Zenit (satellite)

Last updated • 8 min readFrom Wikipedia, The Free Encyclopedia

Zenit
Zenit space vehicle.jpg
Zenit re-entry capsule, showing camera ports
Manufacturer OKB-1
Country of origin Soviet Union
OperatorSoviet space program
ApplicationsPhoto reconnaissance
Production
StatusRetired
Launched688
Lost21
Maiden launch11 Dec 1961
Zenit 2-1
Last launch7 Jun 1994
Kosmos 2281
Last retirement8 Nov 2004
Zenit 8-103
Related spacecraft
Derived from Vostok

Zenit (Russian: Зени́т, IPA: [zʲɪˈnʲit] , Zenith) was a series of military photoreconnaissance satellites launched by the Soviet Union between 1961 and 1994. To conceal their nature, all flights were given the public Kosmos designation.

Contents

Description

The basic design of the Zenit satellites was similar to the Vostok crewed spacecraft, sharing the return and service modules. [1] It consisted of a spherical re-entry capsule 2.3 metres (7.5 ft) in diameter with a mass of around 2,400 kilograms (5,300 lb). This capsule contained the camera system, its film, recovery beacons, parachutes and a destruct charge. In orbit, this was attached to a service module that contained batteries, electronic equipment, an orientation system and a liquid-fuelled rocket engine that would slow the Zenit for re-entry, before the service module detached. The total length in orbit was around 5 metres (16 ft) and the total mass was between 4,600 and 4,740 kilograms (10,140 and 10,450 lb). [1]

Unlike the American CORONA spacecraft, the return capsule carried both the film and the cameras and kept them in a temperature-controlled pressurised environment. This simplified the design and engineering of the camera system but added considerably to the mass of the satellite. An advantage was that cameras could be reused. [1] The camera would either land on the ground or be recovered in midair by a modified Mil Mi-8 helicopter. [2]

Early Zenits were launched using the Vostok rocket; later versions used the Voskhod and the Soyuz rockets. The first flights were launched from Baikonur Cosmodrome but subsequent launches also took place at Plesetsk Cosmodrome.

Most Zenits flew in a slightly elliptical orbit with a perigee of around 200 kilometres (120 miles) and an apogee between 250 and 350 kilometres (160 and 220 miles); the missions usually lasted between 8 and 15 days.

History

In 1956, the Soviet government issued a secret decree that authorised the development of "Object D" which led to the program to launch Sputnik 3 (Sputnik 1 was a simplified spin-off of the Object D program.) The text of the decree remains secret, but it apparently authorised another satellite program – "Object OD-1" – which was to be used for photo-reconnaissance from space.

By 1958, the OKB-1 design bureau was simultaneously working on Object OD-1 and Object OD-2 – an early design for the Vostok crewed spacecraft. The development of Object OD-1 was experiencing serious difficulties so the head of OKB-1, Sergei Korolev, initiated work to see if a design based on Object OD-2 could be used for an uncrewed photo-reconnaissance satellite. This may have been a political manoeuvre that would enable him to continue the crewed space program and avoid diverting more of OKB-1's resources into Object OD-1. [1] [3] [4] [5]

Despite bitter opposition from the military the Soviet government endorsed Korolev's approach and issued decrees on 22 and 25 May 1959 which ordered the development of three different spacecraft, all based on the same basic, Object OD-2, design. Spacecraft 1K would be a simplified prototype, 2K was to be a reconnaissance satellite and 3K was to be for crewed flights. The name Vostok was also initially used for all three of these craft. But in 1961 the name became publicly known as the name of Yuri Gagarin's spacecraft so the "Vostok 2" reconnaissance satellite was renamed "Zenit 2". [6]

The first Zenit launch attempt took place on 11 December 1961, but there was a fault in the rocket's third stage and the spacecraft was destroyed using its destruct charge. The second attempt — publicly referred to as Kosmos 4 — was successfully launched on 26 April 1962 and re-entered three days later. However a failure in the orientation system meant few useful pictures were obtained; usable pictures had a resolution of about 5 to 7 meters. Launch #3 on 1 June 1962 failed dramatically when one of the 8A92 booster's strap-ons shut down at liftoff and fell onto the pad, exploding on impact. The rest of the launch vehicle crashed 300 meters away. This accident caused considerable damage to Site 1, delaying the flights of Vostok 3 and Vostok 4 by two months.

On 28 July 1962, Site 1 was back in service to host the next Zenit flight, which performed successfully. Testing continued over the next year largely without incident but on 10 July 1963, another launch accident occurred in practically identical fashion to the June 1962 failure. Once again, one of the strap-ons shut down at liftoff, separated from the booster, and exploded on impact with the pad while the rest of the launch vehicle crashed a few hundred feet away.

