AI-enabled refuellable orbital propellant depots (2,000 kg) and autonomous rendezvous, docking, and propellant-transfer systems for spacecraft operators in LEO and cislunar space. Features long-duration hydrazine and cryogenic storage, thermal isolation and robust sealing, modular standardized interfaces, and AI-augmented GNC for repeatable, fault-tolerant, high-throughput servicing with minimal ground intervention.