The broader impact of this Small Business Innovation Research (SBIR) Phase II project is to enable the reduction of greenhouse gases by the aviation industry by advancing the development of a lightweight conformable tank capable of storing hydrogen at a gravimetric efficiency of over 10% hydrogen by mass. The development of a conformable tank with a > 10% storage efficiency, which exceeds the potential of existing technology, would have an immediate impact on the potential for hydrogen to replace existing transportation fuels. While the aviation application introduces unique challenges for hydrogen storage, the results of this project will benefit a wider variety of transportation fuel markets, where demand for lightweight, safe, and economically viable storage solutions is increasing. The storage of high-pressure gaseous hydrogen is a significant obstacle for zero emissions fuels, and meeting the standards for minimum burst pressure, cyclic operation, extreme temperature operation, and hydrogen permeation with a conformable tank will open the door to a wide variety of near-term applications, enabling the reduction of transportation-related emissions and reducing the burden of sending carbon fiber tanks to landfills at the end of their lives. This Small Business Innovation Research (SBIR) Phase II project will address the challenges related to the commercialization of a lightweight hydrogen tank for aviation fuel. The decarbonization of the aviation industry requires zero-emissions powertrain technologies. However, current battery technologies lack the storage efficiency to support long-range flights, and existing hydrogen storage tanks are too heavy and cumbersome to be practical. The research objectives of this project are to increase the gravimetric efficiency of conformable tanks, close the gaps in the remaining barriers to component certification compliance, and produce prototype tanks suitable for bench testing and evaluation for flight testing. The research will involve the optimization of the pressure vessel reinforcement structure, the production of conformable tank samples, the testing of samples for the existing hydrogen tank regulations, and the collaboration with airplane manufacturers and regulators to identify and address additional performance requirements. Once completed, the project will result in full-scale (2.5 kg and above), standards-compliant, production scalable tanks for continued component and flight-worthiness evaluations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.