Always the favorite of the von Braun group working for the Army, the Redstone was a direct descendant of the V-2. The Redstone's liquid-fueled engine burned alcohol and liquid oxygen and produced about 75,000 pounds of thrust. Nearly 70 feet long and slightly under 6 feet in diameter, the battlefield missile had a speed at burnout, the point of propellant exhaustion, of 3,800 miles per hour. For guidance it utilized an all-inertial system featuring a gyroscopically stabilized platform, computers, a programmed flight path taped into the rocket before launch, and the activation of the steering mechanism by signals in flight. For control during powered ascent the Redstone depended on tail fins with movable rudders and refractory carbon vanes mounted in the rocket exhaust. The prime contract for the manufacture of Redstone test rockets went to the Chrysler Corporation. In August 1953 a Redstone fabricated at the Huntsville arsenal made a partially successful maiden flight of only 8,000 yards from the military's missile range at Cape Canaveral, Florida. During the next five years, 37 Redstones were fired to test structure, engine performance, guidance and control, tracking, and telemetry.60
The second successful military rocket being developed in 1951 was an Air Force project, the Atlas. The long history of the Atlas, the first American  intercontinental ballistic missile (ICBM),61 began early in 1946, when the Air Materiel Command of the Army Air Forces awarded a study contract for a long-range missile to Consolidated Vultee Aircraft Corporation (Convair), of San Diego. By mid-year a team of Convair engineers, headed by Karel J. Bossart, had completed a design for "a sort of Americanized V-2," called "HIROC," or Project MX-774. Bossart and associates proposed a technique basically new to American rocketry (although patented by Goddard and tried on some German V-2s) - controlling the rocket by swiveling the engines, using hydraulic actuators responding to commands from the autopilot and gyroscope. This technique was the precursor of the gimbaled engine method employed to control the Atlas and other later rockets. In 1947, the Truman administration and the equally economy-minded Republican 80th Congress confronted the Air Force with the choice of having funds slashed for its intercontinental manned bombers and interceptors or cutting back on some of its advanced weapons designs. Just as the first MX-774 test vehicle was nearing completion, the Air Force notified Convair that the project was canceled. The Convair engineers used the remainder of their contract funds for static firings at Point Loma, California, and for three partially successful test launches at White Sands, the last on December 2, 1948.62
From 1947 until early 1951 there was no American project for an intercontinental ballistic missile. The Soviet Union exploded her first atomic device in 1949, ending the United States' postwar monopoly on nuclear weapons. President Harry S. Truman quickly ordered the development of hydrogen-fusion warheads on a priority basis. The coming of the war in Korea the next year shook American self-confidence still further. The economy program instituted by Secretary of Defense Louis Johnson ended, and the military budget, including appropriations for weapons research, zoomed upward. The Army began its work leading to the Redstone, while the Air Force resumed its efforts to develop an intercontinental military rocket. In January 1951 the Air Materiel Command awarded Convair a new contract for Project MX-1593, to which Karel Bossart and his engineering group gave the name "Project Atlas."63 Yet the pace of the military rocket program remained deliberate, its funding conservative.
A series of events beginning in late 1952 altered this cautious approach. On November 1, at Eniwetok Atoll in the Pacific, the Atomic Energy Commission detonated the world's first thermonuclear explosion, the harbinger of the hydrogen bomb. The device weighed about 60,000 pounds, certainly a much greater weight than was practicable for a ballistic missile payload. The next year, however, as a result of a recommendation by a Department of Defense study group, Trevor Gardner, assistant to the Secretary of the Air Force, set up a Strategic Missiles Evaluation Committee to investigate the status of Air Force long-range missiles. The committee, composed of nuclear scientists and missile experts, was headed by the famous mathematician John von Neumann. Specifically, Gardner asked the committee to make a prediction regarding weight as opposed to yield in nuclear payloads for some six or seven years hence. The  evaluation group, familiarly known as the "Teapot Committee," concluded that shortly it would be possible to build smaller, lighter, and more powerful hydrogen-fusion warheads. This in turn would make it possible to reduce the size of rocket nose cones and propellant loads and, with a vastly greater yield from the thermonuclear explosion, to eliminate the need for precise missile accuracy.64 In February 1954 both the Strategic Missiles Evaluation Committee and the Rand Corporation, the Air Force-sponsored research agency, submitted formal reports predicting smaller nuclear warheads and urging that the Air Force give its highest priority to work on long-range ballistic missiles.
