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The National Association of educational broadcasters in cooperation with the National Aeronautics and Space Administration presents the peaceful uses of space. For the age of space. These are the sounds of today and tomorrow. In the spring of 1962 the Seattle World's Fair was the scene of a conference on space research. This is program number four in a series of 13 reports of highlights from that conference. Since the spring the launching of Telstar. Our and other developments in communications satellites has taken
place. However the background considerations to space communications is still a matter of great interest. And from that conference we now hear the remarks of Leonard Jaffe director of communications for the office of applications in the Aeronautics and Space Administration. First transatlantic cable connected the United States and Europe in 1066. This was of course a telegraphic cable trans-Atlantic radiotelephone circuits were established six decades later. The unreliable radio telephone circuits were supplemented three decades later in 1056 by the establishment of the transatlantic telephone cable. Things have begun to increase in pace. We are now adding to our communications technology an extremely rapid rate. Now it is forecast by a great many that the use
of satellites for providing global communications will be realized in more than a decade after the installation of the first submarine telephone cable. Satellite stars of miles above the earth's surface cannot only write telegraph and telephone messages in large numbers but also television pictures not only sat where satellites were able to link the major countries and continents but as President Kennedy noted in his policy statement of rice it will link the farthest corners of the earth not only and we tap a Baptizer Telegraph television transmission but there's a great new area that communications satellites can bring into being the possibility of communicating with computers tying machines together. This is currently just beginning in this country and communication satellites will make this possible on a global basis.
Economic studies which have already been undertaken indicate that communications satellites can provide these services comparable performance. So that of the best systems and perhaps at a lower cost. With channel capacity that would be virtually unlimited. It's certain that in a decade or so. The channel capacities that we have available to us and conventional systems will be exceeded. The future reduce future need is rather dramatically pointed out when one realizes that our line drawn anywhere across these United States would cut across. More than 100 times where a communications facility or capacity then the total communications facility emanating from the United States to other parts of the world forms.
It would be a mistake to minimize the technical problems of the stablish in communications satellite systems as we shall see. There are many in great but equally great are the incentives to get the job done. We're currently running out of communications shortwave radio circuits across the oceans depend on radio reflection from the ionosphere and our extremely poor quality. It sometimes fails fails completely. Submarine cables are greatly superior in quality but lack of broadband or large capacity requirements of the future. But the usefulness of the communications satellite and its importance. In world world wide communications is cleared off. It is not immediately apparent which of the technical approaches to the problem will turn out to be the most rewarding in arriving at the design. Operational systems of the future. Accordingly it is Nasha is a NASA's endeavor to
determine as rapidly as possible which of the various system designs. Which have been proposed should be used in the establishment of operational communication satellite systems. To do this we must first determine which technique has the greatest promise of reliability and economy of operation. So the development of commercial communication satellite systems can be pushed forward. I'd like to stress these two words reliability and economy. You've heard just heard Dr. Tepper talk about one of the most successful satellite programs that we have in this country very tyros satellites have lived for 10 months and the fact that Soros too has perhaps started working again after a short period of. Laziness. Communications satellites cannot rely on this kind of operation as you will see communications satellite systems may embody many satellites in orbit.
Communications satellite systems must be economically viable. They must pay for themselves. In order to pay for themselves or one of the factors determining the economics of communication satellite systems is the lifetime of the satellite in orbit. It's tremendously expensive to put satellites into orbit and the only way to reduce the cost of satellite systems is to make sure that these satellites live for long periods of time. When I say long periods of time I'm talking two three five and ten years. We do not have such systems today. I'd like to discuss now that the kinds of systems that we feel will come into being at various times. The argument is not. Perhaps which is the ultimate system which we might have some years from now. But rather which are the systems. Which we should start with which are the systems which we can afford to gamble on which are the systems which we can make reliable and.
