Project Bumper combined the WAC Corporal with a V-2 rocket boost to create the first successful liquid-fueled rocket with more than one stage. The program left a rich heritage of space technology and a vital base of information, without which space travel would not have been possible.
The Ordnance Guided Missile and Rocket Programs—HERMES—investigated nearly every aspect of rocketry, including missile structures, transonic and supersonic aerodynamics and ramjet engines, missile guidance and control, ground launch equipment and handling, instrumentation, fuels and propellants, and rocket engines. Three categories were defined in the HERMES program: the A3 missile series, the A1 and A2 missile series, and other missiles and supporting research. Project Bumper was in the third category.
The purpose of HERMES, initiated in November of 1944, was to develop long-range guided missiles for use against ground targets and high-altitude aircraft. A group of scientists was to study German missiles used in World War II, with the assistance of military intelligence, then to identify confiscated hardware and collect important pieces for shipment to the United States. Their job was complicated by the fact that almost all of the rocket components and subassemblies had been deliberately damaged by the retreating German army. After assembling and launching eight V-2’s,
The second critical phase of HERMES was the acquisition of top German rocket scientists in Operation Paperclip
The scientists were sent initially to Fort Strong, near Boston, Massachusetts, but they were moved to Fort Bliss, Texas, in January of 1946. Twenty of these scientists were assigned to the White Sands Proving Grounds
The V-2 had five main parts: the warhead or nose cone, the control compartment, the midsection, the thrust frame, and the tail assembly. The nose cone had been used by the German army to loft a one-ton warhead against the Allies. The nose cones of the V-2’s under research at WSPG were filled with about 0.57 cubic meter of instrumentation, including a variety of measuring devices, and with lead weights, when the proper weight could not be obtained with equipment. To achieve stability, the payload weight had to equal the German warhead weight. The control compartment contained gyroscopes, which had to be manufactured in the United States because of the few gyroscopes recovered intact. Later, this compartment also contained Doppler, telemetering, and emergency cut-off radio receivers.
The midsection of the V-2 contained liquid alcohol and liquid oxygen propellant tanks, valves, and piping. Generally, the tanks were recovered after World War II in good condition. Glass wool was used for insulation of the alcohol tanks and piping, protecting them from the extreme cold of the liquid oxygen. The thrust frame contained the propulsion equipment, including the turbopump, the steam-generating plant, the heat exchanger, the combustion unit, and pipelines. Steam was generated by combining hydrogen peroxide and sodium permanganate. Except for the heat exchangers, all of this hardware was recovered in usable condition.
The tail assembly contained the fairing (structure addition to reduce aerodynamic drag) for the propulsion unit, stabilized the flight, steered the missile, and carried the vanes and vane motors. The bearing surfaces of the fins supported the V-2’s upright position on the launch frame. The fins stabilized the flight to maximum altitude, then lost effectiveness in the thinner air, causing the rocket to begin its fall tail-end down. Upon reaching denser air, the fins again took over steering, and the rocket swung around to fall nose down.
Project Bumper was first conceived by Colonel Holger N. Toftoy, later a major general, in the Office of the Chief of Ordnance, who suggested combining the V-2 with the WAC Corporal. In October, 1946, Project Bumper was instituted to investigate separation problems of two-stage liquid rockets and to set a new high-altitude record. It was hoped to gain some data on high-speed, high-altitude phenomena and to attain a velocity record as well.
The WAC Corporal, a small American-made rocket, was named “Without Attitude Control” Corporal, because it followed the Privates A and F. It had a range of only forty kilometers, was 4.88 meters long, and had a thrust of 337.8 newtons for forty-five seconds of burn. It was fueled by a mixture of aniline with 20 percent furfuryl alcohol to depress the freezing point, a mixture that combusted spontaneously with red fuming nitric acid.
The WAC Corporal was fitted as deeply as possible into the V-2 booster, with enough space in the instrument compartment for the necessary guidance equipment. Guide rails and expulsion cylinders (powered by compressed air) for the WAC mid-air launch were also included. The final cutoff signal of the V-2 burn signaled the compressed air valve opening, causing the second-stage fins to slide out of the slots in the nose cone of the V-2.
The forward portion of the V-2 was modified for Project Bumper installation, with General Electric given overall responsibility for the eight V-2 modifications. Frank J. Malina of the Jet Propulsion Laboratory (JPL) was responsible for theoretical investigations, the design of the second stage, and the basic design of the separation system. The Douglas Aircraft Company was responsible for the fabrication of the second stage and the detail design and fabrication of special V-2 parts.
On February 24, 1949, Bumper Five reached an altitude of 410 kilometers, becoming the first true space vehicle. The WAC Corporal rocket was fully tanked, with a burn of forty-five seconds. Only thirty seconds after take-off, the V-2 hit 5,904 kilometers per hour, just prior to separation. The WAC Corporal then attained 8,446 kilometers per hour, breaking the records for both velocity and altitude. In this flight, instrumentation in the nose cone measured temperatures and transmitted technical data pertaining to conditions during the flight. This was the first time radio equipment had operated at extreme altitudes. Although the flight was a complete success, the rocket’s crashed remains were not found for more than a year.
