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COMMUNICATION SATELLITE
ECHO - TELSTAR - IDSCS - DSCS 2 - DSCS 3 - FLTSATCOM, AFSATCOM, MARISAT, LEASAT, TACSAT - SKYNET - NATO satellites - SDS - UFO, MILSTAR - MOLONIJA - STACIONAR RADUGA - POTOK GEIZER - STRELA GONEC - VOJNI COMMUNICATION SATELLITES OF OTHER COUNTRIES
Arthur Clarke
End of childhood
2001: Odyssey in space
HAL 9000
Herman Potočnik - Noordung
Wernher von Braun
V-2
V-2
Saturn V
Echo
Echo
Echo
Telstar
IDSCS
IDSCS
IDSCS
DSCS II
DSCS III
DSCS III
DSCS III
DSCS III
DSCS III
DSCS III
UFO
UFO F8
UFO
FLTSATCOM
FLTSATCOM
FLTSATCOM
LEASAT
LEASAT
LEASAT
LEASAT
LEASAT
LEASAT
TACSAT
TACSAT
TACSAT
TACSAT
TACSAT
TACSAT

COMMUNICATION SATELLITE

From the very beginning, flight into the universe, the spread of communication across state borders is one of the main goals of research, and the development of satellites for these tasks shows how far they have gone in this area. Today, at a time when the weapon is becoming more complex, communication is a basic prerequisite for military success, whether it is about preventing aggression or the most effective way of destroying the enemy. Communication satellites act as relay stations for transmission of communications between two or more points on Earth. Armed forces mostly use satellite communications for the transmission of voice and data messages, but the use of satellite communications for military purposes expands rapidly and includes areas such as photo uploads, teleconferencing, armed system management, and the transmission of a variety of real-time information. Military communication satellites can be divided into two larger groups: satellites in circular and elliptical non-geostationary orbit and geostationary orbit satellites.

The idea of ​​communication satellites is attributed to the British Arthur Clark, one of the most important writers of science fiction. Clarke's work combines science ideas with spiritual optimism in a brilliant way. Works like End of childhood or 2001: Odiseja u svemiru, Which was filmed and Oscar-winning film (1968) became a classic. The success of Space Odyssey has become a popular and nasty computer HAL 9000, which was born on film by 1997. years. So, year 1945. Clarke has announced the idea that three-satellite broadcasts on the 120 spaced path can cover the entire inhabited area of ​​the Earth. On that path, which is in the plane of the Earth's equator, the satellite would move from west to east at an altitude of about 35900 km above the Earth's surface, with the angular velocity of the satellite being equal to the angular velocity of the equator point below the satellite. Therefore, the observer satellite from Earth is idle. And this "immobility" enables earth station transmitters that send and receive signals can be directed to a certain point of the sky. That means that receivers can be easy to handle and - cheap. For artificial satellites, gravity is exploited as a centripetal force, and with the required circular velocity can force the satellite to circulate eg around the Earth. However, a simple formula that, after equalizing the centrifugal force (which seeks out the satellite to expose the universe) and the forces of the Earth's gravity (provided that the phase is equal to one day) is the radius of the circular path of the geostationary satellite, played 1929. Fifteen years before Clarka Hermann Noordung alias Herman Potocnik, which is acknowledged by NASA as well. What is interesting to us is that Potočnik is a Slovene but born in our Pula, then Austro-Hungarian warship. Potočnik's work on space issues is the cornerstone of similar research in Germany and has led Wernhera von Brauna, later the technical director of the German plant in Peenemünde where the rockets were produced V-2, especially the Brits. Von Braun was after II. World War II became a significant US acquisition, and was set up for NASA's Marshall Space Flight Center director while rockets were being developed Saturn V.

The first attempts to establish connections via satellite served for purely propaganda purposes. Conclusion 1958. was launched Atlas a rocket launcher featuring the Christmas message of the president Eisenhower, no doubt destined for those who believed the United States was at the mercy of technological development. But soon after, NASA and the Ministry of Defense begin their own research, often repeated, for the best exploitation of the universe in intercontinental communications.

But the real communications revolution began with satellites Echo (Jeka) i Telstar. While Echo, actually a large balloon with aluminum scatter reflecting radio signals, was the first real (and one of the largest ever-built communication satellites), Telstar had built-in signal amplifiers. A space race began to intensify the cold war. Sputnik has also caused many other changes in America. Namely, American strategies have estimated that the emphasis on math and science in the Soviet education system will provide the enemy with the strategic advantage of 10 years. The American Congress, recognizing the strategic value of education, despite the budget deficit, has passed the law to separate the huge sum of $ 1 billion from the budget to improve the education system, procurement of scientific equipment, and scholarships to gifted students and students. Sputnik has also initiated discussions about rooted and systematic reform of the American educational system, as well as discussing new curricula. New teaching methods have begun to be used to improve the learning process itself. Emphasis has been put on experimental teaching and not just learning the facts memorable.

