Space flight, however, was something else. While in one sense atmospheric flight was the first step toward space flight, extra-atmospheric transport involves much more than a logical extension of aviation technology. The airplane, powered either by a reciprocating or a jet engine, is a creature and a captive of the atmosphere, because either powerplant depends on air - more properly, oxygen - for its operation, and in space there is no air. But the rocket, unlike the gas turbine, pulsejet, ramjet, or piston engine, needs no air. It carries everything needed for propulsion within itself - its own fuel and some form of oxidizer, commonly liquid oxygen, to burn the fuel. So the rocket engine operates independently of its environment; in fact, its efficiency increases as it climbs away from the frictional density of the lower atmosphere to the thin air of the stratosphere and into the airlessness of space.31
Yet even the rocket research airplanes were a long way from spacecraft. Although some of these vehicles provided data on the use of reaction controls for steering in the near vacuum of the upper atmosphere, they were designed to produce considerable aerodynamic lift for control within the lower atmosphere; and, in terms of the mass to be accelerated, their powerplants burned too briefly and produced too little thrust to counterbalance the oppressive force of gravity. Fulfillment of the age-old desire to travel to the heavens, even realization of Hale's nineteenth-century concept of a manned sphere circling Earth in lower space, would have to await the development of rockets big enough to boost thousands of pounds and to break the lock of gravity.
Although black-powder rockets, invented by the Chinese, had been used for centuries for festive and military purposes, not until the late nineteenth and early twentieth centuries did imaginative individuals in various parts of the world begin seriously to consider the liquid-fueled rocket as a vehicle for spatial conveyance. The history of liquid-fueled rocketry, and thus of manned space flight, is closely linked to the pioneering careers of three men - the Russian Konstantin Eduardovich Tsiolkovsky (1857-1935), the American Robert Hutchings Goddard (1882-1945), and the German-Romanian Hermann Oberth (1894- ).
Tsiolkovsky, for most of his life an obscure teacher of mathematics, authored a series of remarkable technical essays on such subjects as reaction propulsion with liquid-propellant rockets, attainable velocities, fuel compositions, and oxygen supply and air purification for space travelers. He also wrote what apparently was the first technical discussion of an artificial Earth satellite.32 Although virtually unknown in the West at the time of his death, in 1935, Tsiolkovsky was honored by the Soviets and had helped establish a long Russian tradition of  astronautics. This tradition helps to account for the U.S.S.R.'s advances with rocket-assisted airplane takeoffs and small meteorological rockets of the 1930s and her space achievements of the 1950s and 1960s.33
In terms of experimentation, Goddard, professor of physics at Clark University, was by far the most important of the rocket pioneers.34 As early as 1914 he secured a patent for a small liquid-fueled rocket engine. Six years later he published a highly technical paper on the potential uses of a rocket with such an engine for studying atmospheric conditions at altitudes from 20 to 50 miles. Toward the end of the paper he mentioned the possibility of firing a rocket containing a powder charge that could be exploded on the Moon. "It remains only to perform certain necessary preliminary experiments before an apparatus can be constructed that will carry recording instruments to any desired altitude," he concluded.35
Goddard's life for the next 20 years was devoted to making those "necessary preliminary experiments." Working in the 1920s in Massachusetts with financial support from various sources and in the New Mexico desert with Guggenheim Foundation funds during the succeeding decade, Goddard compiled an amazing list of "firsts" in rocketry. Among other things, he carried out the first recorded launching of a liquid-propellant rocket (March 16, 1926), adapted the gyroscope to guide rockets, installed movable deflector vanes in a rocket exhaust nozzle for stability and steering, patented a design for a multistage rocket, developed fuel pumps for liquid-rocket motors, experimented with self-cooling and variable-thrust motors, and developed automatically deployed parachutes for recovering his instrumented rockets. Finally, he was the first of the early rocket enthusiasts to go beyond theory and design into the realm of "systems engineering" - the complex and hand-dirtying business of making airframes, fuel pumps, valves, and guidance devices compatible, and of doing all the other things necessary to make a rocket fly. Goddard put rocket theory into practice, as his 214 patents attest.36
