Of the three military services the Air Force moved most rapidly with plans for advanced projects and programs. Responding to a request sent by the Office of the Secretary of Defense to the three military services, Headquarters USAF by mid-January 1958 had completed its review of the comprehensive five-year astronautics program submitted the previous month by the Air Research and Development Command. On January 24 the Air Force submitted the plan to William M. Holaday, Director of Guided Missiles in the Department of Defense. The five-year outline envisaged the development of reconnaissance, communications, and weather satellites; recoverable data capsules; a "manned capsule test system"; then manned space stations; and an eventual manned base on the Moon. The Air Force estimated that funding requirements for beginning such a long-range program in fiscal year 1959 would total more than $1.7 billion.9
The ambitious five-year plan, with its astronomical estimate of costs for the  coming fiscal year, had remained in Holaday's office. The Air Force pressed ahead with its astronautics plans, including the placing of a manned capsule in orbit. On January 29, 30, and 31, 1958, ARDC held a closed conference at Wright-Patterson Air Force Base near Dayton, Ohio, where 11 aircraft and missile firms outlined for Air Force and NACA observers the various classified proposals for a manned satellite vehicle that they had submitted to ARDC during November and December 1957. The industry presentations appear to have varied considerably in thoroughness and complexity. The Northrop Corporation, for example, simply reviewed the boost-glide concept suggested by NACA at the Round Three Conference the previous October and already adopted by the Air Force for its Dyna-Soar project. By contrast, the Avco Manufacturing Corporation, the McDonnell Aircraft Corporation, Republic Aviation, and North American Aviation made detailed presentations, including estimates of the minimum amount of time required to put a man in orbit. Like Avco and other firms, McDonnell of St. Louis had been working on designs for a "minimum" satellite vehicle, employing a pure ballistic shape, since the spring of 1956, when the Air Force had first briefed industry representatives on its original Manned Ballistic Rocket Research proposal. Republic sketched a triangular planform arrangement modeled on the vehicle suggested the previous year by Antonio Ferri and others at the Gruen Applied Science Laboratories.10 The "Ferri sled," as the Republic device was called, was one of two approaches wherein the pilot would parachute after being ejected from the spacecraft, the vehicle itself not being recovered. The other company advocating an expendable spacecraft was North American; an X-15, although designed to land conventionally on skids as a rocket research aircraft, would orbit and then impact minus its parachuting pilot.11
After the Wright-Patterson conference, the Air Force stepped up the pace of its manned-satellite studies. On January 31, ARDC directed the Wright Air Development Center to focus on the quickest means of getting a man in orbit. The center was to receive advice from the Air Force Ballistic Missile Division in Los Angeles on selection of a booster system. A few weeks later the center issued a purchase request, valued at nearly $445,000, for a study of an internal ecological system that could sustain a man for 24 hours in an orbiting capsule.12
On February 27, ARDC officers briefed General Curtis E. LeMay, Air Force Vice Chief of Staff, on three alternative approaches to manned orbital flight: developing an advanced version of the X-15 that could reach orbital velocity; speeding up the Dyna-Soar project, which eventually was supposed to put a hypersonic glider in orbit; or boosting a relatively simple, nonlifting ballistic capsule into orbit with an existing missile system, as proposed by Avco, McDonnell, and other companies. LeMay instructed ARDC to make a choice and submit a detailed plan for an Air Force man-in-space program as soon as possible.13
While the Air Force pushed its manned satellite investigations and its development work on the Thor, Atlas, and Titan, the Army and the Navy initiated  manned space studies of their own in addition to accelerating their ballistic missile efforts with the Jupiter and the Polaris, respectively. Flushed with the success of the Explorer I satellite launching in January, the Army reached the apex of its astronautical prestige. Proud of the prowess of von Braun's rocket team at its Army Ballistic Missile Agency, Huntsville, Alabama, the Army sought a major role in military space technology. Since the Army already had lost operational responsibility for its Jupiter intermediate-range ballistic missile to the Air Force, a space mission was vitally important to its future in astronautics. Central to the Army's space plans was securing authorization, priority, and abundant financing from the Defense Department for one of von Braun's pet ideas, a clustered-engine booster vehicle with more than a million pounds of thrust.14
