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astronautix.com Venera 4V-1

Venera 9 lander test
Venera 9 lander test - Venera 9 lander in test

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Manufacturer's Designation: 4V-1. Class: Planetary. Type: Venus. Nation: USSR. Manufacturer: Lavochkin.

Very successful combination Venus lander / Venus flyby spacecraft. After launch and a three to five month coast to Venus, the descent vehicle separated from the bus and plunged into the Venus atmosphere two days later. As it flew by Venus the bus acted as a data relay for the brief life of the descent vehicle, and then continued into a heliocentric orbit.

The bus was equipped with instrumentation including a gamma-ray spectrometer, retarding potential traps, UV grating monochromator, electron and proton spectrometers, gamma-ray burst detectors, solar wind plasma detectors, and two-frequency transmitters which made measurements before, during, and after the Venus flyby.These instruements studied solar-wind composition, gamma-ray bursts, ultraviolet radiation, and the electron density of the ionosphere of Venus. Instruments carried on other missions included a French 3500 angstrom UV photometer, a 4000-7000 angstrom photo-polarimeter, a 1.5 to 3 micron infrared spectrometer, and a 8 - 30 micron infrared radiometer, and a magnetometer . The orbiter consisted of a cylinder with two solar panel wings and a high gain parabolic antenna attached to the curved surface. A bell-shaped unit holding propulsion systems was attached to the bottom of the cylinder, and mounted on top was a 2.4 meter sphere which held the lander.

The descent craft/lander was a hermetically sealed pressure vessel, which contained most of the instrumentation and electronics, mounted on a ring-shaped landing platform and topped by an antenna. The descent craft included a system of circulating fluid to distribute the heat load. This system, plus precooling prior to entry, permitted operation of the spacecraft for 32 minutes after landing (although up to two hours were actually achieved). During descent, heat dissipation and deceleration were accomplished sequentially by protective hemispheric shells, three parachutes, a disk-shaped drag brake, and a compressible, metal, doughnut-shaped, landing cushion. The descent craft carried instruments designed to study the detailed chemical composition of the atmosphere, the nature of the clouds, and the thermal balance of the atmosphere. Among the instruments on board was a gas chromatograph to measure the composition of the Venus atmosphere, instruments to study scattered solar radiation and soil composition, and a device named Groza which was designed to measure atmospheric electrical discharges. The spacecraft usually carried a camera system, and later versions included an X-ray fluorescence spectrometer, a screw drill and surface sampler, a dynamic penetrometer, and a seismometer to conduct investigations on the surface.



Venera 9 OrbiterVenera 9 Orbiter

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Specification

Total Mass: 5,030 kg.


Venera 4V-1 Chronology


08 June 1975 Venera 9 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824. Mass: 4,936 kg. Perigee: 1,510 km. Apogee: 112,200 km. Inclination: 34.2 deg.

Combined Venus orbiter/lander mission. After separation of the lander, the orbiter spacecraft entered Venus orbit and acted as a communications relay for the lander and explored cloud layers and atmospheric parameters. On October 20, 1975, the Descent Craft was separated from the Orbiter, and landing was made with the sun near zenith at 05:13 GMT on October 22. The Descent Craft included a system of circulating fluid to distribute the heat load. This system, plus precooling prior to entry, permitted operation of the spacecraft for 53 min after landing. The landing was about 2,200 km from the Venera 10 landing site. Preliminary results indicated: (A) clouds 30-40 km thick with bases at 30-35 km altitude, (B) atmospheric constituents including HCl, HF, Br, and I, (C) surface pressure about 90 (earth) atmospheres, (D) surface temperature 485 deg C, (E) light levels comparable to those at earth midlatitudes on a cloudy summer day, and (F) successful TV photography showing shadows, no apparent dust in the air, and a variety of 30-40 cm rocks which were not eroded. Venera 9 and 10 were the first probes to send back black and white pictures from the Venusian surface. They were supposed to make 360 degree panoramic shots, but on both landers one of two camera covers failed to come off, restricting their field of view to 180 degrees. Parameters are for Venus orbit.



Venera 10 / 4V-1Venera 10 / 4V-1

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14 June 1975 Venera 10 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824. Mass: 5,033 kg. Perigee: 1,620 km. Apogee: 113,900 km. Inclination: 29.5 deg.

The orbiter spacecraft entered Venus orbit and was separated from the lander on October 23, 1975. The lander touched down with the sun near zenith, at 05:17 GMT, on October 25. A system of circulating fluid was used to distribute the heat load. This system, plus precooling prior to entry, permitted operation of the spacecraft for 65 min after landing. During descent, heat dissipation and deceleration were accomplished sequentially by protective hemispheric shells, three parachutes, a disk-shaped drag brake, and a compressible, metal, doughnut-shaped, landing cushion. The landing was about 2,200 km distant from Venera 9. Preliminary results provided: (A) profile of altitude (km)/pressure (earth atmospheres) / temperature (deg C) of 42/3.3/158, 15/37/363, and 0/92/465, (B) successful TV photography showing large pancake rocks with lava or other weathered rocks in between, and (C) surface wind speed of 3.5 m/s. Venera 9 and 10 were the first probes to send back black and white pictures from the Venusian surface. They were supposed to make 360 degree panoramic shots, but on both landers one of two camera covers failed to come off, restricting their field of view to 180 degrees.



Venera 10 OrbiterVenera 10 Orbiter - Venera 10 / 4V-1 Orbiter

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09 September 1978 Venera 11 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824M. Mass: 4,715 kg.