Examination of telemetry from the booster indicated that some sort of electrical failure occurred, but subsequent investigation took three months and finally concluded that a switch designed to cut power to the strap-ons at staging had malfunctioned, possibly due to liftoff-induced vibration. The electrical circuit in the 8A92 was redesigned and it never again experienced problems with the strap-ons shutting down at launch. [7]

Many versions of the satellite were developed for different reconnaissance missions and flights continued until 1994. [8] [9]

Zenit variants

Zenit 2

Zenit 2 was the first version to be launched between 1961 and 1970 (there was no Zenit 1). [10] [11]

The arrangement of cameras varied, but most flights carried four cameras of 1000 mm focal length, and one of 200 mm focal length. The single lower resolution camera was intended to provide low-resolution pictures that would help give a context to the high-resolution pictures. [1]

Each camera had 1500 frames of film and from 200 km (120 mi), each frame held an image of a 60 by 60 km (37 by 37 mi) square. The ground resolution was stated to be 10 to 15 m (33 to 49 ft) although some unofficial sources claim it was much better—one source claims the number of cars in a car park could be counted. The cameras were developed at the Krasnogorsk Optical-Mechanical Factory near Moscow. The Krasnogorsk factory, which had been producing a variety of optical equipment for the military since 1942, was also the manufacturer of the popular Zenit SLR cameras. [1]

Zenit 2s also carried ELINT equipment called Kust-12M (bush) to receive NATO radar signals. The satellites carried a parabolic antenna, around 1 m (3 ft 3 in) in diameter, that is associated with this equipment. However, it is unclear if the antenna transmitted recorded signals to the ground or was for intercepting radar signals. In the latter case they would have been recorded on magnetic tape, to be retrieved after the return capsule landed. [1] [12]

There were 81 Zenit 2 launches. 58 were successful and 11 were partially successful. There were 12 failed missions, 5 because of a satellite malfunction and 7 because of a failure in the launch vehicle.

Zenit 2M

Improvements included a new camera system and the addition of solar panels. As the spacecraft mass was increased to 6300 kg, the Vostok rocket was replaced by the Voskhod rocket and Soyuz rockets. In common with Zenit 2 satellites this also had an ELINT payload. [12]

A total of 101 Zenit-2M satellites were launched between 1968 and 1979 [13] [14] [15]

Zenit 4

Unlike Zenit 2, little information on Zenit 4 has been released. The Zenit 4 was intended for high-resolution photography and carried one camera of 3000 mm focal length as well as a 200 mm camera. The focal length of the main camera was greater than the diameter of the capsule so the camera made use of a mirror to fold the light path. The ground resolution is not publicly known but it is believed to have been 1–2 metre.

The Zenit 4 had a mass of 6300 kg — around 1800 kg more than the Zenit 2. So, instead of the Vostok rocket, it was launched by the heavier Voskhod rocket. A total of 76 Zenit-4 satellites were flown between 1963 and 1970. [1] [16] [17]

Zenit 4 M

An improved version of the Zenit 4, the Zenit 4M carried a new camera, solar panels, and a restartable engine so the satellite's orbit could be altered during the course of its mission. The mission duration was 13 days.

A total of 61 Zenit-4M satellites were launched between 1968 and 1974. [18] [19]

Zenit 4 MK

These may have been versions of the Zenit 4 designed specifically to fly in lower orbits to improve image resolution. Some sources claim they were fitted with devices to compensate for aerodynamic drag and to withstand the effects of aerodynamic heating.

A total of 80 Zenit-4MK satellites were launched between 1969 and 1977. [20] [21]

Zenit 4 MKM

Intended to replace the 4MK design, the 4MKM may have been a low altitude variant of the later Zenit-6U and have similar equipment to it [22]

