This astounding book retells the Apollo saga from a fresh perspective: that of young software engineer and “long-haired freak” Don Eyles, who was responsible for developing a significant portion of the Lunar Module code. Moon landing aficionados may think they know all about various close shaves involving the cutting edge technology, such as Apollo 11’s program alarms and Apollo 12’s SCE to AUX. Eyles’s intimate expertise with the ship’s computer sheds new light, for me at least, on exactly what caused those problems, what alternative hypotheses were being considered at the time, and how the eventual workarounds worked to solve the problem until it could be fixed in a future “rope”. The design of the Apollo Guidance Computer and the PGNCS operating system is at once fascinating and familiar. In it one can see the germs of modern computers and their operating systems, distilled to an essence limited by nascent technology and required by the laser focus of the mission.

This would be enough, but Eyles takes us to apogee by weaving in his experiences with 60s counterculture: music, drugs, protests, and free love. And beyond that, the sort of idealism that in part propelled the space program: that together, putting aside our differences, forsaking domination over others, we can achieve truly monumental things.

The writing is superb, and Eyles includes ample useful diagrams and illustrations that help with understanding the technical details.