SP-4206 Stages to Saturn
[1] The passage of time blurs many details. Part One is intended to bring back into focus some of the facts, circumstances, and background of space exploration. The opening section of chapter 1 briefly recapitulates the flight of Apollo 11-the first lunar landing mission-and provides the opportunity to introduce some of the hardware and nomenclature of the Apollo-Saturn program. A historical overview of rockertry, including the main threads of Saturn's origins' provides a background for the scope and boldness of Apollo 11 and the Saturn adventure in the chapters that follow.
[3] Movement of the rocket from the assembly site to the launch pad was scheduled for 20 May 1969. In slow sequence, the 142-meter-high doors ponderously opened, retracting upward like a vertical accordion, revealing the launch vehicle inside the huge gray structure known as the Vehicle Assembly Building. As the folding doors moved higher, the bright morning sun highlighted the whiteness of the three-stage launch vehicle with its scarlet lettering and black markings. Most of the American public, and the world, knew the towering 111-meter rocket as the Saturn V or the Apollo 11. To the men and women who buslt it, it was known better by its official designation: AS-506. Whatever its name, everyone knew its destiny. This rocket was going to be the first to land men on the moon.
Other Saturn rockets had preceded it. From Kennedy Space Center (KSC), the National Aeronautics and Space Administration's facility on Florida's Atlantic coast, 10 Saturn I vehicles were launched from 1961 to 1965, and five Saturn IB vehicles were launched between 1966 and 1968.1 Prior to the launch of Apollo 11, between 1967 and 1969 NASA launched two unmanned Saturn V rockets and three manned vehicles in qualifying flights. The manned lunar landing was the payoff. This mission, with astronauts Neil Armstrong, Edwin Aldrin, and Michael Collins as the crew, commanded attention as none before had done.
The launch of AS-506 took place on schedule. Ignition occurred at 31 minutes and 50 seconds past 9:00 a.m., and seconds later, the rocket left Earth, bound for the moon, at 9:32 a.m. EDT, 16 July 1969.
[4] The intricacies of a successful lunar mission dictated a multiphased operation, and the Saturn V was a multistage rocket. Early plans for the moon rocket included proposals for a comparatively simple "one-shot" vehicle in the form of a single- stage rocket. For all the attraction of the basic simplicity of a single-stage rocket as compared with a multistage vehicle, designers finally discarded it. The single-stage concept would have required a rocket of great girth and structural strength to carry all the required propellants. As a single-stage vehicle climbed into space, a considerable weight penalty developed because all the weight of the empty tankage had to be carried along. This weight penalty severely limited the size of the payload- in this case, a manned spacecraft. The multistage design allowed the first stage, with its big booster engines, to drop off once its rocket propellants were depleted. The second stage was more efficient because it had relatively less weight to push further into the planned trajectory, and it benefited from the accelerative forces imparted to it by the first stage. By the same token, the third stage had an even lighter weight and an even higher acceleration. In addition, the multistage approach permitted the use of special high-energy fuels in the upper stages. These considerations played a large role in the development of the Saturn V as a three-stage launch vehicle.
For the Apollo 11 mission, components of the Saturn V launch vehicle and the Apollo spacecraft had arrived in segments at Cape Kennedy. Whether they reached their destination by ship, barge, plane, or truck, they were all consigned for delivery to the Vehicle Assembly Building (VAB). Inside, they were stacked together to make up the moon rocket. The VAB was the heart of NASA's mobile launch concept, a radical departure from earlier tradition in rocket launching. Previous custom was to "stack" (assemble) the rocket at the launch pad itself, with minimal protection from the elements afforded by a comparatively makeshift structure thrown up around the rocket and its launching tower.
