There are a few books in my library that I like to go back to from time to time and this is one of them. It is a work of fiction but set against the background of real events. Beginning in the closing stages of World War Two it traces the development of the American space program through the eyes of four fictional families. It covers the engineering and scientific aspects very well but also the political. I found the characters believable and even more than 30 years after it was written it poses some interesting questions about space exploration and whether or not we should be doing it.