Satellite Echo NASA has launched 1960. And by refusing radio-wave exercises to receive emissions from the universe. Office for Advanced Research Projects (Advanced Research Projects Agency, ARPA), An armed branch for scientific research, sends the aircraft Courier 1 In the high 1.600 km trail. It became clear that the desire of two very different groups of users would not be so easily aligned, so until NASA started projects Rebound, relay, Syncom i Telstar, intended for a scientific project check that could turn into a lucrative job, the Ministry of Defense formulates its programs.

Only four months after the launch of the first US spacecraft, the Office for Advanced Research Projects establishes an advisory body for space communications, leading to a series of new proposals. This results in the specification of the required military aviation and Army Signal Corps properties. Three projects were proposed: projects Steer i tackle, For patrol and special tasks in the polar path, and the project decree, for a stationary station above the equator, for transmission of information. These three programs are united in the venture called Advent, just at the time of the Echo flight preparation, combining the research started with the Courier project with the operational needs of creating a stationary communications satellite network. The Advent project is only two years old and has already been replaced by a series of smaller aircraft launched next to other satellites, intended for other tasks. Common operational requirements ultimately led to the creation of the Initial Defense Satellite Communications System (Initial Defense Satellite Communications System, IDSCS) with several locomotives in the stationary road around the Earth. Experimental communication orbital aircraft launched together with others developed Lincoln Laboratory, and called it Lincoln Experimental Satellites, or shortened THE.

IDSCS, DSCS

Several paths are perfect for communication purposes. Very low orbits with a fairly incline to the equator have a fairly limited value, unlike high when the satellite is long over the user's radio-horizon. Stationary trajectories are in any case ideal because the aircraft does not move in relation to terrestrial equipment. There is a kind of orbit, with this very role, and Arthur C. Clarke has suggested the second World War immediately. On the other hand, the satellite is quite far from Earth, and the signal reception devices must be very sensitive. Orbital devices can not emit the power of terrestrial equipment, so the captured and transmitted signals will be weak compared to conventional connections. The universe can also be used to set up a simple reflector, but this is not particularly useful when it comes to secret military information and information, as it would be easy to interfere with them. In any case, the strength of the received signal would be much weaker.

Therefore, the US Air Force decides for small 45 kg massages, with a receiver receiving signals from the Earth at the 8 GHz frequency, and the transmitter that sent them back to the 7,2 GHz frequency. IDSCS the aircraft had a polyhedron shape from 24 pages coated with photovoltaic cells, 91 in diameter, and 81 cm in height. They're launched with a bracket Titan 3C-Transtage capable of delivering loads of 1,6 tons on a stationary path, and according to plan should be a total of 26. They would be placed in a slightly lower path, at an altitude of 34 thousand kilometers, so that, compared to the Earth observer, they would slowly move from horizon to horizon to about 4 and half a day. The powerful missile-carrier carries seven or eight IDSCS satellites each, and the last stage, Transtage, is used to accurately set the orbit.

The first group of seven aircraft hits 16. June 1966, but the second attempt, two months later, is dead because the launcher exploded during the launch. Eight new satellites will then be launched in January 1967, three join in July, and the last eight in June will be 1968. So all 26 aircraft are set in the path, separated by the average 14 degrees of latitude, slowly turning around the planet. For that time it continues to work on experimental LES satellites, examining the new communication capabilities applicable in the second phase, under the name of the Defense Satellite Communications System (Defense Satellite Communication System - DSCS) use the stationary trajectory and much larger aircraft.

The initial series of 26 IDSCS satellites was built by the company Ford Aerospace, with a life expectancy of 18 months. They had limited communication capabilities with only one toroidal antenna. phase 2 with the DSCS network, the start of work that was planned at the end of 1971, was supposed to fulfill all the tasks for the whole decade, which would mean achieving a global telex connection, and transferring data and conversations between units of the Navy, Navy, Aviation and Naval Infantry.

DSCS-2 Satellites made according to the specified requirements of the company TRW from Redondo Beach, California, under the control of the Defense Communications Agency. Six aircraft were ordered for the first time, with two sliding narrow band antennae and two broad ones, one of which was used for reception and the other for transmitting. The antennas will be routed to relatively small areas on the Earth's surface, allowing the use of small stationary or mobile stations. The other two will cover the entire side of the planet under the satellite. The narrow beam antenna will route the emissions to the 1600 km range.

