Found some more info on this thing. It uses two Ford 2.3 engines tuned to 150hp and running on liquid hydrogen. A multi-stage turbo system allows it to run at 65,000ft. Most airliners fly at about 40,000ft.
If you watch mythbusters (don't laugh to hard) you'll know that they took a regular engine and cut off the gas fee and tried feeding it pure hydrogen directly into the carb... it ran for a bit till a spark caused a small back fire and started them... but the engine did run (they were testing fuel efficiency myths and this was about home brew hydrogen fuel cells)