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Other Designations: Vostok 2. Article Number: 11F61. Manufacturer's Designation: 2K. Code Name: Zenit-2. Class: Surveillance. Type: Military. Destination: Surveillance Orbit. Nation: Russia. Agency: MOM. Manufacturer: Korolev. The Zenit-2 was a derivative of the manned Vostok that fulfilled the Soviet military's unmanned photo reconnaissance satellite requirement. It was the Soviet Union's first spy satellite, and its later versions remained in use into the 21st Century. 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 authorized 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 fulfill 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 specialized 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 spherical SA descent capsule contained all of the specialized classified apparatus (the camera, the photo-television, the radio apparatus). The Zenit camera was mounted perpendicular to the long axis of the spacecraft. Exposures were made through multiple lens cameras, shooting through one of two large diameter hatches.
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 kilometers. 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.
Flight trials (LKI) Zenit-2s had a mass of 4,610 to 4,760 kg, and production models ranged from 4,700 to 4,740 kg.
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 systems, 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 organization, the TsKB Central Specialized 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 productionized 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 Defense 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 modernized 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. Typical orbit: 222 km x 334 km at 51 to 81.4 degrees inclination. Mass: 4,720 kg (10,400 lb). Associated Launch Vehicle: Voskhod 11A57, Vostok 8A92, Vostok 8K72K.
Zenit-2 Chronology - 1956 September 30 - First official plan for future Soviet spaceflight - Launch Vehicle: Proton 8K82, N1.
This set forth the following objectives: orbiting of satellites of 1.8 to 2.5 tonnes mass by 1958; one week flight of a manned spacecraft by 1964; unmanned reconnaissance satellite by 1970; rocket capable of 12 tonne escape velocity payload by 1970; rocket with 100 tonne low earth orbit payload to be developed, capable of placing 2 to 3 men on the moon (no date set).
- 1958 November 1 - Vostok spacecraft and Zenit spy satellite authorised. -
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.
- 1959 May 22 - Production of Vostok and Zenit-2 authorised. -
Central Committee of the Communist Party and Council of Soviet Ministers Decree 569-264 'On work on a reconnaissance satellite and piloted spaceship' was issued. 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. The military had to develop the recovery forces and techniques for both spacecraft, including appropriate aircraft, helicopters, and handling equipment. At that time it was felt that there was a 60% chance on each launch of an abort requiring rescue operations for the cosmonaut.
- 1959 May 22 - Vostok / Zenit-3 decree issued. -
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.
- 1961 December 11 - Zenit-2 11F61 s/n 1 - Launch Site: Baikonur. Launch Vehicle: Vostok 8K72K. FAILURE: RO-7 engine of block E upper stage cutoff prematurely. Spacecraft liquidated by self destruct system APO in 407th second of flight. Debris landed 100 km north of Vilyuisk. Mass: 4,610 kg (10,160 lb).
First attempted launch of Zenit photo-reconnaisance satellite. According to Kamanin, there was a problem with the third stage, and the capsule landed between Novosibirsk and Yakutsk, but could not be located. There was no information on the nature of the problem. Korolev stayed at Tyuratam, preparing for the next launch attempt.
- 1961 February 22 - Zenit project review - Program: Vostok. Flight: Vostok 1.
Ustinov heads a review of the reconnaissance satellite program, at that time still referred to as the Vostok-2 and Vostok-4 spacecraft. Thirty staff are working on it full time at OKB-1, but Korolev says that due to delays in the photographic, television, and radar equipment for the spacecraft the first launch will be delayed two to three months. But he points out that since Vostok-1 has already proven the recovery systems, the first Vostok-2 should still be ready for launch in June-July 1961. Ustinov notes that the Ministry of Defence has had little input or understanding of the specification for the spacecraft. The launch of the first Vostok-3 is delayed to March due to the need to fully test all systems. The life support system (Vornonin) and the ejection seat (Alekseyev) are the pacing items. The next meeting is set for 27 February. Kustanin testifies as to the readiness of the spacecraft and the cosmonauts.
- 1962 April 26 - Cosmos 4 - Flight: Vostok 3, Vostok 4. Launch Site: Baikonur. Launch Vehicle: Vostok 8K72K. Mass: 4,610 kg (10,160 lb). Perigee: 285 km (177 mi). Apogee: 317 km (196 mi). Inclination: 65.00 deg. Period: 90.50 min. Duration: 3.00 days.
Area survey photo reconnaissance satellite. Program partially completed. Failure of primary spacecraft orientation system. It was to spend four days in space, to be followed by another mission during 5-10 May. This meant that Vostok 3/4 could not be launched before 20-30 May. The cosmonaut prime crew returned from their in-suit parachute training at Fedosiya.
- 1962 August 4 - Launch preparations - Program: Vostok. Flight: Vostok 3, Vostok 4.
Kamanin is at the Syr Darya River at 06:50, and arrives at Area 2 at 09:00. Suit communications tests are underway. From 11:00 to 13:00 there is a discussion on how the cosmonauts will observe the third stage of their booster, and how the spacecraft will be oriented. To stay pointed, they will need to put the spacecraft in a very slow maneuver of 0.06 deg/sec, or one revolution in 1.8 hours. Once they have achieved this, they have to put the spacecraft in a roll of 0.5 deg/sec, or one revolution in 12 minutes, in order to maintain the spacecraft's thermal balance due to solar heating. Kamanin does not understand why this is necessary - the Cosmos 4 spy satellite, of the same design, spent all four days of its mission in stabilised flight, using infrared horizon trackers, and maintained a stable internal temperature of 17 deg C. Korolev mentions that Cosmos 4 could distinguish types of aircraft on airfields, and the form and tonnage of ships at sea.
