The writing of this book would have been impossible without the personal recollections of many people, pilots and non-pilots, who were intimately involved in the beginning of the era of manned rocket flight in America. I wish there were some way to thank them properly for their generosity and for the time and effort it took them to review events that go back twenty years or more in some cases.
The NASA history office at the Johnson Space Center in Houston was unfailingly helpful, especially in giving me access to transcriptions of the post-flight debriefings of the astronauts. I should mention in particular NASA historian James M. Grimwood, the author, with his colleagues, Loyd S. Swenson, Jr., and Charles C. Alexander, of This New Ocean: a History of Project Mercury. Other books I would like to acknowledge are Always Another Dawn, by A. Scott Crossfield with Clay Blair, Jr.; Starfall, by Betty Grissom and Henry Still; Across the High Frontier, by Charles E. Yeager and William Lundgren; The Lonely Sky, by William Bridgeman and Jacqueline Hazard; X-15 Diary, by Richard Tregaskis; and We Seven, by the seven Mercury astronauts.
The names of four figures appearing briefly in the narrative have been changed: Bud and Loretta Jennings, Mitch Johnson, and Gladys Loring.