Communication equipment and antennas are mounted on a platform separated from the hull of a roller-type aircraft that rotates around the longitudinal axis stabilized in the space. The non rotating part enabled the antenna to be precisely routed, and the photovoltaic cells generated enough electrical power for proper operation. Initially, it was about 500 vata, but due to a decrease in cell efficiency at the end of the three-year period this was about the 390 wattage, yet enough to fix the required 245 wattage as much as the satellite equipment consumed.

As the DSCS-2 satellites were to be set up 36.000 km over the equator, with a 3 gradient slope, they were not fully stationary, but in the sky they described the eighth, shifting 3 degrees to the north and the same south. The narrow beam antennas had a device to reset this motion, so they always focused exactly where it was needed.
Compared to IDSCS satellites, the Faze 2 aircraft was large and massive. The length was almost 4 meters, with a diameter of almost 3 meters and each DSCS-2 satellite had a mass of 570 kg. Aircraft transmitters send special encrypted signals needed to roam the receiving antennas on Earth. Planet radio broadcasts on the frequency between 7,2 and 7,4 GHz if it is a wide beam, or 7,5 to 7,7 GHz for narrow. Received satellite information is sent to other terrestrial stations, say on the other side of the Pacific Ocean, on the frequency between 7,9 and 8,1 GHz, respectively 8,1 and 8,4 GHz.

The stationary ground stations of this system are equipped with 18,3 m diameter antennas, while mobile receivers and ships on ships have 1,8 m diameter plates. From the very beginning, the DSCS-2 system was designed for strategic and tactical communication between stationary and mobile stations, defense interests around the world in the scope of quite unpopular technology.

The number of DSCS-2 satellites will not be as much as in the previous prototype systems, so each one will carry a small engine to move from one path to another. If it happens to hang one of them, let's say that over the Indian Ocean, one from the Atlantic region will move around the planet to a new place and take over the rogue duties. This is the first time that the entire Earth will be relayed by a communications network, and information will reach the destination from Earth stations via satellite.

The operation of the DSCS system will be governed by the Air Force Satellite Control Facility, an Air Force Systems Command unit located at Sunnyvale, California. One in New Hampshire, California, and Hawaii, Guam, Greenland and Diego Garcia in the Indian Ocean, monitor, communicate, send commands, and process data from the DSCS network. Each of the two plate antennas is moved according to orders from any of the above ground stations.

Aviation is a fairly changeable happiness in the realization of a global communications network. The first two satellites successfully launched 2. November 1971. one carrier Titan 3C, And the other couple successfully reached the 13 path. December 1973. But soon after leaving the launch tower at Cape Canaveral 20. May 1975. It fires the Titan system and the third pair does not come in the proper orbit. So far, six more satellites were ordered by TRW, and the first two from the series were powered by 12. May 1978. The next couple was sent to orbit 25. March 1978, but due to the cancellation of the second-degree rocket launcher engine lost. A successful launch in December of the same year ends with the first production line of satellites.

The Ministry of Defense orders 1977. Four more DSCS-2 aircraft, which increases the number on the total 16. In this series, TRW incorporates improvements aimed at boosting the emitter power of the transmitter. The first couple of third, modified, groups hang in November 1979, supplementing the existing system in which some of the already launched satellites have stopped working. The Defense Communications Department plans four correct DSCS aircraft in the journey, one on the Atlantic and the Indian Ocean, one over the east, and one over the western Pacific. The two tags are ready to go to the desired latitude, or to replace one of the aforementioned ones.

The lack of adequate coverage, theoretically unavailable even by flying in November 1979, as one of the treasures did not work, and the remaining aircraft came to the end of the working life, the Ministry of Defense has shifted the DSCS series tasks to other NATO satellites, to which we will talk later. Scheduled at the beginning with the Pentagon's inadequate resources, the 2 DSCS Stage system has come from a technological or manufacturing problem to another, never meeting the intended goals.

Several unpredictable hardships delayed Faz 2 until the phase of 3 phase preparation, for a completely different generation of communication satellites. They were supposed to replace the DSCS-2 series from the late seventies. Difficulties of all kinds, especially the lack of financial means, move the first launch to 1981, and the order for the operating series is locked. Only after the success of the trial phase, the Pentagon will decide whether to accept the satellite series that is required by the Defense Communications Commission, as evidence of its properties.

