Molniya Series
SOVIET APPLICATION OF SPACE TO THE ECONOMY
By Lani Hummel Raleigh*
1971-1975
THE MOLNIYA SYSTEM
The first Molniya 1 satellite was launched on April 23, 1965 , in a flight nearly parallel to that performed by Kosmos 41 the previous year. Molniya 1 was described as having the main task of relaying television programs, long distance bilateral, multi-channel telephone, radiophoto, and telegraph communications. Two days after launch, the first trial television broadcast was relayed from Moscow to Vladivostok through Molniya 1. On the 27th of April, a return program was carried from Vladivostok to Moscow for further distribution by land line to all the Soviet bloc country members of the Intervision system.
Since the initial orbit attained was not precisely 12 hours, the satellite would not repeat the same ground trace. Hence, on May 4, 1965 , it was announced that correction engines had been fired to perfect the orbit to that originally hoped for, so that it would not gradually drift to a less desirable relation to Soviet ground stations.
There are now Molniya 2 and Molniya 3 satellites in addition to the Molniya 1 satellites. Molniya 3 provided the first routine color relays and forms the basis of a Washington-Moscow Hotline.
1. Description of Molniya 1
The Molniya 1 is a complex craft somewhat similar to the early lunar and planetary craft. The main body is a pressurized cylinder with conical ends and external cooling/heating coils, related to the temperature regulating system, which are wrapped around the main cylinder. There are also small correcting rockets to maintain the attitude of the spacecraft in the required position. Atop the main cylindrical body are the special correction motor system and Sun-seeking optical sensors. This subsystem is conical in shape and is surrounded by a ring of gas bottles containing fuel for the correction system. At the opposite end of the main body are Earth-seeking optical sensors. Extending from either side of the main body are the structures for two high-gain antenna systems, steer able parabolic dishes used for the main communications tasks. Also, at the bottom of the main body are six fairly long panels which fold outward to radiate from the main body like petals on a daisy. These are covered with solar cells to power the craft. They generate 500-700 watts over a long period of time.
Inside the craft are the main communications receivers and transmitters, the buffer batteries, various sensors and telemetry systems, an on-board computer, and other necessary equipment for housekeeping and control.
The directional parabolic antennas have a gain of approximately 18 db. According to Soviet account, the Molniya 1 Sun sensor locks onto the Sun to maximize the power for the solar cell system; and, there is a gyrostabilizer to maintain this attitude. The Earth seekers then lock onto Earth and are used to point the parabolic antennas to maximize signal strength. The ground stations on Earth also track the satellite and point their own antennas directly at the satellite. The two antennas are not used simultaneously. The second antenna is supplied for redundancy to extend useful life. (2)
2. Operation of Molniya 1
The communications equipment of the satellite includes three complete transceiver systems, one active, and two as standby in the interest of redundancy to extend operational life. Most of the equipment is solid state except for metal-ceramic triodes. klystrons, magnetrons and traveling wave tubes. The useful life of the tubes is 40-50 thousand hours. Although in the first models the input noise level is 2000-3000° K, tunnel diodes were soon to reduce this by a factor of 2 to 3. There are four traveling wave tubes used, three active, and one as a spare. Television service is provided in a frequency range from 3,400 to 4,100 MHz, and other telecommunications in a frequency range of 800 to 1.000 MHz. Television is transmitted at a power level of 40 watts, and data and telephony at 20 watts.
The capability of the payload includes a complete television channel with additional capability for television audio, multi-channel telephony, VHF telegraphy (by multiplexing some of the telephone channels), and photo facsimile. (3)
By flying the eccentric orbit chosen, the Molniya 1 has unique advantages for the Soviet Union . The orbit is easier to attain than a 24-hour synchronous orbit. Since the energy requirements in propulsion are less, a heavier payload may be used. In contrast to the equatorial orbits used by the United States , the inclination of orbit (63°-66°) places the apogee in a very favorable relation to the generally northern location of the Soviet Union . And, there is less ground interference at high look angles than would be true with an equatorial orbit viewed from the Arctic .
Because the first U.S. communications satellites were placed in low orbits, they required active tracking. Each satellite provided limited time coverage, so that many were required for continuous coverage. The number of satellites presented a complicated "handover" problem. often with two antennas required at each ground station. In view of these difficulties, the United States very quickly shifted to the 24-hour synchronous type of operation, once Syncom proved that such orbits could be attained at reasonable cost.
