen (LOX).