Notes: - First published in 1958. - This completely revised edition published by William Luscombe Publisher Limited in 1974. - 32 black-and-white photographs, listed and credited in the beginning. - ''Preface to the Second Edition'' dated ''Colombo, / Sri Lanka, / 1974.'' - 26 chapters (including Introduction), Epilogue, Acknowledgements and Index. - In comparison with the 1958 edition: Chapters 1-22 only slightly updated; Chapter 23 completely rewritten, Chapters 24-25 newly written. - Photo of Clarke with the Intelsat 4 communication satellite on the back flap of the dustjacket; No. 24 inside the book. - Photo of the Telstar satellite on the back cover. - Front cover: ''Microwaves sent via orbitting satellite can travel vast distances / Photo courtesy of Bell Laboratories''