Between 1945 and 1953 the yield of heavy fission weapons had increased substantially from the 20-kiloton bomb dropped on Hiroshima. Now, according to the Air Force's scientific advisers, lighter, more compact, and much more powerful hydrogen warheads could soon be realized. These judgments "completely changed the picture regarding the ballistic missile," explained General Bernard A. Schriever, who later came to head the Air Force ballistic missile development program, "because from then on we could consider a relatively low weight package for payload purposes."65 This was the fateful "thermonuclear breakthrough."
Late in March 1964 the Air Research and Development Command organized a special missile command agency, originally called the Western Development Division but renamed Air Force Ballistic Missile Division on June 1, 1957. Its first headquarters was in Inglewood, California; its first commander, Brigadier General Schriever. The Convair big rocket project gained new life in the winter of 1954-55, when the Western Development Division awarded its first long-term contract for fabrication of an ICBM. The awarding of the contract came in an atmosphere of mounting crisis and urgency. The Soviets had exploded their own thermonuclear device in 1953, and intelligence data from various sources indicated that they also were working on ICBMs to carry uranium and hydrogen warheads. Thus the Atlas project became a highest-priority "crash" program, with the Air Force and its contractors and subcontractors working against the fearsome possibility of thermonuclear blackmail.66
Rejecting the Army-arsenal concept, whereby research and development and some fabrication took place in Government facilities, the Air Force left the great bulk of the engineering task to Convair and its associate contractors.67 For close technical and administrative direction the Air Force turned to the newly formed Ramo-Wooldridge Corporation, a private missile research firm, which established a subsidiary initially called the Guided Missiles Research Division, later Space Technology Laboratories (STL). With headquarters in Los Angeles, the firm was to oversee the systems engineering of the Air Force ICBM program.68
In November 1955, STL's directional responsibilities broadened to include work on a new Air Force rocket, the intermediate-range (1,800-mile) Thor, hastily designed by the Douglas Aircraft Company to serve as a stopgap nuclear deterrent until the intercontinental Atlas became operational. At the same time  Charles E. Wilson, Secretary of Defense in the Eisenhower administration, gave the Army and Navy joint responsibility for developing the Jupiter, another intermediate-range ballistic missile (IRBM), the engineering task for which went to the Army rocketmen at Redstone Arsenal. To expedite Jupiter development, the Army on February 1, 1956, established at Huntsville a Ballistic Missile Agency, to which Wernher von Braun and his Guided Missile Development Division were transferred. Later that year Wilson issued his controversial "roles and missions" memorandum, confirming Air Force jurisdiction over the operational deployment of intercontinental missiles, assigning to the Air Force sole jurisdiction over land-based intermediate-range weapons, restricting Army operations to weapons with ranges of up to 200 miles, and assigning ship-based IRBM's to the Navy. Partly as a result of this directive, but mainly because of the difficulty of handling liquid propellants at sea, the Navy withdrew from the Jupiter program and focused its interest on the Polaris, a solid-propellant rocket designed for launching from a submarine.69
As it developed after 1954, the Air Force ballistic missile development program, proceeding under the highest national priority and the pressure of Soviet missilery, featured a departure from customary progressive practice in weapons management. The label for the new, self-conscious management technique adopted by the Air Force Ballistic Missile Division - Space Technology Laboratories team was "concurrency." Translated simply, concurrency meant "the simultaneous completion of all necessary actions to produce and deploy a weapon system."70 But in practice the management task - involving parallel advances in research, design, testing, and manufacture of vehicles and components, design and construction of test facilities, testing of components and systems, expansion and creation of industrial facilities, and the building of launch sites - seemed overwhelmingly complex. At the beginning of 1956 the job of contriving one ICBM, the Atlas, was complicated by the decision to begin work on the Thor and on the Titan I, a longer-range, higher-thrust, "second generation" ICBM.7l
The basic problem areas in the development of the Atlas included structure, propulsion, guidance, and thermodynamics. Convair attacked the structural problem by coming up with an entirely different kind of airframe. The Atlas airframe principle, nicknamed the "gas bag," entailed using stainless steel sections thinner than paper as the structural material, with rigidity achieved through helium pressurization to a differential of between 25 and 60 pounds per square inch. The pressurized tank innovation led to a substantial reduction in the ratio between structure and total weight; the empty weight of the Atlas airframe was less than two percent of the propellant weight. Yet the Atlas, like an automobile tire or a football, could absorb very heavy structural loads.72