To live during the initial phases of communication satellite use. These are the subjects that we want to study these are the kinds of questions that we want to ask ourselves during the experimental phases of the program. Basically I think we can categorize communication satellite systems in three categories. They're either low or intermediate altitude passive reflectors. Passive reflectors satellites. I might remind you are merely radio mirrors in the sky. They reflect radio energy which is being dumped toward the satellite back toward the earth and can be used as a communications transponder. The second category and second and third categories involve active transponders or active satellites. These are satellites which carry electronics they carry transmitters receivers and power supplies to operate these electronics
and we can broadly separate these into two categories the low altitude or intermediate altitude active satellites. And the high altitude or synchronous orbit through satellites. The next chart. I have the next chart please. Shows pictorially the elements of a low altitude active communications satellite system or for that matter any low altitude system the important. Thing to note in this chart is that we're talking about a tremendous number of satellites in orbit. We would have antennas on the ground which would point toward beam radio wave energy APIs satellite the satellite would either reflect or re transmit this energy to another and somewhat displaced on the earth's surface. But in low altitude orbits the satellites are moving relative to the ground. One has to use
a satellite that is a mutually visible from both communicating stationer's and as the satellite which is currently being used drops below the horizon. One must be ready to replace that satellite with a new satellite. Just moving into the field of view this process must continue and therefore a great number of satellites are required in low altitude systems if one. It would establish a low altitude system. When asked how many satellites does it take and we've indicated here approximately. Or an approximate number of satellites required to provide essentially continuous communications between ground stations approximately 3000 miles apart or perhaps across the Atlantic Ocean and thought of on the left. We see the number of satellites required on the vertical scale versus altitude here on the horizontal scale at 1000 miles
altitude. We're talking about exorbitant numbers of satellites roughly 400 satellites. The number drops off appreciably at 5000 and perhaps 40 satellites are required. It's interesting to note that the curve is rather flat here and if one goes out to the synchronous twenty two thousand three hundred miles to. 900 satellites are still required. If we talk about satellites placed in orbit with normal control over the relative spacing between satellites. If there is no control exercised over these satellites over the spacing between satellites and this is the case for the satellites or the numbers of satellites being considered in this chart. If there is no control over the spacing between these satellites. These satellites will eventually take on a random distribution. So we're talking about randomly space satellites. And these are the numbers required versus altitude. It's interesting to note that beyond five or six or seven or ten thousand miles this number does not reduce
dramatically as we go out to the synchronous altitude. And when we approach the synchronous altitude or when we get there it would be desirable to control the relative spacing between satellites. And here we see the classical illustration of three satellites. Placed at the synchronous or stationary orbit altitude of twenty two thousand three hundred miles above the earth's surface. At this hour the to the period of the orbit is exactly 24 hours so that as the satellite moves around the Earth once every 24 hours the earth moves beneath it or rotates beneath it. In 20 any 24 hour period the satellite appears to remain stationary above a point on the earth's surface. Three satellites placed 120 degrees apart as shown here could theoretically provide almost complete global coverage coverage with the exception of perhaps the polar regions.
Generally we consider the equatorial orbit for synchronous satellites. Now why don't we move immediately to this nice simple synchronous orbit system. While there are many problems for one the twenty two thousand three hundred distance between the Earth and the satellite. Means the tremendous amounts of. Radio energy are required. Since a tremendous but more radio energy is required. If we were to just spread radio energy out in all directions from the satellite we can't afford to do this. So we must aim for being this radio energy back toward the earth. And this requires that we stabilize the satellite or orient it so that it continually points toward the earth. To do this for long periods of time as a problem. We must also provide the period control for the velocity controls of the satellite will indeed have truly a
24 hour period of rotation. This must be adjusted periodic leave we feel that these systems although these can be accomplished to make them. Reliable for long periods of time and again we're talking about years is going to require a period of research and development. Which is probably longer than some of the simpler systems that we can talk about. Now we're going to talk about satellites and low altitude orbits we talk about large numbers. How do we get these up there. Well it appears economical to think about putting a number of satellites in orbit from a single rocket rather than putting them up one of the time. And we're currently considering how this might be done. A project which we call Project rebound is currently in the study phase which we're considering placing three satellites in orbit from a single rocket booster. This might be done as indicated here in which a mother spacecraft if you
