74D6 Kupol Unified Space Detection and Combat Control System (EKS)

As ususal, there is a bit of confusion between the Tundra and Kupol nomenclature. at times, these designations seem to apply to different spaceraft, and at other times it seems that Tundra is the name of the spacecraft and Kupol is the name of the entire system.

A total of nine new devices should be used within the Kupol [Dome] Unified Space System [EKS Edinaya Kosmicheskaya Sistema]. The Kupol is intended to replace the Oko and Oko-1 SPRN space systems that have stopped operating. Russia replaced the failed group of OKO-1 missile warning satellites with the Kupol spacecraft. This follows from the materials for a briefing by the Chief of the General Staff of the RF Armed Forces, Army General Valery Gerasimov, who spoke on 17 December 2019 to foreign military attaches.

As ususal, there is a bit of confusion between the Tundra and Kupol nomenclature. at times, these designations seem to apply to different spaceraft, and at other times it seems that Tundra is the name of the spacecraft and Kupol is the name of the entire system.

Kupol ( Italian cupola - dome, vault, from Latin cupula , diminutive of cupa - egg capsule , goblet ) is a spatial covering of buildings and structures, close in shape to a hemisphere or other surface of rotation of a curve. For many creeds, the dome has a symbolic meaning. So, in Orthodoxy, the dome is a symbol of the Heavenly Kingdom and is sometimes decorated with images of God, angels and saints. Technologically complex and large stone domes of the correct vaulted structure began to be erected after the invention of concrete during the Roman architectural revolution in the construction of temples and large public buildings. The Romans, having developed techniques for laying the dome, during the heyday of their art, boldly used it to overlap very vast centric spaces without supports. Byzantine architects successfully solved the problem of placing a dome over the base of not only a round, but also a square and generally polygonal plan by means of tromps and sails , or pandantivs. The culmination of this period was the use of sailing technology in the construction of St. Sophia Cathedral in Constantinople . The dome became an important element of the Byzantine temple architecture. The onion dome has a convex shape, gradually sharpening at the top, similar to an onion. Most often, such domes are used in Russia. Domes of this shape are most often used in the construction of churches in the Russian Orthodox Church.

In the presentation of Gerasimov, slides were shown reflecting the structure of the missile attack warning system (SPRN) of Russia. In particular, a satellite with the signature "Spacecraft CENTER" Dome (spacecraft of the Unified space system "Dome") was depicted. At a briefing, the general noted that in 2019 the next satellite of the Unified Space System was launched, which increased the ability to detect ballistic missile launches. Earlier, the Ministry of Defense reported that the devices of the new system were called "Tundra". The first was launched in 2015. The Oko-1 system included eight satellites; it stopped working in 2014. The new grouping included three vehicles, including those launched into orbit in 2019. In total, nine new satellites should be launched by 2022.

The new satellites will be able to effectively determine the trajectory of the flight of missiles, in contrast to the satellites of the Oko-1 system, which could only report the very fact of the launch. In addition to detecting enemy missiles, the Tundra satellites, like the SBIRS, provide target designation for anti-missile defense, and can also relay a command to strike back at the enemy.

The launch of Russia’s first Unified Space System satellite was delayed until June 2015 for technical reasons, Russian business daily Kommersant reported February 2015, citing sources in the space industry and Russia’s Defense Ministry. The satellite was due to enter orbit in 2013 and replace the outmoded OKO-1 satellites. The satellite ICBM launch detection system for Oko-1 had not been operational since 2014.

By early 2017 there were already 2 highly elliptical satellites on orbit, and their full-fledged trials had begun. Information on the satellites of the Tundra system is still very small, most of it is still classified as top secret. According to the plans, a full grouping of spacecraft should be created by 2022 - it is obvious that for this purpose it is necessary to launch about 10 satellites, as well as for full-scale operation of SBIRS (4 highly elliptical and 6 geostationary satellites).