Unlike the Phase model or 2, which are rotated by rotation of 150 and 60 per minute, orbit, satellites phases 3 are position stabilized like meteorological aircraft Block 5D, which, in general, proved to be a much more successful solution. Produces them General Electric who needed the experience in making stable orbital platforms was created Nimbus, Meteorological research satellites, and Landsat a spacecraft to study the geological richness of our planet, so it was able to get a job with the DSCS-3. Each satellite box is a long 2,8 m wide 1,9 with a high 1,9 m, and has two folding solar cells with photovoltaic cells. At launch, the aircraft has a mass of 885 kg; after the expiration of the maneuvering fuel remains around 748 kg, about 220 kg more than the replacing DSCS-2 model. The range of the chalk in the orbit is 11,6 m. As we have said, the satellite is stabilized in all three axes, meaning that it can be permanently directed towards the Sun, and the large surface of photovoltaic cells allows the generation of the 1100 wattage needed to operate the control and communication equipment.


DSCS-3 uses six radio channels, two more than the previous series. In addition, the reliability of the system is much greater, with a life span of more than ten years; Therefore, twice the size of DSCS-2. Two complex, electrically-controlled antennas carry 19 elements, which in other words means they work as multiple receivers and transmitters; The only receiving antenna has the capacity of the 61 element or 61 receiver, phase and / or amplitude modulated to work with the appropriate ground station and can also be directed against hostile radio interfering devices. The satellites carry a 91 cm diameter antenna for working with smaller mobile receivers and transmitters. Additional system support provides two broad beam antennas to cover the entire hemispheric earth. The frequency range switching devices enable the reception of the signal at the UKV (ultratratric) area and the transmission at the same frequency, ie the reception on the SEA (supercompatible) and broadcast on the UKV area. The four primary waveguide amplifiers create 10 vata emission power, with two additional 40 watts giving a total of 120 watts, or three times more than DSCS-2 aircraft.

Frequency switching devices allow you to connect any waveguide or antenna combination between the receiver and the transmitter. For example, the signal caught on the receiving antenna can be sent to a 40-powered transmitter amplifier via auxiliary antennas, manageable parabolic plates or some of their combinations. The satellite operating frequencies are the same as those of the DSCS-2 series, with additional telemetry channels and sending commands to the SEA area.

In two years as the program has been out of schedule since the first launch date for 1979, minor alterations and other breaks provided the opportunity for a significant change of the fail-safe satellite protection system and strong electromagnetic impulses directed at it with the intent to destroy communica- tory or control electronic equipment. This "confirmation" is more relevant if Soviet achievements in space destruction are known to the universe. If there is a conflict between the superheroes, the communications and intelligence satellites will be the first to hit, because the development of the events is crucial to them. The DSCS-3 model schedule changed considerably after the decision of the Ministry of Defense to produce only two prototypes. The first DSCS-3 will sail from the Canaveral launch tower on Titan 3C, along with the third improved DSCS-2 satellite. This carrier has a reinforced third tier to lift the bulk of the DSCS-3 aircraft. The next "package", composed of another DSCS-3 prototype and the last revised DSCS-2, the 1982 pass. Year, one year after the first flight. The Rocket Bracket is a new model Titan, called 34D, developed as a reserve for the first flight of missiles that will eventually replace all the current types of disposable aircraft.

DSCS equipment supports the United States strategic defense system and the global communications network of military forces, guarding the National Command Authority's infrastructure, a nervous system that would handle events in the event of World War II. Somewhat specific needs of the US Navy seek to develop additional features of the communication satellites in the model FLTSATCOM, A name that is derived to the function that it fulfills: satellite communications fleet (Fleet Satelitte Communications).

FLTSATCOM, AFSATCOM, MARISAT, LEASAT, TACSAT

The knowledge of the significance of the American Navy's role in the conditions of ever-increasing Soviet fleets encourages at the end of the sixties the specification of the new satellite's capabilities, and the successful naval maneuvers in the Pentagon, the Navy is 1972. it is permissible for TRW to order it FLTSATCOM system. Plans talked about the first launch of 1975, and the network was supposed to consist of five planes in the road around Earth.

The delay, however, slowed down the realization of this program, so the navy was forced to make a new plan called Gapfiller (Flap), just the name you are talking about. On civilian maritime satellites Marisat space for equipment is rented; The Defense Ministry must make a similar step and pay a large sum for communication channels on civilian aircraft. In these examples, you can see how long it has led to deferral and the reduction of previous administration budgets.

The Fltsatcom system is intended for the UKV network and SEA communications to support the most urgent tasks of the US navy and aviation, this latest generation of troops through Afsatcom connections that do not require special aircraft, but receivers and transmitters are incorporated into others, including Fltsatcom. Naval Command of Electronic Systems (Naval Electronics Systems Command) Manages the program, and NASA launches satellites from Cape Canaveral on Atlas-Centaur carriers. The basic idea of ​​the project is to set up at least three satellites in the stationary route over the Earth to connect the ships, aircrafts and branches of the National Command Administration. The aircraft consists of a six-axle enclosure for equipment or communication devices, and a missile engine that leads to a stationary 36 flight thousands of miles above Earth. Titan 3C s Transtage Third-degree could put the satellite in the desired orbit without any additional equipment, but the Atlas-Centaur is inserted in a path where the stationary orbit is only the highest point of the ellipse.