Goddard clearly deserves the fame that has attached to his name in recent years, but in many ways he was more inventor than scientist. He deliberately worked in lonely obscurity, jealously patented virtually all of his innovations, and usually refused to share his findings with others. Consequently his work was not as valuable as it might have been to such of his contemporaries as the young rocket buffs who formed the American Rocket Society in the early thirties and vainly sought his counsel.37
Goddard's disdain for team research prompted his refusal to work with the California Institute of Technology Rocket Research Project, instigated in 1936 by the renowned von Kármán, then director of the Guggenheim Aeronautical Laboratory at CalTech. The CalTech group undertook research in the fundamentals of high-altitude sounding rockets, including thermodynamics, the principles of reaction, fuels, thrust measurements, and nozzle shapes. Beginning in 1939 the Guggenheim Laboratory, under the first Federal contract for rocket  research, carried out studies and experiments for the Army Air Forces, especially on rocket-assisted takeoffs for aircraft. These takeoff rockets were called JATO (for "Jet-Assisted Take-Off") units, because, as one of the CalTech scientists recalled, "the word 'rocket' was of such bad repute that [we] felt it advisable to drop the use of the word. It did not return to our vocabulary until several years later ...."38 In 1944, with the Guggenheim Laboratory working intently on Army and Navy contracts for JATO units and small bombardment rockets, the Rocket Research Project was reorganized as the Jet Propulsion Laboratory.39
In the 1920s and 1930s interest in rocketry and space exploration became firmly rooted in Europe, although the rapid expansion of aviation technology occupied the attention of most flight-minded Europeans. Societies of rocket theorists and experimenters, mostly privately sponsored, were established in several European countries.40 The most important of these groups was the Society for Space Travel (Verein für Raumschiffahrt), founded in Germany but having members in other countries. The "VfR," as its founders called it, gained much of its impetus from the writings of Oberth, who in 1923, as a young mathematician, published his classic treatise on space travel, The Rocket into Interplanetary Space. A substantial portion of this small book was devoted to a detailed description of the mechanics of putting into orbit a satellite of Earth.4l
Spurred by Oberth's theoretical arguments, the Germans in the VfR in the early thirties conducted numerous static firings of rocket engines and launched a number of small rockets. Meanwhile the German Army, on the assumption that rocketry could become an extension of long-range artillery and because the construction of rockets was not prohibited by the Treaty of Versailles, had inaugurated a modest rocket development program in 1931, employing several of the VfR members. One of these was a 21-year-old engineer named Wernher von Braun, who later became the civilian head of the army's rocket research group. In 1933 the new Nazi regime placed all rocket experimentation, including that being done by the rest of the VfR, under strict government control.42
The story of German achievements in military rocketry during the late thirties and early forties at Peenemuende, the vast military research installation on the Baltic Sea, is well known.43 Knowing Goddard's work only through his published findings, the German experimenters contrived and elaborated on nearly all of the American's patented technical innovations, including gyroscopic controls, parachutes for rocket recovery, and movable deflector vanes in the exhaust. The rocket specialists at Peenemuende were trying to create the first large, long-range military rocket. By 1943, after numerous frustrations, they had their "big rocket," 46 feet long by 11½ feet in diameter, weighing 34,000 pounds when fueled, and producing 69,100 pounds of thrust from a single engine consuming liquid oxygen and a mixture of alcohol and water. Called "Assembly-4" (A-4) by the Peenemuende group, the rocket had a range of nearly 200 miles and a maximum velocity of about 3,500 miles per hour, and was controlled by its  gyroscope and exhaust deflector vanes, sometimes supplemented by radio control.44 When Major General Walter Dornberger, commander of the army works at Peenemuende, pronounced the A-4 operational in 1944, Joseph Goebbels' propaganda machine christened it Vergeltungswaffe zwei (Vengeance Weapon No. 2), or "V-2."45 But for the space-travel devotees at Peenemuende the rocket remained the A-4, a step in the climb toward space.
