Chief engineer Thomas J. Kelly gives a firsthand account of designing, building, testing, and flying the Apollo lunar module. It was, he writes, "an aerospace engineer's dream job of the century." Kelly's account begins with the imaginative process of sketching solutions to a host of technical challenges with an emphasis on safety, reliability, and maintainability. He catalogs numerous test failures, including propulsion-system leaks, ascent-engine instability, stress corrosion of the aluminum alloy parts, and battery problems, as well as their fixes under the ever-present constraints of...