When the satellite arrives in an apogee, a rocket engine is routed that pins (the lowest point of the trajectory) to the same height, ie the orbit becomes circular. The Fltsatcom aircraft has a launch with a rocket engine with a solid fuel mass of about 1860 kg; after entering the stationary trajectory or fuel consumption, the mass is reduced to only 840 kg.


On the opposite side of the satellite there is a foldable parabolic antenna made of a stainless steel mesh that travels in the distance to the diameter of 4,9 m. The spiral UKV receiving antenna is extracted by activating the hinges with springs mounted on one side of the parabolic antenna. "Photovoltaic cells are also shipped when launching, and in the 2940 path of some elements the average 1260 battery is used, which is immediately consumed or stored in the batteries.

Each Flsatcom satellite with hydrazine rocket motors is stabilized in all three axes, and they also allow to change the position in the stationary path. The planned life span of the aircraft is about five years. During normal operation the satellite is commanded by the Air Force Satellite Control Facility within a degree of geographic length from the nominal position. Each of them has 23 communication channels on the UKV and SKV area, of which the Navy uses ten, while the rest are rented to Air Force for the Afstacom communication system between nuclear impact forces. One channel serves the Directorate of National Command; Through it, if necessary, it will pass the command to begin an atomic attack.

The first was FTSATCOM successfully launched in February, 1978, and the second, third and fourth launches in May, 1979, January 1980, and October 1980. The fifth aerial from the series went on a path in August 1981. But a strong earthquake in elevation is partially damaged. Fltsatcom equipment is installed on all fleet and submarine fleets, meaning more than 450 floating units. The ship's communication terminals are also used civil Marisat aircraft whose channels are rented.

Made mostly for the needs of the US Navy, Fltsatcom satellites carry most UKV and SKV connections for ships and submarines. But there is one communication channel for aviation, for his Afsatcom program. The unofficial contract differs from the usual practice of leasing free capacities of other military or civilian aircraft. That is why, in the successors of the Fltsatcom series, the bonding of the connection channel will be legalized and through a single project that will Hughes Communication Services (HCS) accomplish by making Leasat satellite, the US government will come to the situation to pay for use! HCS is funded from private sources, and the first funds will be received from outside just by setting the satellite in the path. In selected sites of stationary orbits (above the Antlantics, Indian Ocean, and the Pacific), for which four Leasat aircraft will arrive in the year, and all USV traffic will be transmitted through the US Defense Ministry. Although primarily intended for Navy users, Leasat will also use land-based military, aviation and naval infantry units. Earth stations will be built on the island of Guam, Hawaii, California and Virginia, and the command center under the umbrella of the Naval Telecommunications Command Operations Center will be located in Los Angeles.

Leasat is a large satellite that fully utilizes the rocket space of the missile plan, another advantage for aircraft constructors. The Fltsatcom series has been launched with brackets Atlas-Centaur which allow the maximum diameter of 2,7 m, while the strongest missile available to the Ministry of Defense, Titan 3C, has a space for 3 m. The much larger 4,6 m diameter missile tank provides optimum construction, and Hughes has made the most of it.


Leasat is of cylindrical shape, 4,2 diameter and 4,3 height; After disconnecting the antenna at the top, the length increases to almost 6,2 m. Photovoltaic cells on the hull provide 1260 power even after five years of use in the universe. Several drive systems are used to enter a stationary path, turning an elongated path into circular, and less position changes. Space Shuttle will take the satellite to the height of 296 km. After the two springs are pulled out of the cargo space, Leasat will be activated by activating small missile nozzles around the longitudinal axis. By spinning the main engine for one minute, the aircraft starts off on a geostationary path. This drive unit, built into the body of the satellite, is a slightly engineered engine of the third degree Minuteman missiles. When solid fuel is consumed on the stairway stage, a liquid system is in charge of entering a geostationary trajectory. His engines are similar to those on Apollo aircraft. When Leasat reaches the height of 36 thousands of kilometers, the engines re-burn, lift the perigee, or convert the elliptical orbit to the circular. One inner part of the satellite is rotated in the opposite direction from the satellite, which in other words means that it is idle toward the Earth. Fixed equipment, telemetry and communication equipment are fixed on it. When ejected from a rocket launcher, Leasat has a mass of almost 7 tons, but the fuel consumption decreases to 1,3 tons. The communication equipment has a capacity of 13 UKV channels at frequencies from 244 to 317 MHz. Like the NATO-4 satellite, its lifespan is longer than ten years, which can be considered almost standard by modern spacecraft. Leasat is the first satellite that has to be launched with a rocket launcher because large diameter does not allow the use of other existing carriers.

