Simulating Apollo: Flight Simulation Technology 1945-1975

Abstract

This dissertation examines how flight simulation technology rapidly evolved in the post-World War II period, enabling new regimes of aircraft and missile flight, and eventually becoming “the very heart and soul of the NASA system” during the Apollo program. At the intersection of automatic control systems, stability and control, and analog computing, aeronautical engineers developed simulators that functioned as “a fictious airplane in the electrical realm,” permitting real-time solution of the dynamic equations of motion governing flight vehicles. The aeronautical engineering profession transitioned from a focus on wind tunnels to the use of computer simulation to model flight vehicle performance for both aircraft and spacecraft, enabling the achievement of “faster, farther, and higher” flight domains in the Cold War.

Flight simulation became a foundational capability permitting engineers to explore design options, test algorithms, and exhaustively validate software in a purely virtual world, or in a hybrid virtual and physical world well before the airplanes and spacecraft they were designing first experienced flight. This dissertation focuses on the creators of the new technology of simulation – the engineers, the test pilots, the astronauts, the flight controllers – who utilized the new capability of simulation as prediction machines to design flight vehicles and anticipate how they will perform increasingly complex missions. This dissertation explores the influence of institutions, engineering cultures, and patrons in shaping the new technology of flight simulation. The Apollo mission simulations created an artificial reality with extremely high fidelity such that it became the lens through which astronauts and flight controllers would experience the actual lunar missions. The detailed choreography of the Apollo missions, instantiated in software, procedures, checklists, flight plans, and mission rules, was refined through extensive simulations.

The Apollo simulations precisely orchestrated how future spaceflights would be conducted, creating an artificial reality of a future historical event. This dissertation explores how the presence of the human operator ultimately shaped the question of what constitutes realism and simulation, and who gets to decide. As NASA prepares to return to the moon, the astronauts who will fly Artemis will face many of the same challenges that the Apollo astronauts faced in determining what constitutes realism in simulating their lunar landing. However, the presence of new actors, driven by goals related to privatization, commercialization and proprietary technology could change this outcome in a society that is still grappling with boundaries between real and virtual flight.