This approach completely tied up the launch pad during the careful stacking procedures and lengthy checkout. The size and complexity of the Saturn V dictated a change in tactics. NASA was planning a heavy schedule of Saturn launches and simply could not accept the consequent tie-up of launch sites. In a bold new approach, NASA implemented the mobile launch concept, which entailed the erection and checkout of several of the three-stage vehicles and spacecraft inside one gargantuan building, the VAB, with equipment to move the readied vehicles to a nearby launch site. At KSC's Launch Complex 39, a small army of engineers and technicians received components of the Saturn V, checked them out, assembled the complete vehicle, and conducted the launch. The facilities of the sprawling complex included the VAB, the mobile launcher, the crawler-transporter, the crawlerway to the launch pad, the mobile service structure, and the launch pad itself.2
[5] The first stage of Saturn V, the S-IC, employed a cluster of five F-1 engines of 6 672 000 newtons (1 500 000 pounds) of thrust each, for a total of 33 360 000 newtons (7 500 000 pounds) of thrust. The first-stage propellant tanks contained 767 cubic meters (203 000 gallons) of RP-1 fuel (a kerosene-type fuel) and 1251 cubic meters (331 000 gallons) of oxidizer (liquid oxygen, or LOX). The S-IC consumed these propellants in a fiery holocaust lasting only 2.5 minutes, by which time the Saturn V was boosted to a speed of about 9700 kilometers per hour at the cutoff altitude of around 61 kilometers. The spent first stage fell away, to fall into the sea, and the S-II second stage took over. Like the first stage, the S-II also mounted a cluster of five engines, but these were the 1 112 000 newtons (250 000 pounds) of thrust J-2 type, burning liquid hydrogen as fuel, and using liquid oxygen as the oxidizer. In the course of its six-minute "burn," the second stage propelled the Saturn V to an altitude of 184 kilometers, accelerating to a speed of 24 620 kilometers per hour. At this point, the Saturn vehicle had nearly reached the speed and altitude for Earth orbit. After the second stage dropped away, following its precursor into the ocean, the S-IVB third stage then hurtled the 113 400-kilogram payload into a 190-kilometer orbit, using its single J-2 engine for a burn of 2.75 minutes. In this final part of the orbital mission sequence, the remainder of the launch vehicle and its payload barreled into orbit at a speed of 28 200 kilometers per hour.
The S-1VB did not deplete its fuel during the third-stage burn, because the mission called for the S-1VB to reignite, firing the spacecraft out of Earth orbit and into the translunar trajectory to the moon. During the parking orbit (one to three circuits of the Earth), Astronauts Armstrong, Aldrin, and Collins completed a final check of the third stage and the spacecraft, while ground technicians analyzed telemetry and other data before making the decision to restart the J-2 for the translunar trajectory burn. No problems showed up to suggest the possibility of terminating the flight, so mission personnel waited for the precise moment in Earth orbit for the last five-minute operation of the Saturn V launch vehicle. Two hours and 44 minutes after liftoff, over the southern Pacific, the S-IVB ignited and accelerated the spacecraft to 39 400 kilometers per hour-enough to carry the spacecraft out of Earth orbit and place it in a trajectory bound for the moon. The third stage was not immediately separated from the rest of the spacecraft. First, the command and service module (CSM) separated from the lunar module adapter, reversed itself and performed a docking maneuver to pull the lunar module away from the now spent third stage and the instrument unit. This transposition and docking maneuver signaled the end of the Saturn V launch vehicle's useful life.
As Armstrong, Aldrin, and Collins accelerated toward the moon with the lunar module anchored to the CSM, the S-IVB and the instrument unit were left behind in space. With both the spacecraft and .....
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[7] .....the third stage still in lunar-oriented trajectories, mission planners wanted to minimize the chances of the two elements colliding with each other. The spacecraft performed a three-second burn with its service it propulsion system to impart a velocity increase of six meters per second. This procedure not only widened the distance between the two, but also put the spacecraft and the three-man crew into a free-return trajectory, which used the lunar gravitational field to aid in a return to Earth in case the lunar landing had to be aborted. NASA also wanted to avoid the chances of the S-IVB impacting into the lunar surface in the vicinity of the astronauts' landing zone, so an automated sequence triggered a dump of residual propellants in the S-IV to realign the third stage's trajectory in such a way that the moon's gravitational field increased the S-IVB's velocity in a different direction. This "slingshot" maneuver was effective enough to throw the stage into solar orbit, where it would eventually impact into the sun in a dramatic demise.3
In its soaring flight out of the dominance of Earth's gravity, Apollo 11 marked one of the great milestones in rocket technology. The chemical and solid propulsion systems of the Saturn V and the Apollo spacecraft represented the distillation of concepts and plans and work by a host of people who had continuously worked toward the goal of manned lunar exploration. The rocket itself-the Saturn V-represented the culmination of generations of technological and theoretical work stretching all the way back to the 13th century.
There was one common denominator for the military, whaling, and life-saving rockets from antiquity through World War I: they were powder-burning, or "solid," rockets. A solid rocket, although simple, had several shortcomings. The rate of thrust after ignition of the rocket could not be controlled; there was no guidance after the launch; the powder technology at the turn of the century seemed to dictate a missile with an optimum weight of about 68 kilograms (most were in the 14-23-kilogram category); and the range rarely exceeded 2700 meters. Advances in artillery in the late 19th century had already displaced the rocket as an effective weapon.4 For space exploration, solid-fueled rockets seemed to lack the thrust potential for extreme range or for reaching high altitudes. Visionaries who were thinking of using rockets for space exploration had to consider other sources for fuel, and there were still the problems of guidance, as well as the problem of human survival in the space environment.
At the same time that powder rockets began to fall from favor in the late 19th century, a realistic theory and development of space flight, with a strong interest in new types of propellants, was beginning to evolve.