On February 7, 1958, Secretary of Defense Neil H. McElroy, acting on President Eisenhower's instructions, ordered the creation of an Advanced Research Project Agency (ARPA) to manage all existing space projects. Roy W. Johnson, a vice-president of General Electric, took over the directorship of this new office; Director of Guided Missiles Holaday transferred some of his responsibilities to the agency.15
Three weeks after the establishment of ARPA, Johnson acknowledged publicly that "the Air Force has a long term development responsibility for manned space flight capability with the primary objective of accomplishing satellite flight as soon as technology permits." The statement was reiterated on March 5 by a spokesman for McElroy. The Defense Department also authorized the Air Force to develop its "117L" system - an Atlas or Thor topped by a liquid-propellant upper stage (later named Agena) as a booster combination, together with an instrumented nose cone - "under the highest national priority in order to attain an initial operational capability at the earliest possible date." The 117L system, designed originally to orbit reconnaissance satellites, would now also be used for orbiting recoverable biological payloads, including primates.16
In response to Vice Chief of Staff LeMay's instructions of February 27 and the apparent receptiveness of Defense Department officials to the Air Force's astronautical plans, the Air Research and Development Command moved to "firm up" its plans for manned space flight. On March 8, the Ballistic Missile Division proposed an 11-step program aimed at the ultimate objective of "Manned Space Flight to the Moon and Return." The steps included instrumented and animal-carrying orbital missions, a manned orbit of Earth, circumnavigation of the Moon with instruments and then animals, instrumented hard and soft landings on the Moon, an animal landing on the Moon, manned lunar circumnavigation, and a manned landing on the lunar surface. Then, on March 10, 11, and 12, ARDC staged a large conference at the offices of its Ballistic Missile Division in Los Angeles. On hand were more than 80 rocket, aircraft, and human-factors specialists from the Air Force, industry, and NACA. Although the space sights of the Ballistic Missile Division, under Major General Bernard A. Schriever, were set on the  distant "man on the Moon" goal, the basic objective of the Los Angeles man-in-space working conference was to hammer out an "abbreviated development plan" for getting a man in Earth orbit as quickly and as easily as possible.17
The conference focused on what some Air Force speakers called a "quick and dirty" approach - orbital flight and recovery using a simple ballistic capsule and parachutes for a water landing in the vicinity of the Bahamas. The ballistic vehicle would weigh between 2,700 and 3,000 pounds, and would be about six feet in diameter and eight feet long. Its "life support," or internal ecological, system would be designed to sustain a man in orbit for as long as 48 hours. Because there was no real certainty that man could function under the various stresses of space flight, all systems in the capsule would be fully automatic.18
The human passenger would be essentially a rider rather than a pilot, although for experimental purposes he would try to perform certain tasks. The body support arrangement - showing the influence of Harold J. von Beckh of ARDC's Aeromedical Field Laboratory - would have the spaceman supine on a couch that could be rotated according to the direction of the g forces building up during launch and reentry. The rotatable couch was regarded as necessary because the capsule would both exit and enter the atmosphere front-end forward. Maximum reentry loads on the occupant of the Air Force machine were expected to be about 9 g; the interior temperature during reentry was not supposed to exceed 150 degrees. An ablative nose cone would provide thermal protection. Small retrograde rockets would brake the vehicle enough to allow the pull of gravity to effect a reentry.19
Among the most fervent Air Force champions of a man-in-space project at the Los Angeles conference were the human-factors experts, some of whom had been studying the medical problems of upper- and extra-atmospheric flight for more than a decade. But predictably they were also the most cautious people in assessing the psychophysiological limits of human tolerance under the conditions of flight into space. Air Force medical personnel generally agreed that 15 or more launches of primates and smaller biological payloads should precede the first manned orbital shot. Colonel John P. Stapp of the Aeromedical Field Laboratory felt that the first human space passengers should have both engineering and medical training, that they should go through at least six months of selection, testing, and preparation, and that from a medical standpoint a television camera was an essential piece of equipment in the manned capsule. Major David G. Simons, Stapp's colleague, believed that continuous medical monitoring of the man, including voice contact throughout the orbital mission, should be mandatory.20
