The world's first hydrogen-fueled hypersonic jet may be able to reach a simply astounding speed of 12 times the speed of sound. That's about half the speed of satellites in low Earth orbit. The ...

An aircraft running on hydrogen that races through the upper atmosphere at speeds exceeding twelve times the speed of sound might seem like a fantasy reserved exclusively for science fiction. That, ...

"Hypersonic" refers to speeds over Mach 5, or five times the speed of sound. That's approximately 3,800 miles per hour, a pace that could take you all the way around the equator in less time than it ...