Now, a word of caution. In Part I, in talking about satellite communications in general, we have kept things at a level that should be understandable to almost everyone—even those who have never taken a high school science course. But we warn you this isn’t true of Part II. Our authors have tried to tell their stories as carefully and as logically as possible, but some readers may have trouble in following all they say. This we expect. We haven’t tried to sugar-coat or gloss over any essential details of the problems or their solutions. We don’t want you to think that solving them was any easier than it actually was. And, since this is not intended as a textbook, we may sometimes omit elementary material and go right to the heart of the matter. When this book was written satellite communications was still a technological infant. It is growing and changing so swiftly that much of what we say may soon be out of date. That can’t be helped, of course, and we ask you—who may be reading it long afterward—to be tolerant. Our problems may well be forgotten when new, more sophisticated ones appear. But we are dealing here in methods, not in history; the ways in which these problems were attacked are just as lasting and important as the problems themselves. part 1 Satellite Communications [Illustration: Title image] “_Our intensive research and development in the field of communications satellites have brought us to the point where we are now certain of the technical feasibility of transmitting messages to any part of the world by directing them to satellites.... The actual operation of such a system would provide a dramatic demonstration of our leadership in this area of space activity.... The direct benefits—economic, educational, and political—of this improved world-wide communication will be invaluable_.” —JOHN F. KENNEDY Why Do We Bother With Satellite Communications? That’s a good question to begin with. Why should we get involved in a vast, complicated program such as communication by means of man-made satellites? Is the end result really worth all the trouble that is involved? As you go further, you will see that nothing to do with satellite communications is as simple as it first seems. Even some of the easier questions have been answered only after long hours of perceptive thinking, ingenious experimenting, and shrewd deduction. They have required a lot of hard work, led to many frustrating difficulties, and cost quite a bit of money. But the answer still is yes. Despite all the difficulties, it is clear that the creation of a successful satellite communicating system is worth it.