[1]. The author is grateful to Karl Bender of NASA’s Dryden Research Library for helping to gather source materials. For a concise introduction to sonic boom theory, see Kenneth J. Plotkin and Domenic J. Maglieri, “Sonic Boom Research: History and Future,” American Institute of Aeronautics and Astronautics (AIAA), Paper 2003-3575, June 23, 2003.
[2]. For its development and testing, see Richard P. Hallion, Supersonic Flight: Breaking the Sound Barrier and Beyond: The Story of the Bell X-1 and Douglas D-558 (New York: Macmillan, 1977).
[3]. Some of the personnel stationed at Muroc when Yeager broke the sound barrier later recalled hearing a sonic boom, but these may have been memories of subsequent flights at higher speeds. One of NASA’s top sonic boom experts has calculated that at Mach 1.06 and 41,000 feet above ground level, atmospheric refraction and absorption of the shock waves would almost certainly have dissipated the XS-1’s sonic boom before it could reach the surface. E-mail, Edward A. Haering, Dryden Flight Research Center, to Lawrence R. Benson, Apr. 8, 2009.
[4]. “Ernst Mach,” Stanford Encyclopedia of Philosophy, Mar. 21, 2008, http://plato.stanford.edu/entries/Ernst-mach; Jeff Scott, “Ernst Mach and Mach Number,” Nov. 9, 2003, http://www.aerospaceweb.org/question/history/q0149.shmtl.
[5]. By the end of World War II, ballistic waves were well understood, e.g., J.W.M. Dumond, et al., “A Determination of the Wave Forms and Laws of Propagation and Dissipation of Ballistic Shock Waves,” Journal of the Acoustical Society of America (hereinafter cited as JASA), vol. 18, No. 1 (Jan. 1946), pp. 97–118.
[6]. David Darling: The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity (Hoboken, NJ: John Wiley and Sons, 2003), p. 457. See also “Airpower: Missiles and Rockets in Warfare,” http://www.centennialofflight.gov/essay/Air_Power/Missiles/AP29.htm; and Bob Ward, Dr. Space: The Life of Wernher von Braun (Annapolis: Naval Institute, 2005), p. 43.
[7]. The definitive biography, Van Braun: Dreamer of Space, Engineer of War, by Michael J. Neufeld (New York: Alfred A. Knopf, 2007), pp. 133–136, leaves open the question of whether the Germans at Peenemünde heard the first manmade sonic booms in 1942 when their A-4 test rockets exceeded Mach 1 about 25 seconds after launch.
[8]. For the authoritative history of the NACA/NASA mission at Edwards AFB, see Richard P. Hallion and Michael H. Gorn, On the Frontier: Experimental Flight at NASA Dryden (Washington, DC: Smithsonian, 2003).
[9]. Plotkin and Maglieri, “Sonic Boom Research,” pp. 1–2.
[10]. Introduction to “The Battle of the Bangs,” Flight and Aircraft Engineer, vol. 61, No. 2289 (Dec. 5, 1952), p. 696, http://www.flightglobal.com/pdfarchive/view/1952/%203457.
[11]. G.B. Whitham, “The Flow Pattern of a Supersonic Projectile,” Communications on Pure and Applied Mathematics, vol. 5, No. 3 (1952), pp. 301–348 (available at http://www3.interscience.wiley.com/journal/113395160/issue) and “On the Propagation of Weak Shock Waves,” Journal of Fluid Dynamics, vol. 1, No. 3 (Sept. 1956), pp. 290–318 (available at http://journals.cambridge.org/action/displayJournal?jid=JFM), and described in Larry J. Runyan, et al., Sonic Boom Literature Survey, vol. II, Capsule Summaries, (Seattle: Boeing Commercial Airplane Co. for the FAA), Sept. 1973, pp. 6–8, 59–60. Whitham later taught at both the Massachusetts and California Institutes of Technology.
[12]. Air Force Flight Test Center History Office, Ad Inexplorata: The Evolution of Flight Testing at Edwards Air Force Base (Edwards AFB: AFFTC, 1996), Appendix B, p. 55.
[13]. John G. Norris, “AF Says ‘Sonic Boom’ Can Peril Civilians,” Washington Post and Times Herald (hereinafter cited as Washington Post), Nov. 9, 1954, pp. 1, 12.
