The midday gazette Friday 30 June 1967

HOW WE WILL LIVE IN THE TWO THOUSAND

We will keep the luminaire in our pockets to communicate with whoever we want to communicate with

It will be no bigger than a packet of cigarettes and will work together as a teleselector and amplifier - 
Many traditional types of transmission have been condemned to disappear since the use of artificial satellites and lasers revolutionised telecommunications - 
Interview with Professor Carlo Matteini

Only ten years have passed since the launch of the first artificial satellite, Sputnik 1, which stunned the world in October 1957. And yet, in such a short time, countless discoveries, some unexpected and some taken for granted, have ended up giving an extraordinary rhythm to peaceful space exploration activities.
Astronautical technology, also because of the progressive and logical expansion of space research, has set out on a path of increasingly valid contributions to the development of geophysical sciences and of incalculable contributions to immediate applications for the benefit of the whole of humanity. 
The significant effects on life and society in the year 2000 will be exerted by discoveries and inventions that are currently unpredictable. But it is not a bold statement to say that space technology is already an important tool that will shape the shape of the next century's civilisation.
The continuous development of radio communications, as well as the various radio-assistance systems for air and sea navigation, have brought about a real "congestion" of the airwaves, and therefore the use of artificial satellites, which make it possible to infinitely increase the channels useful for long-distance communications, has been extremely providential. 
When in May 1963, with the satellite Telestar 2, it was possible to perfect the first black and white and colour radio and television links between the United States and Europe, a new era of communications began and it began to be understood that there are no longer limits to the transmission of human thought.
Many types of traditional communication will disappear in the coming decades (it has been shown that where telephone service improves, the use of the telegraph decreases in percentage terms) and this is a problem of incalculable importance that will be solved through satellite transmissions.

ACTIVE AND PASSIVE

Carlo Matteini spoke to us about the future of telecommunications. He has dedicated his entire life to these studies, first as a naval weapons general and as a professor of radio technology (for 30 years he has taught in the Faculty of Engineering at the University of Rome), and now as a director of the "Telemar" company.

D. - Professor, what is the difference between "active" and "passive" artificial satellites?
R. - Active satellites are space repeaters equipped with two-way transmitters and amplifiers that are able to pick up a signal coming from a ground station and retransmit it, after amplification, to a second station outside the range of the first one. 
The passive ones are also repeaters, but without amplification and retransmission systems. In practice they are real spatial reflectors that owe their function as repeaters to the large specular surface they have.

D. - How are satellites used in transmissions?
R. - Everyone to speak calmly must have their own channel, of sufficient amplitude and as communications increase, increase, the number of these channels must be increased. Let's leave aside for a moment the "laser" which still has defects and limitations because, for example, it does not propagate through fog. 
Instead, the electromagnetic waves march well, even in bad weather. It's just that you need to have a sufficient number of them at your disposal, to allow more contemporary communications. So how are these communications possible? 
If I take a very long wave and a long wave, as a propagation property, I can communicate from America, to Italy, to Japan quietly.
But if I take a very short wave, it behaves like light waves, like television waves, for example.
You see that you need a lot of stations to broadcast television programmes.
What Milan broadcasts, Rome doesn't receive; so much so that the two stations work on the same frequency and don't disturb each other, because there is an impossibility of propagation.


Speed at altitude

In other words, propagation only takes place between points that you can see directly, when you go with very high frequencies, which are therefore not suitable for communication with distant points.
All low frequencies are already used. New ones have to be found to communicate. So, to give the optical range, there is nothing else to do but take an object and send it into the air, so that from up there you can see a larger area of the earth.
This is the only way to communicate between distant points, even with very short waves. You have to send up something that reflects or refers back to the dream, that is, the "passive" satellites.
The first "Echo" satellite was in fact a simple reflector, a metal surface. Only that you have to put in the area of formidable power because when you transmit - come and go - evidently the power is consumed.
Instead you prefer to send a much smaller toy, a transceiver that receives and transmits.
The problem is to choose the most suitable satellite. If you want to communicate with the whole world, then you should use three satellites, covering the surface of the earth, but of course you have to go to a certain height.
The satellites move and turn according to the laws of Newton and Kepler: you have to reach a balance between the centrifugal force due to the speed and the attraction force of the Earth or another planet.
Depending on the speed, the altitude is stabilized. Climbing higher one must have a certain speed, descending one must have an even greater speed, because the greater the attraction of the Earth.
Finally we reach a height of 35,900 kilometres, which are those corresponding to a speed of synchronism, i.e. an angular speed of rotation, equal to that of the earth.
A satellite at 5000-6000 kilometres will go round the Earth in 2 hours, while a synchronous one turns in 24 hours, together with the Earth.

D. - What will be the most remarkable advantage for humanity, from the use of artificial satellites for telecommunications?
R. - We will soon get to the point that each of us will carry a little thing the size of a packet of cigarettes in our pockets, and will be able to talk directly to a relative or friend who is anywhere on Earth.
Through a tele-selection system, already tecincally perfected, it will be enough to make a combination of frequencies, letters, or a key.
All the systems known today of amplifiers, of solid state physics, have minimum dimensions.
You see here on my table a 5-stage transistor amplifier, by Texas Instrument, which is much smaller than a normal cigarette lighter: you can concentrate everything you want, including the energy source.
Today, if you want to make a radiotelephone communication from a ship, first you have to get in touch with a station and call it by telegraph unless it is permanently listening.
With teleselection, on the other hand, communication will be immediate.
D. - Basically, however, you will have to have an infinite number of waves...
R. - Sure and we will have them from artificial satellites to lasers.
Last month, NASA, in collboration with the Federal Nation Agency and Bendix, carried out a successful experiment, carrying out a communication of co-commercial aircraft in flight, through a transceiver station, placed on board a satellite.
A Pan American aircraft, flying over the Auletine islands, between Alaska and Japan, was able to communicate, with extreme clarity, not only with its headquarters in Washington, but also with another aircraft taking off from Miami for Latin America.
With a number of satellites available, you can establish all the communications you want.

MANY FREQUENCIES

On the other hand, the "laser" is coming, embracing a huge range of frequeze, a wide bandwidth, i.e. a lot of information that is added together.
If you use a laser that covers the whole range from visible and invisible light, ultraviolet, x-rays etc. etc., you understand that it has so many frequencies that it can make the people of the United States speak at the same time.