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Stages to Saturn: A Technological History of the Apollo/Saturn Launch Vehicles
by Roger E. Bilstein

Essential reading for anyone seeking to understand the development of space flight in America and the course of modern technology, this reprint edition includes a new preface by the author providing a 21st-century perspective on the historic importance of the Saturn project.

Read the complete table of contents, preface and an eleven page excerpt from chapter two.

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The Saturn Building Blocks

The original impetus for Saturn envisioned a brawny booster to launch Department of Defense payloads. The von Braun team at the Army Ballistic Missile Agency (ABMA) received money from the Department of Defense's Advanced Research Projects Agency to demonstrate the concept. Furthermore, von Braun's group eventually became the nucleus of NASA's Marshall Space Flight Center (MSFC.) These convolutions and the vague outlines of evolving Saturn vehicle technology constitute the themes of chapter 2.

The Saturn program eventually included three basic vehicles: Saturn I, Saturn IB, and Saturn V. Chapter 3 describes the events that led to these three separate rockets, whose configuration evolved out of the choice to go to the moon b means of the lunar orbit rendezvous technique. MSFC began development of facilities to develop and test the mammoth boosters. Chapter 3 concludes with a discussion of the design and manufacture of lower-stage boosters for the Saturn I and Saturn IB.


Aerospace Alphabet: AMBA, ARPA, MSFC

In November 1956, when the Air Force finally triumphed over the Army and Navy for leadership in long-range military rockets, planners at ABMA momentarily regrouped to plot a new direction, a strategy for large booster development geared instead to the exploration of space. Having lost round one to the Air Force, ABMA's stratagem was to leapfrog onward and upward to a quantum jump .

In April 1957, ABMA began design studies on an advanced booster concept. With a total thrust of approximately 6 800 000 newtons (1.5 million pounds) in the first stage alone, the proposed vehicle was referred to as the Super-Jupiter. The impetus for the development of a Super-Jupiter class apparently evolved from Department of Defense plans for "certain advanced missions using space devices in communication," as well as space probes and weather satellites. However, such payloads, especially satellite programs, required a booster much larger than existing launch vehicles. The Department of Defense guidelines called for a launch vehicle capable of putting 9000 to 18 000 kilograms into Earth orbit or accelerating space probes of 2700 to 5400 kilograms to escape velocity. At that time, ABMA estimated that satellite carriers on order, such as Thor, Juno II, and Atlas, could be expected to put up to 1400 kilograms into orbit. This capability might be increased to 4500 kilograms with high-energy propellants in upper stages. However, these boosters, with conventional propellants, would not be available for at least two years. The high-energy versions would not be operational until 1961 or 1962. Given the urgency of Department of Defense requirements for large payloads, a new class of booster and associated equipment had to be developed in a very short time, while keeping costs within low DOD limitations.

ARPA's Big Booster

Early design and cost studies a ABMA suggested the possibility of using a single engine of 4 450 000 newtons (1 million pounds) of thrust, for which Rocketdyne Division of North American had made a feasibility study for the Air Force. Although this was an "Air Force engine," no other large propulsion system existed. The F-1 engine seemed unlikely to each the point of full-scale testing for at least two years-too late to meet the accelerated booster development program of the Department of Defense. In any case, a booster with 6 700 000 newtons (1.5 million pounds) of thrust was needed, so the ABMA planning staff gave up on the simplicity of one large engine and turned to a combination of four smaller ones.

Rocketdyne also had a project under way for a 1 600 000-to 1 690 000-newton (360 000- to 380 000-pound) thrust engine known as the E-1. Proposals for the four-engine booster involved the use of what once ABMA official called "off-the-shelf tankage" (presumably a single large-diameter booster propellant tank from the existing stable of military missiles) with the four E-1 engines in a cluster underneath it. This version of Super-Jupiter was closely analyzed by ABMA and technical experts from North American, and a number upper-stage configurations were suggested. ABMA was by now certain that the clustering of engines was the most feasible route to attain quickly the Department of Defense goal of a 6 700 000 newton (1.5-million pounds) first-stage booster. In December 1957, ABMA delivered its proposal to the Department of Defense: "A National Integrated Missile and Space Vehicle Development Program." The document affirmed the clustered engine mode as a shortcut method to achieve large payload capability in the least amount of time .