SKYNET

The United Kingdom Ministry of Defense and Technology finances the development of the Skynet system, which is already 1969. Appears as a link between the domination and overseas forces on the sea and the land. More 1966. The English government signs an agreement with the United States on the satellite system to be developed by companies Ford Aerospace. British interests in that agreement were represented by US Air Force. Skynet 1, with work frequencies between 7 and 8 GHz, was set up in the stationary orbit of the Indian Ocean in November, 1969, and served as a link between the Middle East and the Far East.

Skynet 2, launched nine months later, failed to reach the stationary orbit because it had scheduled a missile maneuvering engine. This second satellite, along with the first one, was supposed to meet the UK's communications needs for a period of five years, but Skynet 2 loss changed plans. Only in February 1974. leaves Skynet 2A, But the launch does not work, so the satellite stays again in the wrong path; Ten months later, in November of the same year, the correct orbit is finally arriving Skynet 2B. The aircraft is located above the Seychelles, and serves for communications in the areas between Central Atlantic and Australia. Two channels were used, one on 20 and the other on 2 MHz, with a special satellite tracking signal.

The UK is currently using geostationary type communications satellites Skynet 4, the last satellite Skynet 4F was launched in February 2001. years.

NATO satellites

The next element of the communication network is the West NATO satellites funded by the member countries of the pact. System specifications are based on research work at the then Research and Development Institute of the Ministry of Aeronautics (Ministry of Aviation's Signal Research and Development Establishment), located in Christchurch, England. The first result of the work was the Skynet system, and it gave birth to a thought about the satellite system that will connect the North American and European countries. During 1967. a deal of representatives of seven countries was reached in Bonn; Belgium, Canada, Germany, Italy, the Netherlands, the United Kingdom and the United States. It was agreed that the satellites would be made in US factories, because no one else had so much experience at that time. The equipment was tested on two LES satellites, the 1967 year. and 1968; making and testing NATO the satellite is taken over by Ford Aerospace. Intended for the major cities of NATO countries, the first satellite was launched from Cape Canaveral's Thor-Delta carrier in March, 1970. It was placed above the eastern Atlantic, and control over it was in the hands of the US Air Force.

NATO 2 will run in February 1971, so that pair is used to test new ground stations, ie communications links, primarily through NATO headquarters in Brussels. The second satellite was used to link NATO units located from Turkey to the United States, both of which were to work until 1976. when a new program phase occurs. Then the Delta Rocket rises first out of three NATO 3 Satellites, far larger than the first two, the mass of 705 kg at launch, or 385 kg in the stationary path over the Atlantic, making it three times more massive than the previous one. The spindle is rotated by rotation of 90 per minute stabilized around the longitudinal axis, and the triad antenna and the two 7 and 8 GHz receive-transmitter units are placed on a stationary platform. Photovoltaic cells generate 425 electricity, and the satellite is fully 3, and a wide 2,2 m. NATO 3B was launched in January 1977, and in November, 1978. in the path arrives NATO 3C, The last of the series. By agreement concluded 1977. The United States has the exclusive right to use the aircraft NATO 2B, and in return NATO units can serve the appropriate DSCS-2 satellite capacity over the Atlantic. NATO-3C was considered a spare.


There are currently two 4 satellites in need. generation NATO 4 , of what it is NATO 4A Operating satellite, NATO 4B Is the primary reserve in orbit and the satellite of the previous generation NATO 3D Is used as the last reserve. The basic features of the fourth
Generation of communication satellites have a lifespan of over ten years, additional amounts of fuel to move from the trajectory, larger electric accumulators, and more communication channels for Earth connections.

SDS

As all satellites DSCS, Skynet and NATO series work stationary across the equator, the polar regions are not well-covered, and a small number of earth stations on the large latitudes of the northern hemisphere are fueling the development of a special aircraft to meet the strategic needs of American bomber forces. And so in March, 1975. launched first SDS (Satellite Data Systems, Satellite data system) that complements the Afsatcom network. All the Strategic Air Command Aircraft and Control Centers for Intercontinental Ballistic Missiles are connected to terminals that allow fast communication in the toughest conditions.

Due to the need to cover the polar regions, SDS 1 flies with an elliptical 64 gradient path, 295 to 39337 km over Earth. In the event of a larger conflict, reliable means of communication will certainly be a decisive factor in the course of the war, and the possibility of continuous contact with the National Command Administration will provide an adequate response and survival of the impact forces, Minuteman i Titan, or about the fleet B-52, Bomber.