The Air Force flight physicians knew that German centrifuge experiments during the Second World War had proved that men could withstand as much as 17 g for as long as 2 minutes without losing consciousness.21 Nevertheless, numerous centrifuge runs at Wright-Patterson and at Johnsville, Pennsylvania, and calculations of the angle of entry from an orbital altitude of about 170 miles had convinced them that a 12-g maximum was a good ground rule for designing the capsule body-support system. With a continuously accelerating single-stage  booster following a steep launch trajectory, an aborted flight and subsequent reentry might subject the rider to as much as 20 g. Consequently the Air Force specialists assumed that a two-stage launch rocket would be necessary to provide a shallower reentry path and lower forces.22
In retrospect, there were two striking aspects of the Los Angeles man-in-space presentation. The first was that the Air Force, historically devoted to piloted, fully controllable aircraft, was thinking in terms of a completely automatic orbital capsule, virtually without aerodynamic controls, whose passenger would do little more than observe and carry out physiological exercises. The other was that no attention was given to using the Atlas, alone as a booster system for a manned satellite. Indeed hardly anyone advocated putting an upper stage on the Atlas to constitute the desired two-stage launch vehicle. Spokesmen for Space Technology Laboratories, technical overseer of the Air Force ballistic missile program, went so far as to declare that a more dependable booster than the Atlas would have to be developed. They favored adapting the intermediate-range Thor and combining it with a second stage powered by a new fluorine-hydrazine engine developing some 15,000 pounds of thrust. By the time the conference adjourned on March 12, the conferees were in fairly general agreement that about 30 Thors and 20 fluorine-hydrazine second-stage rockets would be needed for a manned satellite project. Some 8 to 12 Vanguard second stages would also be needed, to be mated with Thors for orbiting smaller, animal-bearing capsules.23
While the "abbreviated development plan" was emerging from the Los Angeles gathering, a NACA steering committee met at the Ames laboratory. Its members were Hartley A. Soulé and John V. Becker of Langley, Alfred J. Eggers of Ames, and Walter C. Williams of the High Speed Flight Station. They had been appointed by NACA Assistant Director Ira H. Abbott to suggest a course of action on the January 31 proposal by Lieutenant General Donald L. Putt, Air Force Deputy Chief of Staff, Development, to NACA Director Dryden for formal NACA-Air Force cooperation in a manned satellite venture.24 The steering committee agreed that the zero-lift approach - the ballistic capsule - offered the best promise for an early orbital mission. Soulé, Becker, Eggers, and Williams recommended that "NACA accept the Air Force invitation to participate in a joint development of a manned orbital vehicle on an expedited basis," and that "the ballistic type of vehicle should be developed."25
On March 14, a month and a half after Putt's letter to Dryden, NACA officially informed Headquarters USAF that it would cooperate in drawing up a detailed manned satellite development plan. On April 11, Dryden sent to General Thomas D. White, Chief of Staff of the Air Force, a proposed memorandum of understanding declaring an intention to set up a "joint project for a recoverable manned satellite test vehicle." Before a final agreement was actually signed, however, NACA Assistant Director for Research Management Clotaire Wood, at Dryden's direction, suggested to Colonel Donald H. Heaton of Headquarters USAF that the NACA-Air Force arrangement "should be put aside for the time  being." Heaton agreed, and in mid-May the joint Air Force-NACA manned space undertaking was tabled indefinitely.26
8 See Historical Sketch of NASA, SP-29 (Washington, 1965), 5-9.
9 "Chronology of Early USAF Man-in-Space Activity, 1945-1958," Air Force Systems Command, 11-12; "Chronology of Early Air Force Man-in-Space Activity, 1955-1960," Air Force Systems Command, 24.
10 See n. 39, chap. III.
11 Memo, Clarence A. Syvertson to Dir., Ames Aeronautical Laboratory, "Visit to WADC, Wright-Patterson AFB, Ohio, to Attend Conference on January 29-31, Concerning Research Problems Associated with Placing a Man in a Satellite Vehicle," Feb. 18, 1958. For a more detailed rundown of the company proposals presented at the conference, see James M. Grimwood, Project Mercury: A Chronology, NASA SP-4001 (Washington, 1963), 14-15.
