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The Tselina signal-intelligence satellite family Well before the space age began, the intelligence services around the world used electronic sensors to intercept and interpret radio signals generated by the enemy. This field of espionage became known as electronic intelligence or the ELINT. Among the early examples of lethal potential of the electronic intelligence was the British effort to intercept and decode the German secret communications during the World War II. It is known, that the German battleship Bismarck was hunted down and sank by the British Navy thanks to the intercepted radio messages. As the military use of the electromagnetic waves proliferated, so did the secret art of intercepting and analyzing the electromagnetic information. In addition to regular radio transmissions, the radar and telemetry signals provided wealth of material for the analysis by the ELINT experts on another side of the front line. During the Cold War, both sides introduced the aircraft, ships and submarines specifically equipped for the electronic espionage. With the dawn of the Space Age, the electronic intelligence war was destined to spread into orbit. One obvious advantage of space-based electronic intelligence is the satellites' ability of flying over enemy's territory with impunity. In the USSR, the very first photographic reconnaissance satellites soon demonstrated to the Soviet developers the possibility of this yet another military role for the spacecraft. Recent Russian sources (70) confirmed what Western analysts (34) suggested before: along with photo-cameras, the early spy satellites launched by the Soviet Union carried ELINT hardware. So-called Kust (bush) payload developed by TsNII-108 research institute led by M.E. Zaslavskiy was installed on the first Zenit photo recoinassance satellites. The Kust equipment proved the possibility of space-based interception of the radio signals originated on the ground. These first experiments led to the development of the satellites dedicated to the electronic intelligence. Tselina O/D development According to OKB-586 based in Dnepropetrovsk, in August 1960, the center has already received its first assignment to develop DS-K8 spacecraft with the goal of testing the methods and hardware for the determination of characteristics of the military radar installations from space. After initial studies, it was decided to implement a two-stage development program of the space-based radar tracking system. During the first stage, OKB-586 (now known as KB Yuzhnoe) developed two experimental spacecraft designated DS-K40, where DS stands for Dneprovskiy Sputnik (a generic name for KB Yuzhnoe spacecraft). Both DS-K40 were based on the DS-U1 and DS-U2 platforms. The second stage of the project, initiated in 1964, called for the development of the operational Tselina (Virgin Land) space-based electronic intelligence system. In its turn, the operational system would consist of the low-sensitive Tselina-O satellites and the high-sensitive Tselina-D spacecraft. TsNII-108 under the State Committee of Radio Electronics would be responsible for the development of the payload and OKB-586 for the overall design of the spacecraft. Tselina family overview:
*A modified version of the Tselina-O spacecraft, designated Tselina-OK, was also developed, apparently under index name 11F616M. Tselina development cooperation:
The launches of the experimental DS-K40 satellites were conducted on Dec. 28, 1965 and Feb. 21, 1966 onboard the 11K63 (Kosmos-2) rocket from the silo-based Dvina complex in Kapustin Yar. However, both attempts were unsuccessful. After these failures, KB Yuzhnoe proceeded with the development of Tselina-O and D spacecraft. Less complex, Tselina-O was ready for testing first. The spacecraft had no attitude control system and used some of-the-shelf hardware. The flight testing of the Tselina-O spacecraft started in Plesetsk in 1967. General G.I. Alpaidze, the chief of the NIIP-53 (Plesetsk) test range, served as the chairman of the State Commission overseeing the test program. According to the official Russian sources (70), in June 1970, the testing of the Tselina-O spacecraft and its ground control complex was completed and the next year the system was declared operational, confirming earlier suggestions by the Western analysts (34). The government decree accepting Tselina-O system