Nevertheless, Super-Jupiter still remained a feasibility study, existing only on paper and within the fertile imaginations of von Braun and his group at Huntsville. The Department of Defense had its stated requirements for payloads of many tons, and ABMA had its proposals for possible booster configurations, but there was still no priority or money to get the Super-Jupiter past the level of paperwork. The immediate catalyst came in the form of a new Department of Defense organization whose high-priority recommendations cut through layers of red tape and allocated dollars for converting studies into hardware-the Advanced Research Projects Agency (ARPA).

During the turbulent months of late 1957 and early 1958, the Eisenhower administration wrestled with the challenges posed by Sputnik I, the abortive launches of Vanguard, and the last ditch mission of Explorer I. A long-term, reasoned, and integrated space program called for some informed and firm decisions. In February, President Eisenhower chartered a special committee under the guidance of Dr. J. R. Killian to study the issues and make recommendations for a national space program. As the Killian committee convened, the Department of Defense moved on its own to rationalize space research involving the armed services. On 7 February 1958, ARPA was formally established by Secretary of Defense Neil H. McElroy, and after part-time guidance through most of two months, Roy W. Johnson became the new agency's director on 1 April. Johnson, a graduate of the University of Michigan, had been executive vice-president at General Electric. There was no doubt that Johnson had extensive authority: he reported directly to the Secretary of Defense. The influence of ARPA became evident when William M. Holaday, Director of Guided Missiles in the Department of Defense, received orders to transfer some of his activities to the new agency. Johnson insisted on running ARPA as a mechanism for establishing goals and coordinating research efforts, as opposed to active R&D work and management of contracts. ARPA made top decisions and allocated the money, giving full rein to whatever organization was nominated to run a project. ARPA remained a small, tightly-knit organization, numbering about 80 people "including the girls (in the office)," as Johnson put it, and drew the core of its technical staff from specialists in the Army, Navy, and Air Force.

Through the spring of 1958, ARPA began to get its own organization in line while ABMA continued its preliminary studies for the Super-Jupiter with E-1 engines. Then in July, ARPA began to show more specific interest in the huge 6 700 000-newton (1.5-million pound) booster but argued for the use of available engine hardware, as opposed to the still untried E-1 propulsion systems. ARPA's line of reasoning was tied to its objective of developing the big booster in the shortest amount of time and doing the job within a framework of limited funds. The von Braun group in Huntsville possessed considerable experience with the engines for its own Jupiter series of rockets, and so a new cluster, with eight Jupiter engines instead of four E-1 types, began to evolve. Even though no formal agreements existed as yet between ARPA and ABMA, the close working relationship between the two organizations was evident in the name chosen for the new eight-engine booster. Known as Juno V, the designation followed ABMA's prior conceptual studies for advanced Juno III and Juno IV multistage rockets. By using off-the-shelf hardware, including the engines, it was estimated that Juno V, compared with the Super-Jupiter with E-1 engines, would save about $60 million and as much a two years research and development time.

With such preliminaries out of the way, ARPA issued more specific instructions to ABMA, granting authority and authorizing funds for the Juno V. ARPA Order Number 14-59, dated 15 August 1958, clarified the discussions of the previous weeks:

Initiate a development program to provide a large space vehicle booster of approximately 1 500 000-lb. (6 700 000 newton) thrust based on a cluster of available rocket engines. The immediate goal of this program is to demonstrate a full-scale captive dynamic firing by the end of CY 1959.

This was a historic document, for it committed money and engaged the von Braun team at Huntsville in an effort they had long dreamed about. Juno V became the progenitor of a new family of launch vehicles that would be used in the nation's future space program. As von Braun himself put it, "Juno V was, in fact, an infant Saturn."