To achieve the required tactical and technical characteristics and quality, Russian enterprises need to use the most advanced element base (after the collapse of the USSR, this became somewhat easier due to the ability to purchase technology abroad), and to raise the culture of production to the highest level. This will not only revive the most important element of the missile warning system, but will also lead to the creation of competitive civilian spacecraft.

Russia and Early Warning Systems

The Russian missile attack warning system is designed to signal attacks on state and military control points, provides information for the Moscow missile defense system, and also issues data on space objects for the space control system. It consists of two echelons: a space echelon, which currently includes four Tundra satellites, and a ground echelons, consisting of a network of Voronezh-type stations covering all missile-hazardous directions with its radar field.

As is well known, global security in the modern world is provided by nuclear deterrence, and, first of all, between the United Statesand Russia. At the same time, it is completely inadequate to have a countless number of nuclear warheads and their delivery vehicles - it is also necessary to be able to detect in a timely manner an attempt at a preemptive strike by the enemy. The main strategic nuclear forces of the United States and Russia are intercontinental ballistic missiles (ICBMs), ground-based ballistic missiles, submarine-launched ballistic missiles (SLBMs) ??and strategic bombers (to a lesser extent). Detect ICBMs and SLBMs of the enemy in two ways - either in flight, with the help of specialized radar stations (RLS), or at the time of launch, with the help of satellites with highly sensitive infrared telescopes (they must distinguish the heat of the flare of the engines of the rocket, against billions of other lights of the planet Earth ).

The Soviet early warning satellite program did not officially begin until the early 1970's under the leadership of Academician Anatoli Savin (later the General Designer and General Director of the Kometa Central Scientific Production Association). The Scientific Supervisor of the project was M.M.Miroshnikov of the Vavilov State Optics Institute, which led to the program sometimes being referred to as Project M (for Miroshnikov). Without extensive Earth observational data in the portions of the electromagnetic spectrum of interest, Soviet designers selected for evaluation three basic types of sensors which might be capable of detecting and tracking a ballistic missile during powered flight. Vidicon tubes sensitive to the near infrared and the ultraviolet were tested for the first-generation system, and infrared solid-state detectors with a mechanical scanner were viewed as a logical improvement for a second-generation spacecraft (Reference 86).

An inability to detect missile engine plumes against the natural background of the Earth led to a decision which directly affected the design of the satellite and the orbital characteristics of the subsequent constellation. Sensors would be positioned to concentrate surveillance on a region just above the Earth's limb in the vicinity of anticipated ballistic missile launches, i.e., American and Chinese ICBM silos. This requirement in turn made highly elliptical, inclined orbits (of the Molniya class) more attractive than geostationary orbits, which the USSR had yet to exploit.

In September 1983 the newly established satellite early-warning centre showed that five American Minuteman missiles had been launched against the Soviet Union. The officer on duty decided this was a false alarm because he did not believe the Americans would launch a surprise attack on such a small scale, and the ground-based radar was showing no signs of the missiles coming over the horizon.

On January 19, 2006, former Russian colonel Stanislav Petrov received an award from the Association of World Citizens “for a unique act of heroism that saved the world”. According to representatives of the Association in 1983 Petrov did not react to an erroneous computer warning of a US missile attack on the Soviet Union and thus “saved the world from nuclear war”.

It is not a secret that warnings of missile launches took place both in the Soviet Union and in the United States. Often natural phenomena like flocks of birds or the Northern Lights were taken as ICBMs. Under no circumstances a decision to use nuclear weapons could be made or even considered in the Soviet Union (Russia) or in the United States on the basis of data from a single source or a system. For this to happen, a confirmation is necessary from several systems: ground-based radars, early warning satellites, intelligence reports, etc. Therefore, even if one officer “had reported a satellite signal about an incoming nuclear missile”, the nuclear war would have never started.

The Russian UN Missione stated "Besides, one should keep in mind that both in the United States and in the Soviet Union (Russia) the information automatically fed from satellites is directed to various recipients, and a single hero or miscreant cannot stop it. It is also worth mentioning that soon ten years will pass since the Russian Federation and the United States agreed not to aim active duty ICBMs against each other. In the language of experts that means that “a missile does not have mission input data” or “zero mission input data”. Thus, none of the sides can launch an ICBM against the other side as a result of an error or due to other virtual reasons."

