Air travel accounts for approximately 2.5 percent of global CO2 emissions, prompting efforts to develop more sustainable alternatives. NASA has taken a significant step towards this goal by supporting the development of a Hybrid Hydrogen-based aircraft engine. The engine, named Hy2PASS, is being developed by Phillip Ansell at the University of Illinois Urbana-Champaign with a grant from NASA's Institute for Advanced Concepts (NIAC). Hy2PASS is a hybrid engine that combines a fuel cell and a gas turbine, but its unique feature lies in its air handling system. Unlike traditional hybrid systems, Hy2PASS decouples the compressor from the turbine, enhancing efficiency by eliminating waste heat and allowing for optimized speed control. The emissions from this system are minimal, mainly producing water. The project aims to revolutionize air travel sustainability by significantly reducing emissions and increasing efficiency. If successful, it could mark a milestone in the aviation industry's quest for environmentally friendly air travel. While still in the concept phase, the project shows promise for a future where hydrogen-powered aircraft could become a reality, transforming the way air travel impacts the environment.