¹ Report of the Committee on Special Capabilities to Assistant Secretary of Defense for Research and Development, 4 Aug 1955, RDB 55-1607A, B-3.

² Homer J. Stewart, notes on draft manuscript, R. Cargill Hall, "Origins … of the Vanguard and Explorer Satellite Programs," August 1963.

³ Memo RDB 55-1607A, C, 1-4.

⁴ See pp. 28-29.

⁵ NRL Memo Report 487, "A Scientific Satellite Program," 5 July 1955. The Laboratory had worked out the design of both the M-10 and the M-15 when pursuing the guided missile reentry problem for the Air Force in 1954. See p. 12.

⁶ NRL Memo Report 487, 5 July 1955. See also pp. 121-123.

⁷ NRL Memo Report 487, 5 July 1955. See also William R. Corliss, The Evolution of STADAN, Goddard Historical Note No. 3 (Greenbelt: Goddard Space Flight Center, January 1967), pp. 17-18.

⁸ See Kurt R. Stehling, Project Vanguard (Garden City, New York: Doubleday & Co., Inc., 1961), p. 53.

⁹ Tape-recorded interview, Homer J. Stewart with Eugene Emme, 1960.

¹⁰ RDB 55-1607; ltr, as dictated to Thomas Lauritsen by his father Charles Lauritsen, to C. McL. Green, 29 May 1967.

¹¹ Interviews, Richard Porter, 1 Feb 1968, and George Clement, 8 Mar 1968.

¹² H. J. Stewart's notes to C. McL. Green, 14 Mar 1968.

¹³ RDB 55-1607A and RDB 55-1607.

¹⁴ Clifford C. Furnas, "Why Vanguard?" Life, vol. 43, no. 17 (21 Oct 1957), pp. 22-25.

¹⁵ RDB 55-1607; Homer J. Stewart's notes to C. McL. Green, 14 Mar 1968.

¹⁶ "Project Vanguard, a Scientific Earth Satellite Program for the International Geophysical Year," Report to the Committee on Appropriations, U.S. House of Representatives, by Surveys and Investigations Staff, in U.S. Congress, House of Representatives, Committee on Appropriations, Subcommittee on Department of Defense Appropriations, Hearings on Department of Defense Appropriations for 1960, part 6, 86th Cong., 1st Sess., 14 Apr 1959, pp. 62f. See pp. 8-9 and 16-18.

¹⁷ Notes, Homer J. Stewart to C. McL. Green, 11 Oct 1966.

¹⁸ See n. 16.

¹⁹ See n. 17 and chapter 12.

²⁰ Memo, Rosen to C. McL. Green, 12 Oct 1966; memo, Director NRL to Chief of Naval Research, 15 Aug 1955, S-1000-26/55 LP, Ser 2307.

²¹ Memo, Rosen to Director, NRL, 23 Aug 1955, sub: Addendum to NRL Memo Report 487 of July 1955.

²² Memo, Rosen to C. McL. Green, 12 Oct 1966.

²³ Encls 1-4 to Rosen memo cited in n. 21.

²⁴ Notes, H. J. Stewart to C. McL. Green, 11 Oct 1966.

²⁵ Encl 2, "Chronology of Significant Events in the Vanguard Program" to Hagen ltr, NRL 4100-227, 10 Oct 1957; memo, Dpty Sec/Def to Secs/Army, Navy, and Air Force, Sec/Navy Cont. S-2303, S-229.

²⁶ Interview, Commander George W. Hoover, 5 Mar 1968; "Death of the First Satellite," in Erik Bergaust, Reaching for the Stars (Garden City, N.Y.: Doubleday & Co., 1960), p. 214.

²⁷ See n. 10 and n. 11.

²⁸ See n. 10 and n. 17; interview, Alan T. Waterman, 15 Oct 1966.

²⁹ Interview with Milton Rosen, 2 Nov 1966.