[14]. One of the first studies on focused booms was G.M. Lilley, et al., “Some Aspects of Noise from Supersonic Aircraft,” Journal of the Royal Aeronautical Society, vol. 57 (June 1953), pp. 396–414, as described in Runyan, Sonic Boom Capsule Summaries, p. 54. AFFTC used F-100s to conduct the first in-flight boom measurements: Marshall E. Mullens, “A Flight Test Investigation of the Sonic Boom,” AFFTC TN-56-20, May 1956.
[15]. History of the 3201 Air Base Group, Eglin AFB, Jul.–Sept. 1951, Abstract from Information Retrieval and Indexing System (IRIS) No. 438908, Air Force Historical Research Center, Maxwell AFB, AL.
[16]. F. Walkden, “The Shock Pattern of a Wing-Body Combination Far from the Flight Path,” Aeronautical Quarterly, vol. 9, pt. 2 (May 1958), pp. 164–194; described in Runyan, Sonic Boom Capsule Summaries, 8–9. Both Walkden and Whitman did their pioneering studies at the University of Manchester.
[17]. Fred Keefe and Grover Amen, “Boom,” The New Yorker, May 16, 1962, pp. 33–34.
[18]. Albion B. Hailey, “AF Expert Dodges Efforts to Detail ‘Sonic Boom’ Loss,” Washington Post, Aug. 25, 1960, p. A15.
[19]. J.P. and E.G.R Taylor, “A Brief Legal History of the Sonic Boom in America,” Aircraft Engine Noise and Sonic Boom (Neuilly Sur Seine, France: NATO Advisory Group for Aerospace Research and Development [AGARD], 1969), Conference Proceedings (CP) No. 42, Paris, May 1969, pp. 2-1–2-11.
[20]. “Warplanes Fill Skies Over U.S. and Canada,” Los Angeles Times, Sept. 10, 1960, p. 4; Albion B. Halley and Warren Kornberg, “U.S. Tests Air Defenses in 3000-Plane ‘Battle,’’’ Washington Post, Oct. 15, 1961, pp. A1, B1; Richard Witkin, “Civilian Planes Halted 12 Hours in Defense Test,” New York Times, Oct. 15, 1961, pp. 1, 46.
[21]. Marcelle S. Knaack, Post-World War II Bombers, 1945–1973 (Washington, DC: Government Printing Office (hereinafter cited as GPO) for Office of Air Force History, 1988), pp. 394–395 (vol. 2, Encyclopedia of U.S. Air Force Aircraft and Missile Systems).
[22]. “Jet Breaks 3 Records—and Many Windows,” Los Angeles Times, Mar. 6, 1962, p. 1. In reality, most of the damage was done while accelerating after the refuelings.
[23]. For the definitive account of political and economic aspects of the SST and subsequent programs (as well as many technical details), see Erik M. Conway, High-Speed Dreams: NASA and the Technopolitics of Supersonic Transportation, 1945–1999 (Baltimore: Johns Hopkins, 2005), pp. 27–45 cited here. For an earlier study by an insider, see F. Edward McLean, “Supersonic Cruise Technology,” NASA Special Publication (SP) 472 (Washington, DC: GPO, 1985). For an account focused on its political aspects, see Mel Howitch, Clipped Wings: The American SST Conflict (Cambridge: MIT, 1982).
[24]. McLean, Supersonic Cruise Technology, pp 35–46; Joseph R. Chambers, Innovation in Flight; “Research of the NASA Langley Research Center on Revolutionary Concepts for Aeronautics,” NASA SP-2005-4539, pp. 25–28.
[25]. FAA Historical Chronology, 1926–1996, http://ww.faa.gov/about/media/b-chron.pdf. For Quesada’s role, see Stuart I. Rochester, Takeoff at Mid-Century: Federal Civil Aviation Policy in the Eisenhower Years, 1953–1961 (Washington, DC: GPO for FAA, 1976). For the activism of Halaby and the demise of the SST after his departure, see Richard J. Kent, Jr., Safe, Separated, and Soaring: A History of Civil Aviation Policy, 1961–1972 (Washington, DC: GPO for FAA, 1980).
[26]. NASA’s HSFRC became the FRC in 1959. For an overall summary of Langley’s supersonic activities, see Chambers, Innovations in Flight, ch. 1, “Supersonic Civil Aircraft: The Need for Speed,” pp. 7–70.