12 "Chronology of Early USAF Man-in-Space Activity, 1945-1958," 13-15; "Chronology of Early Air Force Man-in-Space Activity, 1955-1960," 27-32.
13 "Chronology of Early USAF Man-in–Space Activity, 1945-1958," 16; George D. Colchagoff, interview, Washington, Dec. 3, 1964.
14 See John B. Medaris, Countdown for Decision (New York, 1960); and David S. Akens, Historical Origins of the George C. Marshall Space Flight Center (Huntsville, Ala., 1960).
15 House Committee on Science and Astronautics, 86 Cong., 1 sess. (1959), U.S. Aeronautics and Space Activities, Jan. 1 to Dec. 31, 1958: Message from the President of the United States, 8; Mary Stone Ambrose, "The National Space Program," unpublished M.A. thesis, 2 vols., American University, 1960-1961, I, 5153; Levine, "U.S. Aeronautical Research Policy," 149-150.
16 "Chronology of Early USAF Man-in-Space Activity, 1945-1958," 16; "Chronology of Early Air Force Man-in-Space Activity, 1955-1960," 33-34. The first successful flight of the Atlas, as noted earlier, came on Dec. 17, 1957, when an Atlas-A, a test rocket minus the sustainer engine, impacted on its target about 500 miles downrange from Cape Canaveral. On Dec. 19, 1957, a Thor made its first fully guided flight with an all-inertial guidance system. See Julian Hartt, The Mighty Thor: Missile in Readiness (New York, 1961), 70-75.
17 "Chronology of Early USAF Man-in-Space Activity, 1945-1958," 17-18; memo, Lawrence A. Clousing to Dir., Ames Aeronautical Laboratory, "Working Conference for the Air Force 'Man-in-Space Soonest' Program, held March 10-11-12, 1958, at the Air Force Ballistic Missile Division Offices, Los Angeles," March 24, 1958.
20 Ibid.; John P. Stapp and David G. Simons, interviews, San Antonio, April 24, 1964.
21 See Otto Gauer, "The Physiological Effect of Prolonged Weightlessness," in U.S. Air Force, German Aviation Medicine, World War II (2 vols., Washington, 1950), I, 577.
22 Clousing memo; "Chronology of Early USAF Man-in-Space Activity, 1945-1958," 11-12.
23 Ibid., "Chronology of Early Air Force Man-in-Space Activity, 1955-1960," 37-38; Clousing memo.
24 See pp. 73-74.
25 Memo, Ira H. Abbott, Asst. Dir. for Research, to Langley Aeronautical Laboratory, Ames Aeronautical Laboratory, Lewis Flight Propulsion Laboratory, and High Speed Flight Station, "Meeting of the Steering Committee for a New Research Vehicle," Feb. 19, 1958; memo, Hartley A. Soulé, "Meeting of the Steering Committee for a New Research Vehicle System at Ames Laboratory on March 11, 1958," March 12, 1958.
26 Memo, John W. Crowley, Assoc. Dir. for Research, NACA, to Comdr., Air Research and Development Command, "Man-in-Space - NACA Participation in Preparing Abbreviated Development Plan," March 14, 1958; Proposed Memorandum of Understanding, "Principles for the Conduct by the NACA and the Air Force of a Joint Project for a Recoverable Manned Satellite Test Vehicle," April 11, 1958; memo, Clotaire Wood, Asst. Dir. for Research Management, to Dir. of Research and Development, Office of Deputy Chief of Staff, Development, Hq. USAF, "Transmittal of Copies of Proposed Memorandum of Understanding Between Air Force and NACA for Joint NACA-Air Force Project for a Recoverable Manned Satellite Test Vehicle," April 11, 1958; memo for files, Wood, "Tabling of Proposed Memorandum of Understanding Between Air Force and NACA for a Joint Project for a Recoverable Manned Satellite Test Vehicle," May 20 1958. See also memo for historical files, Dryden, "The Signed Agreement of April 11, 1958, on a Recoverable Manned Satellite Test Vehicle," Sept. 8, 1965. The postponed joint NACA-Air Force manned satellite project should not be confused with the cooperative arrangement set up for Dyna-Soar, a formal agreement on which was signed by NACA and the Air Force in May 1958.