¹ Hagan notes, to C. McL. Green, 19 Mar 1968; conf rpt, 25 Nov 1955, sub: Facilities for materials research; conf rpt, 9-10 Dec 1955, sub: UDMH heat transfer stability and ignition lags, and high-frequency, lightweight instrumentation. See also Stehling, Project Vanguard, pp. 127-34; and Klawans and Burghardt, Vanguard Launch Vehicle, p. 51.

² Interview, Hagen, Captain Winfred E. Berg and Thomas Jenkins, 19 Mar 1968; GLM Semi-Monthly Progress Reports 1 and 2, pp. 5 and 7; 3, pp. 5-6; 4, pp. 5-7; 5, p. 1; 6, p. 5. Ltr, NRL to GLM, 1 Nov 1955; conf rpt, 14 Nov 1955; Project Vanguard Rpt to Asst/Sec/DeE (R&D) Policy Council, 12 Dec 1955, NRL Memo Rpt 548, p. 7.

³ See chapter 4, n. 26; interview Capt. WinFred E. Berg, 10 Apr 1967.

⁴ Conf rpt, 27 Oct 1956, sub: Dovap Equipment; conf rpt, 4 Nov 1956, sub: FPS-16 Radar; interview Hagen, Captain Winfred E. Berg, and Thomas Jenkins, 19 Mar 1968.

⁵ Memo, Mazur to Rosen, 25 Nov 1955, sub: Telemetering System Requirements; Martin Semi-Monthly Progress Reports 1 and 2, pp. 6, 9, 3, p. 4, 7, p. 6; interview, Robert Schlechter, 13 Mar 1967; minutes, NRL Project Vanguard staff meeting, 2 Dec 1955.

⁶ Memo, GLM to Dir NRL, 28 Nov 1955, sub: Recommended Launching Systems Specification.

⁷ NRL Memo Rpt 548, pp. 7, 9-10; memo, Dir/NRL to CNO, 29 Nov 1955, sub: Project Vanguard-Frequency Allocation for Minitrack System; Memo, Robert MacKay, Jr., for Mazur, 23 Nov 1955, sub: Relative Qualifications of Bidders … Telemetering Ground Stations; conf rpt, 6 Dec 1955, sub: Progress of Antenna Development. See also chapter 9.

⁸ Minutes, NRL Project Vanguard staff meeting, 2 Dec 1955; interview Paul Walsh, 18 Apr 1967.

⁹ Conf rpt, 6 Dec 1955, sub: NRL-GLM Relationships; conf rpt, 6 Dec 1955, sub: Meeting of Scientific Officer and Operations Manager.

¹⁰ Martin Semi-Monthly Progress Letters 6, p. 5, 10, p. 2; conf rpt, 19 Jan 1956, sub: Weight Optimization Study; NRL Design Specification No. 4100-1, Design Specification for Vanguard Launching Vehicle, Contract Nonr-1817 (00), 29 Feb 1956, Appendix 2; interview Paul Walsh, 18 Mar 1967.

¹¹ Klawans and Burghardt, Vanguard Launch Vehicle, pp. 26-28, 40-51. An example of unexpected problems encountered in preparing the specifications is to be found in Martin Semi-Monthly Progress Letter 13, p. 13. Interviews: Daniel Mazur, 2 Mar 1967; Alton Jones, 14 Mar 1967; and Milton Rosen, 28 Mar 1967.

¹² See NRL Design Specification No. 4100-1, 29 Feb 1956, p. 18, and Appendix 2, p. 1; interview, Rosen, 28 Mar 1967. Like many another decision critically important to the Vanguard program, no written record exists of how this agreement came about. Only the ensuing action testifies to its validity and only Rosen's memory supplies an oral version of the circumstances.

¹³ NRL Design Specification No. 4100-1, pp. 18-20; Stehling, Project Vanguard, p. 132.

¹⁴ Martin Semi-Monthly Progress Letters 5, p. 3, 6, p. 3, 9, pp. 5-6; Klawans and Burghardt, Vanguard Launch Vehicle, pp. 51-62; Conf rpt, 19 Jan 1956, sub: Weight Optimization Study.

