Yantar-4K1

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Yantar-4K1

Soviet Reconnsats - Soviet reconnaissance satellites. Top row: Zenit-2, Zenit-4, Advanced Zenit with aerodynamic orientation; Middle Row: Yantar 1K, Yantar 2K, Orlets-1 with multiple return capsules; bottom row, Buran-serviced pallet-based satellite; Yantar 4KS electrooptical

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Article Number: 11F693. Code Name: Oktant. Class: Surveillance. Type: Military. Nation: USSR. Manufacturer: TsKB.

Flight trials of the Yantar-2K indicated the satellite was not capable of providing strategic warning of attack. A meeting of the Council of Chief Designers at TsSKB in May 1977 reviewed alternative approaches. Three additional variants were to be developed, one of them the high resolution Yantar-4K. The project was to be implemented in two phases: the Yantar-4K1, launched by the existing Soyuz-U launch vehicle, and the Yantar-4K2, to be launched by the new more powerful Zenit launch vehicle.

The Yantar-4K1 would increase the satellite’s operational lifetime by 50%, to 45 days, and have an improved camera system, the PO Krasnogorskiy Zavod’s Zhemchug-18. These changes were relatively minor. Externally the spacecraft were difficult to distinguish, and the masses were essentially the same. Therefore the same Soyuz 11A511U rocket and 11S516 payload fairing could be used for the Yantar-4K1.

The project went smoothly and rapidly. The first flight model was ready only two years later. The first launch in the flight trials was in April 1979, for 30 days. A second full-duration flight a year later was also successful, leading to the acceptance test flight in October 1980, also without problem. Yantar-4K1 was accepted into service in 1982 with the code name Oktan. Due to capacity problems as TsKB in Samara, production was handed over to KB Arsenal from 1984.

The Yantar-4K1 ultimately replaced the Zenit reconnaissance satellite series, with the final military flight of the Zenit in October 1980. Zenit civilian models continued in use after the retirement of the Yantar-4K1 (Oblik, Resurs F-1 and F-2). From 1984 Yantar-4K1 was flown for durations of up to 60 days. Launches continued into 1999. Typical orbital profile was: inclination 64.9, 67.1, or 70 degrees with altitude of 170-340 km. Transmission frequency observed in the West was 240.5 PCM-FM.

Specification

Total Length: 6.3 m. Maximum Diameter: 2.7 m. Total Mass: 6,600 kg.

Yantar-4K1 Chronology

21 July 1967 US Project reassigned; R-36-O booster development approved; Yantar-2K and Zvevda 7K-VI approved. Launch Vehicle: R-36-O, Tsyklon 2, Soyuz 11A511M.

Decree 715-240 'On the Creation of Space Systems for Naval Reconnaissance Comprising the US sat and the R-36-based booster -further work on the US naval reconnaissance satellite, approval of work on the Yantar-2K, and course of work on 7K-VI Zvezda'.

An entire family of Yantar spacecraft was proposed by Kozlov’s design bureau during the initial development; information on two film return models has been declassified. Yantar was initially derived from the Soyuz spacecraft, including systems developed for the Soyuz VI military model. During design and development this changed until it had very little in common with Soyuz.

Following numerous problems in the first flight tests of the Soyuz 7K-OK, Kozlov ordered a complete redesign of the 7K-VI manned military spacecraft. The new spacecraft, with a crew of two, would have a total mass of 6.6 tonnes and could operate for a month in orbit. The new design switched the positions of the Soyuz descent module and the orbital modules and was 300 kg too heavy for the standard 11A511 launch vehicle. Therefore Kozlov designed a new variant of the Soyuz launch vehicle, the 11A511M. The project was approved by the Central Committee of the Communist Party, with first flight to be in 1968 and operations to begin in 1969. The booster design, with unknown changes to the basic Soyuz, did not go into full production.

01 May 1977 Council of Chief Designers reconsiders Yantar Soviet reconnsat designs

Flight trials of the Yantar-2K indicated the satellite was not capable of providing strategic warning of attack. The planned Yantar-6K series, in development since 1969, were overweight and behind schedule. A meeting of the Council of Chief Designers at TsSKB reviewed alternative approaches. It was decided that three variants of the Yantar-2K were to be developed, one of them the high resolution Yantar-4K.

27 April 1979 Cosmos 1097 Launch Site: Plesetsk . Launch Vehicle: Soyuz 11A511U. Mass: 6,600 kg. Perigee: 173 km. Apogee: 331 km. Inclination: 62.8 deg. Duration: 30.00 days.

First flight test of Yantar-4K1 satellite. Returned as planned after 30 days. High resolution photo reconnaissance; returned film in two small SpK capsules during the mission and with the main capsule at completion of the mission.

29 April 1980 Cosmos 1177 Launch Site: Plesetsk . Launch Vehicle: Soyuz 11A511U. Mass: 6,600 kg. Perigee: 167 km. Apogee: 331 km. Inclination: 67.2 deg. Duration: 44.00 days.

Second flight test of Yantar-4K1 satellite. Demonstrated full spacecraft design duration of 45 days. High resolution photo reconnaissance; returned film in two small SpK capsules during the mission and with the main capsule at completion of the mission.

30 October 1980 Cosmos 1218 Launch Site: Baikonur . Launch Vehicle: Soyuz 11A511U. Mass: 6,600 kg. Perigee: 158 km. Apogee: 285 km. Inclination: 64.9 deg. Duration: 43.00 days.

Successful state acceptance test flight of Yantar-4K1 satellite. Led to Yantar-4K1 acceptance for Red Army service the following year. High resolution photo reconnaissance; returned film in two small SpK capsules during the mission and with the main capsule at completion of the mission.

21 August 1981 Cosmos 1298 Launch Site: Baikonur . Launch Vehicle: Soyuz 11A511U. Mass: 6,600 kg. Perigee: 170 km. Apogee: 328 km. Inclination: 64.8 deg. Duration: 42.00 days.