For the Atlas powerplant the Air Force contracted with the Rocketdyne Division of North American Aviation. The thermonuclear breakthrough meant that the original five-engine configuration planned for the Atlas could be scrapped in favor of a smaller, three-engine design. Thus Rocketdyne could contrive a unique  side-by-side arrangement for the two booster and one sustainer engines conceived by Convair, making it possible to fire simultaneously all three engines, plus the small vernier engines mounted on the airframe, at takeoff. The technique of igniting the boosters and sustainer on the ground gave the Atlas two distinct advantages: ignition of the second stage in the upper atmosphere was avoided, and firing the sustainer at takeoff meant that smaller engines could be used. The booster engines produced 154,000 pounds of thrust each; the sustainer engine, 57,000 pounds; and the two verniers, 1,000 pounds each. The propellant for the boosters, sustainer, and verniers consisted of liquid oxygen and a hydrocarbon mixture called RP-1. The basic fuel and oxidizer were brought together by an intricate network of lines, valves, and often-troublesome turbopumps, which fed the propellant into the Atlas combustion chambers at a rate of about 1,500 pounds per second. The thrust of the "one and one-half stage" Atlas powerplant, over 360,000 pounds, was equivalent to about five times the horsepower generated by the turbines of Hoover Dam or the pull of 1,600 steam locomotives.73
The Atlas looked rather fat alongside the Army Redstone, the Thor, or the more powerful Titan. The length of the Atlas with its original Mark II blunt nose cone was nearly 76 feet; its diameter at the fuel-tank section was 10 feet, at its base, 16 feet. Its weight when fueled was around 260,000 pounds. Its speed at burnout was in the vicinity of 16,000 miles per hour, and it had an original design range of 6,300 miles, later increased to 9,000 miles.74
The prototype Atlas "A" had no operating guidance system. The Atlases "B" through "D" employed a radio-inertial guidance system, wherein transmitters on the rocket sensed aerodynamic forces acting on the missile and sent radio readings to a computer on the ground, which calculated the Atlas' position, speed, and direction. Radio signals were then sent to the rocket and fed through its inertial autopilot to gimbal the booster and sustainer engines and establish the Atlas' correct trajectory. After the jettisoning of the outboard booster engines, the sustainer carried the Atlas to the desired velocity before cutting off, while the vernier engines continued in operation to maintain precise direction and velocity. At vernier cutoff the missile began its unguided ballistic trajectory. A few moments later the nose cone separated from the rest of the rocket and continued on a high arc before plunging into the atmosphere. Radio-inertial guidance, the system used on the Atlas D and in Project Mercury, had the advantage of employing a ground computer that could be as big as desired, thus removing part of the nagging Atlas weight problem.75
By the mid-1950s the smaller thermonuclear warhead predicted by the Teapot Committee was imminent, so that the 360,000-pound thrust of the Atlas was plenty of energy to boost a payload of a ton and a half, over the 6,300-mile range. But while nose-cone size ceased to be a problem, the dilemma of how to keep the ICBM's destructive package from burning up as it dropped into the ever-thickening atmosphere at 25 times the speed of sound remained. At such speeds even the thin atmosphere 60 to 80 miles up generates tremendous frictional heat, which  increases rapidly as an object penetrates the denser lower air. The temperature in front of the nose-cone surface ultimately may become hotter than the surface of the Sun. The atmospheric entry temperatures of the intermediate-range Thor, Jupiter, and Polaris were lower than those of the Atlas, but even for these smaller-thrust vehicles the matter of payload protection was acute.76
In the mid-fifties the "reentry problem" looked like the hardest puzzle to solve and the farthest from solution, not only for the missile experts but also for those who dreamed of sending a man into space and bringing him back. As von Kármán observed in his partially autobiographical history of aerodynamic thought, published in 1954:
Any rocket returning from space travel enters the atmosphere with tremendous speed. At such speeds, probably even in the thinnest air, the surface would be heated beyond the temperature endurable by any known material. This problem of the temperature barrier is much more formidable than the problem of the sonic barrier.77
Years of concerted research by the military services, NACA, the Jet Propulsion Laboratory, and other organizations would be necessary before crews at Cape Canaveral, either preparing a missile shot or the launching of a manned spacecraft, could confidently expect to get their payload back through the atmosphere unharmed.