into armaments apparently dated March 26, 1972. The western analysts observed that since 1972, the satellites of this type have been placed in orbit 45 degrees apart, apparently to maximize their coverage. Also in 1970, a more complex Tselina-D spacecraft started flying. Since Tselina D used the orbits similar to the first generation Meteor weather satellites, but showed no signs of activity, in the West, they were initially misidentified as failed Meteors. At the peak of the program, two Tselina-D spacecraft were operating in orbit at a time. Both Tselina O and D versions were flying side by side until 1984, when Tselina-O subsystem was abandoned and its functions integrated into those conducted by the Tselina-D spacecraft. As the Western observers noted, the Tselina-D spacecraft, known in the West as the "heavy ELINT," would orbit the Earth in groups of six satellites spread 60 degrees apart in their orbits. In 1981 the second ground control station capable of receiving and processing of the data from Tselina spacecraft was declared operational. Tselina-2 development By the beginning of the 1970s, the operations of the first generation electronic intelligence spacecraft allowed TsNII KS, a "think tank" of the Soviet space forces, compiling a map of the potential targets of radio emissions. The Soviet military expected to obtain even more detailed picture on its electronic targets with the next-generation system, which was under study since March 1973. In the first quarter of 1974, the same industrial team, which built Tselina-O/D network, completed the preliminary design of the follow-on ELINT system, designated Tselina-2, or Tselina (2). In May 1974, the Soviet Ministry of Defense issued to the prime contractors its requirements for the Tselina (2) system and in July 1975, the Military Industrial Commission, VPK, of the Soviet government, approved the development schedule for the spacecraft. An official government decree, issued on December 10, 1976, called for the first test launch of the Tselina-2 spacecraft in the 1st quarter 1980 and the bringing the system into operational status in 1982. The same December 1976 decree declared the Tselina system, including "O" and "D" subsystems, operational. The original purpose of the previous generation Tselina spacecraft was limited to detection and pinpointing of the sources of the radio transmissions. However, during the flight testing, the satellites also demonstrated their capability to determine the type, characteristics and performance modes of their targets. The official Russian sources claim that the analysis of the intensity and the nature of the radio-exchange between the targeted military installations provided important clues about upcoming movements of the troops, which would be later confirmed by photo-surveillance satellites. As the Soviet military was gaining more and more experience in using space-based electronic intelligence during the 1970s, it kept expanding the list of requirements for the range, sensitivity and lifespan of the spacecraft for the follow-on ELINT system. The addition of the new capabilities into the design of the next-generation spacecraft finally left the Tselina-2 satellites too heavy for the standard Tsyklon-3 booster, which was delivering Tselina-D spacecraft. The Ministry of General Machine Building, MOM, which oversaw the space industry, proposed to launch Tselina 2 by the yet-to-be developed Zenit rocket. Even though, such move would certainly delay the introduction of the new satellites until the Zenit rocket enters service, the Ministry of Defense agreed with the MOM's proposal. The switch to Zenit opened the door for even more drastic upgrades and for further increase in the size and weight of the future electronic intelligence satellites. Among latest additions to the Tselina-2 spacecraft was the equipment for transmitting the intelligence data to the "customer" through a relay satellite. On April 27, 1979, the Military Industrial Commission, VPK, officially approved the Zenit as a launcher for the Tselina-2 satellite. The VPK scheduled the beginning of flight tests for the 2nd quarter of 1981. Due to continuous delays with the Zenit development, the Ministry of Defense in cooperation with MOM and the Ministry of the Radio Industry, which oversaw subcontractors developing the payload for Tselina-2, worked out a back up plan of launching the new satellite onboard