Although the total military effect of the 3,745 V-2s fired at targets on the Continent and in England was slight, this supersonic ballistic missile threw a long shadow over the future of human society. As the Western Allies and the Soviets swept into Germany, they both sought to confiscate the elements of the German rocket program in the form of records, hardware, and people. Peenemuende was within the Russian zone of occupation, but before the arrival of the Soviet forces von Braun and most of the other engineers and technicians fled westward with a portion of their technical data. The Americans also captured the underground V-2 factory in the Harz Mountains; 100 partially assembled V-2s were quickly dismantled and sent to the United States. Ultimately von Braun and about 125 other German rocket specialists reached this country under "Project Paperclip," carried out by the United States Army.46
The Soviets captured no more than a handful of top Peenemuende engineers and administrators. "This is absolutely intolerable," protested Josef Stalin to  Lieutenant Colonel G. A. Tokaty, one of his rocket experts. "We defeated the Nazi armies; we occupied Berlin and Peenemuende; but the Americans got the rocket engineers."47 The Russians did obtain a windfall, however, in the form of hundreds of technicians and rank-and-file engineers, the Peenemuende laboratories and assembly plant, and lists of component suppliers. From those suppliers located in the Russian zone the Soviets secured enough parts to reactivate the manufacture of V-2s. The captured technicians and engineers were transported to the Soviet Union, where the Russian rocket specialists systematically drained them of the technical information they possessed but did not permit them to participate directly in the burgeoning postwar Soviet rocket development program.48
During the war Russian rocket developers, like their American counterparts, had concentrated on JATO and small bombardment rockets. "Backward though they were often said to be in matters of technology," observed James Phinney Baxter right after the war, "it was the Russians who in 1941 first employed rockets on a major scale. They achieved a notable success, and made more use of the rocket as a ground-to-ground weapon than any other combatant."49 In the postwar years the Soviets quickly turned to the development of large liquid-propellant rockets. Lacking an armada of intercontinental bombers carrying atomic warheads, such as the United States possessed, they envisioned "trans-Atlantic rockets" as "an effective straightjacket for that noisy shopkeeper Harry Truman," to use Stalin's words.50 Consequently the U.S.S.R. undertook to build a long-range military rocket years before nuclear weaponry actually became practicable for rockets; indeed, even before the Soviets had perfected an atomic device for delivery by aircraft.
The U.S.S.R. began exploration of the upper atmosphere with captured V-2s in the fall of 1947. Within two years, however, Soviet production was underway on a single-stage rocket called the T-1, an improved version of the V-2. The first rocket divisions of the Soviet Armed Forces were instituted in 1950 or 1951. Probably in 1954, development work began on a multistage rocket to be used both as a weapon and as a vehicle for space exploration. And in the spring of 1956 Communist Party Chairman Nikita Khrushchev warned that "soon" Russian rockets carrying thermonuclear warheads would be able to hit any target on Earth.51
31 Discussions of the principles of rocketry can be found in many places, but some of the most lucid explanations from the layman's standpoint are in Ley, Rockets, Missiles, and Space Travel, 60-65; Erik Bergaust and Seabrook Hull, Rocket to the Moon (Princeton, N.J., 1958), 33-43; Ralph S. Cooper, "Rocket Propulsion," Report of the Smithsonian Institution for 1962, 299-313; and Andrew G. Haley, Rocketry and Space Exploration (Princeton, N.J., 1958), 33-43. See also NASA news release, unnumbered, "Liquid Propellant Rocket Engines," Jan. 1962. Equally informative as an introduction to rocketry but historically important as a spur to enthusiasts was G. Edward Pendray's The Coming Age of Rocket Power (New York, 1945), wherein rocket efficiency was pictured as opening "the way to an entire new world of velocities, altitudes, and powers which have hitherto been closed to us; and consequently to a whole new world of human experiences and possibilities" (p. 9).
32 See A. A. Blagonravov, ed., Collected Works of K. E. Tsiolkovsky, Vol. II: Reactive Flying Machines, NASA TT F-237 (Washington, 1965).
33 For biographical information on Tsiolkovsky, see A. Kosmodemyansky, Konstantin Tsiolkovsky, His Life and Work, trans. X. Danko (Moscow, 1956); Albert Parry, Russia's Rockets and Missiles (Garden City, N.Y., 1960), 94-104; Beryl Williams and Samuel Epstein, The Rocket Pioneers on the Road to Space (New York, 1955), 52-69; Heinz Gartmann, The Men Behind the Space Rockets (New York, 1956), 26-35; and K. E. Tsiolkovsky, "An Autobiography," trans. A. N. Petroff, Astronautics, IV (May 1959), 48-49, 63-64; V. N. Sokolskiy, "The Works of the Russian Scientist-Pioneers of Rocket Technology," in T. M. Melkumov, ed., Pioneers of Rocket Technology (Moscow, 1964), NASA TT F-9285 (Washington, 1965), 125-162.