- 1962 December 6 - Soviet Space Plans for 1963-1964 - Program: Soyuz, Vostok, DS. Flight: Vostok 7, Vostok 8, Vostok 9.
Meeting of the Interdepartmental Soviet of the Academy of Sciences reviews space exploration plans. In the next two years, 5-6 Luna probes will be sent to the moon, including soft landers with a mass of 100 kg, and orbiters to map the surface. There will be flybys and landings of Mars and Venus. Two Zond spacecraft will study the space environment out to 20 million kilometres from the earth. In earth orbit, 10 Zenit spy satellites, 10 to 12 Vostok manned spacecraft, 4 to 6 Soyuz spacecraft, and 10 to 12 Kosmos satellites will be launched. The Kosmos will fly missions in meteorology, communications, television transmission, and heliographic, and geological studies. Kamanin finds this a good program, but it nearly all relies on a single launch pad and one-time transmission of data from a few satellites. The military plan is not reviewed; it must go through the VPK Military-Industrial Commission first. An Expert Commission is to be formed on the Soyuz spacecraft. Smirnov and Korolev have dictated a letter to Ustinov asking that eight more Vostoks be built. On the other hand, some on the general staff want 60 cosmonauts trained in the next two to three years, to support 8 to 10 flights of single-place spacecraft and 7 to 8 flights of multiplace spacecraft.
- 1962 June 1 - Zenit-2 11F61 s/n 3 - Launch Site: Baikonur. Launch Vehicle: Vostok 8A92. FAILURE: Shutdown of Block B strap-on engine stage 1.8 seconds after liftoff. The booster crashed 300 m from the pad. Pad damaged. Mass: 4,610 kg (10,160 lb).
Area survey photo reconnaissance satellite. Third attempted launch of Zenit photo-reconnaissance satellite. It blew up 300 m from the pad, and did enough damage to put the launch complex out of operation for a month. Therefore the Vostok 3/4 launches could not take place until the end of July at the earliest.
- 1962 June 22 - Zenit booster failure damages pad, delays Vostok 3/4 - Program: Vostok. Flight: Vostok 3, Vostok 4.
A briefing by engineer V A Smirnov predicts that the Americans will make a 17-18 revolution flight of the earth by the end of 1962. Kamanin disagrees, believing they will not achieve this until the second half of 1963. Another Zenit-2 spy satellite has failed to achieve orbit. The first had failed due to a third stage problem, and now the third attempt failed due to a first stage problem. It blew up 300 m from the pad, and did enough damage to put the launch complex out of operation for a month. Therefore the Vostok 3/4 launches cannot now take place until the end of July at the earliest. Kamanin has continued arguments over the reorganisation of VVS space units and the role of IAKM. Korolev has never supported a leading role for the VVS or Kamanin in the Soviet space program. He is complaining about the 'offences' of the VVS, Kamanin, and the cosmonauts. Korolev cites Gagarin's trauma and Titov's motor accidents. He believes cosmonauts should be selected only from OKB-1 engineers. He also believes the cosmonauts are wasting too much time on publicity tours. Vershinin and Keldysh are hearing all of these complaints.
- 1968 January 16 - Cosmos 199 - Launch Site: Plesetsk. Launch Vehicle: Voskhod 11A57. Mass: 4,720 kg (10,400 lb). Perigee: 206 km (128 mi). Apogee: 363 km (225 mi). Inclination: 65.60 deg. Period: 90.20 min. Duration: 16.00 days.
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.
Bibliography and Further Reading
- McDowell, Jonathan, Jonathan's Space Home Page, Harvard University, 1997-present. Jonathan McDowell's complete on-line listing of all objects orbited and over 20,000 rocket launches Accessed at: http://www.planet4589.org/jsr.html.
- Grahn, Sven, Sven Grahn's Space History Pages, . Sven Grahn's occasional essays on specific topics of the Russian and Chinese space programs are outstanding. Accessed at: http://www.svengrahn.pp.se/.
- Isakowitz, Steven J,, International Reference to Space Launch Systems Second Edition, AIAA, Washington DC, 1991 (succeeded by 2000 edition). ISBN: 1563473534. Superseded by the later editions. More at amazon.com...
- Agapov, V, Novosti Kosmonavtiki, "Zapuski kosmicheskikh apparatov 'Zenit-2'", 1996, Issue 10, page 65.
- Agapov, V, Novosti Kosmonavtiki, "K zapusku pervovo ISZ serii 'DS'", 1997, Issue 6.
- Siddiqi, Asif A, The Soviet Space Race With Apollo, University Press of Florida, 2003. ISBN: 0813026288. The definitive history of the Soviet manned space program in the 1960's to the early 1970's. Originally published as the the latter part of 'Challenge to Apollo' by NASA in 2000 as NASA SP-2000-4408. More at amazon.com...
- Melnik, T G, Voenno-Kosmicheskiy Siliy, Nauka, Moscow, 1997.. Two-volume official history of the (now defunct) Russin space forces.
- Kamanin, N P, Skritiy kosmos, Infortext, Moscow, 1995. The diary of the Commander of the Soviet Cosmonaut Team in the 1960's - a source of great insights into the space program. Four volumes issued to date.
- Varfolomyev, Timothy, Spaceflight, "Soviet Rocketry that Conquered Space - Part 3", 1996, Volume 38, page 206. 1: Sp 95/37-260; Sp 96/38-31 (8K71 launches); 2: Sp 96/38-48; 3: Sp 96/38-206; Sp 96/38-317 (designatons); 4: Sp 98/40-28; 5:Sp 98/40-85
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