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, ...

Liftoff of the "That's Not a Knife" suborbital mission occurred at 7 p.m. ET on Friday (Feb. 27). When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

For decades, the SR-71 Blackbird stood as the pinnacle of American aerospace engineering, a reconnaissance aircraft so fast and so high-flying that no missile ever caught it. Now, more than 25 years ...