The rocketship X-15, now undergoing trials at Edwards Air Force Base, is the supersonic hero of this interesting documentary. The sleek black craft capable of screaming through space at well over 2,000 mph is approached from all sides. There is first, history to consider; all the supersonic aviation which has gone before it. Then there is experimentation; the years of planning and research by North American which produced the X-15. There are the people too, such as Scott Crossfield, the test pilot. Finally comes the three day countdown period before every flight. A battery of scientists, technicians, officers, pilots, and the inevitable publicists, prepare for the brief moments when the X-15 is aloft and sailing earthward again. Terse, informative, yet written in a kind of public relations style which is not journalism at its best.