Unfortunately, the Russian satellite system for detecting the launches of the Oko-1 ICBMs, which began to be deployed since 1991, proved to be very unreliable and unsuccessful. Combined with a lack of funding, this led to the fact that the planned grouping of 11 satellites (7 in geostationary orbits, 4 on highly elliptical) was never created. A total of 8 satellites were launched, most of them out of service after about 2 years (only 3 satellites fell within the range of the official "shelf life" of 5-7 years). In addition, the Oko-1 satellites were already out of date at the time of their appearance, so they could only record the very fact of launching the missile, but could not at the same time give information about the trajectory and the intended goal. The last geostationary satellite of the system failed in 2014,

The de facto Russian missile warning system had been operating only from radar stations. They can effectively detect enemy ICBMs and calculate their trajectories, but given the altitude of their flight, it can be done maximum at a distance of about 3700 km, when the rocket was left to fly about 10 minutes. This puts the country's leadership and strategic nuclear forces in a very limited time frame, which is very dangerous. Especially if we imagine that in the long-term future effective strategic missile defense systems will be created and the loss of an appreciable part of the potential of a retaliatory strike can be a catastrophe.

According to Russian media reports, by 2014 the geostationary constellation of Oko-1 satellites was completely out of order, and two of the highly elliptical Oka satellites remained in service. According to some estimates, as a result, the Space Forces of the Russian Federation were able to observe the continental territory of the United States for only a smaller part of the day. In fact, the space warning echelon ceased to exist at that time.

The creation of a unified space-based ballistic missile warning system in Russia was announced by Russian Defense Minister Sergei Shoigu in October 2014. The system was set to replace Soviet-made ballistic missile early warning systems and will comprise next-generation space vehicles and modernized space centers that would ensure control over satellites and allow automatic information processing.

As Russian Defense Minister Sergei Shoigu said earlier, the creation of the Unified Space System (CES) will allow Russia to detect launches of both existing and promising ballistic missiles from the waters of the World Ocean and from the territories of countries conducting tests. According to him, this system will replace the missile attack warning devices developed back in Soviet times. The EKS will include new-generation spacecraft, as well as modernized command posts that provide control of the orbital group, receive and process information in an automatic mode.

The Unified Space System (CES), being created in Russia, will receive ten satellites by 2018, the first of which will be launched into orbit in 2015, the Deputy Commander of the Space Command of the Aerospace Defense (VKO) Major General Anatoly Nestechuk said 29 November 2014. "The work on the creation of the Unified Space System is developing at a colossal pace. If we talk about specific dates, the launch of a new spacecraft of the system is planned in 2015, I think that the orbital group of 10 spacecraft of this system will function in full in 2018," - said Nestechuk on the air of the radio station "Echo of Moscow".

An improved early warning system in space for detecting ballistic missile launches will be in place by 2020, a chief engineer from the Russian defense corporation Almaz Antey said 08 Decembe 2014. “In the development of the space echelon, everything necessary has been accepted and the technical solutions have been tested, and we expect that the low-Earth orbit space echelon early warning ballistic missile system in its improved form will by 2020, or even earlier, provide the necessary characteristics of a constant warning of ballistic missile launches,” Pavel Sozinov said during a conference.

The possibilities to detect moving targets have significantly improved in recent years, Sozinov stated, speaking of the creation of an identification system over the territory of Russia at medium and high altitudes. When it comes to detecting enemy targets at low and very low altitudes, "the possibilities at this perimeter are, of course, very limited," the chief engineer said.

The very knowledge of foreign "partners" that Russia has such a system, including a working space echelon, is an important element of nuclear deterrence. If they are confident that Russia will detect their missiles in time and Russian nuclear forces will have time to deliver a full-fledged retaliatory strike, using their entire arsenal, then any determination regarding aggressive plans against Russia should lose its sharpness.