Indeed, during this early period the Saturn designation was frequently used by von Braun and others inside ABMA. A new name seemed appropriate, because Saturn was seen as a distinct break from the Juno series-a new breed of launch vehicle that would see an active lifetime of a decade or more. "The SATURN," observed one ABMA report, "is considered to be the first real space vehicle as the Douglas DC-3 was the first real airliner and durable work-horse in aeronautics." In the autumn of 1958, however, the full development of the Saturn was only beginning. As two engineers from Huntsville commented, "The state of the art at this time classified the Saturn booster as almost impossibly complex."

The decision not to use the E-1 engines and to go to off-the-shelf hardware did not catch ABMA personnel flatfooted. Technicians and engineers at Huntsville were already working on propulsion systems related to the Jupiter to increase thrust, simplify operation, and improve overall mechanical and other systems. This work gave the engine development an important momentum early in the game and encouraged ABMA's optimism when ARPA requested a program for static firing a multiple engine cluster within 18 months, while operating on a shoestring budget. Still, "it was not easy," Willy Mrazek, one of the top ABMA planners, mused years later. One of the problems involved the engine manufacturer. When ABMA contacted Rocketdyne and laid out the program, company officials were intrigued by the big cluster idea but protested that the dollar allocation simply could not stretch far enough to finance the rebuilding and testing of engines and spares for the size of and even a little "arm twisting," as Mrazek recalled, the von Braun group convinced Rocketdyne to take the plunge, including the authorization for the company to glean hardware from their stockrooms that was left over from prior manufacturing and development programs sponsored by the government. By 11 September 1958, Rocketdyne had signed a contract with ABMA to uprate the original Thor-Jupiter engine, known as the S-3D propulsion system, creating a unit suitably modified to operate in the cluster configuration. The new engine was called the H-1, and ABMA signed away half of its available funds to get it.

With the money they had left, ABMA went to work in Huntsville to decide how to allocate their scarce dollars for oversized test stands and to define the configuration of the tankage. An early decision was made to modify and existing test stand "out in our backyard," as Mrazek phrased it, keeping in mind that, although it had been designed to take Army missiles like the Jupiter 2.67-meter-diameter tank and a thrust of 734 000 newons (165 000 pounds) the test stand had to be reworked to take a "monster" that was 24 meters high, 6 meters in diameter, and bhuilt to put out a thrust of almost 6 700 000 newtons (1.5 million pounds). The lean budget also had to cover a miscellany of items such as tooling to fabricate the oversized tanks and development of a thrust structure to take the maximum force of eight engines firing together at full throttle. There was also the need for oversized assembly jigs for manufacturing and checkout of the big new booster and for the costs of getting all the materials and the manpower to put the thing together. Like Rocketdyne, ABMA found that short funds made a virtue of scrounging in the dark corners of warehouses and stockrooms and put a premium on imaginative shortcuts.

Because ARPA Order Number 14-59 called only for a static demonstration in the test stand, non a flight-configured launch vehicle, the booster that began to take shape on the Redstone Arsenal drawing boards and in the shops was definitely a bargain-basement and patch-work affair. The volume of the tankage posed a special problem. The fabrication and welding of a single 6-meter-diameter tank, with separate compartments for fuel and oxidizer, meant new techniques and working jigs. Consumption of time and money threatened to become exorbitant. A different approach to the problem evolved, and existing tanks were used instead. From its own earlier production runs, ABMA located partial rejects and incomplete 1.78-meter tanks from the Redstone and 2.67-meeter tanks from the Jupiter missiles. Since the engines were going to be clustered, why not the tanks? "The dire need made us more inventive," Mrazek pointed out, "and we bundled the containers to be loaded with propellants." So the vaunted big booster emerged from the drawing boards as a weird compromise of eight separate 1.78-meter Redstone tanks surrounding a s2.67-meter Jupiter tank. It did not look exactly like a smooth, streamlined futuristic vehicle for the exploration of space, nor was it intended to be. Designed solely to see if a blockbuster of a rocket could run its eight engines in concert, ABMA was satisfied with its awkward-looking compromise.

