Communications Satellites - Key to World-Wide TV
March 1960 Popular Electronics
In 1960, futurists were predicting that within 10 years it would be possible to beam television signals between continents and directly into homes. It was the eve of Project Echo, which boosted a 100-foot-diameter inflatable metallized plastic ball into low Earth orbit to reflect signals efficiently back through the atmosphere. Engineers and scientists were already planning the next best thing - a satellite that not only reflected, but also amplified, possibly frequency converted, and would even steer signals that impinge upon it. Envisioned in this article is hundreds of satellites being available for relaying signals between all regions of the Earth on then-standard VHF channels. We now have successful satellite television systems, but they operate at Ku-band due to bandwidth requirements and need special converters to interface with a television.
March 1960 Popular Electronics
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Communications Satellites - Key to World-Wide TV
By Ken Gilmore
Early this spring, a powerful rocket will roar into space and eject a strange payload: a rumpled bundle of plastic that will within minutes puff itself into a shining sphere one hundred feet in diameter. As this weird space balloon soars through its orbit 1000 miles above the earth, thousands of radio signals will shoot skyward from ground stations, ricochet from the satellite's polished surface, and dive back to earth to be received thousands of miles from where they started. The experiment, run by the U. S. National Aeronautics and Space Administration (NASA), will be known as Project Echo.
A short time later - probably before summer - the U. S. Advanced Research Projects Agency (ARPA), which directs our military space program, will hurl a different kind of "talking satellite" into orbit. It will be much smaller than NASA's hundred-foot sphere, and packed with complex electronic equipment. As it glides over one continent, signals will flash from the earth to be received by the satellite and recorded on tiny magnetic tape recorders. A few minutes later and half a world away, it will play back the message to a ground listening station. This operation will be known as Project Courier.
Sooner than you thinkWhile Echo and Courier are the most comprehensive space communications projects planned to date, they are not alone. At least one talking moon is already in orbit; scores of others will soon be filling the air with electronic signals. Almost overnight, sooner than anyone believes possible, the age of satellite communications will begin.
-- probably within ten years -- satellites will make it possible for you to watch live TV programs from foreign countries.Balloon satellites
to be used in Project Echo are made of tough plastic film coated with a thin layer of aluminum. Entire satellite, including the firing container, weighs only 190 pounds. Balloon is inflated when sun's rays cause water inside it to turn into steam. Operation
of a "passive" satellite relay system - such as Project Echo - is diagrammed below. While signals are being bounced off satellite 1, the second antenna begins to track satellite 2, preparatory to switching from 1 to 2. Scientists calculate that 25 such "sky-mirrors" in orbit would give world-wide coverage. A "24·hour"
active satellite repeater like the one at left designed by Space Electronics would appear to hang suspended over one spot on the earth's surface. This satellite is basically similar to the one to be launched in early 1962 by ARPA, but it is much smaller, measuring only six to eight feet long, and weighing only 500 pounds. Solar cells would provide the power for relaying trans-Atlantic television, telephone, and teletype signals.
Space Timetable. Communications satellites will bring about profound changes in our everyday lives. These pioneering accomplishments are coming soon:
These are not just dreams. We have all the know-how and resources needed to accomplish everyone of these projects right now. A crash program to get the hardware into the sky has already started.
- Before another year goes by, television signals will probably have been transmitted back and forth across the Atlantic.
- By 1961, the Signal Corps will have enough Project Courier satellites in orbit to form a regular communications system between our far-flung military outposts around the globe. This system will be operational in 1961, not experimental.
- By early 1962, ARPA will have an electronic repeater satellite in orbit at an altitude of slightly over 22,000 miles. Termed a "24-hour" repeater, it will rotate at the same speed as the earth and will appear to hang over one spot on the earth's surface - probably the mid-Atlantic. The thrust rocket designed to hurl this five-ton moon into orbit is under construction.
- By 1962 or 1963, we will be watching live television from Europe.
- By 1970 - a short decade away - we will spin the dial and bring in hundreds of stations from all over the world. Bullfights from Spain, exotic dances from the South Seas, floor shows from Paris night spots - all will flood into our living rooms through the magic of satellite video.
Before 1980, there will probably be super communications satellites aloft, operated by crews who commute back and forth from earth by rocket. The illustration on page 41 pictures one of these advanced satellites which is already being designed by Radio Corporation of America.
Communicating with satellites. themselves is, of course, not new. (See "Telemetering - Vital Link to the Stars," POPULAR ELECTRONICS, Nov., 1959.) Every satellite launched by either the United States or Russia has maintained some kind of radio contact with earth. But this contact has been used only to control the satellite or to report on its operation to ground stations.
Now, we are beginning to use satellites as another link in our regular communications networks. Employed as relay stations a thousand miles or more above the earth, they will enable us to transmit radio, television, teletype, and other signals around the world far better than we could do it any other way.
Early Experiments. The age of space communications was born - by accident - in October, 1958. The scene was Cape Canaveral. As Pioneer I streaked skyward, headed for outer space, the ground station signaled the rocket to fire its next stage. But something went wrong. Repeated signals to fire somehow got channeled into the missile's transmitter and were relayed to half the world before the space vehicle destroyed itself.
A few months later, satellite communications of a more reliable type went into operation with the launching of Project Score. The most publicized feat of Score was the broadcasting of President Eisenhower's 1958 Christmas message to the world. But it performed a series of more valuable experiments as well.
As Score circled the earth, Signal Corps engineers sent aloft radio and teletype messages that were received and recorded by the satellite, then played back on command to other stations thousands of miles away. When ground stations were within two or three thousand miles of each other, the satellite relayed the message instantaneously, without recording it first.
