This proposal describes the development of an inflatable and lightweight polymer-fabric structured pressure vessel designed for the containment of cryogenic fluids. Technology Applications, Inc. (TAI) in collaboration with the Thin Red Line Aerospace (TRLA) proposes to develop a cryogen tank design solution with fully determinate load paths that addresses the need for lightweight pressure containment at extremely low temperatures without the reliability issues that exist in composite tank structures. Ultra High Performance Vessel (UHPV) technology that has already been developed for many other applications will be extended for use into the cryogenic temperature operating range. The Phase I feasibility study encompasses the design and critical support elements for creating a robust lightweight cryogenic tank structure that meets NASA mission specifications. The Phase II program will involve fabricating and demonstrating the performance of a prototype cryogen tank based upon the inflatable UVHP architecture.