While the work in Huntsville progressed, representatives from ARPA kept a close watch on the proceedings and made frequent visits to Redstone Arsenal. They increasingly liked what they saw. So much so, in fact, that they decided to propose a series of test flights. On 23 September 1958, ARPA and the Army Ordinance Missile Command (AOMC) drew up and additional memorandum of agreement enlarging the scope of the booster program. Signed by Major General J. B. Medaris for AOMC and Roy Johnson for ARPA, the joint memorandum stated: "In addition to the captive dynamic firing…, it is hereby agreed that this program should now be extended to provide for a propulsion flight test of this booster by approximately September 1960." Further, the von Braun group was called on to produce three additional boosters, the last two of which would be "capable of placing limited payloads into orbit." Along with the new scheme came much needed funds. ABMA could now count on $13.4 million in FY 1959 and $20.3 million in FY 1960 for the captive firing test and first launch, in addition to $8.6 million in the same period for development of appropriate facilities. For the three additional flights by 1961, ABMA would receive as much as $25 million to $30 million.

The decision to make the Juno V into a flight vehicle added new dimensions to planning problems. First, a launch site had to be selected. Moreover, the size of the booster posed unique transportation problems. As long as the launch location remained undermined (possibly a remote site in the Pacific), ABMA planned to dismantle the entire booster and airlift the components separately, a concept that would be possible because of the use of individual propellant tanks, engines, and associated structural modules. Still, the Juno V engineering team was never quite sure the dismantling and rebuilding scheme would work effectively. "Thank goodness," Mrazek admitted, "we never had to disassemble the first flight vehicle." In the end, it was agreed to launch from the Atlantic Missile Range at Cape Canaveral, and ABMA worked out a more feasible method of transporting its launch vehicles intact by relying on water routes.


While ARPA proceeded to hammer out a program for booster development, a number of government committees were at work, attempting to clarify overall priorities for a national space program. On the heels of Sputnik, Senator Lyndon B. Johnson began probing the status of America's national security and the space program through hearings of the Senate Preparedness Investigation Subcommittee of the Senate Armed Forces Committee. As chairman of the subcommittee, Johnson kicked off the hearings on 25 November 1957. The National Advisory Committee for Aeronautics (NACA) was gearing up its own studies about the same time, and the White House also had a high-powered study in progress-the Killian committee, directed by President Eisenhower's recently appointed Special Assistant for Science and Technology, James R. Killian. The subcommittees of Killian's group reporting early in 1958 evidently had the most influence in shaping the Administration's approach. Even though the committee reports were shot through with overtones of national security and the notion of a space race with the Russians, Administration officials generally agreed that proposals for a new space agency should result in an organization that was essentially nonmilitary. Because of its civil heritage, existing programs, and general programs, NACA was singled out as the most likely candidate to form the nucleus, though a new name was recommended. Strictly military programs would continue under the Department of Defense.

During April 1958, Eisenhower delivered the formal executive message about the national space program to Congress and submitted the Administration's bill to create what was then called the "National Aeronautics and Space Agency." The hearings and committee work that followed inevitably entailed revisions and rewording, but the idea of a civilian space agency persisted, and the old NACA role of research alone began to change to a new context of large-scale development, management, and operations. Congress passed the National Aeronautics and Space Act of 1958 on 16 July, and Eisenhower signed the bill into law on the 29th. During August, the Senate speedily confirmed Eisenhower's nominations of T. Keith Glennan as Administrator and Hugh Dryden as Deputy Administrator. At the time of his appointment, Glennan was president of Case Institute of Technology and had been a member of the Atomic Energy Commission. Dryden, a career civil servant, had been Director of NACA but was passed over as the new chief of NASA. The subsequent days and months included jockeying and horse trading to establish the principal directives of the new organization.

When the Space Act was signed, no mention was made as to the management of a program for manner space flight, and the Army, Navy, and Air Force continued to maneuver for position until late August, when Eisenhower specifically designated NASA as the agency to conduct manned space flight programs. In September, NASA's new Administrator, T. Keith Glennan, and Roy Johnson of ARPA agreed to cooperate in the development of a manned satellite. NASA's effective date of birth was 1 October 1958. The employees who left their NACA offices Tuesday evening, 30 September, returned to the same offices Wednesday morning as personnel of the National Aeronautics and Space Administration. With the passage of time, ARPA's entire big-booster program would find a niche in the new organization. These were bold plans, and neither the old NACA nor the new NASA possessed an existing capability for the job. Glennan wanted ABMA's von Braun team for its abilities in launch vehicles and the Jet Propulsion Laboratory (a major Army contractor) for its general expertise in astronautical engineering and payload development. NASA had to accept a compromise: the space agency got the Jet Propulsion Laboraty (officially transferred on 3 December 1958), but ABMA's missile team stayed in the Army. ABMA and its big booster were, however, already enmeshed in NASA planning, and it was only a matter of time before assimilation was complete.