the Proton (8K82K) booster. After the modifications had been conducted during 1983 and 1984, the first Tselina-2 blasted off in September 1984 under official name Kosmos-1603. Colonel General German Titov, the legendary cosmonaut, served as a chairman of the State Commission overseeing the tests. The Kosmos-1603 generated major discussions among Western analysts, who were puzzled by strange maneuvers of the craft, which initially remained attached to the upper stage of the Proton rocket. Together the stage and the spacecraft entered the initial orbit with the inclination 51 degrees, then raised the inclination to 66 and finally to 77 degrees. Such flight path seemed totally irrational in comparison with, say, direct launch to 77-degree orbit from Baikonur. Obviously, today, after knowing that the Proton was considerably oversized for the Tselina-2, such orbital behavior becomes understandable. Total three spacecraft were scheduled to fly onboard Proton, before the Zenit would pick the torch, however only two of those have actually taken place. Tselina-2 system was declared operational in December 1988, which was confirmed by a government decree issued in December 1990. Tselina-2 description Although the much of the information about the Tselina-2 system is still classified, the spacecraft is known to be equipped with the three-axis attitude control system, the pressurized instrument section, the deployable boom, providing gravitational stabilization, and the Korvet radio-receiving hardware. The solar panels apparently have one-axis orientation. The top section of the spacecraft consists of a separate pressurized container carrying optical sensors for the high-precision attitude control system. The energy supply system provides 350 Watt of electricity after the launch and around 315 Watt at the end of the lifespan. The attitude control system designed to provide at least five-degree accuracy for roll control and 10-degree accuracy for yaw and pitch control. The angular rotation speed can be maintained with the accuracy of 0.02 degrees per second. Tselina-2 status According to reliable sources, during the visit of the Russian president Vladimir Putin to Ukraine in January 2001, two sides agreed to proceed with the plans of launching a pair of Tselina-2 satellites for Russia's Armed Forces. Both spacecraft were apparently in the state of assembly at the time of the agreement. Tselina launch chronology: (Launches from Plesetsk: Tselina-O is launched by Kosmos-3M; Tselina-D by Vostok (1970-1983) and Tsyklon-3 (1981-1992); Launches from Baikonur: Tselina-2 is launched by the Proton in the first two flights and then by the Zenit-2 rocket) 1967 Oct. 30: The first Tselina-O (Kosmos-189) spacecraft reached the orbit after the launch by the 11K67M (Kosmos-3M) rocket from Plesetsk. 1968 Jan. 20: Tselina-O (Kosmos-200) Oct. 31: Tselina-O (Kosmos-250) 1969 March 5: Tselina-O (Kosmos-269) Dec. 20: Tselina-O (Kosmos-315) 1970 April 7: Tselina-O (Kosmos-330) Dec. 16: Tselina-O (Kosmos-387) Dec. 18: The first Tselina-D (Kosmos-389) launched from Plesetsk by the 8A92M/Vostok rocket. 1971 Feb. 18: Tselina-O (Kosmos-395) April 7: Tselina-D (Kosmos-405). The spacecraft reentered over the Pacific Ocean on Nov. 3, 2023, at 03:27 UTC. May 29: Tselina-O (Kosmos-425) Sept. 7: Tselina-O (Kosmos-436) 18 fragments originated from this launch were detected by Western radar. They were probably a result of an explosion of the upper stage or the spacecraft itself. (34) Sept. 10: Tselina-O (Kosmos-437) Nov. 71 Tselina-O (Kosmos-460) 1972 March 1: Tselina-D (Kosmos-476) March 22: Tselina-O (Kosmos-479) July 10: Tselina-O (Kosmos-500) Nov. 3: Tselina-O (Kosmos-536) Dec. 28: Tselina-D (Kosmos-542) 1973 Jan. 20: Tselina-O (Kosmos-544) Feb. 26 Tselina-O (Kosmos-549) Aug. 28: Tselina-O (Kosmos-582) Oct. 29: Tselina-D (Kosmos-604) Nov. 27: Tselina-O (Kosmos-610) 1974 Feb. 6: Tselina O (Kosmos-631) May 21: Tselina-O (Kosmos-655) June 21: Tselina-O (Kosmos-661) Aug. 16: Tselina-D (Kosmos-673) Dec. 18: Tselina-O (Kosmos-698) 1975 Feb. 5: Tselina O (Kosmos-707) June 20: Tselina-D (Kosmos-744) July 4: Tselina-O (Kosmos-749) Aug. 14: Tselina-D (Kosmos-755) Aug. 22: Tselina-D (Kosmos-756) Nov. 21: Tselina-OK (Kosmos-781) 1976 Jan. 6: Tselina O (Kosmos-787) Jan. 23: Tselina-O (Kosmos-790) March 16: Tselina-D (Kosmos-808) April 6: Tselina-O (Kosmos-812) July 27: Tselina-O (Kosmos-845) Aug. 27: Tselina-D (Kosmos-851) Dec. 2: Tselina-O (Kosmos-870) 1977 Feb. 27: Tselina-D (Kosmos-895) March 25: Tselina-O (Kosmos-899) July 5: Tselina-OK (Kosmos-924) July 7: Tselina-D (Kosmos-925) Sept. 20: Tselina-D (Kosmos-955) Oct. 25: Tselina-O (Kosmos-960) 1978 Jan. 10: Tselina-D (Kosmos-975) May 12: Tselina-D (Kosmos-1005) May 17 Tselina OK (Kosmos-1008) June 28: Tselina-D (Kosmos-1025) Oct. 10: Tselina-D (Kosmos-1043) Dec. 15: Tselina-O (Kosmos-1062) Dec. 18: Tselina-D (Kosmos-1063) 1979 Feb. 14: Tselina-D (Kosmos-1077) April 14: Tselina-D (Kosmos-1093) July 11: Tselina-O (Kosmos-1114) July 20: Tselina-D (Kosmos-1116) Oct. 26: Tselina-D (Kosmos-1143) Nov. 27: Tselina-D (Kosmos-1145) 1980 Jan. 30: Tselina-D (Kosmos-1154) March 18: 48 people died in Plesetsk during the on-pad explosion and fire of the Vostok-2M (8A92) launcher with the Tselina-D spacecraft. June 4: Tselina-D (Kosmos-1184) Aug. 15: Tselina-D (Kosmos-1206) Oct. 14: Tselina-O (Kosmos-1215) Nov. 21: Tselina-D (Kosmos-1222) 1981 Jan. 27: Tselina-D (Kosmos-1242) May 19: Tselina D (Kosmos-1271) Aug. 25: Tselina-D (Kosmos-1300) launched by a Tsyklon-3 rocket for the first time. Oct. 14: Tselina-D (Kosmos-1315) Dec. 3: Tselina D (Kosmos-1328) 1982 Feb. 19: Tselina-D (Kosmos-1340) March 31: Tselina-O (Kosmos-1345) March 31: Tselina-D (Kosmos-1346). The satellite reentered the Earth's atmosphere on Dec. 17, 2017. May 5: Tselina D (Kosmos-1356) June 10: Tselina-D (Kosmos-1378) Aug. 5: Tselina D (Kosmos-1400) Sept. 16: Tselina-D (Kosmos-1408). The defunct satellite was destroyed in an apparent test of a Russian Nudol direct ascent anti-satellite system in the early hours of Nov. 15, 2021, forcing crew members aboard the ISS to take shelter in their return vehicles during close passes with a debris cloud. According to the US Space Command, the intercept generated up to 1,500 trackable objects and orbital elements for more than 100 were made publicly available by the 18th Space Control Squadron of the US military on Nov. 30, 2021. The analysis of official warnings about downrange impact sites and the known orbit of Kosmos-1408 indicated that the interceptor lifting off from Plesetsk between 02:00 and 05:00 UTC had an opportunity to approach its target from behind, most likely at 02:52 UTC, a satellite observer Marco Langbroek wrote on the Seesat mail list. Kosmos-1408 passed over Plesetsk for the final time before its destruction at 02:47 UTC on Nov. 15, 2021. 1983 Jan. 20: Tselina-D (Kosmos-1437) Feb. 16: Tselina-D (Kosmos-1441) launched by the Vostok rocket for the last time. April 23: Tselina-D (Kosmos-1455) June 23: Tselina-D (Kosmos-1470) July 20: Tselina-D (Kosmos-1483) Dec. 15: Tselina-D (Kosmos-1515) 1984 Feb. 8: Tselina D (Kosmos-1536) March 15: Tselina-D (Kosmos-1544) Sept. 28: The Proton booster launched the first Tselina-2 prototype, announced as Kosmos-1603. Oct. 18: Tselina-D (Kosmos-1606) 1985 Jan. 24: Tselina-D (Kosmos-1626) March 5: Tselina-D (Kosmos-1633). The satellite reentered on April 5, 2024, at around 11:30 UTC. April 13: The first Zenit-2 rocket lifts off from Baikonur. Due to problems with the controller of the propellant consumption on the second stage of the rocket, its engine run out of fuel and prematurely shot down at T+400 seconds. (67) The payload did not reach the orbit and the launch was not announced at the time. The rocket carried EPN 03.0694 payload equivalent, representing general dimensions, shape, weight and the center of gravity of the Tselina-2 spacecraft. To measure sound and vibration loads during the launch, the EPNs carried acustic sensors and vibration accelerometers. A separate set of accelerometers also tracked the process of payload fairing jettison. The EPN also carried hardware to measure orbit parameters. May 30: The Proton rocket launched the second Tselina-2 spacecraft announced as Kosmos-1656. June 21: The Zenit-2 rocket lifts off from Baikonur, however its second stage shot down prematurely. Some fragments from this launch reached the orbit, however the launch was not announced at the time. (67) The rocket carried EPN 03.0694 payload equivalent, representing the Tselina-2 spacecraft. July 9: Tselina D (Kosmos-1666) Aug. 8: Tselina D (Kosmos-1674) Oct. 22: The Zenit-2 launched successfully. The rocket carried EPN 03.0694 payload equivalent, representing the Tselina-2 spacecraft. The payload was announced as Kosmos-1697. Nov. 23: Tselina-D (Kosmos-1703) Dec. 12: Tselina-D (Kosmos-1707) Dec. 28: The Zenit-2 launched the Tselina-2 satellite. The spacecraft entered wrong orbit due to the malfunction of the second stage of the launch vehicle. The payload announced as Cosmos 1714. 