Figure out how to use liquid hydrogen as fuel
• Burning hydrogen to produce electricity has water vapor as exhaust.
• Solving challenges related to safety, engineering, electrical, thermal, infrastructure, and societal acceptance helps aviation.
Increase power and efficiency without increasing weight
• Liquid hydrogen is very cold (cryogenic), which enables using superconductors to greatly increase power density.
• Fuel cells and electric motors provide cruise thrust instead of heavy batteries and turbofans.