It is worth noting that a retaliatory strike will be more terrible: there is no point in hitting the empty silos of the enemy's ballistic missiles, his headquarters and military bases, so other objects will become targets. As noted in the above-mentioned Putin's decree: "Nuclear deterrence is ensured by the presence in the Armed Forces of the Russian Federation of combat-ready forces and means capable of inflicting unacceptable damage to a potential adversary through the use of nuclear weapons in any stopping conditions."

SOVIET MILITARY SPACE ACTIVITIES

By Charles S. Sheldon II*

1971-1975

VII. EARLY WARNING MILITARY SATELLITES

A special kind of detection satellite which senses and transmits electromagnetic signals is the early warning class for either nuclear explosions or missile launchings. These functions could be combined.

The United States over several years launched a number of Vela Hotel payloads which were put at a high circular orbit about 100,000 kilometers above the surface. They were calibrated to look for the kinds of frequencies associated with the initial burst of radiation from nuclear explosions such as gamma rays, neutrons, or infrared, whether occurring at the surface, in the atmosphere, or in space. They also kept track of solar and other sources of similar radiation, so that they could recognize the difference between natural phenomena and those triggered by men.

The United States also started a series of Midas flights which were in about 3,500 kilometer circular orbit above the Earth to watch for the infrared signals of rocket exhausts as launches rose from the Earth, particularly above clouds. Later, several other classes of U.S. warning satellites were put up at about 36,000 kilometers circular and synchronous orbit, either over the Equator, or inclined so as to trace a figure-8 pattern near a particular longitude. Some of these payloads were pictured as having an angled sensor system. Presumably such payloads keep watch not only on Eurasia where missile launching silos are located, but on ocean areas which might be the sites for submarine-launched missiles as well.

One assumes that data in various parts of the electromagnetic spectrum as appropriate to what is being watched for are scanned and sensed by these satellites, with results transmitted in such a form that computers can distinguish between spurious signals and the kind guarded against, and that data also permit the rapid calculation of trajectories in the case of missile or space launchings. If so, such signals may give close to instantaneous warning of new launchings or of nuclear explosions and this information constitutes in some cases an earlier warning than might be developed through a BMEWS radar or a seismic or acoustic wave sensor.

Since U.S. interest has been translated into flight hardware, one assumes the Soviet Union has similar protective interests and has examined these technical possibilities and perhaps put such satellites into service. This would be consistent with their also heavy investment in air defense and missile defense systems on home territory.

* Dr. Sheldon [1917-1981], was Chief, Science Policy Research Division, Congressional Research Service, The Library of Congress.

UNMANNED SPACE ACTIVITIES

1976-1980 EARLY WARNING OF MISSILE AND SPACE LAUNCHES

The reason for the choice of an initial 80° plane spacing for the Kosmos satellites in semisynchronous orbits, differing only in partial parameters from the Molniya communication satellites in having arguments of perigee at 315° rather than at 280°, was obscure but between 1981 and the end of 1983 Kosmos launches into planes midway between these resulted in the development of a constellation of nine satellites spaced at 40° intervals.

Four of the 1981 launches—Kosmos 1247, 1261. 1278, and 1317— entered the new orbital planes and only Kosmos 1285 was a direct replacement of an earlier satellite in the system, Kosmos 1261, which had broken up within a month of its launch.

Five more launches in 1982 saw the ninth location filled by Kosmos 1367 with Kosmos 1341, 1348, 1382, and 1409 replacing Kosmos 1247, 1172, 1223, and 1217 respectively.

There were three such launches only in 1983, Kosmos 1456, 1481, and 1518 replacing Kosmos 1191, 1285, and 1341 respectively.

Neither Kosmos 1285 nor Kosmos 1481, its replacement, were ground track stabilized on reaching orbit. Nor were they speedily replaced. Whereas the orbital period of Kosmos 1285 was higher than the truly semisynchronous period, that of Kosmos 1481 was less, due to differences in launch profile. One feels that this can hardly be coincidental. A constellation of nine satellites provides some redundancy and it might be that this particular orbital plane is used to hold an in-orbit spare.