1986 Jan. 17: Tselina-D (Kosmos-1726) Feb. 20: Tselina-D (Kosmos-1733) May 15: Tselina D (Kosmos-1743) June 12: Tselina-D (Kosmos-1758) July 30: The Zenit-2 rocket launched successfully. The rocket carried EPN 03.0695 payload equivalent, designed to test the Zenit's performance at its maximum cargo capacity. The EPN 03.0695 consisted of the Tselina-2 mockup attached to a four-segment cargo article. The payload was announced as Kosmos-1767. Sept. 30: Tselina-D (Kosmos-1782) Dec. 10: Tselina-R (Kosmos-1805) 1987 Jan. 14: Tselina-D (Kosmos-1812) Feb. 14: 11:30:00 Moscow Time: Zenit-2 launched Kosmos-1820, thought to be a prototype of the Orlets-2 imaging reconnaissance spacecraft. In reality, the rocket carried EPN 03.0695 payload equivalent, designed to test the Zenit's performance at its maximum cargo capacity. The EPN 03.0695 consisted of Tselina-2 mockup attached to a four-segment cargo article. March 3: Tselina-D (Kosmos-1825) March 18: The Zenit-2 launched successfully. The rocket carried EPN 03.0694 payload equivalent, representing general dimensions, shape, weight and the center of gravity of the Tselina-2 spacecraft. The payload was announced as Kosmos-1833. April 27: Tselina-D (Kosmos-1842) May 13: Zenit-2 successfully launched the Tselina-2 spacecraft. The payload announced as Kosmos-1844. Michael Gorbachev, the head of the ruling Communist Party at the time, personally witnessed the launch in Baikonur. July 1: Tselina D (Kosmos-1862) Aug. 1: 06:59:00 Moscow Time: Zenit-2 launched Kosmos-1871, thought to be a prototype of the Orlets-2 imaging reconnaissance spacecraft. In reality, the rocket carried EPN 03.0695 payload equivalent, designed to test the Zenit's performance at its maximum cargo capacity. The EPN 03.0695 consisted of Tselina-2 mockup attached to a four-segment cargo article. Aug. 28: 11:20:00 Moscow Time: Zenit-2 launched Kosmos-1873, thought to be a prototype of the Orlets-2 imaging reconnaissance spacecraft. In reality, the rocket carried EPN 03.0695 payload equivalent, designed to test the Zenit's performance at its maximum cargo capacity. The EPN 03.0695 consisted of Tselina-2 mockup attached to a four-segment cargo article. This was the last test launch of the Zenit rocket. Oct. 20: Tselina-D (Kosmos-1892) 1988 Jan. 6: Tselina D (Kosmos-1908) March 15: Tselina-D (Kosmos-1933) May 15: Tselina-2 (Cosmos 1943) June 14: Tselina-D (Kosmos-1953) Oct. 11: Tselina-D (Kosmos-1975) Nov. 23: Tselina-2 (Kosmos-1980) 1990 Jan. 30: Tselina-R (Kosmos-2058) May 22: Tselina-2 (Kosmos-2082) Oct. 4: Zenit-2 failed 4 seconds after the launch with the Tselina-2 spacecraft destroying "right" launch pad at Site-45 in Baikonur. From now on, only the "left" pad was used for the Zenit launches. 1991 June 13: Tselina-R (Kosmos-2151) Aug. 30: Zenit-2 failed to place a satellite into orbit due to the second stage failure. 1992 Feb. 5: Zenit-2 failed to place a satellite into orbit due to the second stage failure. Nov. 17, 10:42 Moscow Time: Tselina-2 (Kosmos-2219) Nov. 24: Tselina-D (Kosmos-2221). On Feb. 28, 2024, at 1:30 a.m. EST, Kosmos-2221, long defunct, passed in close proximity from NASA's TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamic Mission) satellite at an altitude of 600 kilometers, according to NASA and US Department of Defense. None of the spacecraft had capability to maneuver, the agencies said. Dec. 25: Tselina-2 (Kosmos-2227) Dec. 25: Tselina-D (Kosmos-2228) 1993 March 26: Tselina-2 (Kosmos-2237) April 16: Tselina-R (Kosmos-2242) Sept. 16: Tselina-2 (Kosmos-2263) 1994 April 23: Tselina-2 (Kosmos-2278) May 24: The Tselina spacecraft failed to reach orbit due to the separation failure between second and third stages of the Tsyklon-3 vehicle at T+279 seconds. (67) Nov. 24: Tselina-2 (Kosmos-2297) 1995 Oct. 30: Tselina-2 (Kosmos-2322) 1996 Sept. 4: Tselina-2 (Kosmos-2333) 1997 May 20: A Zenit rocket exploded 48 seconds after launch, while carrying a Tselina-2 spacecraft. The debris fell eight miles downrange. 