Communications in which the satellite is a passive element and acts as a mirror, rather than as a relay station, have also been successful. The spent rocket case that propelled Score into orbit was used by RCA for successful "bounce" communications tests. In addition, signals have been bounced off the moon repeatedly in the last few years.
THE NECESSITY FOR SATELLITE COMMUNICATIONS
Ultra-high-frequency signals - the kind used for television - travel only in straight lines. They do not follow the curvature of the earth and therefore cannot be picked up more than a few miles from the transmitter. Even the 1000-foot towers now used by some television stations increase the maximum range to only a few hundred miles. But a satellite, since it can "see" a large part of the earth, would give vast coverage with u.h.f. signals.
Why must we use u.h.f.? Why not transmit TV by "short wave" - the kind used by some radio communications? The answer: there simply isn't room. A voice signal uses a very narrow channel, only a few thousand cycles wide. But television takes at least five million cycles.
Even if we forget television, we still have a serious problem. The volume of overseas communications has grown so rapidly that we are running out of channels. International Telephone and Telegraph Company estimates that the message load will be seven times as large in 1970 as it was in 1950. By 1963, all presently available channels will be jammed to capacity. The only answer is more channels, and the only ones still available are in the u.h.f. range. This means that satellite communications systems must be developed quickly.
Civilian Projects. Although various systems could be used in world-wide networks, most space experts feel the so-called "24-hour" active satellite repeater, (the type scheduled to be launched by ARPA in early 1962) offers the greatest promise. This advanced type may actually be the first to go into use for civilian TV. There is even some chance that a civilian-built active satellite repeater will be in orbit before ARPA's military version.
Dr. James C. Fletcher, president of Space Electronics, Inc., of Glendale, California, says there is no reason why such a satellite could not be in operation within two years. He estimates it would cost from $25,000,000 to $40,000,000. Dr. Henri G. Busignies, president of International Telephone and Telegraph Laboratories, says it might cost slightly more. But both men think it would pay its own way.
Forty or fifty million dollars may sound like a lot of money. But the recently completed Atlantic cable cost $40,000,000, and can only handle about 50 telephone conversations at one time. It cannot, under any circumstances, transmit a live television program. The satellite proposed by Space Electronics would carry 250 telephone conversations simultaneously - five times as many as the cable - or 125 telephone conversations and one television signal.
Although enthusiasts like Dr. Fletcher are ready to begin, the project now - efforts to round up financial backing are under way - other communications industry leaders feel that since NASA plans to fire a 24-hour satellite repeater in 1962, it would be better to wait and profit from this experiment. So the timetable for the launching of a space outpost for civilian TV is uncertain.
Looking to the Future. Exactly how will satellite communications affect our everyday lives? Imagine the year as being 1970 - just ten years away. Hundreds of satellites of every nationality are now soaring through the skies, pouring down torrents of information, entertainment, propaganda. You turn on the TV set and bring in the BBC or Moscow just as clearly as you received home-town stations back in 1960.
Since there are thousands of channels and since each has a potential audience of billions of people, it has now become practical to televise programs of interest to minorities - Greek drama, chess matches, lectures in differential calculus.
Asia and Africa have been flooded with inexpensive TV receivers, and Russian and U. S. satellites are engaged in a fierce ideological battle for uncommitted minds. (Long before the year 2000, the struggle to determine whether English or Russian becomes the world's dominant language will have been won or lost on this electronic battlefield.)
Mail is delivered anywhere on earth in less than a day. We write our letters on a special form. At the post office, the words are transformed into electronic signals which are transmitted via the mail satellite relay within a few millionths of a second. A high-speed printer on the other end turns the signals back into words, and the letter is delivered. The only delay is in getting it to and from the post office.
By 1980, the changes will be even more dramatic. Newspapers will be produced on demand in the home. All you will have to do is flip a switch on your facsimile printer and out will roll the sports page, the funnies, the news section, or any combination you select. You will have your own personal radio-telephone and you will be able to call any place on earth at a moment's notice. Most business conducted by personal contact back in 1960 will be handled over the video and facsimile channels in 1980. Of course, your telephone will have already been equipped with a TV screen for many years.
These wonders will begin to appear far earlier than most of us think. Everyone of the devices described above is already in use. Not one new invention or development will be needed to put any part of this system into operation.
Businesses all over the country, for example, now have their own facsimile systems which transmit letters, pictures, and plans instantaneously from one plant or office to another. Miniature radios which could be used in a world-wide paging system have already been built. Complete engineering plans and specifications have been drawn up for an intercontinental mail system using equipment which is already available.
The only new ingredient we need to make all of these miracles available is long-distance satellite communications - and we will have it soon.
Profound Significance. The impact of global radio and TV will be profound. It will mean not merely bigger and better entertainment, but it will change our civilization. Arthur C. Clarke -- the internationally recognized space expert - summed it up this way in an article in the September 1959 issue of Holiday magazine:
"Soon, the great highway of the ether will be thrown open to the whole world, and all men will become neighbors, whether they like it or not. Any form of censorship, political or otherwise, would be impossible; to jam signals coming down from the heavens is almost as difficult as blocking the light from the stars. The Russians could do nothing to stop their people from seeing how Americans live; on the other hand, Madison Avenue and blue-nose committees might be equally distressed - though for different reasons - at a nation-wide switch to uninhibited telecasts from Montmartre.
"No one can ever anticipate the full significance of any major invention; did Henry Ford dream that the very foundation of commerce, warfare, entertainment - yes, and morality - would be shaken by the automobile? And what radio and TV have done to our lives in the last decade merely hints at the revolution real telecommunications will bring 20 or 30 years from now.
"How mankind will cope with the avalanche of information and entertainment about to descend upon it from the skies, only the future can show."
One thing is sure, the sciences of rocketry and electronics have launched the human race into the age of space communications, and there's no turning back!