[8] Three pivotal figures in the new era of rocket technology were Konstantin Tsiolkovsky (1857-1935), Robert H. Goddard (1882-1945), and Hermann Oberth (1894- ). They were imaginative men who drew their theories and experiments from the growing bank of science and technology that had developed around the turn of the century. For one thing, the successful liquefaction of gases meant that sufficient quantities of fuel and oxidizer could be carried aboard a rocket for space missions. Research into heat physics helped lay the foundations for better engine designs, and advances in metallurgy stimulated new standards for tanks, plumbing, and machining to withstand high pressures, heat, and the super-cold temperatures of liquefied gases. Progress in mathematics, navigational theory, and control mechanisms made successful guidance systems possible.
Although Tsiolkovsky did not construct any working rockets, his numerous essays and books helped point the way to practical and successful space travel. Tsiolkovsky spent most of his life as an obscure mathematics teacher in the Russian provinces, but he made some pioneering studies in liquid chemical rocket concepts and recommended liquid oxygen and liquid hydrogen as the optimum propellants. In the 1920s, Tsiolkovsky analyzed and mathematically formulated the technique for staged vehicles to reach escape velocities from Earth. In contrast to the theoretical work of Tsiolkovsky, Robert Goddard made basic contributions to rocketry in flight hardware. Following graduation from Worcester Polytechnic Institute, Goddard completed graduate work at Clark University in 1911 and became a member of the faculty there. In the l920s, he continued earlier experiments with liquid-fueled vehicles and is credited with the first flight of a liquid-propellant rocket on 16 March 1926. With private support, Goddard was able to pursue development of larger rockets; he and a small crew of technicians established a test site in a remote area of the Southwest not far from Roswell, New Mexico. From 1930 to 1941, Goddard made substantial progress in the development of progressively larger rockets, which attained altitudes of 2300 meters, and refined his equipment for guidance and control, his techniques of welding, and his insulation, pumps, and other associated equipment. In many respects, Goddard laid the essential foundations of practical rocket technology, including his research paper entitled "A Method of Attaining Extreme Altitude" (published by the Smithsonian Institution in 1919)-a primer in theory, calculations, and methods-and his numerous patents that comprised a broad catalog of functional rocket hardware. In spite of the basic contributions of Tsiolkovsky in theory, and of Goddard in workable hardware, the work of both men went largely unheralded for years. Tsiolkovsky's work remained submerged by the political conditions in Russia and the low priority given to rocket research prior to World War II. Goddard preferred to work quietly, absorbed in the immediate problems of [9] hardware development and wary of the extreme sensationalism the public seemed to attach to suggestions of rocketry and space travel.
Although the work of Hermann Oberth was original in many respects, he was also significant as advocate and catalyst because he published widely and was active in popularizing the concepts of space travel and rocketry. Born in Transylvania of German parentage, Oberth later became a German citizen. He became interested in space through the fictional works of H.G. Wells and Jules Verne and left medical school to take up a teaching post where he could pursue his study and experimenting in rocketry. Oberth's work was independent of Tsiolkovsky's, and he heard of Goddard's brief paper of 1919 just as his own book, The Rocket into Planetary Space, was going to press in 1923. The Rocket into Planetary Space was read widely, translated into English, and was the precursor of many other books, articles, and lectures by the energetic author. Oberth analyzed the problems of rocket technology as well as the physiological problems of space travel, and his writings encouraged many other enthusiasts and researchers. In 1928, Oberth and others were consultants for a German film about space travel called The Girl in the Moon. The script included the now-famous reverse countdown before ignition and liftoff. As part of the publicity for the movie, Oberth and his staff planned to build a small rocket and launch it. The rocket was only static-fired and never launched, but the experience was a stimulating one for the work crew, including an 18-year-old student named Wernher von Braun.
