Project Orion by George Dyson

An amazing book about engineering unleashed in the heady days of nuclear successes. A story about how the possible almost becomes the actual and in retrospect seems unbelievable. A giant spaceship powered by nuclear bombs going off each second raising a ship the size of a small town at unbelievable speed leaving a trail of fallout behind. As a thought experiment it perhaps is the father of plasma propulsion and other out-of-the-box thinking. In any case an interesting book.