The Soviet system does not have the difficulties which characterized the earlier American system. Although the Soviet system requires; active ground tracking with mobile antennas, the orbit chosen for Molniya 1 is so high that the movement of the ground station antenna is fairly slow. And, approximately 8 hours of useful coverage of the Soviet Union is provided from a single pass of the satellite over Soviet territory and its environs.
The United States began its communications satellite program with a small satellite and a few expensive ground stations and progressed toward satellites of much greater capacity and power. In contrast, from its inception the Soviet system has utilized 'a fairly large and heavy satellite with 'a high power output. The Russians have thus been able to economize on the size and cost of their large number of ground stations.
Some U.S. analysts have speculated that the Molniya 1 communications satellites have been shifted to a government role, particularly if not exclusively military. This deduction is based on the fact that Molniya 1 launches have continued despite the initiation of the Molniya 2 and 3 launches. (4)
3. Molniya 2.
On November 24, 1971 , the U.S.S.R. launched its first Molniya 2 communications satellite. The same launch vehicle was used for the Molniya 1 launch so it may be presumed that there is no great increase in the size and weight of the satellite and that .the main improvement lies in the electronics. Solar panels have been increased, adding about 50 percent to the power. With the change to higher frequencies, the earlier umbrella-like antennas have disappeared.
The Molniya 2 announcements mention "international cooperation", a phrase absent from standard Molniya; 1 announcements. This fact, along with the use of higher frequencies (6,987 GHz), may suggest a move towards compatibility, with the Intelsat, system. (5)
The appearance of Molniya 2 did not displace the Molniya 1 satellites which continue to be launched. Originally, Molniya satellites were flown in groups of three, an orbits separated by 120°. At present they are flown as 4 triplets (each triplet .consisting of one Molniya 1, one Molniya 2, and one Molniya 3. satellite) in orbits separated by 90 degrees. (6)
4. Molniya 3
The first Molniya 3 was launched on November 2, 1974 . The principal difference between Molniya 3 and the earlier Molniya satellites seems to be its color television, relay and higher communications frequencies. Previous Molniya's have broadcast mainly black and white television with numerous experimental color programs.
5. Launch Programs of Molniya -1, Molniya 2, and Molniya 3
There follows a brief table 5-1 of Molniya launches, together with a few Kosmos launches with the same characteristics, which represented either test flights, Molniya failures., or military communications satellites outside the Molniya program but using essentially the same hardware.
6. The Orbita Ground Station System
Orbita is the name used to describe the total complex of ground stations used in conjunction with the Molniya satellites. Each can receive television transmission relayed through the Molniya satellites, with further relay to the surrounding area. Additionally, the Orbita stations can receive and transmit telephone, telegraph, facsimile, and weather data via the Molniya satellites.
The first year of operation was limited to tests between Moscow and Vladivostok of the several types of service possible through the system. By 1966, the first phase of installation of Orbita stations was completed to make the service more widespread. Each later year has brought an additional increment of ground stations. A special effort was made to have the Orbita system operational over much of the country by the fall of 1967 to carry the celebrations of the 50th anniversary of the U.S.S.R. On November 2, 1967 , operations opened to 23 points for regular service to 100 million persons. (7) Another concentrated effort to add stations in more remote regions of the Arctic and Eastern Siberia was made before the celebration of the 100th anniversary of Lenin's birth on April 22, 1970 .
(a) Station Construction.—Orbita stations are circular and constructed of reinforced concrete. Each station serves as the foundation for the 12-meter diameter parabolic reflecting antenna. A central hall under the antenna houses the receiving equipment, the antenna aiming apparatus, and the switchboard which transfers the signal to local land lines after the signal has been converted from the space transmission mode. (8)
Separate compartments and rooms located around the outside of the central hall contain the air conditioning and cooling equipment for the entire apparatus and the automatic control system for the antenna aiming equipment. An extra equipment block is necessary to separate the audio and video signal components. (9)
(b) Orbita Station Locations.—When the first phase of Orbita station location was complete in November 1967, there were two-way transmission stations at Moscow and Vladivostok as well as receiving stations at Murmansk, Arkhangelsk, Syktyvkar, Ashkhabad, Frunze, Alma-Ata, Novosibirsk, Surgut, Vorkuta, Kemerovo, Norilsk, Krasnoyarsk, Bratsk, Irkutsk, Ulan-Ude, Chita. Yakutsk , Magadan, Komsomolsk , Yuzhno-Sakhalinsk, Khabarovsk , Petropavlovsk-Kamchatka. By 1975 stations which were either completed or under construction included those at Gur'yev, Abakan , Kyzyl, Dzhezkazgan, Bilibino, Nikolayeysk-na-Amure. Aldan , Pevek. Sangar, Tazovskiv, Anadyr , Nar'yan-Mar. Skovorodino, Nadym, Ust'llimsk. Dushanbe , Khorog, Yuzhno-KuriPsk, and the television center located in Tadzhikistan in the Pamir mountains. Plans for new stations include Aleksandrovsk and Poronaysk. The general target is to add six to eight stations a year, so that by 1980, virtually all of the Soviet Union will have television service.10 According to the Russians there are presently 56 Orbita stations. The Soviet plan calls for 60 operating stations by the end of 1975. (11)
(c) Orbita stations outside the borders of the Soviet Union include those at Ulan Bator in the Mongolian Peoples Republic , at Haruco , Cuba , seventeen miles from Havana , and at Prague , Czechoslovakia .
