“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.
There is a double reason for this. On the one hand, it is a technological target that is now clearly within our range. We must either reach it or let progress pass us by. Satellite communications is one field in which, as far as we know, American engineering and science have been well in the lead—so we have an even greater incentive to press on in this direction as hard and as fast as we can.
But perhaps more important than the prestige it would give our country is a second reason for our great interest in satellite communications: We need it. The world today is going through one of its great periods of change. This has caused many complications, and one of the most important is the need for much better communications between nations and peoples. By “communications” we mean all the various ways of sending information from one place to another: mail, telephone calls, business data, radio, television. The demand for these services—especially when we look ahead to the 1970’s and 1980’s—will be tremendous. Our international communications channels will be completely swamped unless some major improvements are made.
Fortunately, modern technology—given a boost by the world’s interest in rockets, missiles, and the exploration of space—has shown us one answer to this problem: the communications satellite. The conventional pathways for long-distance communication have led along the earth’s surface, under the oceans, and through the lower atmosphere. No one of these routes has yet provided all the capacity, speed, or quality we need. Present underseas cables have a limited capacity; surface travel by ship is too slow for anything but routine mail; short-wave radio is subject to distortion and noise, and the available frequencies are rapidly being used up. Although jet planes can span the oceans in a few hours with mail and such things as taped television shows, the big need will be to send information instantaneously. And the communications satellite offers us a very promising way to do this.
What a Communications Satellite Can Do
One of the attractive things about using a satellite is that it doesn’t require a revolutionary breakthrough in technical knowledge. It can employ a satisfactory means of communicating that is already available: the microwave radio relay. Today, this kind of transmission is used on a routine basis to send thousands of telephone calls and television programs across long distances. It gives high-quality performance and has a large message capacity. But there has always been one difficulty keeping us from using it for overseas communications: Extremely high frequency waves can travel almost unlimited distances, but they can go only in straight lines. This means that the curvature of the earth limits a microwave’s line-of-sight path to about 30 miles; so we must build a series of transmission relay towers spaced every 30 miles or so. Obviously, this isn’t possible when you send messages across an ocean. But, if we could find a way to send a signal high up into the sky and then bounce it from there back again to a far-off spot, we could send microwave messages great distances.
