BHL Cryotank for Long Term Use

GTL has already made substantial progress in developing and validating the BHL<SUP>TM</SUP> technology for application to cryotanks. Earlier coupon testing of the temperature-dependent material properties confirmed the potential of the BHL technology to eliminate the microcracking issue. This was followed by the fabrication and cryo-pressure cycle testing of small BHL cylinders. No laminate leaks or degradation were detected in a test with more than 40 cryo-pressure cycles.While other efforts are exploring the reliability aspects of the BHL technology at larger scales, the proposed effort will focus on evaluating the long-term cryogenic propellant storage capabilities of the BHL technology. Specifically, this effort will include initial tests to examine the implications of long-term oxygen exposure on the BHL laminate as the first step towards validating the technology for long-term NASA exploration and other missions.The effort will also refine the BHL laminate design to optimize it for long-term cryogenic propellant storage. This will include an effort to increase the insulating capability of the structural laminate to minimize the need for secondary insulation. A small BHL cylinder shall be fabricated using these refinements as a proof-of-concept.