During the ensuing years, Oberth continued to teach while writing and lecturing on space flight, and he served as president of the Verein fur Raumschiffahrt (VfR) (Society for Space Travel), which had been formed in 1927. The existence of organized groups like the VfR signaled the increasing fascination with modern rocketry in the 1930s, and there were frequent exchanges of information among the VfR and other groups like the British Interplanetary Society and the American Interplanetary Society. Even Goddard occasionally had correspondence in the American Interplanetary Society's Bulletin, but he remained aloof from other American researchers in general, cautious about his results, and concerned about patent infringement. Because of Goddard's reticence, in contrast to the more visible personalities in the VfR, and because of the publicity given the German V-2 of World War II, the work of British, American, and other groups has been overshadowed. If not as spectacular as the work on the V-2 rockets, their work nevertheless contributed to the growth of rocket technology in the prewar era and the successful use of a variety of Allied rocket weapons in the war. Although groups such as the American Interplanetary Society (which later became the American Rocket Society) succeeded in building and launching several small rockets, much of their significance lay in their role as the source of a growing number of technical papers on rocket technologies. But rocket [10] development was complex and expensive. The costs and the difficulties of planning and organization meant that sooner or later the major work in rocket development would occur under the aegis of permanent government agencies and government-funded research bodies.5
In America, significant team research began in 1936 at the Guggenheim Aeronautical Laboratory of the California Institute of Technology. In 1939 this group received the first Federal funding for rocket research. Research on rockets to assist aircraft takeoff was especially successful. The project was known as JATO, for Jet-Assisted Take-Off, because the word rocket still carried negative overtones in many bureaucratic circles. During World War II, U.S. armed forces made wide use of the bazooka (an antitank rocket) as well as a variety of barrage rockets launched from ground batteries or from ships, and high-velocity air-to-surface missiles. The JATO work also led to the development of a significant liquid-fueled rocket, a two-stage Army ballistic missile with a solid booster known as the....
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[11] ....Wac Corporal. The first-stage booster, adapted from an air-to-ground rocket dubbed the Tiny Tim, developed 222 000 newtons (50 000 pounds) of thrust, and the second stage, filled with nitric acid-aniline liquid propellants, developed 6700 newtons (1500 pounds) of thrust, a combination that fired a payload up to an altitude of 69 kilometers. But the Corporal program did not reach full development until after 1945.6 The most striking military rocket of the wartime era came from Germany.
In the early 1930s, the VfR attracted the attention of the German Army because the Treaty of Versailles, which restricted some types of armaments, left the door open to rocket development, and the military began rocket research as a variation of long-range artillery. Captain Walter Dornberger, an Army artillery officer with advanced degrees in engineering, spearheaded military rocket development. One of his chief assistants was a 20-year-old enthusiast from the VfR, Wernher von Braun, who joined the organization in October 1932. By December 1932, the Army rocket group had static-fired a liquid-propellant rocket engine at the Army's proving ground near Kummersdorf, south of Berlin.
Wernher von Braun was born in 1912 at Wirsitz, Germany, in Posen Province, the second of three sons of Baron and Baroness Magnus von Braun. A present of a telescope in honor of his church confirmation started the youthful von Braun's interest in space, spurring him to write an article about an imaginary trip to the moon. Fascination with the prospects of space travel never left him, and in 1930 he joined the VfR, where he met Oberth and other rocket enthusiasts. At the same time, he attended the Charlottenburg Institute of Technology and did apprentice work at a machine factory in Berlin. Before completing his bachelor's degree in mechanical engineering in 1932, he had participated in the space-travel film project and had come into contact with German ordnance officers. This contact led to the Army's support of von Braun's doctoral research in rocket combustion, which he completed in a brief period of two years, and he received his degree from Friedrich-Wilhelms Universitat of Berlin in 1934.7
By the next year, it became evident that the available test and research facilities at Kummersdorf were not going to be adequate for the scale of the hardware under development. A new location, shared jointly by the German Army and Air Force, was developed instead. Located on the island of Usedom in the Baltic, the new Peenemuende facility (named for the nearby Peene river) was geographically remote enough to satisfy military security and boasted enough land area, about 52 square kilometers, to permit adequate separation of test stands, research facilities, production areas, and residential sections. Test shots could be fired into [12] the Baltic Sea, avoiding impact in inhabited regions. Starting with about 80 researchers in 1936, the facility comprised nearly 5000 personnel by the time of the first launch of the V-2 in 1942. Later in the war, with production in full swing, the work force numbered about 18 000.
The V-2 (from Vergeltungswaffen-2, or "weapon of retaliation") had no counterpart in the Allied inventory. The V-2 was 14 meters long, with a diameter of 1.5 meters, and capable of speeds up to 5800 kilometers per hour to an altitude of 100 kilometers. By the end of the war, Germany had launched nearly 3000 of the remarkable V-2 weapons against targets in England and elsewhere in western Europe at ranges up to 320 kilometers. With the support of government, private, and university sources for research and development, the von Braun team at Peenemuende solved numerous hardware fabrication problems and technical difficulties (such as the production, storage, and handling of liquid oxygen in large quantity), while developing unique management skills in rocket technology.8
Early in the V-2 development program, its creators began looking at the rocket in terms of its promise for space research as well as for military applications. The continuous undercurrent of fascination with space travel was real enough to land von Braun in the clutches of the Gestapo. Late in the war, the German SS made attempts to wrest control of Peenemuende from Dornberger. After von Braun himself turned down "direct overtures from SS chieftain Heinrich Himmler, he was arrested at two o'clock one morning by a trio of Gestapo agents. Following two weeks of incarceration in prison at Stettin, von Braun was hauled into an SS court to hear the charges against him. Among other accusations, his prosecutors accused him of opposing the V-2 strikes on England and charged that he was more interested in rocketry for space research than in rocketry for warfare. Dornberger had to intercede directly with Adolf Hitler to get von Braun released.