Zenit-4MKM (Gerakl) [23] [24]
No.MissionLaunch date
(GMT)
Landing dateCOSPAR IDOrbitDuration
(in orbit)
Outcome
1 Kosmos 927 12 July 1977
09:00
25 July 19771977-063A153 x 361 km13 daysSuccess
2 Kosmos 932 20 July 1977
07:35
2 August 19771977-069A150 x 358 km13 daysSuccess
3-10 August 1977
10:40
--(Suborbital)-Failure
4 Kosmos 938 24 August 1977
14:30
6 September 19771977-078A181 x 340 km13 daysSuccess
5 Kosmos 953 16 September 1977
14:30
29 September 19771977-089A180 x 330 km13 daysSuccess
6 Kosmos 957 30 September 1977
09:46
13 October 19771977-098A171 x 361 km13 daysSuccess
7 Kosmos 964 4 December 1977
12:00
17 December 19771977-110A171 x 362 km13 daysSuccess
8 Kosmos 969 20 December 1977
15:50
3 January 19781977-120A180 x 317 km14 daysSuccess
9 Kosmos 974 6 January 1978
15:50
19 January 19781978-001A178 x 334 km13 daysSuccess
10 Kosmos 986 24 January 1978
09:50
7 February 19781978-010A172 x 318 km14 daysSuccess
11 Kosmos 987 31 January 1978
14:50
14 February 19781978-013A189 x 322 km14 daysSuccess
12 Kosmos 989 14 February 1978
09:30
28 February 19781978-017A169 x 318 km14 daysSuccess
13 Kosmos 993 10 March 1978
10:42
23 March 19781978-027A190 x 325 km13 daysSuccess
14 Kosmos 999 30 March 1978
07:50
12 April 19781978-033A174 x 352 km13 daysSuccess
15 Kosmos 1003 20 April 1978
15:30
4 May 19781978-040A178 x 328 km14 daysSuccess
16 Kosmos 1007 16 May 1978
10:40
28 May 19781978-048A168 x 350 km13 daysSuccess
17 Kosmos 1021 10 June 1978
08:35
23 June 19781978-057A173 x 313 km13 daysSuccess
18 Kosmos 1022 12 June 1978
10:30
25 June 19781978-059A171 x 344 km13 daysSuccess
19 Kosmos 1029 29 August 1978
15:00
8 September 19781978-082A194 x 316 km10 daysSuccess
20 Kosmos 1031 9 September 1978
15:00
22 September 19781978-085A182 x 329 km13 daysSuccess
21 Kosmos 1042 6 October 1978
15:30
19 October 19781978-092A179 x 299 km13 daysSuccess
22 Kosmos 1047 15 November 1978
11:45
28 November 19781978-104A171 x 354 km13 daysSuccess
23 Kosmos 1049 21 November 1978
12:00
4 December 19781978-107A169 x 338 km13 daysSuccess
24 Kosmos 1059 7 December 1978
15:30
20 December 19781978-110A180 x 338 km13 daysSuccess
25 Kosmos 1068 26 December 1978
15:30
8 January 19791978-123A191 x 389 km13 daysSuccess
26 Kosmos 1071 13 January 1979
15:30
26 January 19791979-002A179 x 339 km13 daysSuccess
27 Kosmos 1073 30 January 1979
15:15
12 February 19791979-006A182 x 328 km13 daysSuccess
28 Kosmos 1078 22 February 1979
12:10
2 March 19791979-016A168 x 280 km8 daysSuccess
29 Kosmos 1080 14 March 1979
10:50
28 March 19791979-023A169 x 294 km14 daysSuccess
30 Kosmos 1098 15 May 1979
11:40
28 May 19791979-040A170 x 354 km13 daysSuccess
31 Kosmos 1113 10 July 1979
09:00
23 July 19791979-064A173 x 330 km13 daysSuccess
32 Kosmos 1117 25 July 1979
15:20
7 August 19791979-068A177 x 325 km13 daysSuccess
33 Kosmos 1120 11 August 1979
09:15
24 August 19791979-073A170 x 362 km13 daysSuccess
34 Kosmos 1128 14 September 1979
15:30
27 September 19791979-081A173 x 328 km13 daysSuccess
35 Kosmos 1148 28 December 1979
13:00
10 January 19801979-106A170 x 340 km13 daysSuccess
36 Kosmos 1165 21 February 1980
12:00
5 March 19801980-017A170 x 350 km13 daysSuccess
37 Kosmos 1170 1 April 1980
08:00
12 April 19801980-025A178 x 379 km11 daysSuccess
38 Kosmos 1173 17 April 1980
08:30
28 April 19801980-029A174 x 352 km11 daysSuccess
39 Kosmos 1214 10 October 1980
13:10
23 October 19801980-082A170 x 347 km13 daysSuccess

Zenit 4 MKT

Another variant of the Zenit-4 design equipped with a Priroda-3 camera, intended for the investigation of natural resources in the interests of the Soviet economy and international cooperation. [25]

A total of 27 Zenit-4MKT satellites were launched between 1975 and 1985. [26] [27]

Zenit 4 MT

A special version of the Zenit 4M intended for topographical photography. It carried an SA-106 topographic camera, a laser altimeter and Doppler apparatus.