will would be carrying three communications satellites would be placed in and what they call orbit initially when the. Spacecraft reached the Apogee altitude or the point furthest away from the earth a communications satellite would be dispensed. And a rocket carried aboard the communication satellite would give it the additional voracity necessary to make its orbit circular rather than elliptical and the condition would then be the conditions shown in the second part of this figure which this the communication satellites in the circular orbit the other spacecraft is in the initial loop tickle our bit and continues in that orbit. When the other spacecraft gets back to its point of apogee the communication satellite will be lagging behind because its orbital period is wrong or we can then pick out a second satellite and repeat the process by repeating this process a number of times we can. Dispense satellites somewhat
uniformly in orbit. But this is just in the design study phase. We think that if. These kinds of things can be done if we can dispense numbers of satellites from a single rocket launcher. But perhaps the lower altitude systems will not be as costly. This technique although it will be aimed in our experimental program. Toward or will use passive satellites. In its six in the space experiment in the flight program. Can be applied to both active satellites or passive satellites. Obviously this is a rather complex mission and there's a couple of years off. On having discussed some of the reasons for the different orbital configurations proposed for communication satellites let me review some of the satellite programs themselves. Basically the simplest of communication satellite Texan techniques is the passive reflector the radio mirror in the sky. The passive reflector can take on many
forms. And over the years a number of specific configurations have been suggested. At the present time NASA's investigating four of these configurations as they appear to have the most promise for the immediate application. The first is the simple reflecting sphere. This of course has been tried already in Project eco. Eco run. As you all know it was a hundred foot diameter sphere placed in orbit in 1960. I was a fire onto the simple sphere with a continuous surface. There are two varieties of surface structure which promise better overall performance. So far as the passive reflector communication system is concerned. One of these is a sphere which has been lightened by holes in the metallic coil. Which is being used currently on the solid sphere. We're interested in making these figures as large as possible and as loud as possible. The larger
we make them the more energy they capture the more radio frequency energy they capture in space and consequently the more energy they reflect toward the ground and make our ground problems that much reduced. This process of etching holes of course reduces the weight of the sun. An alternative method of reducing weight and that would be the use of a mesh type structure. We're not sure we're not sure at this time which of the two techniques for lightning this ferrites will prove to be most effective. As we wish to make this for a very much larger insofar as its reflection characteristics are concerned. We're also looking into the possibilities of effectively accomplishing this without using or without orbiting the holes in normal circumstances only the bottom portion of the sphere facing the Earth is actually used in reflecting the signal from one station to another.
For this reason it seems rather unnecessary to orbit the upper portion. The problem then becomes one of erecting and then orienting part of a sphere or circle segment those placed in orbit with a complete sphere regardless of its stabilisation there is always a lower surface available to act as a reflector. The circle segment if not provided with a stabilization system or an orienting system very often would not face in the proper direction as a result the reflecting area of the antenna. As a result the reflecting area that the antenna on the ground would see would be very small. Third we want to use a stabilization system of some sort and currently we would like to explore the so-called passive stabilization systems or the systems which use the gravity gradient of the earth itself. It does not make much sense to put a so-called active.
Stabilization orientation system that which uses propellant stored rocket fuel or gas aboard a passive satellite. All of the virtues vary advantages of the passive satellite in terms of its simple concept and reliability would then be lost. Not as passive satellite program includes several flight tests. The properties of the sphere as a communications reflector are being evaluated in these flight tests. The first of these tests was of course the Ekka one project most of most of you have probably seen Echo one moving across the sky. I may be interested to learn that we are continuing to measure its reflection characteristics and to see if any more significant changes occur in its shape. The problem is in developing communication satellite systems are many and perhaps I've indicated them by indicating the numbers of programs that we're pursuing but they are being pursued vigorously. When Arthur C.
Clarke a British science writer first proposed the use of satellites for communications in 1945. 12 years before the advent of satellites. The profit of the use of manned space stations for this purpose if it were indeed possible to keep communications satellites working. Many of our current problems with vanished. We cannot however rely on man to reach us in space. Certainly not for the next. Several decades. The satellites of the near future must therefore be designed to exhibit extra dependability on attended in the space environment for many years. If we are to have economically viable communication satellite systems this is the problem. As I said earlier there would not be under. It should not be underestimated for the rewards are great. Most of the world is now familiar with projects Mercury and Gemini in the field of
manned space flights by the United States. This is the area that attracts the greatest public excitement. The actual conquest of space by human beings in orbit. Robert Gill Ruth is director of the manned spacecraft center of NASA's I would like to summarize his remarks. He said it was just a short time ago that President Kennedy in a special address to Congress established manned lunar landing as a national goal. The president's statement followed by only a few weeks the flight of Allonby Shefford in a mercury spacecraft. Shepard's flight was repeated a few months later by Gus Grissom in a similar Mercury Redstone flight. Then several orbital flights were made first unmanned then with a chimpanzee named Venus and most recently according to Mr Gill Ruth by John Glenn in the three orbit flight in February. Of course we can add that since then we have had even greater developments by our astronauts but this speech was made in the spring of