[27]. Based on author’s review of Section 7.4, “Noise, Aircraft” in volumes of the Index of NACA Technical Publications (Washington DC: NACA Division of Research Information) covering the years 1915–1957.
[28]. Telephone interview, Domenic Maglieri by Lawrence Benson, Feb. 6, 2009.
[29]. A.B. Fryer, et al., “Publications in Acoustics and Noise Control from the NASA Langley Research Center during 1940–1976,” NASA TM-X-74042, July 1977. The following abbreviations are used for NASA publications cited in the notes: Conference Publication (CP), Contractor Report (CR), Reference Publication (RP), Special Publication (SP), Technical Memorandum (TM), formerly classified Tech Memo (TM-X), Technical Note (TN), Technical Paper (TP), and Technical Report (TR). Bibliographic data and often full text copies can be accessed through the NASA Technical Reports Server (NTRS), http://ntrs.nasa.gov/search.jsp.
[30]. For a chronological summary of selected projects during first decade, see Johnny M. Sands, “Sonic Boom Research (1958–1968),” FAA, Nov. 1968, Defense Technical Information Center (DTIC) document AD 684806.
[31]. Domenic J. Maglieri, Harvey H. Hubbard, and Donald L. Lansing, “Ground Measurements of the Shock-Wave Noise from Airplanes in Level Flight at Mach Numbers to 1.4 and Altitudes to 45,000 Feet,” NASA TN-D-48, Sept. 1959; Lindsay J. Lina and Domenic J. Maglieri, “Ground Measurements of Airplane Shock-Wave Noise at Mach Numbers to 2.0 and at Altitudes to 60,000 Feet,” NASA TN-D-235, Mar. 1960.
[32]. Maglieri, Vera Huckel, and Tony L. Parrott, “Ground Measurements of Shock-Wave Pressure for Fighter Airplanes Flying at Very Low Altitudes . . .,” NASA TN-D-3443, July 1966 (superseded classified TMX-611, 1961).
[33]. Gareth H. Jordan, “Flight Measurements of Sonic Booms and Effects of Shock Waves on Aircraft,” in Society of Experimental Test Pilots Quarterly Review, vol. 5, No. 1 (1961), pp. 117–131, presented at SETP Supersonic Symposium, Sept. 29, 1961.
[34]. John O. Powers, J.M. Sands, and Maglieri, “Survey of United States Sonic Boom Overflight Experimentation,” NASA TM-X-66339, May 1969, p. 5; USAF Fact Sheet, “Sonic Boom,” Oct. 2005, http://www.af.mil/factsheets/fsID=184; Telephone interview, Maglieri by Benson, Mar. 19, 2009.
[35]. Maglieri and Hubbard, “Ground Measurements of the Shock-Wave Noise from Supersonic Bomber Airplanes in the Altitude Range from 30,000 to 50,000 Feet,” NASA TN-D-880, July 1961.
[36]. Jordan, “Flight Measurements of Sonic Booms.”
[37]. Ibid.; Maglieri and Donald L. Lansing, “Sonic Booms from Aircraft in Maneuvers,” NASA TN-D-2370, July 1964; Hubbard, et al., “Ground Measurements of Sonic-Boom Measurements for the Altitude Range of 10,000 to 75,000 Feet,” NASA TR-R-198, July 1964. (Both reports were based on the tests in 1961.)
[38]. Harriet J. Smith, “Experimental and Calculated Flow Fields Produced by Airplanes Flying at Supersonic Speeds,” NASA TN-D-621, Nov. 1960; J.F. Bryant, Maglieri, and V.S. Richie, “In-Flight Shock-Wave Measurements Above and Below a Bomber Airplane at Mach Numbers from 1.42 to 1.69,” NASA TN-D-1968, Oct. 1963.
[39]. NASA Flight Research Center, “X-15 Program” [monthly report], Sept. 1961, Dryden archive, File LI-6-10A-13 (Peter Merlin assisted the author in finding this and other archival documents.); Karen S. Green and Terrill W. Putnam, “Measurements of Sonic Booms Generated by an Airplane Flying at Mach 3.5 and 4.8,” NASA TM-X-3126, Oct. 1974. (Since hypersonic speeds were not directly relevant for the SST, a formal report was delayed until NASA began planning reentry flights for the Space Shuttle.) For a history of the X-15 program, see Hallion and Gorn, On the Frontier, pp. 101–125.