Zenit-4MT (Orion) [28] [29]
No.MissionLaunch date
(GMT)
Landing dateCOSPAR IDOrbitDuration
(in orbit)
Outcome
1 Kosmos 470 27 December 1971
14:04
6 January 19721971-118A192 x 259 km10 daysSuccess
2 Kosmos 502 13 July 1972
14:30
25 July 19721972-055A203 x 262 km12 daysSuccess
3 Kosmos 541 27 December 1972
10:30
8 January 19731972-105A218 x 348 km12 daysSuccess
4 Kosmos 576 27 June 1973
11:50
9 July 19731973-044A204 x 332 km12 daysSuccess
5 Kosmos 616 17 December 1973
12:00
28 December 19731973-102A206 x 332 km11 daysSuccess
6 Kosmos 664 29 June 1974
12:50
11 July 19741974-049A205 x 341 km12 daysSuccess
7 Kosmos 693 4 November 1974
10:40
16 November 19741974-088A219 x 243 km12 daysSuccess
8 Kosmos 720 21 March 1975
06:50
1 April 19751975-019A212 x 273 km11 daysSuccess
9 Kosmos 759 12 September 1975
05:30
23 September 19751975-084A231 x 276 km11 daysSuccess
10 Kosmos 811 31 March 1976
12:50
12 April 19761976-030A206 x 338 km12 daysSuccess
11 Kosmos 855 21 September 1976
11:40
3 October 19761976-095A221 x 321 km12 daysSuccess
12 Kosmos 916 10 June 1977
08:00
21 June 19771977-046A255 x 304 km11 daysSuccess
13 Kosmos 988 8 February 1978
12:15
20 February 19781978-015A201 x 335 km12 daysSuccess
14 Kosmos 1046 1 November 1978
12:00
13 November 19781978-102A202 x 324 km12 daysSuccess
15 Kosmos 1069 28 December 1978
16:30
10 January 19791978-124A254 x 289 km13 daysSuccess
16 Kosmos 1119 3 August 1979
10:45
15 August 19791979-071A213 x 245 km12 daysSuccess
17 Kosmos 1139 5 October 1979
11:30
18 October 19791979-088A199 x 329 km13 daysSuccess
18 Kosmos 1180 15 May 1980
05:35
26 May 19801980-038A245 x 279 km11 daysSuccess
19 Kosmos 1211 23 September 1980
10:30
4 October 19801980-077A211 x 236 km11 daysSuccess
20 Kosmos 1239 16 January 1981
12:00
28 January 19811981-004A210 x 231 km12 daysSuccess
21 Kosmos 1309 18 September 1981
09:30
1 October 19811981-092A212 x 257 km13 daysSuccess
22 Kosmos 1332 12 January 1982
12:30
25 January 19821982-002A207 x 251 km13 daysSuccess
23 Kosmos 1398 3 August 1982
11:30
13 August 19821982-077A211 x 231 km10 daysSuccess

Zenit 6U

A "universal" version of the Zenit, intended for both low-altitude, high-resolution missions and higher-altitude, general observation missions. All flights used the Soyuz launch vehicle. There were a total of 97 Zenit-6U satellites launched between 1976 and 1984. [30] [31]

Zenit 8

This was intended for military cartographic photography. It used a Soyuz launch vehicle and launches took place from both Baikonur and Plesetsk. It had a 15-day orbital life. Similar satellites were referred to using the "Resurs-DK No.1" designation.

A total of 102 Zenit-8 satellites were launched between 1984 and 1994, in addition to one sent into a suborbital trajectory during the maiden flight of the Soyuz-2 rocket in 2004. [32] [33] [34] [35]

A Zenit satellite was mentioned in the movie Mission: Impossible – Dead Reckoning Part One .

Related Research Articles

The Soyuz-U2 was a Soviet, later Russian, carrier rocket. It was derived from the Soyuz-U, and a member of the R-7 family of rockets. It featured increased performance compared with the baseline Soyuz-U, due to the use of syntin propellant, as opposed to RP-1 paraffin, used on the Soyuz-U.