The launch on February 19, 1981, of Kosmos 1247 reverted to the method of placing the satellite at the desired location last used in 1976 for Kosmos 862. The initial orbital period of only 707 minutes produced an eastward drift of the ascending node to 49°W where, on February 23, the ground track was stabilized by raising the apogee. That this was no accident was confirmed by the simultaneous relocation of the four satellites currently operational at that date. On February 21, the apogee of Kosmos 1191 was lowered inducing an eastward drift and during the next few days the apogees of Kosmos 1172, 1217, and 1223 were also lowered. The rapid east-ward drifts were arrested by raising the apogees once more when the ascending nodes reached the vicinity of 60°W in the first week of March and, as expected, complete stabilization was achieved with all ascending nodes located close to 55'W. Figure 2, originally produced for a meeting of the Gatwick Branch of the Royal Aeronautical Society on March 20, shows the manner of placing Kosmos 1247 at its desired location together with the relocation of Kosmos 1191. Plots for Kosmos 1172, 1217 and 1223 would be similar to that for Kosmos 1191 and are not shown to avoid confusion. Kosmos 1261 used the same procedure for achieving a stabilized location at 55° was as that for Kosmos 1247.

military space activities observation missions

Reconnaissance is a general term encompassing a variety of tech­ niques aimed at the collection of intelligence. Imaging techniques are usually referred to as photographic reconnaissance, but in addi­ tion to lens systems, include scanning radiometers and radar sys­ tems. Passive electronic intelligence gathering systems depend upon the reception of electromagnetic emanations from Earth- based radars and the interception of radio transmissions.

1981-1983 EARLY WARNING OF MISSILE AND SPACE LAUNCHES

As stated above, the Soviets lacked the capability to launch spacecraft into geosynchronous equatorial orbits until they had de­ veloped the D-le, or Proton, launch vehicle. Instead they used semi-synchronous orbits of high eccentricity, inclined at 65° to the equator, with a long dwell time near apogee in the northern hemi­ sphere, for the Molniya communications satellites operating within the Orbita system.

Cosmos 41, Cosmos 174 and Cosmos 260 may be considered as tests or Molniya replacement failures, but Cosmos 520, in 1972, and later Cosmos satellites with similar orbital parameters, did not fall into the well-defined Molniya groupings. Furthermore, their argu­ ments of perigee, rather than lying between 280° and 288° as for the Molniys, were all close to 315°.

The relocation of perigee produced broader northern hemisphere ground-track loops near apogee than those of the Molniyas and the ascending node was shifted from 115° to 90°W. In this new position the satellites could perform an early warning role for a consider­ able part of each orbit, able simultaneously to view the ICBM sites in the mid-western United States and communicate directly with the Soviet Union.

By 1980, a system of four satellites with orbital planes spaced at 80° was quasi-operational. The reason for the adoption of an 80° or­ bital plane spacing remained obscure until the launch of Cosmos 1247 in February 1981, when it was placed 40° away from the plane occupied by Cosmos 1191. The constellation of nine planes at 40° spacing was completed with the launch of Cosmos 1367 in 1982.

Notes:

• Orbital planes are separated by 900 in right ascension of the ascending node.
• Cosmos numbers immediately below the double line at the top of the table indicate the operational status as of Dec. 31, 1983.
• The ground-tracks of Cosmos 1285 and 1481, which should have replaced Cosmos 1261, were never stabilized.
• The ascending node of Cosmos 1661 was situated in the constellation's pre-1981 location.
• The ascending node of Cosmos 1729 was moved to the constellation's pre-1981 location at the end of 1986.
• Due to the premature shut-down of the final stage of the A-2e, Cosmos 1783 failed to attain the intended orbit and was never operational.
• Table prepared for the Congressional Research Service by G. E. Perry.

1984-1987 Eearly Warning ofMmissile and Space Launches

Early warning satellites in the Cosmos series occupy nine planes with 40 ° inter-plane spacing’s providing the necessary global cover­ age. Although the constellation of nine planes was completed with the launch of Cosmos 1367 in 1982, all planes had never been si­ multaneously operational through the end of 1983. Ascending nodes of the semi-synchronous, highly eccentric, orbits were located

close to 60°W and 240°W, having been relocated from 90°W and 270°W in 1981.