NACA, for its part, had already been speculating about its role in the space program, and several committees had been at work in late 1957 and early 1958 studying the various factors a space program entailed: vehicles; reentry; range, launch, and tracking; instrumentation; space surveillance; human factors; and training. Late in March 1958, a NACA group studying "Suggestions for a Space Program" included notations for a launch program in January 1959 to put satellites of 135,000 to 225,000 kilograms in orbit (reflecting the earlier Department of Defense plans) and development of a rocket of 4,450,000 newtons (1 million pounds) thrust, as well as "development of hydrogen fluorine and other special rockets for second and third stages."

The ABMA large booster program first entered NASA planning through the NACA Special Committee on Space Technology chaired by Guyford Stever. The Working Group of Vehicular Program included tee made its final report on 28 October, when NASA was already a month old. Von Braun's working group on vehicles had already made its preliminary report on 18 July. The language did not differ much from that of the final draft. The report began with harsh criticism of duplication of effort and lack of coordination among various organizations working on the nation's space programs. "The record shows emphatically," the report said, that the Soviet Union was definitely ahead of the United States in space travel and space warfare.

How was the United States to catch up? There were several existing vehicle systems to help the United States proceed on a logical and consistent space research program. At least two large booster types under development or in the planning stages would place the Americans in a better position. The von Braun paper described five generations of boosters. First was the Vanguard class of launch vehicles, and second were the Juno and Thor IRBM vehicles. Third were the Titan and Atlas boosters from the ICBM inventory. Fourth came the clustered boosters, which would yield up to 6 700 000 newtons (1.5 million pounds) of thrust. Fifth, and last, was the possibility of using an advanced 6 700 000 newton (1.5-million-pound) thrust single-barrel engine in a cluster of two to four engines to give up to 25 000 000 newtons (6 million pounds) of thrust. How were they to be employed? The working group conjectured that the United States might put into operation a four-man space station in 1961 with the use of ICBM boosters. By using clustered boosters, with first flights beginning in 1961, the committee estimated a manned lunar landing in 1965-1966. The clustered vehicles would also support the deployment of a 50-man space station in 1967, and the fifth generation of boosters would support sizable moon exploration expeditions in 1972, set up a permanent moon base in 1973-1974, and launch manner interplanetary trips in 1977. "The milestones listed… are considered feasible and obtainable as indicated by the supporting information presented in the body of the report," the working group concluded.

The recommendations to achieve these goals included NASA's rapid development as the major director and coordinator of the vehicle program, working in partnership with ARPA. "The immediate initiation of a development program for a large booster, in the 1.5 million pound [6 700 000 newton] thrust class, is considered key to the success of the proposed program," the report stated, and urged the development of such an engine. The program would cost about $17.21 billion to pay for 1823 launches, including the as-yet undeveloped ICBM and clustered boosters. There would be considerable savings, the group noted, if a comprehensive booster recovery scheme were incorporated.

With von Braun representing ABMA on the Stever committee, his presence marked an early meshing of ABMA and NACA in the nation's space programs. Indeed, the Stever committee was intended to fill in the gaps in NACA space technology. NACA officials James Doolittle, Dryden, and Stever selected committee members with an eye to their future roles in the space programs as well as educating NACA personnel in space R&D. Large rocket boosters certainly constituted a big gap in NACA competence, so that the selection of von Braun was a key move, along with Sam Hoffman of Rockeydyne, Abe Hyatt of the Office of Naval Research, and Colonel Normal Appold, representing Air Force General Bernard Schriever, who spearheaded the development of big rockets in the Air Force.

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