The Development of Propulsion Technology for U.S. Space-Launch Vehicles, 1926–1991 (review)

On 26 March 1926, Robert H. Goddard launched the world’s first liquidfueled rocket in Auburn, Massachusetts. His pioneering work, along with other lines of effort in rocket development in the United States and Germany, grew after World War II into a large enterprise of missile development by the military services, and then that of space transportation by the National Aeronautics and Space Administration. Now at the fiftieth anniversary of NASA, we have at hand detailed historical accounts of many important projects. The relationships between those individual projects had not yet been examined, however. Here, J. D. Hunley seeks to draw a comprehensive picture of the evolution of rocket technology in the United States.

The first two chapters provide a reliable and balanced account of the development of all major space-launch vehicles, military and civilian, flown up to 1991. Chapter 1 traces the increase in the size, power, and sophistication of mostly military rockets from the prewar period to 1966, while chapter 2 covers civilian launch vehicles after 1958, such as Thor-Delta, Saturn, and the space shuttle. The rest of the book goes deep into details of the evolution of specific propulsion technologies: with alcohol and kerosene fuels, with storable fuels and oxidizers, with liquid hydrogen and oxygen, and with solid fuels. Hunley follows each of these lineages of technological evolution, taking up one relevant project after another across the entire times pan of the book. He focuses on the technology of propulsion rather than that of structures or guidance/control because he believes that propulsion is “arguably more fundamental” than other engineering fields pertaining to rocket development (p. 3).

The central question Hunley poses is: “What allowed the United States to proceed so quickly from the comparatively primitive rocket technology of 1955 to almost routine access to space in the 1980s?” (p. 1). This question might sound ill-conceived to those who consider that the actual technological advance in this period fell short of initial public expectations. Be that as it may, in answering this question Hunley highlights a new factor in the history of American space programs. While recognizing the cold war as the fundamental driving force of technological development, Hunley also argues that “an innovative and flexible engineering culture that brought together a variety of talents and disciplines in a large number of organizations spanning the nation” was critical for the evolution of rocket technology in the United States (p. 4). In such a culture, effective technology transfer and cooperation among different organizations took place. For example, part of the navy’s Vanguard launch vehicle was used in the air force’s Thor-Able launch vehicle, which in turn evolved into the Delta launch vehicle of NASA. Federal organizations facilitated technological transfer in general by often precluding manufacturers from withholding innovations developed under federal contracts. More important, engineering skills and knowledge traveled when engineers moved among organizations. Also, organizations such as the Chemical Propulsion Information Agency arranged for information-sharing among the three services and NASA. Hunley notes that both interservice competition and interservice/ interagency cooperation spurred innovations in this field.

Another of Hunley’s central arguments is that rocketry was not so much science as engineering. He provides lots of evidence. Engineers constantly solved problems that were out of the reach of contemporary scientific knowledge. For example, in rocket development, scaling-up itself often posed difficult problems which only informed trial-and-error could solve. Though Hunley argues this point very clearly, it likely would not surprise historians of technology.

This book is based on Hunley’s total mastery of the literature in relevant fields. Both primary and secondary sources are so vast that integrating and synthesizing them is no small feat. Moreover, as Hunley points out, the sources are often inconsistent. Thanks to Hunley’s critical examination of the sources, this book will be a valuable reference for historians of American space programs...