By early 1945, it was apparent that the war was nearing its end. Von Braun called a secret meeting of his top staff and reviewed their options: stay on at Peenemuende in the face of the advancing Russian units or try to head south and surrender to the Americans. There was no dissent-go south. In railroad cars, trucks, and automobiles emblazoned with red and white placards reading Vorhaben zur besonderen Verwendun (Project for Special Disposition), the Peenemuende convoy bluffed its way through military and Gestapo checkpoints, arriving in the Harz mountain region in Bavaria with tons of documents and hundreds of Peenemuende personnel and their families. After regrouping, the von Braun team, unaware that the United States was already formulating a program to round up leading German scientific and technical personnel, began making plans for contacting the Americans. Best known as Operation Paperclip, the American search for the von Braun team had top priority.9
[13] On 2 May 1944, von Braun's younger brother Magnus climbed on a bicycle and set off down a country road in search of the Americans. Magnus was delegated for this delicate mission because he spoke better English. Contact was established, and several months of effort cleared the bureaucratic hurdles and prepared the way for over 100 selected German personnel to come to the United States. Finally, von Braun six others arrived at Fort Strong in Boston on 29 September l945. If the vanguard found the circumstances of their entry into the United States somewhat confusing and disorganized, they found American rocket development in much the same state of affairs.10
The National Security Act of 1947 established a unified military organization under the Secretary of Defense, with separate and equal departments for the U.S. Navy, U.S. Army, and U.S. Air Force. In the nascent field of military rocketry, guidelines for responsibilities of research, development, and deployment were decidedly fuzzy. As a result, American missile development in the postwar era suffered from interservice rivalry and lack of strong overall coordination, a situation that persisted to the mid-1950s. The Air Force, successful in long-range bombardment operations during the war, made a strong case for leadership in missile development. On the other hand, the Navy worked up studies showing the capabilities of missile operations from ships and submarines, and the Army viewed missiles as logical adjuncts to heavy artillery. But the Air Force had initiated long-range missile development even before the end of the war, and this momentum gave them early preeminence in the field of missile development.
Because American missile technology did not yet have the capability for large rocket-propelled vehicles, the Air Force at first concentrated on winged missiles powered by air-breathing turbojet powerplants. The Air Force stable of cruise missiles possessed ranges from 1000 to 11 000 kilometers and were capable of carrying the heavy, awkward nuclear warheads produced in the early postwar era. Until the Atomic Energy Commission made lighter and less unwieldy warheads available, the Air Force pressed on with cruise missiles at the expense of development of rocket-powered intercontinental ballistic missiles (ICBMs) such as the Atlas. The Navaho project represented the peak of the cruise missile. Weighing in at 136 000 kilograms and capable of Mach 3 speeds, the Navaho's research and development costs came to $690 million. It never reached operational status before cancellation in 1957, when ICBM technology overtook it. The Navaho made three successful flights, and the fallout from certain aspects of Navaho research and development [14] turned out to be very significant in other areas. The experience in high-speed aerodynamics was applied to other aeronautical research programs, and the missile's all-inertial guidance system found application in ICBMs and submarine navigational systems. Moreover, the booster units for Navaho were noteworthy in ICBM designs. Even though the Navaho used a ramjet engine for sustained flight to the target, the heavy vehicle was boosted into the air by three liquid-propellant rocket engines of 600 000 newtons (135 000 pounds) of thrust each. Developed by Rocketdyne (a division of North American Aviation, Inc.), variants of these powerplants were developed for the Air Force's Thor and Atlas missiles, and for the Army's Redstone and Jupiter rockets. The rocket engines for the latter played a highly significant role in the evolution of the Saturn vehicles.11
In the early postwar era, while the Air Force developed cruise missiles, the Army generated an increasing expertise in liquid propulsion rocketry through special projects at the White Sands Proving Ground in New Mexico. At White Sands, von Braun and the rocketry experts from Peenemuende not only made lasting contributions to American ballistic missile capabilities but made early ventures into space exploration. Besides test firing a series of captured V-2 rockets for the Army's operational experience, the German experts helped coordinate a series of upper atmospheric research probes. One such project, known as the Bumper Series, employed a V-2 as the first stage with a Wac Corporal upper stage, one of which reached an altitude of 393 kilometers. In 1950, the last two Bumper launches took place in Florida, at the Long Range Proving Ground, located at Cape Canaveral-a prelude to U.S. space launches of the future. Another major activity included the Hermes program and involved the General Electric Company's working with the von Braun team under Army Ordnance cognizance. During Hermes operations, the basic V-2 rocket underwent successive modifications, increasing its performance envelope and payload capabilities, while giving the American contractors progressive experience in rocket technology. A number of more-or-less indigenous American vehicles were also flown. Although none became operational, they afforded a highly useful exposure to rocket development for government and contractor agencies alike, and one of the concepts, Hermes C-1, contributed directly to the development of the first significant American ballistic missile, the Army's Redstone.12
As the l940s drew to a close, the Army decided to establish a new center of rocket activity. Although White Sands remained active as a test range, a facility devoted to basic research and prototype hardware development was needed. A site selection team finally settled on Redstone Arsenal in Huntsville, Alabama. Established in 1941 for the production of various chemical compounds and pyrotechnic devices (including small [15] solid-fuel rockets), Redstone had all the necessary attributes: shops, laboratories, assembly areas, and ample surrounding land to ensure both security and space for static-firing tests. Moreover, it was accessible to the Long Range Proving Ground, a rocket launch area of growing significance at Cape Canaveral. The transfer of von Braun's work from Fort Bliss was approved, and the Ordnance Guided Missile Center was in operation in Huntsville by the close of 1950.