62. Mr. Gale Ruth continued that Project Mercury is well known is this nation's initial manned space flight effort. It used as basic concepts the Atlas launch vehicle and its guidance a blunt non lifting re-entry body with retrorockets for recovery from orbit. A parachute landing on water. An automatic escape system or escape tower and a progressive build up of tests. The basic problems encountered in Project Mercury said Mr Gill Ruth the basic technical problems where development of the spacecraft and its systems pilot selection and training flight control in real time automatic versus men control procedures and booster spacecraft integration pilot selection and training was a problem said Mr Gill Ruth. And he continued I would say here that the original concept was very good. We are well satisfied with the techniques used and we are well satisfied with the
criteria we established. We are using test pilots experience test pilots. We feel that this has been wise and I would say said Mr Gill Ruth that pilot training is one area in the future work in our spaceflight programs where we can come close to predicting lead time. To summarize then Mr. Gill Ruth went on. Our present position we have taken Project Mercury from a concept to the actual hardware and train flight and ground crews. The specification and orbital flight occurred February 20th one thousand sixty two. That of course was John Glenn's another such flight is now imminent and it has taken place since the speech was made and then flight in space has become with President Kennedy's public announcement on May 25th 1961 a national goal. And said Mr. Gale Ruth I would all so say that acceptance of new concepts by both the public and by the technical community has been largely achieved. Many of these concepts are being used directly in projects
Gemini and Apollo. Project Gemini is an intermediate step between Mercury and Apollo the manned lunar landing project. The program is designed to extend our studies of man's capabilities in space to include long duration missions of days rather than hours and to include studies of man's abilities to rendezvous in space by locating another vehicle maneuvering it and his spacecraft until they are in close proximity and then joining the two. Basically the spacecraft is quite similar in shape to the mercury spacecraft but is enough larger to house a two man crew in order to permit the long duration missions. The launch vehicle is a Titan 2 second generation ICBM propulsion unit which is being produced for Gemini by the Space Systems Division of the Air Force and the spacecraft will rendezvous and dock within the genus stage launched by an atlas similar to that used in mercury. In Gemini we are exploring advanced concepts in system
engineering for space vehicles based on Mercury experience. Every effort is being made to redo systems interfaces to package systems to facilitate their development access and checkout and to minimize problems of final assembly and maintenance. This experience should have a direct influence in Apollo design. So much for the remarks of Mr Gill Ruth. For all that has been accomplished and is being accomplished each day of this new era of space research so much remains to be done. This is no day of immediate answers. We cannot set hours for final determinations. Scientists technicians builders designers thinkers. Yes the very astronomical pioneers themselves accept failure with success. Slowly but steadily replacing tiny portions of the unknown with the known nearing achievements yet on foreseen. Man is dealing with the heavens and
infinity quite in comprehensible to most of us. This is why the element of patience is most needed from the rest of us from the man in the street from John Q. Public patience with the knowledge that men are stretching the limits of their minds and in durance in the search for solutions to problems that have so long the FIDE solution. It is good to keep this in mind and to recognize the need for fundamental understanding as America and the world watch the developments that are so dramatic both adverse and successful in this era's climb toward the stars. This broadcast is one in a series of special reports from the 1962 Seattle World's Fair symposium on the peaceful uses of space presented by the National Association of educational broadcasters in cooperation with the National Aeronautics and Space Administration from Washington. This is John F. Lewis reporting.
Program
Peaceful Uses of Outer Space
Producing Organization
National Association of Educational Broadcasters
National Aeronautics and Space Administration
Contributing Organization
University of Maryland (College Park, Maryland)
AAPB ID
cpb-aacip/500-4b2x763x
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Description
Description
Peaceful Uses of Outer Space. Produced in cooperation with NASA, National Aeronautics and Space Administration.
Description
No information available.
Broadcast Date
1963-01-07
Topics
Science
Media type
Sound
Duration
00:28:40
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Credits
Producing Organization: National Association of Educational Broadcasters
Producing Organization: National Aeronautics and Space Administration
AAPB Contributor Holdings
University of Maryland
Identifier: 63-Sp. 1-4 (National Association of Educational Broadcasters)
Format: 1/4 inch audio tape
Duration: 00:28:28
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Citations
Chicago: “Peaceful Uses of Outer Space,” 1963-01-07, University of Maryland, American Archive of Public Broadcasting (GBH and the Library of Congress), Boston, MA and Washington, DC, accessed July 3, 2022, http://americanarchive.org/catalog/cpb-aacip-500-4b2x763x.
MLA: “Peaceful Uses of Outer Space.” 1963-01-07. University of Maryland, American Archive of Public Broadcasting (GBH and the Library of Congress), Boston, MA and Washington, DC. Web. July 3, 2022. <http://americanarchive.org/catalog/cpb-aacip-500-4b2x763x>.
APA: Peaceful Uses of Outer Space. Boston, MA: University of Maryland, American Archive of Public Broadcasting (GBH and the Library of Congress), Boston, MA and Washington, DC. Retrieved from http://americanarchive.org/catalog/cpb-aacip-500-4b2x763x