The Promise of Space is written for the same intelligent laymen the author had in mind in The Exploration of Space (1951) "all those who are interested in the 'why' and 'how' of astronautics, yet do not wish to go into too many scientific details." Even the least scientifically inclined reader will be able to follow some of his history of space flight, his explanation of how one proceeds when there is "nothing to push against," his run-through of an Apollo mission or discussion of time dilation and the Theory of Relativity. Dr. Clarke eschews the military in his space probe (the moon may be of value for radio astronomy, as a colony, for example), accentuates the positive. "In the long run, the Comsat will be mightier than the ICBM." He bemuses with such thoughts as a million year trip to Proxima Centauri, or the fact that if there were an elevator to the moon, it would only cost ten dollars per passenger. Somehow he convinces that while the universe may be way out, it is also within reach. Publication is aimed to coincide with the release of the Clarke-Kubrick production, 2001: A Space Odyssey.