This sequel to Richard Feynman’s Surely Youâ€™re Joking covers some of the same ground as the prior book, though it is focused on the inquiry conducted after the Challenger space shuttle disaster. The book includes an appendix to that report, written by Feynman exclusively. Apparently, he was going to remove his name from the findings on account of his section being censored. Eventually, they printed something largely identical to his final copy.
As he explains it, the solid rocket booster failure that destroyed Challenger was largely the result of disjointed and poor communication between layers of administration at NASA and its supplier companies. The statistical modeling of the behaviour of the O-rings in the boosters was very poorly done. Information on the vulnerabilities of the shuttle either did not reach the most senior levels or was paid insufficient heed there. In any case, it seems likely that even if cold weather and design problems hadn’t caused this specific failure, something would have eventually gone wrong anyhow. For example, Feynman describes in detail some technical and procedural issues associated with the main engines. Such problems are not really surprising, given the overall complexity of the vehicle, the ‘top-down’ manner in which it was constructed (designing whole systems before testing individual components), and its fundamentally experimental nature. That being said, Feynman’s assessment probably has continuing relevance for other projects with similar associated risks and management structures. In particular, the contrast he draws between the strong protocols used in programming the shuttle’s computer – as compared with the protocols for sensors and engines – demonstrates that it is possible to do things well, provided sufficient attention and resources are devoted to the task.
Overall, the previous book is more entertaining and shows more of Feynman’s character. Aside from a section on Feynman’s first marriage, as well as the illness and death of his first wife, this book focuses on the details of Feynman’s investigation, including his famous demonstration with the O-ring and glass of ice water. All told, I found the earlier book more diverse and interesting. This book may be more useful for those whose professional work involves dangerous machines.