Summary and Key Points: Before NASA led U.S. space exploration, there was debate over whether the U.S. Air Force or the newly formed NASA should shuttle astronauts to space and in what type of craft. ...

-Air-launched from a B-52, the X-15 reached a record-breaking speed of Mach 6.7 and flew high enough to earn astronaut wings for eight of its pilots. -While never intended as a weapon, the X-15 was a ...

Soar to the threshold of space in NASA's experimental rocket plane with this exclusive interview and clip. When you purchase through links on our site, we may earn an affiliate commission. Here’s how ...