1998 July 28: 13:15 Moscow Time: Tselina-2 (Kosmos-2360) 2000 Feb. 3, 12:26:00 Moscow Time: Tselina-2 (Kosmos-2369) 2004 June 10, 05:28 Moscow Time: A long-delayed military mission finally took off successfully from a Russian launch site in Kazakhstan. A Zenit-2 rocket carrying a classified payload for the Russian Ministry of Defense blasted off from Site 43 in Baikonur Cosmodrome at 05:28 Moscow Time on June 10, 2004. According to the Russian Space Forces, the spacecraft separated from the upper stage of the launch vehicle at 05:41 Moscow Time and successfully established radio contact with ground control. The payload was designated as Kosmos-2406. (The same designation had been previously assigned to a military payload, which was later renamed, freeing number 2406.) According to North American Aerospace Defense, NORAD, Kosmos-2406 entered a 848 by 865-kilometer orbit, with an inclination of 71 degrees toward the Equator. Both, the altitude and inclination exactly match orbital parameters of the Tselina-2 series of electronic intelligence, ELINT, spacecraft. According to KB Yuzhnoe of Dnepropetrovsk, Ukraine, the manufacturer of the Tselina satellites, the mass of Kosmos-2406 payload was 3,100 kilograms, which is close to known specifications for the Tselina-2 payload. This mission was expected as early as mid-February 2004, as part of Security 2004 exercise, however did not take place. Technical problems reportedly delayed the mission again from February 28 and April 6. On April 25, 2004, the countdown for the launch was scrubbed at T-55 minutes due to failure in the ground power supply system. On April 26, 2004, another problem in the ground launch equipment stopped at T-88 minutes preparations for a launch scheduled for 14:42 Moscow Time at T-88 minutes. The launch was then reportedly rescheduled to 02:46 on April 27, but never took place. The vehicle was then removed from the launch pad and returned to the assembly building. The mission was then rescheduled for June 5-15 period. 2007 June 29: Russian military received a new "ear in the sky," launching a satellite designed to intercept electronic communications. The Zenit-M rocket blasted off from Site 45 in Baikonur Cosmodrome, Kazakhstan, on June 29, 2007, at 14:00 Moscow Time. In accordance with the usual practice for the Russian military launches, the payload was identified as a satellite from the Cosmos series (Kosmos-2428). No details on the goals of the mission was officially released, however it is widely believed that the Zenit rocket delivered its most frequent military payload - the Tselina-2 satellite. According to official Russian media, Titov Main Test and Control Center of the Russian space forces had established contact with the satellite at 14:16:36 Moscow Time and all the systems onboard the spacecraft worked well. The satellite is likely to be the last spacecraft in the series built by KB Yuzhnoe of Dnepropetrovsk, Ukraine. The development of the new generation spacecraft for electronic intelligence had been apparently transferred to contractors inside Russia, after the fall of the Soviet Union. During the summit of Russian and Ukrainian head of states in 2001, they reportedly reached an agreement to complete the construction and launch of last two Tselina payloads. The first was sent aloft in 2004. The latest launch was previously expected to take place in August-September 2006 and then it was postponed to December 16, 2006, January and February 14, 2007, and the beginning of the second quarter of 2007. The Zenit-M rocket (also known as No. 1-2005), which has been used for the latest launch, differed from the standard Zenit-2 launcher by a modified first stage engine, known as RD-171M and capable of delvering a five-percent increase in thrust, comparing to the standard RD-171 engine. The rocket also featured a different guidance system and a new main flight control computer, designated Biser-3. While lighter then the previous system, Biser-3 enables more accurate delivery of the payload into the orbit. The rocket was originally built to deliver Globalstar satellites on December 19, 1998, however the mission was cancelled in the wake of the failure of a similar vehicle in 1998. The launch vehicle was then refurbished for the Zenit-M program, which Roskosmos considers a stepping stone toward the Zenit-3M vehicle. In combination with Block DM and Fregat upper stages and larger diameter payload fairing, Zenit-3M would be capable of delivering from 2 to 3.6 tons of payload to the geostationary orbit, according to Russian space agency, Roskosmos. |
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