"Hypersonic" is the most extensively researched history of the X-15 program yet produced. The book was written with the cooperation of surviving X-15 pilots as well as many other program principals and is based on six years of research in Air Force, NASA, and North American archives assembling. It covers the tasks of converting and testing the B-52 carrier airplanes, building the first full-pressure suits to protect the pilot, building the first engineering mission simulators, acquiring the remote lakebed landing sites, and building the radar range. It also covers the flight program is covered in detail, including the most authoritative flight log ever assembled; in many instances, information in this log was derived from the original flight data recordings. Also covered are each of the experiments that were flown aboard the X-15 late in its career when it became the workhorse of the space program, carrying such things as startrackers destined for the Apollo program and missile detection systems that would later be sent into orbit on satellites.