Problem of communicating from the area above 70. the degree of latitude over stationary orbits indicates the difficulties of Soviet viziers. The system they have chosen is based on an elliptical 12 hourly travel with an 63 or 74 inclination to the equator. The lack of non-stationary orbits, satellite tracking as it travels from horizons to horizons, is largely avoided because the aircraft are set so high that the sight of the receiving station remains about eight hours.

Like SDS-1, SDS 2 i Capricorn (jarac) are satellites also in high-elliptical orbit, a TDRSS (Tracking and Data Realy Satellite System, satellite tracking and data transmission systems) are in a geostationary orbit, where they are used as relay communication satellites for connecting low-orbital survey satellites to land monitoring and reception stations. SDS-2 and Capricorn satellites in high-elliptical orbit are also equipped with infrared fade detection sensors to monitor polar areas, from where the opposing nuclear submarines could fired their ballistic missiles, and where satellite programs DSP In a geostationary orbit I can not detect.

UFO, MILSTAR ...

satellites UFO (Ultra High Frequency Follow-On) of 1993. naval and aerial satellite communications systems (FLTSATCOM, AFSATCOM), tactical communication satellites (TACSAT) And satellites (LEASAT). In addition to basic high-frequency (UHF) communications, part of the satellite enables high-frequency (SHF) and extreme-high-frequency (EHF) communications, three of the 11 satellites are equipped with a Global Transmission System (GBS) for one-way communication of great potential. The exceptionally fast data transfer of the GBS system enables, for example, that the transmission time of a large photo with comments (size 24 MB) from 22,2 hours, as it lasted over the LDR system on satellites Milstar I, reduce to just 8,4 seconds.

satellites Milstar I i Milstar II Are today the most modern military communications satellites. They operate on an extremely high frequency band (EHF), which provides reliable, safe, and interfering and nuclear electromagnetic pulse resistance communication. The first Milstar I satellite was launched in February 1994. Year, the second in November 1995. In April 1999. They joined a new, improved Milstar II, which, due to the last-degree missile failure, remained caught in a useless orbit. The second Milstar II was successfully placed in the orbit in February 2001. And the third in January was 2002. With four operating satellites in orbit the constellation will become fully operative, and another satellite will be set up, which will probably serve as a reserve. All Milstar satellites are equipped with a crosslink system that allows the interconnection of satellites without using land-based stations and a low-speed data transmission system (Low Data Rate, LDR) With a transmission from 75 to 2400 bits / sec, with 192 four channel per channel communication channel. Milstar II satellites still have a system for medium speed data transfer (Medium Data Rate, MDR) with a rate from 4,8 to 1544 kbits / sec, with 32 communication channels and up to 70 per channel user. Milstar is the first communications satellite that uses satellite signal processing algorithms and therefore enables users to make network connections in minutes, compared to existing networks, which had to be established on the ground, which could take several weeks. Milstar are also the first satellites that use frequency jams for greater communication security. In terms of possibilities, there is also the price of one satellite - 800 million dollars.

MOLONIJA, STACIONAR, POTOK, STRELA .

The first experiments for communication satellites started in the Soviet Union yet with 1964. years. Three years later, the first operating system was created, Molonija, Launched in a very elliptical orbit with a perigee of 500 and with an apogee of even 39 thousand kilometers, a slope of 65 degrees.

As the Soviet Union for the First Space Flight used a very large missile rack, so too Molnár founded an intercontinental ballistic missile SS-6 with additional rocket levels. That is why engineers constructed a massive airplane over a ton and a half, which is significantly more massive than any American aircraft from that period. The satellite was a complex form, and six panels with photovoltaic cells created 500-700 electrical power. The Soviet communica- tions were great and from the very beginnings they were overcome by the difficulties typical of American models. Namely, the transmit power is sufficient for reception on conventional receivers.

The elliptical path chosen for Molnaya has an apogee over the northern latitudes, so the satellite for a long time (more specifically, eight o'clock) in the sight of earth stations. The mesh network was initially made up of three spaceships spaced by 120 degrees, and later, due to better coverage, the fourth was dropped, so the clearance was reduced to 90 degrees. The system is up to 1976. the 12 satellite entered, and then the 45 range was accepted. Molly had three basic forms in her lifetime.

The first model was used at the beginning of the program, primarily for military purposes. In November, 1971. The polish is processed Molnar 2, with 50 percent more power. She does not replace it Molnaya 1 It is already complementing the original system. The third version appears in November 1974, with the ability to transfer color TV and higher communication frequencies. The satellites are in the trajectory placed in the groups so that in the distance from the 90 degrees at one point there were three, all kinds of Molnaria 1, 2 and 3. It was in this sense that the first model used to serve mainly for the army and the other two for civilian purposes. The usual constellation of Molnar satellite system was the 16 satellite (with two in 8 orbit) but the number of satellites decreased, probably due to reduced needs. 2001. Two new satellites of Molnion-3 were launched.

