Zenit 2 - Zenit-2. Later improved version Zenit-2M commonly had a Nauka module mounted on the forward end of the sphere. 18,612 bytes. 321 x 194 pixels.

The Zenit spacecraft had its origins before Sputnik. In 1956, the Soviet military identified a requirement for a photo-reconnaissance satellite (see Zenit). Sergei Korolev, flushed after the success of Sputnik, instead advocated that manned spaceflight should have first priority. After bitter disputes, a compromise solution was reached. Korolev was authorised to proceed with development of a spacecraft to achieve manned flights at the earliest possible date. However the design would be such that the same spacecraft could be used to fulfil the military's unmanned photo reconnaissance satellite requirement. A series of 1K prototypes would prove the essential design; the 2K and 4K versions would be unmanned spy satellites, and the 3K the manned spaceship. The military resisted, but in November 1958 Korolev won, and the Council of Chief designers approved the Vostok manned space program, in combination with Zenit spy satellite program.

Development work was begun in May 1959. Project leader was Ryazanov until 1961; thereafter Tsybin. Section heads were Yu M Frumkin for the spacecraft and Ts V Solovyov for the communications. The agreed technical specifications for the 2K satellite (given the code name Zenit-2) were for a photo apparatus with a focal length of not less than a meter, limited only by the size of the spacecraft itself. Electronics were to include secure radio systems that would only transmit and receive data when the spacecraft was over the territory of the USSR. These included transmission of photo-television images and receipt of secure command and programming data.

There were many difficult problems during development. The requirement for 10-15 m camera resolution from 200-400 km altitude and a speed of 8,000 m/s meant that a motion compensation system was needed. Pointing requirements were very demanding, resulting in the first Soviet use of a gyroscopic platform, infrared horizon sensors, and integration of the sensors into an automated orientation system. Technical challenges existed not just in the spacecraft but in the ground control center, which had to generate spacecraft command sequences. This was the first development of an on0board system to execute complex commands from the ground. The spacecraft optics required that internal temperatures be kept within 1 degree Centigrade, and that temperature variations be no more than 0.1 degrees/hour. Since the spacecraft was normally oriented to the sun, an active thermal regulation system was needed.

The Vostok and Zenit satellites differed from each other as follows:

• The Zenit had an extended cylindrical section in the PAO instrument/propulsion module, and lacked the aft communication antennae of the Vostok;
• The SA descent capsule and the PAO of the Zenit had large directional dish antennae for use with the secure radio-command system;
• Zenit deleted man-related life support systems, the ejection seat, and the systems for manual control of the spacecraft.
• Added were specialised intelligence systems, telemetry systems, and information systems control electronics. The Zenit-2 needed its own radio-guidance system. It couldn't use Vostok systems, since it needed to upload all instructions for the entire daily work program of automatically-controlled photography over enemy territory within a five minute pass over USSR ground stations. All communications also had to be encrypted.

  The radio control system was to have been developed on the basis of preliminary work on the Podsnezhnik radio control system. A competitor was the Kub system developed by OKB-1. The conflict between the two systems was elevated to Marshal Moskalenko. The matter was decided at a meeting between Moskalenko, Korolev, and Chertok. Korolev was very possessive, and argued the case not on the technical merits but rather on keeping all Zenit-2 work within OKB-1. Moskalenko finally decided to develop both systems. Mikhail Pavlovich Petelin was the Chief Designer of Podsnezhnik and Armen Sergeyevich Mnatsoskanian was Chief Designer of Kub. Kub was finally selected as having nearly competed development.

• While the Vostok needed to control its orientation only during descent, the photographic mission required constant 3-axis high precision control. For successful photography it needed to very precisely determine its position in orbit and point its camera at the correct target
• While the life support system was not required, control of the internal temperature of the capsule was even more critical than on the Vostok, due to the temperature sensitivity of the camera optics.
• To guarantee the security of the secret equipment aboard Zenit, the APO-2 automatic destruct system was installed. The APO-2 could not only operate on command but would also automatically destroy the spacecraft if certain complex logical parameters were met - for example, if it determined that the capsule was going to land on enemy territory.

The first Zenits were fitted out with the SA-20 camera, with a focal length of 1 meter, the SA-10 camera, with a focal length of 0.2 m, the Baikal photo-television device, and the Kust-12M ELINT radio apparatus (developed by M E Zaslavskiy). Baikal was installed in Zenit serial numbers 1, 2, 3,4, 7 and 8. However after four successful trial flights (Cosmos 4, 7, 9, and 15) it became clear that the Baikal did not live up to its expected specifications (the United States had a similar experience with its early electro-optical systems on the Samos series). Subsequent Zenits dropped the Baikal and used the Ftor-2P, which combined the SA-20 and SA-10 cameras and the Kust-12M ELINT apparatus into a single system. The Ftor-2P was designed to photograph, from altitudes of 180 to 200 km, 1500 frames of film, each frame covering a 60 x 60 km area, for a total coverage per mission of 5.4 million square kilometres. The system could not only take photographs at the nadir but also at oblique angles to the side of the flight path. Yu V Ryabushkin of the Krasnogorsk Mechanical Factory was chief designer of the camera.