34 Biographical material on Goddard, little known outside of scientific circles until recent years, is accumulating rapidly. A valuable but not definitive biography is Milton Lehman, This High Man: The Life of Robert H. Goddard (New York, 1963). See also E. R. Hagemann, "Goddard and His Early Rockets: 1882-1930," Journal of the Astronautical Sciences, VII (Summer 1961), 51-59; Eugene M. Emme, "Yesterday's Dream - Today's Reality," Air Power Historian, VII (Oct., 1960), 216-221; G. Edward Pendray, "Pioneer Rocket Development in the United States," in Emme, The History of Rocket Technology, 19-23; also published in Technology and Culture, IV (Fall 1963), 384-388; Williams and Epstein, Rocket Pioneers, 70-110; Shirley Thomas, Men of Space (6 vols., Philadelphia, 1960-1963), I, 23-46; Gartmann, Men Behind the Space Rockets; and Emme, A History of Space Flight (New York, 1965), 85-87.
35 Goddard's 1920 Smithsonian Institution report and a less famous report to the Smithsonian summarizing his findings to 1936 are in Robert H. Goddard, Rockets, Comprising "A Method of Reaching Extreme Altitudes" and "Liquid-Propellant Rocket Development" (New York, 1946). A condensation of Goddard's notebooks is Esther C. Goddard and G. Edward Pendray, eds., Rocket Development: Liquid-Fuel Rocket Research, 1929-1941 (New York, 1961). The eastern daily newspapers seized on Goddard's "moon-rocket" reference in his first Smithsonian paper and blew it completely out of proportion. Some journals, having no conception of the mechanics of rocketry, even ridiculed the idea that a rocket could ascend into space, because in a vacuum it would have nothing to "react against." See, for example, the lead editorial in New York Times, Jan. 13, 1920. The storm of embarrassing publicity doubtless abetted the aversion to notoriety that characterized Goddard throughout his career.
36 Pendray, "Pioneer Rocket Development in the United States," 21-23; Pendray, The Coming of Age of Rocket Power, 35-43; Ley, Rockets, Missiles, and Space Travel, 443.
37 Pendray, "Pioneer Rocket Development in the United States," 23-24; Pendray, "The First Quarter Century of the American Rocket Society," Jet Propulsion, XXV (Nov. 1955), 586-593.
38 Frank J. Malina, "Origins and First Decade of the Jet Propulsion Laboratory," in Emme, ed., History of Rocket Technology, 52-54.
39 Ibid., 46-66; Haley; Rocketry and Space Exploration, 97-99; Ley, Rockets, Missiles, and Space Travel, 249-250, 436, 438; Perry, "Antecedents of the X-1," 20-23.
40 An exception to the pattern of private sponsorship of rocket societies was the "Group for the Study of Rocket Propulsion Systems," known as GIRD, established under government auspices in the Soviet Union in 1931. House Committee on Science and Astronautics, 87 Cong., 1 sess. (1961), House Report No. 67, A Chronology of Missile and Astronautic Events, 3; G. A. Tokaty, "Soviet Rocket Technology," in Emme, ed., History of Rocket Technology, 275-276; also published in Technology and Culture, IV (Fall 1963), 520-521.
41 On Oberth see Williams and Epstein, Rocket Pioneers, 111, 143; Gartmann, Men Behind the Space Rockets; Ley, Rockets, Missiles, and Space Travel, 108-130; William Meyer-Cords, "Introduction" to Hermann Oberth, Man into Space: New Projects for Rocket and Space Travel, trans. G. P. H. deFreville (New York, 1957), vii-xiv; Hermann Oberth, "From My Life," Astronautics, IV (June 1959), 38-39, 100-104; and G. V. E. Thompson, "Oberth - Doyen of Spaceflight Today," Spaceflight, I (Oct. 1957), 170-171.