The Soviets in the first 16 years of space activities are not trying to use the stationary trajectory, so the first satellite of that kind, cosmos 637, Will only be launched in March 1974. Called even i Molnar 1-S Was set up to cover Europe, Asia, Africa and Australia, and was preceded by aircraft of type infirmary. The development of new, stationary satellite systems follows the planned plans, leading to a commercially competitive enterprise that responded to the Western Telecommunication Consortium with more than 100 member states. As such, it is not part of the military network of communications, although the old rule followed, so it is very difficult to determine where it ends civilly, and the military interest area begins. The Molnar Series 2 stops working with 1978, but the first version still links military users. Development gals stationary satellites that will play the role of the American DSCS-2 series, is just underway. The aircraft, which will be four in total, will be set over the Indian Ocean, the Atlantic and the Pacific.

Russia has now in use two geostationary communications satellite systems for military and defense tasks. System infirmary make satellites raduga And improved Raduga-1, which enable communication not only with fixed stations but also with mobile platforms. The largest range of Stacionar systems is 1994. reached 13 Raduga-1 satellites in nine different locations, to the end of 2000. the number of satellites dropped on 5 satellites at 5 locations. From 1999. to 2001. every year a satellite of Raduga-1 was launched, with which they replaced the satellites whose life span was extended.

Another geostationary system is called Potok, and make it satellites Geizer for transferring data from digital photographic survey satellites and satellites to electronic surveys to land-based reception stations. Usually, three satellites were operating on two locations, and in August, 2001. there were only two satellites. The last one was launched in August 2000.

In the lower Middle Earth orbit, at about 1400 km, there is another type of Russian military communications satellite, satellites Lightning-3 and their commercial versions Gonec-D1. These are easy-to-send satellite communications satellites (they receive and record messages during transmission over the transmitter, which they then send to the Earth as they cross over the control center). In addition to military communications and satellites (the first version of Strela-1 started to use 1965), they also connect with the receipt and transmission of secret messages of former Soviet spies throughout the world. Now the satellites are launched in 6 groups on one carrier rocket Ciklon, of which three satellites are usually military versions of Strela-3 and three commercial versions of Gonec-D1. Gonec-D1 satellites can store up to 12 MB data, and the rate of delivery is 2,4 kb / s. The usual constellation consists of 24 satellites in two orbits with incidence of 82,6 °, but given the present state of Russia, this number is probably less. The latest launch of the 6 satellite band Strela-3 / Gonec-D1 was at the end of December 2001. years.

SERIES
SATELLITE NAME
DATE OF LANSING
LIGHTNING-3
Kosmos 2337-9
14. February 1997.
Kosmos 2352-7
15. liposuction 1998.
GEIZER
Kosmos 2319
30. August 1995.
Kosmos 2371
4. July 2000.
Raduga
Raduga 29
25. March 1993.
Raduga 30
30. September 1993.
Raduga-1 4
28. February 1999.
Raduga-1 5
28. August 2000.

Overview of Russian Operational Military Communications Satellite (data from July 2001)

VOJNI COMMUNICATION SATELLITES OF OTHER COUNTRIES

France has its military part of satellite communications called Syracuse II, Furnished in French civil-military geostationary satellites Telecom 2, and from 2003. will continue to have dedicated military communications satellites Syracuse III.

In February 2001. is a geostationary communication satellite SICRAL-1 became the first Italian military satellite. It is also the first European satellite to operate in the UHF and SHF area, and also operates on the EHF (extremely high frequency) frequency band. The planned lifetime of the satellite is 10 years.

China launched its first geostationary military communications satellite in January, 2000. years. Satellite Zongksing 22 (Zhongxing, The Chinese star) is intended to connect the units of the Chinese army. In January 2002. China signed an agreement with Israel on the purchase of three types of communication satellites AMOS, which are primarily commercial satellites, but would nevertheless increase Chinese capabilities in the field of military satellite communications.

Today, satellite communications are quite widespread, and besides the aforementioned benefits of many other countries, both for civilian and military purposes. To this end, there are still numerous satellite service providers, whose services also use the armed forces of many countries, including the United States, but only for less critical needs.

Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
Milstar
SDS - Launch
SDS
SDS
Capricorn - launch with Atlas IIA
TDRSS
Potok
Molniya-2
Gonec
Gonec-D1
Raduga - launch
raduga
arrow
arrow
Cyclone - Launch
Skynet-1
Skynet-4
Skynet-4
Skynet-4D
Sycral
Sycral
Sycral
NATO
NATO III
Telecom
Telecom
Zongksing
Zongksing