<span class="mw-page-title-main">Yantar (satellite)</span> Series of Russian reconnaissance satellites

Yantar were a series of Russian reconnaissance satellites, which supplemented and eventually replaced the Zenit spacecraft. Kosmos 2175, a Yantar-4K2 or Kobalt spacecraft, was the first satellite to be launched by the Russian Federation following the dissolution of the Soviet Union. Yantar-Terilen was the first real-time digital system. Yantar satellites also formed the basis for the later Orlets, Resurs and Persona satellites. 179 have been launched, nine of which were lost in launch failures. All Yantar satellites were launched using the Soyuz-U carrier rocket until Kosmos 2480 in 2012 which was announced as the last launch of that rocket from Plesetsk. Subsequent launches used the modernized Soyuz-2.1a rocket. The last Yantar mission was Kosmos 2505, a Yantar-4K2M or Kobalt-M, launched on 5 June 2015. Reconnaissance missions have been taken over by the Persona class of satellites.

<span class="mw-page-title-main">Kosmos 12</span> Soviet reconnaissance satellite (Zenit 2-7)

Kosmos 12 or Zenit-2 No.7 was a Soviet optical film-return reconnaissance satellite launched in 1962. A Zenit-2 spacecraft, Kosmos 12 was the seventh of eighty-one such satellites to be launched.

<span class="mw-page-title-main">Kosmos 15</span> Soviet reconnaissance satellite (Zenit 2-9)

Kosmos 15 or Zenit-2 No.9 was a Soviet optical film-return reconnaissance satellite which was launched in 1963. A Zenit-2 spacecraft, Kosmos 15 was the ninth of eighty-one such satellites to be launched.

<span class="mw-page-title-main">Kosmos 18</span> Soviet reconnaissance satellite (Zenit 2-11)

Kosmos 18 or Zenit-2 No.11 was a Soviet optical film-return reconnaissance satellite launched in 1963. A Zenit-2 satellite, Kosmos 18 was the eleventh of eighty-one such spacecraft to be launched.

<span class="mw-page-title-main">Kosmos 37</span> Soviet reconnaissance satellite (Zenit 2-21)

Kosmos 37 or Zenit-2 No.21 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1964. A Zenit-2 spacecraft, Kosmos 37 was the twentieth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

<span class="mw-page-title-main">Kosmos 48</span> Soviet reconnaissance satellite (Zenit 2-23)

Kosmos 48 or Zenit-2 No.23 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1964. A Zenit-2 spacecraft, Kosmos 48 was the twenty-third of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

<span class="mw-page-title-main">Kosmos 66</span> Soviet reconnaissance satellite (Zenit 2-27)

Kosmos 66 or Zenit-2 No.27 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1965. A Zenit-2 spacecraft, Kosmos 66 was the twenty-seventh of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

<span class="mw-page-title-main">Kosmos 104</span> Soviet reconnaissance satellite (Zenit 2-33)

Kosmos 104 or Zenit-2 No.33 was a Soviet first-generation low-resolution optical film–return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 104 was the thirty-second of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

<span class="mw-page-title-main">Kosmos 107</span> Soviet reconnaissance satellite (Zenit 2-35)

Kosmos 107 or Zenit-2 No.35 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 107 was the thirty-fifth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

<span class="mw-page-title-main">Kosmos 112</span> Soviet reconnaissance satellite (Zenit 2-36)

Kosmos 112 or Zenit-2 No.36 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 112 was the thirty-sixth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb). It was the first satellite to be launched from the Plesetsk Cosmodrome.

<span class="mw-page-title-main">Kosmos 115</span> Soviet reconnaissance satellite (Zenit 2-37)

Kosmos 115 or Zenit-2 No.37 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 115 was the thirty-seventh of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 117 or Zenit-2 No.39 was a Soviet optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 117 was the thirty-eighth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 120 or Zenit-2 No.41 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 120 was the thirty-ninth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 129 or Zenit-2 No.33 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 129 was the forty-second of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 132 or Zenit-2 No.46 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 132 was the forty-third of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 136 or Zenit-2 No.47 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1966. A Zenit-2 spacecraft, Kosmos 136 was the forty-fourth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb). In addition to its reconnaissance mission, the satellite was also used for scientific research.

Kosmos 138 or Zenit-2 No.43 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1967. A Zenit-2 spacecraft, Kosmos 138 was the forty-fifth of eighty-one such satellites to be launched and had a mass of 4,730 kilograms (10,430 lb).

Kosmos 143 or Zenit-2 No.45 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1967. A Zenit-2 spacecraft, Kosmos 143 was the forty-sixth of eighty-one such satellites to be launched and had a mass of 1,730 kilograms (3,810 lb).

Kosmos 147 or Zenit-2 No.44 was a Soviet, first generation, low resolution, optical film-return reconnaissance satellite launched in 1967. A Zenit-2 spacecraft, Kosmos 147 was the forty-seventh of eighty-one such satellites to be launched. and had a mass of 4,000 kilograms (8,800 lb).

References

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