[Illustration: Satellite Communications Physics] Satellite Communications Physics BY MEMBERS OF THE STAFF OF BELL TELEPHONE LABORATORIES EDITOR: RONALD M. FOSTER, Jr. How scientists and engineers use basic physical principles to solve some of the problems in communicating by means of man-made satellites © 1963 Bell Telephone Laboratories, Incorporated All rights reserved. Permission to reproduce any material contained in this book must be obtained, in writing, from the publisher. Library of Congress Catalog Card Number 63-21667 Printed in U.S.A. Foreword John R. Pierce _Executive Director, Research, Communications Principles and Communications Systems Bell Telephone Laboratories_ When I first talked about the possibilities and advantages of communications satellites to the Princeton Section of the Institute of Radio Engineers on the evening of October 14, 1954, I was diligent in my analysis and enthusiastic in my presentation but, I must confess, a little skeptical as to whether or not anything would come of the idea. Still, others and I at Bell Laboratories remained interested, and, after the launching of Sputnik I on November 3, 1957, and of Explorer I on January 31, 1958, we worked actively toward satellite communications experiments. This led to our work with Echo I (launched August 12, 1960) and finally to the launching on July 10, 1962, of Telstar I—that satellite which became, in the words of Queen Elizabeth, “the invisible focus of a million eyes.” This work on communications satellites has been a grand exploration and opening up of a hitherto dark continent of science and technology. My courageous friends at Bell Laboratories encountered therein surprising difficulties and perplexing problems which I had never dreamed of, and these intrepid and indefatigable adventurers grappled with them and mastered them all. Now you, who have in your own homes seen pictures transmitted across the ocean by satellite, can learn first hand from the men who worked on hard and varied technical problems just what these problems were and how they were solved. And, by reading you can find out what sort of knowledge, training, and habits you yourself will need if you wish some day to adventure into those undiscovered or unexplored fields of technology which will be new and exciting when Telstar has become old hat. June 5, 1963 High School Science Teaching Aids Prepared by Bell Telephone Laboratories Classroom units including books, motion pictures, and demonstration devices: _Similarities in Wave Behavior_ _Ferromagnetic Domains_ _The Speech Chain_ Bell System Science Experiments for the advanced student: _From Sun to Sound_ _Solar Energy Experiment_ _Speech Synthesis_