Zenits from the beginning carried small supplemental experimental packages, for example meteoroid or cosmic particle detectors. On Zenit number 80 the Nauka autonomous sub-satellite was flown. The Nauka containers served a dual purpose. Mounted on the forward end of the re-entry sphere, they provided ballast on the spacecraft during its mission. When the Zenit had completed its work, the Nauka would be released for autonomous flight. Over 40 Nauka containers were installed on Zenit-2 and Zenit-2M spacecraft, and they achieved noteworthy results in scientific and military space research.

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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 21,799 bytes. 340 x 332 pixels.

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Five prototype Vostok 1K spacecraft were launched in May to December 1960; only one of the flights was completely successful. These were followed two entirely successful Vostok 3KA launches in March 1961. The third Vostok 3KA, on 12 April 1961, put the first human into space. This was followed by Gherman Titov�s day-long flight in August of the same year.

Focus now turned to testing of the 2K spacecraft, code named Zenit-2. A modification of the 8K72 three-stage launch vehicle, the 8A92, was developed for Zenit. The first launch on 11 December 1961 was a failure, due to a fault in the third stage.

The first flight trials Zenit-2 was launched on 11 December 1961. However the launch ended in failure of the launch vehicle upon ignition of the third stage. The spacecraft APO destruct system at least proved its operation by detecting the shut down and automatically destroying the spacecraft.

The second Zenit-2 successful reached orbit on 26 April 1962, officially being designated Cosmos 4. However leaks from the oxygen system tanks used for the orientation system resulted in the premature return of the spacecraft after three days of flight. During most of the flight the spacecraft was uncontrollable, although the photographic material returned could be used to determine the performance of the Baikal and SA-10 systems. In all 13 LKI trials launches were made of Zenit-2, three of which ended in failure of the launch vehicle. Each flight was used methodically to test all systms, verify guidance commands, etc. Lessons learned were applied to the modernized spacecraft, which had improved cameras, on-board systems, and autonomous guidance methods. The ineffective television system was deleted.

Zenit-2 number 14 began the production flights of the spacecraft. Production and design responsibility was moved at that point from Korolev�s main OKB-1 facility near Moscow to OKB-1 Filial No.3 in Samara, headed by D I Kozlov. Later Kozlov was also given responsibility for the R-7 ICBM and its space-launch derivatives. Filial No. 3 was made a separate organisation, the TsKB Central Specialised Construction Bureau, which incorporated the Progress production factory in Samara. The TsKB to this day has been the leading supplier to the Soviet military of imaging spacecraft, all of them using Soyuz launch vehicles produced at the same factory.

The first two Zenits were launched by the same 8K72K launcher used for the Vostok manned spacecraft. The rest, from 1962 to 1967, used productionised Vostok 8A92 launchers. The Zenit-2, given article number 11F61, and the 8A92 launchers, were adopted as armament of the Soviet Army on 10 March 1964 by decree of the Defence Ministry of the USSR number 0045.

From 1967 launch of most Zenit-2�s was moved to the northern Plesetsk cosmodrome. To reach the higher-inclination orbits required use of a more powerful launch vehicle, the Soyuz 11A57. Decree no 0015 of 1967 amended the earlier decree to add to the Zenit-2 complex the 11A57 and the newer APO-4B destruct system.

From 1968 flights gradually transitioned to the modernised spacecraft Zenit-2M. The last launch of a Zenit-2 was on 12 May 1970. In all, including the state trials launches, 81 Zenit-2�s were launched, of which 7 were lost on launch vehicle failures. Of the 74 that reached orbit, 13 had only partially successful missions due to various equipment failures; three were complete failures, with the spacecraft being destroyed. Notable Zenit flights included:

• Cosmos 12, the first successful full-duration flight;
• Cosmos 48, which resulted in the spacecraft returning two days early when the thermo-regulation system failed and internal temperature rose to 43 degrees C;
• Cosmos 50, which completed a full duration mission, but was destroyed by the APO system when the braking engine failed at retrofire;
• Cosmos 66, which suffered a parachute deployment failure. The spacecraft was destroyed in the crash.
• Cosmos 199, which failed to separate from Block I stage. An attempt was made to conduct the mission without the orientation system. The APO self destruct system destroyed the spacecraft on its 126th revolution over the Sea of Okhotsk
• Cosmos 216, which landed in River Volga 1 km from shore and sank after 42 minutes. 85% of the data was ruined.
• Cosmos 235, which suffered a hard landing due to parachute system failure. 30% of the film was damaged.
• Cosmos 253, where on the 13th orbit the SA-20-1 camera's shutter responded to an uncommanded order to open. Radiation levels inside reached 3 times normal levels. 53% of the data was lost.