[40]. Charles W. Nixon and Hubbard, “Results of the USAF–NASA–FAA Flight Program to Study Community Response to Sonic Booms in the Greater St. Louis Area,” NASA TN-D-2705, May 1965; Clark, et al., “Studies of Sonic Boom Damage,” NASA CR-227, May 1965.
[41]. Sands, “Sonic Boom Research (1958–1968),” p. 3.
[42]. Maglieri and Garland J. Morris, “Measurement of Response of Two Light Airplanes to Sonic Booms,” NASA TN-D-1941, Aug. 1963.
[43]. D.A. Hilton, Maglieri, and R. Steiner, “Sonic-Boom Exposures during FAA Community Response Studies over a 6-Month Period in the Oklahoma City Area,” NASA TN-D-2539, Dec. 1964.
[44]. Conway, High-Speed Dreams, pp. 121–122.
[45]. Thomas H. Higgins, “Sonic Boom Research and Design Considerations in the Development of a Commercial Supersonic Transport,” JASA, vol. 39, No. 5, pt. 2 (Nov. 1966), pp. 526–531.
[46]. David. A. Hilton, Vera Huckel, and Maglieri, “Sonic Boom Measurements during Bomber Training Operations in the Chicago Area,” NASA TN-D-3655, Oct. 1966.
[47]. Histories of the 4700 Air Defense Wing, Jan.–Mar. and Apr.–June 1960, IRIS abstracts; History of the 84th Fighter Group, Jan.–Dec. 1961, IRIS abstract; Telephone interview, Maglieri by Benson, Mar. 13, 2009.
[48]. William H. Andrews, “Summary of Preliminary Data Derived from the XB-70 Airplanes,” NASA TM-X-1240, June 1966, pp. 11–12. Despite being 3.5 times heavier than the B-58, the XB-70’s bow wave proved to be only slightly stronger.
[49]. Maglieri, et al., “A Summary of XB-70 Sonic Boom Signature Data, Final Report,” NASA CR-189630, Apr. 1992. Until this report, the 1965–1966 findings were filed away unpublished. The original oscillographs were also scanned and digitized at this time for use in the High-Speed Research Program.
[50]. FRC, “NASA XB-70 Flight Research Program,” Apr. 1966, Dryden archive, File L2-4-4D-3, p. 10 quoted. See also C.M. Plattner, “XB-70A Flight Research: Phase 2 to Emphasize Operational Data,” Aviation Week, June 13, 1966, pp. 60–62.
[51]. NASA Dryden Fact Sheet, “XB-70,” http://www.nasa.gov/centers/dryden/new/FactSheets/FS-084-DFRC_prt.htm; Hallion and Gorn, On the Frontier, pp. 176–185, 421.
[52]. Maglieri, “Summary of XB-70 Sonic Boom,” pp. 4–5.
[53]. R.T. Klinger, “YF-12A Flight Test Sonic Boom Measurements,” Lockheed Advanced Development Projects Report SP-815, June 1, 1965, Dryden archive, File LI-4-10A-1.
[54]. John O. Powers, J.M. Sands, and Maglieri, “Survey of United States Sonic Boom Overflight Experimentation,” NASA TM-X-66339, May 1969, pp. 9, 12–13.
[55]. Peter W. Merlin, From Archangel to Senior Crown: Design and Development of the Blackbird (Reston, VA: AIAA, 2008), pp. 106–107, 116–118, 179; Hallion and Gorn, On the Frontier, p. 187.
[56]. NSBEO, “Sonic Boom Experiments at Edwards Air Force Base; Interim Report” (prepared under contract by Stanford Research Institute), pp. 1–2, (hereinafter cited as SRI, “Edwards AFB Report”). For political and bureaucratic background on the NSBEO, see Conway, High-Speed Dreams, pp. 122–123.
[57]. SRI, “Edwards AFB Report,” p. 9.
[58]. Maglieri, et al., “Summary of Variations of Sonic Boom Signatures Resulting from Atmospheric Effects,” Feb. 1967, and “Preliminary Results of XB-70 Sonic Boom Field Tests During National Sonic Boom Evaluation Program,” Mar. 1967, Annex C-1 and C-2, in SRI, “Edwards AFB Report;” H.H. Hubbard and D.J. Maglieri, “Sonic Boom Signature Data from Cruciform Microphone Array Experiments during the 1966–1967 EAFB National Sonic Boom Evaluation Program,” NASA TN-D-6823, May 1972.
