Active Mass Redistribution for Thermal Mitigation in Orbital Cryogenic Depots

Long-duration storage of cryogenic propellants in Low Earth Orbit (LEO) is critically limited by thermal boil-off. We propose a Single-Launch Orbital Depot (SLOD) architecture utilizing a Hexagonal Tank Configuration (HTC). We introduce an Active Mass Redistribution (AMR) protocol, where propellant is cyclically transferred to shadowed sectors, utilizing empty tanks as radiative thermal shields. A first-order nodal analysis demonstrates that this configuration reduces the aggregate thermal load by approximately 45%. Based on a 1200-ton propellant capacity, this thermal efficiency yields a passive propellant savings of over 36 tons per year, significantly reducing the logistical burden of station-keeping.