GTL proposes a dramatic improvement in launch and space vehicle technology for NASA space and exploration missions. The modified BHL (mBHL) technology provides significant reductions in weight while exceeding the helium permeability requirements needed to meet NASA long term cryogenic propellant storage requirements. The proposed effort builds upon a substantial DARPA investment in BHL cryotank technology for shorter storage duration mission applications and takes the next step, extending the technology to long-term storage cryogenic propellant applications. The phase I effort conducts trade studies to identify and define the optimum metal laminate coating technology that can be incorporated into a BHL cryotank composite. The proposed effort will also evaluate several lightweight multifunctional insulation design concepts synergistic with mBHL technology and identify optimum solutions to be incorporated in the phase II program. With the proposed development of mBHL, the advantages of the technology will be achieved for long term cryogenic propellant storage, providing the means to significantly lower cryotank mass, reduce permeability and provide a significant improvement in propellant tank insulation performance reducing propellant boil off, thereby enhancing NASA's ability to achieve its exploration and science mission goals for less cost.