Reaction Engine A2 Powered by Hydrogen

While the MPG per person is fairly good. People have been pointing their fingers towards the airline industry when it comes to pollution. Reaction Engine has a hydrogen-poweed A2 aircraft concept that would be capable of hitting Mach-5 – five times the speed of sound (3400 mph), making it somewhat the spiritual successor of the Concorde. What makes it different is range and efficiency, capable of ferrying up to 300 passengers from Brussels to Sydney before four hours are up. It uses a 2-mode engine that makes it efficient at low speeds as well as hitting top gear with relative ease. However, production of hydrogen fuel on a large scale (without emitting carbon dioxide) remains a problem… (photo from Nick Kalpterakis/PopularScience)