During the Korean War, the new research center was assigned the development of a surface-to-surface ballistic missile with a range of 160 kilometers. A propulsion system adapted from the Navaho program enhanced rapid development, and the first launch of the new Redstone occurred at Cape Canaveral on 20 August 1953. Before declaring it operational in 1958, the von Braun team fired 36 more test vehicles. The prolonged Redstone development program epitomized the thorough, step-by-step engineering conservatism developed during the early years of rocket development at Peenemuende. This conservatism was a continuing trait of the von Braun team throughout the evolution of the Saturn program. Another point of significance concerned the involvement of the Chrysler Corporation as the prime contractor who built the last 20 R&D models and continued production of the operational models. The Chrysler connection provided valuable experience in government- contractor relationships that was the keynote of the development of the Saturn series of launch vehicles, and Chrysler, like Rocketdyne, also became an important contractor in the Saturn program.
In the meantime, the accumulated design experience of the Redstone program contributed to a joint Army-Navy development program involving the Jupiter vehicle, a direct derivative of the Redstone. This short-lived but interesting cooperation had its origins in the immediate postwar era. Because the Navy had its own interests in rocket technology and the Army possessed a reasonable supply of V-2 rockets, the two services collaborated in experimental V-2 launches from the flight deck of the aircraft carrier Midway in 1947. At an altitude of 1500 meters above the carrier's deck, a missile disintegrated in a ball of flame and debris. The specter of catastrophe, if such a large liquid-fueled rocket accidentally exploded on a ship at sea and spewed its huge volume of volatile propellants everywhere, led the Navy to proceed cautiously with liquid-propellant rockets. Nevertheless, the Department of Defense encouraged the formation of the joint Army-Navy venture in ballistic missiles in 1955, and the Army's designated organization in the partnership was the Army Ballistic Missile Agency (ABMA), created in 1956 and staffed primarily out of von Braun's group at the Redstone Arsenal. Major General John B. Medaris became ABMA's commanding officer. Wise in the ways of military bureaucracy, the enterprising Medaris also won unusually wide latitude in determining the direction of ABMA's research and allocation [16] of funds. Medaris and the equally venturesome von Braun made ABMA a remarkably resourceful and aggressive organization, especially when ABMA found itself in a solo role in Jupiter's eventual development.
This situation came late in 1956, when naval experts decided to concentrate on solid-fuel rockets. This direction eliminated logistic and operational difficulties inherent in the deployment of liquid-propellant rockets in seaborne operations, particularly with missiles launched underwater from submarines. The Navy gave official authorization to its own strategic missile-the Polaris- early in 1957. Based on a solid-fuel motor, the Polaris nevertheless borrowed from the Jupiter program in the form of its guidance system, evolved from the prior collaboration of ABMA and the Navy.
ABMA continued Jupiter development into a successful intermediate range ballistic missile (IRBM), even though the Army eventually had to surrender its operational deployment to the Air Force when a Department of Defense directive late in 1956 restricted the Army to missiles with a range of 320 kilometers or less. Even so, ABMA maintained a role in Jupiter R&D, including high-altitude launches that added to ABMA's understanding of rocket vehicle operations in the near-Earth space environment. It was knowledge that paid handsome dividends later.
