Hydrogen in high-speed air transportation

Abstract This paper briefly reviews the history of hydrogen use in aviation and aerospace and goes on to discuss current international developments, which are centered around plans for supersonic/hypersonic aircraft using hydrogen as a fuel. The development work which must be accomplished before the first test flights can take place, possibly at the end of this century, includes rather straightforward technological challenges relating to components, systems and infrastructures and to safety and security considerations. A more complex challenge includes achieving environmental compatibility for this technology, which is well possible in the areas of producing and handling hydrogen fuel, but probably not in the area of end use, if the benefits of this fuel are to be fully exploited. Another formidable precondition is achieving an international political consensus that a transition from the established global hydrocarbon energy economy to a potential global hydrogen energy economy, in which aviation and aerospace could have a trail-blazer function, is necessary, achievable and urgent.