[59]. SRI, “Edwards AFB Report,” pp. 17–20, Annexes C-F; Maglieri, et al., “Sonic Boom Measurements for SR-71 Aircraft Operating at Mach Numbers to 3.0 and Altitudes to 24834 Meters,” NASA TN-D-6823, Sept. 1972.
[60]. SRI, “Edwards AFB Report,” pp. 11–16, Annex B; K.D. Kryter, “Psychological Experiments on Sonic Booms Conducted at Edwards Air Force Base, Final Report,” (Menlo Park: SRI, 1968), summarized by Richard M. Roberds, “Sonic Boom and the Supersonic Transport,” Air University Review, vol. 22, No. 7 (July–Aug. 1971), pp. 25–33.
[61]. SRI, “Edwards AFB Report,” pp. 20–23, Annexes G and H; David Hoffman, “Sonic Boom Tests Fail to Win Any Boosters,” Washington Post, Aug. 3, 1967, p. A3; A.J. Bloom, et al. (SRI), “Response of Structures to Sonic Booms Produced by XB-70, B-58, and F-104 Aircraft . . . at Edwards Air Force Base, Final Report,” NSBEO 2-67, Oct. 1967; D.S. Findley, et al., “Vibration Responses of Test Structure No. 1 during the . . . National Sonic Boom Program,” NASA TM-X-72706, June 1975, and “Vibration Responses of Test Structure No. 2 . . . ,” NASA TM-X-72704, June 1975.
[62]. TRACOR, Inc., “Public Reactions to Sonic Booms,” NASA CR-1665, Sept. 1970.
[63]. Hilton and Herbert R. Henderson documented the sonic boom measurements from the Apollo 15, 16, and 17 missions in NASA TNs D-6950, D-7606, and D-7806, published from 1972 to 1974.
[64]. George T. Haglund and Edward J. Kane, “Flight Test Measurements and Analysis of Sonic Boom Phenomena Near the Shock Wave Extremity,” NASA CR-2167, Feb. 1973; Telephone interview, Maglieri by Benson, Mar. 13, 2009.
[65]. Harry W. Carlson, “Some Notes on the Present Status of Sonic Boom Prediction and Minimization Research,” Third Conference on Sonic Boom Research . . . Washington, DC, Oct. 29–30, 1970, NASA SP-255, 1971, p. 395.
[66]. Carlson, “An Investigation of Some Aspects of the Sonic Boom by Means of Wind-Tunnel Measurements of Pressures about Several Bodies at a Mach Number of 2.01,” NASA TN-D-161, Dec. 1959. Carlson used Langley’s 4 by 4 Supersonic Pressure Wind Tunnel, completed in 1948, for most of his experiments.
[67]. For examples of these wind tunnel experiments, see Runyan, “Sonic Boom Capsule Summaries,” as well as the NTRS bibliographical database.
[68]. Carlson, “Wind Tunnel Measurements of the Sonic-Boom Characteristics of a Supersonic Bomber Model and a Correlation with Flight-Test Ground Measurements,” NASA TM-X-700, July 1962.
[69]. Carlson, “Correlation of Sonic-Boom Theory with Wind Tunnel and Flight Measurements,” NASA TR-R-213, Dec. 1964. p. 1.
[70]. Evert Clark, “Reduced Sonic Boom Foreseen for New High-Speed Airliner,” New York Times, Jan. 1965, pp. 7, 12 (based on visit to NASA Langley).
[71]. F. Edward McLean, “Some Nonasymptotic Effects of the Sonic Boom of Large Airplanes,” NASA TN-D-2877, June 1965.
[72]. Carlson, “Correlation of Sonic-Boom Theory,” pp. 2–23. For an earlier status report on supersonic work at Langley and some at Ames, see William J. Alford and Cornelius Driver, “Recent Supersonic Transport Research,” Astronautics & Aeronautics, vol. 2, No. 9 (Sept. 1964), pp. 26–37; Chambers, Innovation in Flight, pp. 32–34.
[73]. Carlson, “Configuration Effects on Sonic Boom,” Proceedings of NASA Conference on Supersonic-Transport Feasibility Studies and Supporting Research, Sept. 17–19, 1963 . . . Hampton, VA, NASA TM-X-905, Dec. 1963, p. 381.