¹⁵ Stehling Report, 20 Jan 1956, sub: Engine Model Specifications; Comparison of Vanguard Vehicle Delivery and Launch Schedules, no date, but after the autumn of 1957; conf rpt, 9-10 Feb 1956, sub: Agreement on Martin Spec. 925, Propulsion System for Second Stage; interviews, Elliott Felt, 22 June 1967, and Capt. Berg, 10 Apr 1967.

¹⁶ Ltr, GLM to ONR, 19 Jan 1956, sub: Contract Nonr 1817 (00), Return of Amendment 1; Ltr, CNR to Dir NRL, 23 Jan 1956, sub: Extension of Period of Interim Contract; memo, Dir NRL for ONR, 31 Jan 1956, sub: Extension of Interim Contract Nonr-1817 (00) .

¹⁷ NRL Design Specification No. 4100-1, 29 Feb 1956, Revised 29 Mar 1956, Appendix 1, p. 2, and Appendix 2, pp. 1-2. See pp. 79-80.

¹⁸ Ibid., pp. 18-20; Klawans and Burghardt, Vanguard Launch Vehicle, pp. 59, 70-71; interview, Robert Schlechter, 13 Mar 1967; Stehling, Project Vanguard, pp. 132-34.

¹⁹ Martin Semi-Monthly Progress Letters 9, p. 5, 11, p. 2; memo, GLM to NRL, 3 Jan 1956; ltr, NRL to GLM, 20 Jan 1956; ltr, GLM to NRL, 3 Feb 1956; ltr, NRL to GLM, 29 Feb 1956; ltr, Van Allen to Hagen, 1 Feb 1956, attachment to minutes 3rd Meeting Technical Panel on Earth Satellite Program, 31 Jan 1956; interviews, Hugh Odishaw, 12 Apr 1967; Paul Walsh, 18 Apr 1967, and John Hagen, 19 Mar 1968.

²⁰ Conf rpt, 20 Jan 1956, sub: Engine Model Specs; ltr, GLM to BAR, 24 Feb 1956; ltr, GLM to ONR, 19 Jan 1956, sub: Amendment No. 1 to Contract; Martin Progress Ltr 9, pp. 5-6, 10, p. 5, 11, p. 4; conf rpt, 6 Feb 1956, sub: Evaluation of Final Third Stage Rocket Proposals; NRL Design Specification No. 4100-1, 29 Feb 1956, pp. 22-23, and Appendix 2, pp. 1-2.

²¹ Ltr, GLM to NRL, 3 Feb 1956, sub: Request for Approval of Clearance of Subcontractors for Third Stage Engine; ltr, NRL to GLM, 7 Mar 1956.

²² Interview, Milton Rosen, 28 Mar 1967.

²³ NRL Design Specification No. 4100-1, 29 Feb 1956, revised 29 Mar 1956, p. 2, Appendixes 1 and 3; interviews, Elliott Felt, 13 Mar 1967, and Capt. Berg, 10 Apr 1967.

²⁴ NRL Design Specification No. 4100-1, 29 Feb 1956, pp. 4-6; interview, Milton Rosen, 28 Mar 1967; memo of telephone call, Baumann for Mensshing, 14 Jan 1956; Stehling, Project Vanguard, p. 33.

²⁵ NRL Design Specification No. 4100-1, p. 6; interviews Milton Rosen, 28 Nov 1966, and Paul Walsh, 18 Apr 1967.

²⁶ Interview, Capt. Berg, 10 Apr 1967.

²⁷ NRL Design Specification No. 4100-1, pp. 9, 11.

²⁸ Ibid., pp. 24-30.

²⁹ Interview, Hagen and Captain Berg, 19 Mar 1968; anon. notes on meeting 13 Sept 1955, cited in chapter 4, n.7. See also chapters 7, 9, and 13.

³⁰ Memo, GLM to CNR, 8 Mar 1956, sub: Submittal of Proposal for Vanguard Program; NRL Design Specification No. 4100-1, revised 29 Mar 1956, and 4100-1, addendum 1, 27 Apr 1956.