SP-4206 Stages to Saturn




[xv] The gigantic Saturn V launch vehicle may well be the first and last of its kind. Subsequent space ventures will be based on new vehicles, such as the smaller, reusable Space Shuttle. Manned launches in the near future will be geared to orbital missions rather than planetary excursions, and unmanned deep-space missions will not demand the very high thrust boosters characteristic of the Apollo program. As the space program moves into the future, it also appears that the funding for elaborate "big booster" missions will not be forthcoming for NASA. The Saturn V class of launch vehicles are the end of the line of the Saturn generation. It is not likely that anything like them will ever be built again.

Because of the commanding drama of the awesome Saturn V, it is easy to forget the first Saturn-the Saturn I and Saturn IB. This history is an attempt to give due credit to these pioneering vehicles, to analyze the somewhat awkward origins of the Saturn I as a test bed for static testing only, not as an operational vehicle, and to discuss the uprated Saturn IB as an interim booster for the orbital testing of the first Apollo capsules. Evolution of the engines is also given considerable space early in the narrative. Because the Apollo-Saturn program was expected to put a man on the moon within a fixed time span, the use of available hardware was particularly attractive-an aspect of the program that is not generally appreciated by the public. The development of the early Saturn I and IB vehicles, as well as the engines, illustrates this approach. Inevitably, the unique nature of the mission called for advances in the state of the art, and the Saturn history includes some examples. One outstanding example is the development of high-energy liquid hydrogen engines. Other examples include the development of insulation for extended storage of large quantities of hydrogen in vehicle tanks and the advances in the computer technology of the guidance and control systems.

The development of Saturn was enormously expensive and time- consuming. Even given the expected costs of developments to advance the state of the art, why were the costs of the development time so great if [xvi] the program still relied so much on existing hardware? Part of the answer involves the uniqueness of dimensions. Even a proven component, to be used in the huge Saturn, had to be scaled up in size. The larger component had to withstand a similar increase in the amount of punishment inflicted on it, and this fact opened up a whole new regime of operational headaches. The scaling up of components and systems for lunar missions seemed to involve geometrical progressions rather than simple arithmetic progressions. The F-1 engines for the S-IC first stage graphically illustrate this difficulty. The size of the Saturn stages and engines also called for enlargement of test stands and other facilities, with attendant increases in time and costs. The logistical challenge assumed gargantuan proportions. The managers of the Apollo-Saturn programs also discovered unanticipated expenses in storing and maintaining exotic hardware that was subject to degradation unless constantly monitored, refurbished, and attended by additional cadres of technicians.

This book is a technological history. To many contemporaries the narrative may read too much like a technical manual, but the author's concern is for posterity, when the technical manuals may be lost or dispersed (as many are already) and knowledgeable participants have long since died. The narrative approach was largely predicated on questions that might well be asked by future generations: How were the Saturns made? How did they work? Two other histories, already published, deal with subjects keyed to the Apollo-Saturn program: (1) the development of the Apollo command and service modules along with the lunar module, and (2) the construction and operation of launch facilities at Cape Kennedy. These books contain much of the political and administrative struggles surrounding the origins and development of the Apollo program, and it would be redundant to retell the whole story for the Saturn history. I have therefore included only the background that seemed necessary to put the Saturn in proper perspective, and Part Two recapitulates the programmatic and administrative origins of Saturn. The bulk of the text is devoted to the theme of technological development. Even chapter 9, on management, is geared to the specifics of the technological management of Saturn vehicles.

The decision to treat the history of the Saturn program as a technological narrative shaped the nature of all sections of the book. So that some of the innovations and advances might be appreciated, it seemed advisable to include a brief historical overview of rocket technology. Against this background, I hope the Saturn story will stand out with greater clarity.

The narrative itself is organized into seven parts. The question was how to deal with the complexity of many simultaneous programs during the Saturn development that involved the various engines, stages, and associated equipment for three separate launch vehicles. A strict chronological organization seemed unnecessarily confusing. The topical approach, [xvii] although constructed in a loose chronological sequence, provided the opportunity to deal with the early technology involved in Saturn I and Saturn IB launch vehicles primarily in terms of the concept of clustering tanks and engines. The engines themselves, although they possessed inherent differences, evolved out of common principles of engine design and cryogenic technology. Dealing with these propulsion systems as a separate unit made the significance of their development stand out more clearly. Similarly, I analyzed the evolution of rocket stages as a unit and emphasized propellant tankage for the Saturn V vehicle. Although many early Saturn flights were concurrent with the research and development phases, all the launches are summarized in two chapters toward the end of the book. Just as the flights were the culmination of Apollo-Saturn, discussion of them all at the end of the narrative seemed logical.

The manned operations involving the spacecraft-the activities of the launch crews at liftoff-the role of the astronauts-these events involved discrete numbers of human actors. The inherent drama in launches and missions tended to spotlight the people involved. On the other hand, development of the Saturn launch vehicle rested on millions of hours of prior research and development and on thousands of designers, engineers, technicians, and specialists who worked behind the scenes. It was often impossible to single out a specific individual responsible for a specific achievement because most of the major decisions and breakthroughs resulted from elaborate team efforts. In fact, one veteran of the Marshall Space Flight Center told me that he preferred that the Saturn history not mention people at all. It was too hard, he explained, to isolate significant achievements without mentioning dozens of people who made successful contributions,

The launch vehicle, as dramatic as it was during liftoff, played a minor role in the total duration of a mission. It was visible to observers for only eight minutes or so as it blazed into orbit. The personnel of Houston's Mission Control and the astronaut crew occupied center stage for the lion's share of the lunar mission. For all the spectacular effects of the Saturn vehicle's awesome launch, most of the Saturn story deals with many years of unglamorous research, development, and test. It is a story of prior work: of nuts, bolts, and pyrotechnics-and that is the story I have tried to tell in these pages.


June 1979