Challenger: A True Story of Heroism and Disaster on the Edge of Space

by Adam Higginbotham

NASA soon began using the three X-15s as platforms for scientific experiments, mounting equipment in wingtip pods that the pilots opened in the upper reaches of the atmosphere, to gather data on esoteric high-altitude phenomena. Their exploration expanded knowledge of both aerospace engineering and medicine: flight surgeons discovered that the pilots’ heart rates during X-15 flights were more than double those recorded on tests of other aircraft, due to the seemingly inexorably rising strain they felt while confined in their cockpits, anticipating each launch. The pressure suits they wore provided the basis for those used to outfit the Mercury astronauts. But testing the limits of existing technology in such an unforgiving environment was fraught with risk, and the pilots’ experimental role often required them to push their aircraft far into the unknown. In an aircraft traveling at more than a mile a second, the smallest mechanical fault—or the tiniest miscalculation—could escalate at bewildering speed.