Elliott said each one tells the story of its own X-15 launches, and a quest back in the late 1950s and throughout the 1960s to reach hyper-sonic speeds of 4,500+ miles an hour.

X-15 Launches from Mothership NASA/U.S. Air Force The X-15 #2 launches away from the B-52 mothership with its rocket engine ignited.

Sixty years hence, the X-15 rocket plane remains a marvel of aerospace engineering.

The X-15 that hangs in the Smithsonian Institution's National Air Space Museum is the first of three built by North American Aviation. It was rolled out on October 15, 1958, 15 days after its ...

The crew behind the successful X-15 program left a legacy of achievement and a foundation for success in space.

SpaceX has delivered a new crew to the International Space Station in just 15 hours. The team, consisting of astronauts from ...