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[17] During the early 1950s, the Atomic Energy Commission successfully perfected smaller hydrogen-bomb warheads. In the Air Force, these warheads caused cruise missile development to be replaced by new emphasis on the Thor IRBM and the longer range missiles such as the Atlas intercontinental ballistic missile (ICBM). Successful launches of the single-stage Thor and the one-and-a-half-stage Atlas occurred in 1957 and 1958, and the Air Force also began work on an advanced ICBM, the Titan, a two-stage vehicle launched for the first time in 1959. The increasing payload capability of these various missiles opened the possibility of replacing their warheads with satellites and using them as boosters to launch heavy scientific payloads into space. The United States had already applied the growing expertise of rocket technology to the development of a family of sounding rockets to carry instrumentation for upper atmospheric research, such as the Navy's Aerobee and the Viking, which would reach altitudes between 160 and 320 kilometers. During the period of the International Geophysical Year 1957-1958, many nations around the world conducted a coordinated program of sounding rocket launches, including 210 sent up by the United States and 125 launched by the Soviet Union. However, the United States had an even more ambitious goal than launching sounding rockets during the International Geophysical Year. America planned to orbit its first small satellite.
The satellite project began in 1955. In spite of the international spirit of cooperation inherent in International Geophysical Year programs, a strong sentiment in the United States was that America should not waste time and should attempt to orbit a satellite ahead of the Russians. For the booster, a blue-ribbon selection panel from military and industry analyzed a list of candidates that included the Atlas, the Redstone, and the Viking. ABMA argued that Atlas was still untested in 1955. The Viking vehicle, its opponents noted, still required a program to uprate its first-stage engines and develop new second and third stages before it could become operational. On the other hand, the Army's Jupiter C vehicle-a direct derivative of the proven Redstone-appeared to have all the capabilities necessary to launch a satellite successfully. For complex reasons, the committee selected the Viking; they argued that the Viking had been intended from the start as a vehicle for space research and that its development would not impinge on America's ballistic missile program, which was considered to be lagging behind the Russians' program. The choice of Viking, in the context of Cold War concerns over international prestige and technological leadership, was a controversial decision. The new program, to be known as Project Vanguard, was authorized in September 1955 under the Department of the Navy.13
[18] Although the first stage was successfully launched on 23 October 1957, the first Vanguard with three "live" stages blew apart on the pad, and its successor veered off course and disintegrated before it had ascended six kilometers. As if these last two fiascos were not enough, Vanguard was already overtaken by events. The Russians had orbited Sputnik I on 4 October 1957. Within four weeks the Soviet Union demonstrated that Sputnik was no fluke by launching a second orbital payload; Sputnik II, carrying the dog "Laika," went into orbit on 3 November.14 The potent Russian boosters threw a long shadow over Vanguard. Plans to use an existing military booster gained support once again.
The honor of launching America's first satellite fell to the close-knit group of pioneers who had dreamed of space exploration for so many years, the von Braun team. When the Army's Redstone-Jupiter candidate for the International Geophysical Year satellite was rejected, ABMA assumed a low profile but kept up work. As one ABMA insider explained, von Braun found a "diplomatic solution" to sustain development of the Jupiter C by testing nose cones for the reentry of warheads. Following launch, solid-propellant motors in the second and third stages accelerated an inert fourth stage attached to an experimental nose cone. The nose cones tested ablative protection as they reentered Earth's atmosphere. After successful tests during the summer of 1957, von Braun declared that a live fourth stage and a different trajectory would have given the United States its orbiter. In any case, ABMA was not unprepared to put an American payload into Earth orbit. Slightly more than four weeks after the launch of Sputnik, the Secretary of Defense finally acceded to persuasive pleas from ABMA to put up an artificial satellite, using its own vehicle. Authorization from the secretary for two satellite launches came on 8 November 1957, and the initial launch was set for 30 January 1958. ABMA missed the target date by only one day, when a Jupiter C orbited Explorer I on 31 January 1958.15 The unqualified success of Explorer I and its successors derived in large part from the existing operational capability of the Jupiter C launch vehicle, from the flexibility of ABMA's in-house capability, and from the technical expertise of the Jet Propulsion Laboratory (JPL), which functioned administratively as a unit of the California Institute of Technology and got a large share of its funds through Army contracts. JPL developed the solid-fuel propulsion units for the upper stages of the Jupiter C as well as the payloads for the Explorer satellite. Within the next few months, the Jupiter C vehicles, designated as Juno boosters for space launches, also carried payloads into orbit around the moon and the sun.16
During the public consternation and political turmoil in the wake of the Soviet space spectaculars, the American government began a thorough reappraisal of its space program. One result was the establishment of the National Aeronautics and Space Administration (NASA) in place [19] of the old National Advisory Committee for Aeronautics (NACA). Created when President Eisenhower signed the National Aeronautics and Space Act into law on 29 July 1958, NASA was organized to ensure strong civil involvement in space research so that space exploration would be undertaken for peaceful purposes as well as for defense. Although late in success, Project Vanguard was not without its benefits. Vanguard I finally got into orbit on 17 March 1958, and two more Vanguards attained orbit in 1959. The program yielded important scientific results, as well as valuable operational experience. Upper stages of the Vanguard vehicle were used in conjunction with later booster vehicles such as the Thor and the Atlas, and the technique of gimbaled (movable) engines for directional control was adapted to other rockets. 17
The period 1958-1959 seemed to trigger feverish activity in space exploration. In the months and years that followed, dozens of satellites and space vehicles were launched, including space probes that landed on Venus and the moon. Although other nations inaugurated space programs and launched their own boosters and scientific payloads, most public attention fastened on the manned "space race" between the U.S.S.R. and the United States. Within the first week of NASA's existence in October 1958, Project Mercury was authorized to put an American astronaut into orbit, and the space agency began negotiations to obtain the necessary boosters and select candidates for astronaut training.
