Reviewed by: Assured Access: A History of the US Air Force Space Launch Enterprise, 1945–2020 by David N. Spires Michael W. Hankins (bio) Assured Access: A History of the US Air Force Space Launch Enterprise, 1945–2020 By David N. Spires. Maxwell Air Force Base: Air University Press, 2022. Pp. 505. The establishment of the United States Space Force in December 2019 initiated a wide public discourse on the militarization of space. What much of that discourse failed to acknowledge was that space had been militarized long before the popular crewed space programs of the 1960s. This history of U.S. Air Force (USAF) involvement in space is the subject of Assured Access, the latest work from David Spires, who has previously published several books documenting the service's activities in the final frontier. Based almost entirely on secondary sources, Assured Access offers little new information but does present a useful single-volume overview of the evolution of USAF space launch capabilities over a broad timespan. Spires traces how the USAF's quest to control the space domain in the years immediately after World War II brought it into sharp rivalry with the U.S. Army and Navy and, later, the National Aeronautics and Space Administration (NASA). Readers who may not be familiar with the level of Defense Department participation in NASA programs—for example, the heavy influence the Air Force had on the space shuttle's design—will find Spires's coverage excellent. The key turning point in Spires's narrative is the 1986 Challenger explosion, in which seven astronauts tragically lost their lives. This event caused the USAF to focus on its own fleet of Evolved Expendable Launch Vehicles built by United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing. ULA soon had competition from companies such as SpaceX and Blue Origin, as the USAF sought "on demand" launches to lift payloads into orbit with increasingly short timeframes. One of the book's major themes is the USAF's reluctance to make major investments in the space domain. "Air Force leaders were less than enthusiastic about human spaceflight and frequently ambivalent about space in general" (p. 215), Spires says of the space shuttle era. This ambivalence continued into the twenty-first century, as Spires describes how the U.S. Space Force was created largely because Congress became frustrated with "Air Force stewardship of space and what they [Congress] perceived as the secondary role of space in a service dominated by air interests" (p. 350). Spires argues [End Page 629] that events such as the creation of the space shuttle program and the Space Force were powerful motivators in spurring the USAF to action in space and that the service has achieved its goals there. Published by the Air Force, Assured Access has some of the limitations common to institutional histories. Specifically, there is little historical argument present. There is also an almost exclusive focus on hardware, and the text often resorts to lengthy lists of specifications of particular systems. Broader connections to culture and society are mostly unexplored. This is not meant as a criticism: Spires's approach presents a valuable resource for collecting detailed specifications in one volume, and the fact that Air University Press offers the book as a free, searchable PDF adds to its usefulness. What is missing from the book is a clearer explanation of what the Air Force was trying to accomplish in space operationally. Spires frequently describes the purpose of these launches as "classified reconnaissance" missions with no elaboration. In fairness, some of the more recent programs might still be classified. Still, the reader is left with little idea of what all these Air Force satellites were doing and how their missions related to broader Air Force operations. Also, little mention is made of the Soviet and Chinese space efforts, some of which undoubtedly influenced USAF decision-making. These critiques do not detract from the value of Spires's work as a resource for contextualizing the evolution of Air Force space capabilities throughout the Cold War and beyond. Assured Access deserves a place on the shelves, or, as it were, in the browser bookmarks lists, of historians of...