Benefits to NASA Funded Missions: Future exploration missions beyond Low Earth Orbit will require long-term (>2 weeks) in-space storage of large quantities (>4 metric tons) of Liquid Hydrogen without a significant loss of propellant due to boil off from radiation heat sources. Benefits to NASA Unfunded & Planned Missions: Large space-based platforms having science instrumentation (optics, focal planes) that require cooling from sub-Kelvin to 70k to reduce noise and isolate/detect desirable wavelengths (target emissions). Liquefaction of LOX and LCH4 propellants on Mars surface. Benefits to Other Government Agencies: DoD (Office of Naval Research, Air Force, Naval Research Laboratory, Naval Surface Warfare Center): Cooling optics for space telescopes and other instruments; superconducting electronics at 4K; power system for underwater crawlers. Benefits to the Commercial Space Industry: Interested in zero boil off liquid hydrogen for commercial depots and long durations missions. Benefits to the Nation: This item has significant benefit the nation with respect to space-based, high reliability, long duration, distributed cryo-cooling.