(c) Operation, of Orbita. Stations.—The operation of each of the Orbita stations is similar. The two-mirror parabolic dish antenna has a low noise temperature of 30-40 degrees Kelvin (including the wave guide run), and a low level of side lobes. The antennas have a high surface utilization with a focal length of 3 meters. The effective noise temperature of the entire receiver unit is 60-70 degrees Kelvin.
The signals from the antenna are fed through the wave-guide to the band-pass filter, through two low-noise parametric amplifiers, which increase signal strength 100 million times, and then on to the rest of the receiving terminal equipment. The first parametric amplifier is cooled by liquid nitrogen and operates without frequency conversion. The second parametric amplifier is not cooled and operates with a double frequency conversion. For operating convenience, even at the cost of some noise, all the receiving equipment is located in the same chamber. The equipment is mounted on a standard bay with an IF filter and preamplifier, as well as quartz crystal heterodyne oscillator with a frequency multiplier and an additional IF filter which prevents overload of the amplifiers by locally generated noise. A tunable beat frequency oscillator is included to provide for manual tuning of the signal in addition to automatic tuning provided by the quartz crystal heterodyne oscillator with a frequency multiplier. (12)
The quality of the television picture output from the ground stations in most respects is fully adequate by international standards. The scanning standard is 625 lines/frame, 25 frames/second with audio integral to the video band on a PCM basis. The signal is transmitted from the Orbita ground station to the local broadcast television station by a single hop, point-to-point microwave or coaxial cable link. Further improvements in the Orbita stations have been adding the capability of sending and receiving radio telephone and facsimile signals between the station and six Molniya satellites. Still other equipment being added to Orbita stations will greatly expand their capacity to provide the complete range of telecommunications activity, including computer data relay. (13)
References:
(A) SOVIET SPACE PROGRAMS, 1971-75, OVERVIEW, FACILITIES AND HARDWARE MANNED AND UNMANNED FLIGHT PROGRAMS, BIOASTRONAUTICS CIVIL AND MILITARY APPLICATIONS PROJECTIONS OF FUTURE PLANS, STAFF REPORT , THE COMMITTEE ON AERONAUTICAL AND SPACE .SCIENCES, UNITED STATES SENATE, BY THE SCIENCE POLICY RESEARCH DIVISION CONGRESSIONAL RESEARCH SERVICE, THE LIBRARY OF CONGRESS, VOLUME – I, AUGUST 30, 1976, GOVERNMENT PRINTING OFFICE, WASHINGTON : 1976.
1. Pravda, Moscow , Sept. 24, 1969 , p. 3.
2. Aviatsiya i Kosomonavtika, No. 7, 1968, pp. 17-20.
3, Idem.
4. Aerospace Daily, September 8, 1975 . p. 33.
5. Flight International, February 8. 1973. p. 206a.
6. Flight International, December 19, 1974 , p. 880, plus current observations.
7. Moscow Radio, October 26, 1967 , 1900 GMT
8. Pravda, Moscow , October 29, 1967 , p. 3.
9. Idem.
10. Aviatsiya i Kosmonavtika, No. 5, 1970, pp. 12-13 ; Vestnik Suyazi No. 4. April 1970, p. 29.
11. Moscow Radio, May 7, 1975 , 0100 GMT; An Audience of Millions, Izvestiya, Moscow .
12. Pravda, Moscow, October 29, 1967, p. 3; Radio Moscow, No. 10, pp. 16-17 ; Elektrosvyaz', No. 11.
13. Radio Moscow , No. 10, October 1967, pp. 18-16. This source discusses more technical aspects of the circuits than is presented here. See also Elektrosvyaz', No. 11, 1967, pp. 4-8.
• Ms. Raleigh Is a physical sciences analyst In the Science Policy Research Division, Congressional Research Service, The Library of Congress.
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