The Earth is the cradle of mankind, but one cannot live forever in the cradle."" Prophetic comment made some seventy-five years ago by a Russian schoolteacher who could hardly have foreseen that an American president would spur his country to an appointment on the moon by 1970. Kennedy launched and deadlined America's space program and his high hopes seem to be on the verge of realization after some of the most dramatic frustrations and triumphs in the history of technology. Mr. Lewis does an excellent job detailing our efforts from post-World War II experimentation through inter-service squabbles to the ""Black Friday"" when our Sputnik successor went Kaputnik. Astronauts and astronomical feats are chronicles complete with taped recordings, earth to orbit. There are the new discoveries and their impact--from the Van Allen belt to craters on Mars. And there's the Apollo tragedy and its strange tie-up with Bobby Baker. It's hardly been all systems Go but the climax of the book fortunately comes at the end with the spectacular success of Saturn 5. It lifted off with such enthusiasm that the roof literally fell in on Walter Cronkite. And with it goes the hope that this fine history book is only the beginning.