At that time, NASA did not have the resources to develop its own boosters for space exploration. Mission planners reached into the inventory of American ballistic missiles and finalized agreements with the Army and ABMA for use of the Redstone, as well as the Atlas ICBM to be acquired from the Air Force. To check out requirements and systems for manned orbital operations, NASA planned to employ the Redstone for suborbital launches, and the more powerful Atlas would be used for the orbital missions. Selection of the first seven Mercury astronauts was announced in the spring of 1959, and work proceeded on the development and testing of the Mercury space capsule, including unmanned test launches in 1960. Early in 1961 a Mercury-Redstone launch from Cape Canaveral carried the chimpanzee "Ham" over 640 kilometers down-range in an arching trajectory that reached a peak of 253 kilometers above Earth. The chimp's successful flight and recovery confirmed the soundness of the Mercury-Redstone systems and set the stage for a suborbital flight by an American astronaut. But the Americans were again upstaged by the Russians.
On 12 April 1961, Major Yuri Gagarin was launched aboard Vostok I and completed one full orbit to become the first human being to travel in orbit about the Earth. Just as the Russians appeared to have overtaken the Americans in the area of unmanned space projects, they now seemed to have forged ahead in manned exploration as well. Although Alan B. Shepard made a successful suborbital flight atop ABMA's Redstone [20] booster on 5 May, even this milestone was overshadowed when Soviet Cosmonaut Gherman Titov roared into space aboard Vostok II on 6 August and stayed aloft for 17 1/2 orbits. It was not until the following year that Astronaut John H. Glenn became the first American to orbit the Earth. Boosted by a modified Atlas ICBM, Friendship 7 lifted off from Cape Canaveral on 20 February 1962 and orbited the Earth three times before Glenn rode the capsule to splashdown and recovery in the Atlantic.
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[21] These and other manned flights proved that humans could safely travel and perform various tasks in the hostile environment of space. Over the next few years, both Russian and American manned programs improved and refined booster and spacecraft systems, including multicrew missions. The Russians again led the way in such missions with the flight Voshkod I in 1964 (a three-man crew), and a Russian cosmonaut recovery in the Aleksey Leonov performed the first "space walk" during the Voshkod II mission in 1965. The same year, NASA began its own series of two-man launches with the Gemini program. With a modified Titan II ICBM as the booster, the first Gemini mission blasted off from Cape Kennedy on 23 March 1965, and the Gemini program, which continued into the winter of 1966, included the first American space walks, as well as highly important rendezvous and docking techniques. The maneuvers required to bring two separate orbiting spacecraft to a point of rendezvous, followed by the docking maneuver, helped pave the way for more ambitious manned space missions. Plans for multimanned space stations and lunar exploration vehicles depended on these rendezvous and docking techniques, as well as the ability of astronauts to perform certain tasks outside the protected environment of the spacecraft itself. The successive flights of the Mercury-Redstone, Mercury-Atlas, and Gemini-Titan missions were progressive elements in a grand design to launch a circumlunar mission to the moon and return to the Earth.18
Against the background of Mercury and Gemini developments, work was already progressing on the Apollo-Saturn program. The spacecraft for the Apollo adventure evolved out of the Mercury and Gemini capsule hardware, and other research and development was directed toward new technology required for a lunar lander and associated systems. A parallel effort involved the development of an entirely different family of boosters. Heretofore, NASA had relied on existing boosters requisitioned from the armed services-the Redstone missile, along with Thor, Atlas, and Titan. For manned lunar missions, a rocket of unusual thrust and lifting capacity was called for-literally, a giant of a booster. During 1960, the von Braun team was transferred from ABMA to NASA, bringing not only its conceptual understanding of manned space flight (based on preliminary studies in 1957 and 1959) but also its acknowledged skills in the development of rockets. For manned missions, the von Braun team developed a totally different big booster-the Saturn.