Of the eight Bumper flights, three were successful, two had limited success, and three were failures. During one flight, the V-2 reportedly passed the second stage. The first flight, on May 13, 1948, was of short duration, with a solid propellant motor in the WAC Corporal. The second stage attained only a little more speed and altitude than the V-2 booster. Flight two, on August 19, 1948, contained a partial propellant charge in the WAC Corporal, as in the first flight. Unfortunately, a controlling circuit failure in the V-2 prevented the success of the second-stage launch. On September 30, 1948, the third flight ended in an explosion of the second stage shortly before separation, although the V-2 was successful. The fourth flight ended with a tail-section explosion, probably the result of modifications, and control was lost.
Flight six was the last to launch at the WSPG, on April 21, 1949. It was fully tanked with propellant and contained cosmic radiation telemetry. Again, there was a malfunction in the control system, possibly caused by excess vibration. Flights seven and eight were launched from Cape Canaveral, partly for the inauguration of the new Florida Missile Test Center, but mostly because of the need for an extended flight range. These two flights were almost horizontal, at a 322 kilometer range. The second-stage rockets were fired after the horizontal flight configuration was attained, causing a high-speed, flat flight.
Project Bumper was significant in the history of spaceflight for several reasons. First of all, Bumper’s program of origin, the HERMES project, was invaluable for the immense amount of research and development attained with relatively little monetary investment, particularly after the war, when cutbacks in research were prevalent. Also, these projects encouraged organizational growth, both in governmental and private sectors, to accommodate the tremendous amount of data collected. Complex management structures, particularly with regard to the interaction among German scientists, United States Army Ordnance, and private companies, had to be constructed. The competitive nature of interservice rivalry, which began with HERMES, kept the impetus for space research and development alive. The heritage of research data provided a strong base for future developments in space technology, especially the data concerning the many problems associated with high-altitude separations, attachments, and ignition.
An interesting and satisfying effect of Project Bumper was the proof of ideas long in existence, but unproven for lack of technology. One example is Tartaglia’s rule
Probably the most significant consequence of Project Bumper was the database obtained from successfully launching a two-stage rocket. Following the V-2 were the Jupiter and Redstone ballistic missiles. Then followed the Saturn series of rockets, the rockets that took humankind to the Moon.
On the political scene, the end of World War II heralded the beginning of the Cold War, when the two world powers—the United States and the Soviet Union—were in heavy competition to achieve “firsts” in space. Although both nations got a head start with technology confiscated from Germany after the war, the nature of their acquisitions guided somewhat the course of the future. While the Soviets were attempting to produce V-2’s from the factory fittings, the Americans were putting together rockets with the assistance of the German rocket scientists and were adding to the technology.
Although the Soviets achieved the first events in space, such as the first man, first woman, and first extravehicular activity, the Americans were the first to produce a functional, reliable heavy-launch vehicle capable of taking humans to the Moon and returning safely. This activity required advanced technology in the rocketry necessary to separate capsules for lunar descent, for launch from the Moon, and for reunification of the capsules prior to return to Earth. Project Bumper, with its integration of two separate stages and the technology required to launch successfully the second stage in mid-flight, left a rich heritage of space technology and a vital base of information, without which space travel would not be possible.
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Dornberger, Walter R. V-2. New York: Bantam Books, 1979. A fascinating eyewitness account of the development of the V-2; covers the political and financial maneuvering necessary for the project. -
Emme, Eugene M., ed. The History of Rocket Technology. Detroit, Mich.: Wayne State University Press, 1964. A technical history that also discusses the political and social background for rocket developments. A compilation of essays on the development, research, and use of the various launch vehicles. College level. -
Goodwin, Harold L. All About Rockets and Space Flight. New York: Random House, 1964. An elementary-level book; explains basic rocketry and spaceflight theories in easily understood terms. Good for beginning studies for any age. -
Gruntman, Mike. Blazing the Trail: The Early History of Spacecraft and Rocketry. Reston, Va.: American Institute of Aeronautics and Astronautics, 2004. Massive history focused on the first spacecraft and rockets. Bibliographic references and index. -
Kennedy, Gregory P. Vengeance Weapon 2: The V-2 Guided Missile. Washington, D.C.: Smithsonian Institution Press, 1983. A pleasant combination of history and technology and very readable. Some technical passages, such as those dealing with the actual mechanics of the V-2. Beautiful black-and-white archival photographs. -
Ley, Willy. Rockets, Missiles, and Space Travel. 7th ed. New York: Viking Press, 1959. Written by one of the most prolific writers of space history. Very readable, college-level materials, yet dense with information. Details history and theory from early concepts through the V-2. Contains technical tables. -
Ordway, Frederick J., and Mitchell R. Sharpe. The Rocket Team. Cambridge, Mass.: MIT Press, 1982. A detailed history of the V-2, with many references to the V-1 as well. College-level reading, with fascinating black-and-white photographs. An excellent resource.
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Yeager Breaks the Sound Barrier
Test Aircraft Exceeds Twice the Speed of Sound
Soviet Union Launches the First Artificial Satellite
Dyna-Soar Space Plane Is Developed
United States Launches Its First Orbiting Satellite