Despite an annual launch rate of seven satellites per year, it was not until 1986 that all nine planes were occupied by an operational satellite and, even then, one of those was not working in conjunc­ tion with the others. Full operational status was not attained until 1987, 15 years after the introduction of the program.

Table 49 lists the early warning Cosmos satellite launches from 1984 through 1987.

TABLE 49. — COSMOS EARLY WARNING SATELLITES: 1984-1987

Cosmos number and designator Launch dat, Apogee, Perigee, Inclination, periodl

1541 84-24A ....................... 3/6/84 39747 599 62.9 717.6

1547 84-33A.........................4/4/84 39750 594 62.9 717.6

1569 84-55A ........................6/6/84 39758 594 62.9 717.7

1581 84-71A ....................... 7/3/84 39723 621 63.0 717.6

1586 84-79A ....................... 8/2/84 39741 610 63.0 717.7

1596 84-96A......................... 9/7/84 39728 626 62.9 717.8

1604 84-107A ..................... 10/4/84 39722 598 62.9 717.1

1658 85-45A......................... 6/11/85 39758 592 62.9 717.7

1661 85-49A ........................6/18/85 39761 586 63.0 717.6

1675 85-71A ........................ 8/12/85 39732 602 62.9 717.4

1684 85-84A ........................ 9/24/85 39762 583 62.9 717.6

1687 85-88A...........................9/30/85 39710 626 63.0 717.4

1698 85-98A .........................10/22/85 39726 605 62.9 717.3

1701 85-105A ........................ 11/9/85 39719 619 63.0 717.5

1729 86-11A .......................... . 2/1/86 39733 633 62.9 718.0

1761 86-50A ............................ 7/5/86 39757 585 62.9 717.5

1774 86-65A ......................... .. 8/28/86 39723 616 63.0 717.5

1783 86-75A .......................... . 10/3/86 20057 597 62.8 358.1

1785 86-78A .......................... 10/15/86 39759 604 63.1 718.0

1793 86-91A ........................... 11/20/86 39755 594 63.0 717.7

1806 86-98A ............................12/12/86 39730 619 62.9 717.7

1849 87-48A ............................... 6/4/87 39728 627 62.9 717.8

1851 87-50A ............................... 6/12/87 39743 611 62.9 717.8

1903 87-10A ............................... 12/2/87 39757 588 63.0 717.6

Notes:

• All satellites were launched from Piesetsk by the A-2e.
• Apogee and perigee heights in kilometers, inclination in degrees and orbital period in minutes.
• Orbital data, which may differ from that given in the Master Log, has been computed from two line orbital element sets provided by NASA's Goddard Space Flight Center.
• Due to the premature shut-down of the final stage of the A-2e, Cosmos 1783 failed to attain the intended orbit and was never operational.
• Table prepared for the Congressional Research Service by G. E. Perry.

Cosmos 1317, which was launched in 1981, apparently broke up in January 1984, with NORAD cataloging three fragments in the only instance of fragmentation of such a satellite.

Replacement satellites were launched in every month, except May, during the period from March through October, 1984. All were launched into different orbital planes. Cosmos 1317 was not replaced until July. One month earlier, Cosmos 1518, which had been launched at the end of 1983, was lowered and permitted to drift off station after only five months of operation and was re­ placed, five days later, by Cosmos 1569. At the end of the year a replacement was still awaited for Cosmos 1261, which was launched in 1981 and failed in under a month, and whose intended replacements, Cosmos 1285 and Cosmos 1481, had never stabilized their ground tracks.

The long-awaited replacement came on June 11, 1985, with Cosmos 1658, the first of seven early warning launches in less than 5 months. The launch of Cosmos 1661, seven days later, reverted to the old launch profile with the higher period transfer orbit, last used for Cosmos 1317 in 1981, and stabilized its ground track with ascending nodes close to the original 1981 locations. Cosmos 1604 remained on station in that plane until it began to drift off in Octo­ ber and, at end of year, Cosmos 1661 was the only satellite in the nine planes with its ascending nodes displaced from the rest.

