Supercritical air at cryogenic temperature is an attractive source of breathing air because of its very high density and low pressure. However, heat leak into the cryogenic tank causes the stored air to expand and vent, thus limiting the storage life of a charged system. We propose to develop a storage system for supercritical air tanks that provides cryogenic cooling that will intercept heat leaks to prevent venting and enable long-term storage of charged, supercritical air tanks. The innovative, mechanical cryocooling system provides flexible coupling and quick disconnection from the storage tanks, as well as high reliability and efficient, low-power operation. In addition to storage, the system can be used to charge the tanks with supercritical air without the use of expendable cryogens. In Phase I, we will prove the feasibility of the system through design trade-off and optimization analyses that will produce a conceptual design and operational description of a supercritical air storage system. The system will be designed to store multiple units of NASA?s existing supercritical air self-contained breathing apparatus (SCBA) system. In Phase II, we will build and demonstrate a prototype storage system for supercritical air SCBAs.