The American ballistic missile program of the 1950s produced some remarkable managerial and engineering achievements. Eventually the United States would deploy-reliable ICBMs in larger numbers than the Soviet Union. Yet the fact remains that the Russians first developed such an awesome weapon, first tested it successfully, and first converted their larger ICBM for space uses.78 Thus American missile developers fell short of what had to be their immediate goal - keeping ahead or at least abreast of the Soviets in advanced weaponry. Bureaucratic delays, proliferation of committees, divided responsibility, interservice rivalry, sacrificial attachment to a balanced budget, excessive waste and duplication, even for a "crash" program - these were some of the criticisms that missile contractors, military men, scientists, and knowledgeable politicians lodged against the Defense Department and the Truman and Eisenhower administrations. From 1953 to 1957, Secretaries of Defense Wilson and Neil H. McElroy presided over 11 major organizational changes pertaining directly to the missile program.79 "It was just like putting a nickel in a slot machine," recalled J. H. Kindelberger, chairman of the board of North American Aviation, on the difficulty of getting a decision from the plethora of Pentagon committees. "You pull the handle and you get a lemon and you put another one in. You have to get three or four of them in a row and hold them there long enough for them to say 'Yes.' It takes a lot of nickels and a lot of time."80 And even Schriever, certainly not one to be critical of the pace of missile development, admitted that "in retrospect you might say that we could have moved a little faster."81
59Akens, Historical Origins of the Marshall Space Flight Center, 36-37; Wernher von Braun, "The Redstone, Jupiter, and Juno," in Emme, ed., History of Rocket Technology, 108-109; also published in Technology and Culture, IV (Fall 1963), 452-455; A. A. McCool and Keith B. Chandler, "Development Trends in Liquid Propellant Engines," in Stuhlinger, Ordway, McCall, and Bucher, eds., From Peenemünde to Outer Space, 292; John W. Bullard, "History of the Redstone Missile System," Hist. Div., Army Missile Command, Oct. 1965, 135-151. The creation of the North Atlantic Treaty Organization in 1949 had provided a clear military need for a battlefield rocket.
60Jane's All the World's Aircraft, 1962-1963 (London, 1963), 391-392; von Braun, "The Redstone, Jupiter, and Juno," 109-110; McCool and Chandler, "Development Trends in Liquid Propellant Engines," 292; Bullard. "History of the Redstone," 53-93.
61The term "ballistic missile" refers to a projectile fired along a ballistic, or high-arc, trajectory, reaching an altitude of several hundred miles before falling freely toward its target. Such a vehicle is to be distinguished from the jet-propelled guided missile, which is controlled throughout its flight, requires oxygen within the air for its propellant oxidizer, and can operate only within the atmosphere. Thus by definition a ballistic missile, which reaches well into space, is a rocket.
62John L. Chapman, Atlas: The Story of a Missile (New York, 1960), 30-54; Inquiry into Satellite and Missile Programs, testimony of James R. Dempsey, Part 2, 1871-1872.