Cosmos 1687 failed in January, 1986, after only three months of operation and was not replaced until November when Cosmos 1793 was launched.

At the beginning of February, 1986, Cosmos 1729 was launched to replace Cosmos 1569, which had been in orbit for 20 months and then began to drift off station. Cosmos 1675, which had been re­ placed by Cosmos 1701 some three months earlier, also began to drift off station around this time. Cosmos 1698 was replaced by Cosmos 1761 in July after less than one year of operation. Cosmos 1547, which had failed nearly a year earlier, was replaced by Cosmos 1774 in August.

A premature shut-down of the final stage of the A-2e launch ve­ hicle left Cosmos 1783 in an orbit with approximately half the de­ sired orbital period and apogee rendering it useless for its intended role. Its orbital plane coincided with that of Cosmos 1661 so this still left that plane without an operational satellite with ascending nodes co-located with the others. Cosmos 1785, launched only 12 days later, was not a replacement for Cosmos 1783 but replaced the aging Cosmos 1596 after an operational life of more than two years.

Cosmos 1806 was launched on December 12 to replace Cosmos 1729, launched earlier in the year. On the following day Cosmos 1729 was maneuvered to relocate its ascending nodes close to those of Cosmos 1661. By the end of the year it had re-stabilized its ground tracks and eight of the planes contained satellites with as­ cending nodes in the locations adopted during 1981 while the ninth plane and one other were occupied by operational satellites with ascending nodes at the original locations used for the system.

The ninth plane was filled with a satellite having ascending nodes co-located with the others in June, 1987, but Cosmos 1661, with the displaced ascending nodes in that plane, remained active through mid-1988, as did Cosmos 1729. It is possible that these two satellites function as in-orbit spares which could be recalled to full operational status should the need arise.

The only other launches in 1987, Cosmos 1851 and Cosmos 1903 in June and December, were routine replacements of satellites which had been operational for two years or more. Therefore, since mid-1987, the Soviet Union could be considered to possess a fully operational constellation of satellites, with on-orbit spares, for the early warning of satellite and missile launches.

• Orbital planes are separated by 900 in right ascension of the ascending node.
• Cosmos numbers immediately below the double line at the top of the table indicate the operational status as of Dec. 31, 1983.
• The ground-tracks of Cosmos 1285 and 1481, which should have replaced Cosmos 1261, were never stabilized.
• The ascending node of Cosmos 1661 was situated in the constellation's pre-1981 location.
• The ascending node of Cosmos 1729 was moved to the constellation's pre-1981 location at the end of 1986.
• Due to the premature shut-down of the final stage of the A-2e, Cosmos 1783 failed to attain the intended orbit and was never operational.
• Table prepared for the Congressional Research Service by G. E. Perry.

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,

A. SOVIET SPACE PROGRAMS: 1976-80 (WITH SUPPLEMENTARY DATA THROUGH 1983), UNMANNED SPACE ACTIVITIES, PREPARED AT THE REQUEST OF Hon. JOHN C. DANFORTH, Chairman, COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION, UNITED STATES SENATE, Part 3, MAY 1985, Printed for the use of the Committee on Commerce, Science, and Transportation, 99th Congress, 1 st. session, COMMITTEE PRINT, S. Prt. 98-235, U.S. GOVERNMENT PRINTING OFFICE WASHINGTON : 1985

A . SOVIET SPACE PROGRAMS: 1981-87, SPACE SCIENCE, SPACE APPLICATIONS, MILITARY SPACE PROGRAMS, ADMINISTRATION, RESOURCE BURDEN, AND MASTER LOG OF SPACEFLIGHTS, Part 2, April 1989, Printed for the use of the Committee on Commerce, Science, and Transportation, U.S. GOVERNMENT PRINTING OFFICE, WASHINGTON, D.C. 1989, Committee print 1981-87- part-2