Venera 11 was part of a two-spacecraft mission to study Venus and the interplanetary medium. Each of the two spacecraft, Venera 11 and Venera 12, consisted of a flight platform and a lander probe. Identical instruments were carried on both spacecraft. Venera 11 was launched into a 177 x 205 km, 51.5 degree inclination earth orbit from which it was propelled into a 3.5 month Venus transfer orbit. After ejection of the lander probe, the flight platform continued on past Venus in a heliocentric orbit. Near encounter with Venus occurred on December 25, 1978, at approximately 34,000 km altitude. The flight platform acted as a data relay for the descent craft for 95 minutes until it flew out of range and returned its own measurements on interplanetary space. The Venera 11 descent craft separated from its flight platform on December 23, 1978 and entered the Venus atmosphere two days later at 11.2 km/sec. During the descent, it employed aerodynamic braking followed by parachute braking and ending with atmospheric braking. It made a soft landing on the surface at 06:24 Moscow time on 25 December after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s.


Venera 10 DetailVenera 10 Detail - Venera 10 / 4V-1 Details

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Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought.

Two further experiments on the lander failed as well. Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.


14 September 1978 Venera 12 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824M. Mass: 4,715 kg.

Venera 12 was part of a two-spacecraft mission to study Venus and the interplanetary medium. Each of the two spacecraft, Venera 11 and Venera 12, consisted of a flight platform and a lander probe. Identical instruments were carried on both spacecraft. Venera 12 was launched into a 177 x 205 km, 51.5 degree inclination Earth orbit from which it was propelled into a 3.5 month Venus transfer orbit which involved two mid-course corrections, on 21 September and 14 December. After ejection of the lander probe on 19 December, two days before encounter, the flight platform continued on past Venus in a heliocentric orbit. Near encounter with Venus occurred on December 21, 1978, at approximately 34,000 km altitude. The flight platform acted as a data relay for the descent craft for 110 minutes until it flew out of range and returned to its own measurements on interplanetary space. The Venera 12 descent craft entered the Venus atmosphere at 11.2 km/sec two days after separation from the flight bus. During the descent, it employed aerodynamic braking followed by parachute braking and ending with atmospheric braking. It made a soft landing on the surface at 06:30 Moscow time on 21 December after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s.


Venera 10 LanderVenera 10 Lander - Venera 10 / 4V-1 lander

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Both Venera 11 and 12 landers failed to return colour television views of the surface and perform soil analysis experiments. All of the camera protective covers failed to eject after landing (the cause was not established) The soil drilling experiment was apparently damaged by a leak in the soil collection device, the interior of which was exposed to the high Venusian atmospheric pressure. The leak had probably formed during the descent phase because the lander was less aerodynamically stable than had been thought. Therefore the landing gear of the following two landers (Venera-13/14) were equipped with tooth-shaped stabilisers.

Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.

The Venera-12 flyby bus continued in solar orbit and successfully used its Soviet-French ultraviolet spectrometer to study Comet Bradfield on 13 February 1980 (one year and two months after its Venus encounter). At that time the spacecraft was 190,373,790 km from Earth.


30 October 1981 Venera 13 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824M. Mass: 4,500 kg.


Venera 13Venera 13

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Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart. After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on 1 March 1982. As it flew by Venus the bus acted as a data relay for the brief life of the descent vehicle, and then continued on into a heliocentric orbit. After the descent vehicle braked to subsonic speed a parachute was deployed. At an altitude of 47 km the parachute was released and simple airbraking was used the rest of the way to the surface. Venera 13 landed about 950 km northeast of Venera 14 at 7 deg 30 min S, 303 E, just east of the eastern extension of an elevated region known as Phoebe Regio. The area was composed of bedrock outcrops surrounded by dark, fine-grained soil. After landing an imaging panorama was started and a mechanical drilling arm reached to the surface and obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample, as determined by the X-ray flourescence spectrometer, put it in the class of weakly differentiated melanocratic alkaline gabbroids. The lander survived for 127 minutes (the planned design life was 32 minutes) in an environment with a temperature of 457 degrees C and a pressure of 84 Earth atmospheres. The bus carried instruments built by Austrian and French specialists, as well as Soviet scientific equipment.

Venera 13 LanderVenera 13 Lander

Credit: NASA. 28,679 bytes. 337 x 314 pixels.


04 November 1981 Venera 14 Program: Venera. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K / 11S824M. Mass: 4,000 kg.

Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart. After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on 5 March 1982. As it flew by Venus the bus acted as a data relay for the brief life of the descent vehicle, and then continued on into a heliocentric orbit. The parachute of the descent vehicle opened after the lander reached subsonic speed. At an altitude of about 50 km the parachute was released and simple airbraking was used the rest of the way to the surface. Venera 14 landed about 950 km southwest of Venera 13 near the eastern flank of Phoebe Regio at 13 deg 15 min S by 310 E on a basaltic plain. After landing an imaging panorama was started It has been reported that the surface analysis arm accidentally landed on one of the ejected camera covers and therefore didn't send back any data on the Venusian soil. This is visible in photographs sent back. On the other hand, the official account very specifically states that the mechanical drilling arm obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample was determined by the X-ray flourescence spectrometer, showing it to be similar to oceanic tholeiitic basalts. The lander survived for 57 minutes (the planned design life was 32 minutes) in an environment with a temperature of 465 degrees C and a pressure of 94 Earth atmospheres.



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Last update 12 March 2001.
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