63Chapman, Atlas, 60-62; Inquiry into Satellite and Missile Programs, testimony of Dempsey, Part 2, 1872; Robert L. Perry, "The Atlas, Thor, Titan, and Minuteman," in Emme, ed., History of Rocket Technology, 143; also published as "The Atlas, Thor, and Titan," in Technology and Culture, VI (Fall 1963), 467.
64House Select Committee on Astronautics and Space Exploration, 85 Cong., 2 sess. (1958), Astronautics and Space Exploration, Hearings, testimony of Bernard A. Schriever, 668; Chapman, Atlas, 70-74; Bernard A. Schriever, "The USAF Ballistic Missile Program," in Kenneth F. Gantz, ed., The United States Air Force Report on the Ballistic Missile (Garden City, N.Y., 1958), 2-28; House Committee on Government Operations, 86 Cong., 1 sess. (1959), House Report No. 1121, Organization and Management of Missile Programs, 70-71; Ernest G. Schwiebert, A History of the U.S. Air Force Ballistic Missiles (New York, 1965), 67-73.
65Astronautics and Space Exploration, testimony of Schriever, 668. See also, Herman Kahn, On Thermonuclear War (Princeton, N.J., 1961), and Thinking about the Unthinkable (New York, 1962).
66See Schwiebert, Air Force Ballistic Missiles, 75-95.
67On this point Schriever elaborated: "I think the Air Force philosophy of having industry do development and having the capability of planning for production simultaneously is a much better way.... The Air Force had quite a number of German scientists right after the war at Wright Field, and made, deliberately made, the decision not to try to retain that group of scientists as a group, similar to what they have done at Redstone, and . . . most of them have gone into American industry.... They are at Convair, they are at Bell, and a number of other companies, and . . . my feeling is that these people, distributed to American industry, are doing equally as good a job for the United States as this one small group that are still assembled at the Redstone Arsenal." Inquiry into Satellite and Missile Programs, Part 2, testimony of Schriever, 1637-1638.
68Chapman, Atlas, 74, 78; Schriever, "USAF Ballistic Missile Program," 28; Perry, "Atlas, Thor, Titan, and Minuteman," 144-148; Organization and Management of Missile Programs, 73-79; Thomas, Men of Space, II, 143-149. The Ramo-Wooldridge Corporation was established by Simon Ramo and Dean Wooldridge, missile experts who, as employees of the Hughes Aircraft Company, had served on the Teapot Committee. They left Hughes in 1953 to set up their missiles research and management firm. For a description of the role of Space Technology Laboratories in the American missile effort and a critique of the STL/Air Force arrangement, see Organization and Management of Missile Programs, 81-100. In 1958 the Ramo-Wooldridge Corporation merged completely with an initial financial backer, the Thompson Products Company of Cleveland, to form the Thompson Ramo Wooldridge Corporation. See Robert Sheehan, "Thompson Ramo Wooldridge: Two Wings in Space," Fortune, LXVII (Feb. 1963), 95-99ff.
69Inquiry into Satellite and Missile Programs, Part I, 471; Wyndam D. Miles, "The Polaris," in Emme, ed., History of Rocket Technology, 164-166; also published in Technology and Culture, VI (Fall 1963), 480-482. The competition deliberately established by the Defense Department between the Air Force and the Army over the Thor and the Jupiter, while perhaps necessary, proved intense, acrimonious, and apparently wasteful. The full story of the Thor-Jupiter rivalry in the period 1955—1958 is yet to be told, but some valuable insight can be gained from Organization and Management of Missile Programs, 101-116. An account heavily biased in favor of the Army is John B. Medaris, Countdown for Decision (New York, 1960), 86-150. The Air Force side of the story is presented in Julian Hartt, The Mighty Thor: Missile in Readiness (New York, 1961).