42 Ley, Rockets, Missiles, and Space Travel, 118-162, 197-201; Walter Dornberger, "The German V-2," in Emme, ed., History of Rocket Technology, 29-33; also published in Technology and Culture, IV (Fall 1963), 394-395. Williams and Epstein, Rocket Pioneers, 144-170. Von Braun received a doctorate in physics from the University of Berlin in 1934.
43 See Walter Dornberger, V-2 (New York, 1954); Dornberger, "The German V-2," 33-45; Williams and Epstein, Rocket Pioneers, 204-231; Ley, Rockets, Missiles, and Space Travel, 202-231; Dieter K. Huzel, Peenemünde to Canaveral (Englewood Cliffs, N.J., 1962); Leslie G. Simon, German Research in World War II: An Analysis of the Conduct of Research (New York, 1947), 33-35; and Theodore Benecke and A. W. Quick, eds., History of German Guided Missiles (Brunswick, Ger., 1957).
44 Ley, Rockets, Missiles, and Space Travel, 212-217; Kurt H. Debus, "Evolution of Launch Concepts and Space Flight Operations," in Ernst Stuhlinger, Frederick I. Ordway III, Jerry C. McCall, and George C. Bucher, eds., From Peenemünde to Outer Space: Commemorating the Fiftieth Birthday of Wernher von Braun (Huntsville, Ala., 1962), 45. During the powered phase of its flight within the atmosphere the V-2 was stabilized by large aerodynamic fins.
45 Chronology of Missile and Astronautic Events, 7; Dornberger, "The German V-2," 32-33. "Vengeance Weapon No. 1" - V-1 - was a radio-controlled, subsonic guided missile powered by a pulsejet engine, developed by the German Air Force. Besides the A-4, the accomplishments of the Peenemünde rocket workers included the launching in the early part of 1945 of a winged A-4, called the A-9, which they had designed as the upper stage of a rocket to attack the United States. And by the end of the war Eugen Sänger, already well-known as an Austrian rocket scientist before going to work for the Luftwaffe, and Irene Bredt, a noted German physicist, had written an elaborate report containing a design for an antipodal rocket bomber that would skip in and out of the atmosphere to drop its payload and land halfway around the world. See also Eugen Sänger, Rocket Flight Engineering, NASA TT F-223 (Washington, 1965).
46 Senate Preparedness Subcommittee of the Committee on Armed Services, 85 Cong., 1 and 2 sess. (1957-58), Inquiry into Satellite and Missile Programs, Hearings, testimony of Wernher von Braun, Part 1, 850; David S. Akens, Historical Origins of the George C. Marshall Space Flight Center (Huntsville, Ala., 1960), 24-29; Tokaty, "Soviet Rocket Technology," 278-279; James McGovern, Crossbow and Overcast (New York, 1964); Clarence G. Lasby, "German Scientists in America: Their Importation, Exploitation, and Assimilation, 1945-1952," unpublished Ph.D. dissertation, University of California at Los Angeles, 1962. All together, Paperclip brought nearly 500 aeronautical and rocket scientists, engineers, and technicians to the United States.
47 Quoted in Tokaty, "Soviet Rocket Technology," 279.
48 Inquiry into Satellite and Missile Programs, testimony of von Braun, Part 1, 581; Parry, Russia's Rockets and Missiles, 118-125.
49 James P. Baxter, Scientists Against Time (Boston, 1946), 201.
50 Quoted in Tokaty, "Soviet Rocket Technology," 281.
51 Ibid., 282-283; Parry, Russia's Rockets and Missiles, 131- 133; Frederick I. Ordway III, and Ronald C. Wakeford, International Missile and Spacecraft Guide (New York, 1960), 3-4; Donald J. Ritchie, "Soviet Rocket Propulsion," in Donald P. LeGalley, ed., Ballistic Missile and Space Technology, Vol. II: Propulsion and Auxiliary Power Systems (New York, 1960), 55-85; Chronology of Missile and Astronautic Events, 26; Charles S. Sheldon II, "The Challenge of International Competition," paper, Third American Institute of Aeronautics and Astronautics/NASA Manned Space Flight Meeting, Houston, Nov. 6, 1964.