Typical orbital profile: inclination 65 degrees with an altitude of 197-318 km; inclination 51.8 degrees with an altitude of 200-272 km; inclination 72.8 degrees with an altitude of 203-337 km; inclination 81.3 degrees with an altitude of 201-368 km. Transmission frequencies observed in West: 19.995 PDM; sometimes 19.990 PDM.

Total Mass: 4,720 kg.

Studies were undertaken for military reconnaissance satellites. Code names for these studies were: Shchit - military reconnaissance systems; Osnova - military reconnaissance equipment; Ediniy KIK - military reconnaissance control systems.

Council of Chief Designers Decree 'On course of work on the piloted spaceship' was issued. Council of Chief designers approved the Vostok manned space program, in combination with Zenit spy satellite program Korolev was authorised to proceed with development of a spacecraft to achieve manned flights at the earliest possible date. However the design would be such that the same spacecraft could be used to fulfil the military's unmanned photo reconnaissance satellite requirement. The military resisted, but Korolev won. This was formalised in a decree of 25 May 1959.

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Zenit 2 Reconnsat Credit: © Mark Wade. 13,312 bytes. 425 x 230 pixels.

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Due to a bitter fight with the military over the nature and priority of the manned spacecraft and photo-reconnaissance space programs, the final decree for the Vostok manned spacecraft was delayed until seven months after drawing release began. This authorised production of a single design that could be used either as a manned spacecraft or as a military reconnaissance satellite. These were the Zenit-2 and Zenit-4 spacecraft based on the Vostok design. This marked the end of the original Zenit configuration.

First attempted launch of Zenit photo-reconnaisance satellite.

Area survey photo reconnaissance satellite. Program partially completed. Failure of primary spacecraft orientation system.

Area survey photo reconnaissance satellite. Third attempted launch of Zenit photo-reconnaissance satellite.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also carried weather, radiation experiments.

Program partially completed. Part of the information lost due to failure of engine block stabilization system. Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite. Also performed radiation measurements.

Area survey photo reconnaissance satellite.

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Zenit Optical Paths 7,445 bytes. 332 x 120 pixels.

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Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Defence Ministry of the USSR decree 0045 'On adopting the Zenit-2 satellite launched on the 8A92 into armaments' was issued.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Program partially completed. Break in the film fof the SA-10 camera.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Program partially completed. Returned early due to failure of spacecraft thermoregulation system; internal temperature rose to 43 degrees C.

Area survey photo reconnaissance satellite. Unsuccessful mission. Failure of the braking engine system. Spacecraft ordered to self destruct.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Returned after 8 days. Unsuccessful mission. Parachute deployment failure. Spacecraft destroyed in crash.

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Zenit Aerosurface - Zenit Reconnaisance satellite with aerodynamic control services for orientation in orbit. 12,184 bytes. 333 x 222 pixels.

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Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Program not completely met. Spacecraft put into incorrect orbit by abnormal function of second and third stages of booster.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

. Program partially completed. Abnormal operation of SA-10 camera.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Also carried science package.

Ministry of Defence Decree 15 'On transfer of Zenit-2 from the 8A92 to the 11A57 launcher' was issued.

Area survey photo reconnaissance satellite.

Placed into orbit with 22.8 second period different from that planned. Area survey photo reconnaissance satellite. Also carried science package.

Area survey photo reconnaissance satellite. Program partially completed.

Area survey photo reconnaissance satellite. Program partially completed. Failure of primary SA-20 camera.

Area survey photo reconnaissance satellite. Program partially completed. Bad quality film loaded into SA-20 camera.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Unsuccessful mission. Spacecraft failed to separate from Block I stage. Attempt was made to conduct mission without orientation system. APO self destruct system destroyed spacecraft on 126th revolution over Sea of Okhotsk. First generation, low resolution photo surveillance; recovery probably failed.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Unsuccessful mission. Spacecraft landed in River Volga 1 km from shore and sank after 42 minutes. 85% of the data was ruined.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Partially successful. Hard landing due to parachute sytem failure. 30% of the film damaged.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Unsuccessful mission. On 13th orbit the SA-20-1 camera's shutter responded to an uncommanded order to open. Radiation levels inside reached 3 times normal levels. 53% of the data was lost.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. First flight with Nauka external experiment container.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite.

Area survey photo reconnaissance satellite. Partially successful. Failure of SA-10B camera on 42nd orbit.

• 93 - Agapov, V, Novosti Kosmonavtiki, "Zapuski kosmicheskikh apparatov 'Zenit-2'", 1996, Issue 10, page 65.
• 102 - Voevodin, Sergey A, VSA072 - Space Apparatus, "Sergey A. Voevodin's Reports", . HTML when accessed: http://www.mcs.net/~rusaerog/sergeyv/VSA.html
• 110 - Grahn, Sven, Sven Grahn's Space History Pages, . HTML when accessed: http://www.users.wineasy.se/svengrahn/
• 445 - Melnik, T G, Voenno-Kosmicheskiy Siliy, Nauka, Moscow, 1997..