70Perry, "Atlas, Thor, Titan, and Minuteman," 148. On concurrency see also Schriever, "USAF Ballistic Missile Program," 30-39; and Osmond J. Ritland, "Concurrency," Air University Quarterly Review, XII (Winter-Spring 1960-1961), 237-250. Parallel development of components had characterized numerous advances in 20th-century science and technology, of course, notably the Manhattan Project that produced the atomic bomb in the Second World War. (See Baxter, Scientists Against Time, 419-447; and Richard G. Hewlett and Oscar E. Anderson, A History of the United States Atomic Energy Commission, Vol. I: The New World, 1939-1946 [University Park, Pa., 1962], 9-407.) But "concurrency" as a formal research and engineering management technique is properly credited to the Air Force ballistic missile program of the fifties.
71Perry, "Atlas, Thor, Titan, and Minuteman," 149-150. The Strategic Air Command assumed operational planning responsibility for all intermediate and intercontinental missiles in 1958.
72Chapman, Atlas, 88-89; Jane's All the World's Aircraft, 1962-1963, 394. On the intricacies involved in fabricating the extremely thin Atlas airframe, see Robert Sweeney, "Atlas Generates Fabrication Advances," Aviation Week, LXXII (Jan. 4, 1960), 38-49; and "Manufacturing the Atlas at Convair," Interavia, LXXI (1959), 810-811.
73Chapman, Atlas, 136-137; Jane's All the World's Aircraft, 1962-1963, 394; Ordway and Wakeford, International Missile and Spacecraft Guide, 1-3; NASA/MSC news release, "The Mercury-Atlas 8 Launch Vehicle," Oct. 1, 1962; C. L. Gandy and I. Hanson, "Mercury-Atlas Launch-Vehicle Development and Performance," in Mercury Project Summary, Including Results of the Fourth Orbital Flight, May 15 and 16, 1963 (Washington, 1963), 84-91. On Rocketdyne's problems in developing the powerplant for the Atlas see Thomas F. Dixon, "Development Problems of Rocket Engines for Ballistic Missiles," Interavia, LXXI (1959), 818-821.
74Ordway and Wakeford, International Missile and Spacecraft Guide, 1-3; Jane's All the World's Aircraft, 1962-1963, 395.
75Chapman, Atlas, 81-82; Gandy and Hanson, "Mercury-Atlas Launch-Vehicle Development and Performance," 91-92; Jane's All the World's Aircraft, 1962-1963, 394-395; Ordway and Wakeford, International Missile and Spacecraft Guide, 2. Beginning in late 1960 with the "E" version, the guidance system of the Atlas became all-inertial, meaning that all guidance components were carried aboard the rocket. General Electric and Burroughs Corp. developed the radio-inertial guidance system for the Atlas, while the American Bosch Arma Corp. produced the all-inertial system.
76Atmospheric entry heating was not a critical problem for the medium-range (200-mile) Redstone, which did not develop the velocities of the intermediate and intercontinental rockets. Thus protecting the astronaut during the reentry phase of the suborbital (Redstone) flights in Project Mercury, while deserving attention, was not of acute concern.
77Von Kármán, Aerodynamics, 189. In view of the continually modifying nature of astronautical terminology, the authors throughout this work have used the terms "entry" and "reentry" interchangeably. They realize that some aerodynamicists make a distinction between the two.
78Colonel Oleg Penkovsky, the now-famous Russian "master spy" for the West in the Soviet intelligence system, supposedly wrote as late as the first part of 1962: "Only the smaller (IRBM) missiles are in production.... Right now we have a certain number of missiles with nuclear warheads capable of reaching the United States or South America; but these are single missiles, not in mass production, and they are far from perfect." (Frank Gibney, ed., The Penkovsky Papers, trans. Peter Deriabin [Garden City, N.Y., 1965], 331-348.) Thus while the Soviets may have been able to fire an ICBM over its design range before the United States and use it to launch relatively heavy satellites, they apparently had great troubles producing such a military rocket in quantity, as the United States was doing by 1962 with its Atlas, Titan, and Minuteman.
79House Committee on Science and Astronautics, 86 Cong., 2 sess. (1960), House Report No. 2092, Space, Missiles, and the Nation, 5-7; Organization and Management of Missile Programs, 108-109.
80Inquiry into Satellite and Missile Programs, testimony of J. H. Kindelberger, Part 1, 1280.
81Astronautics and Space Exploration, testimony of Schriever, 669.