Soviet Craft - Venera

Venera (1961-1983)

The Venera program was bent towards studying Venus. The program included 16 probes, three of which failed. Venera 1 was the first probe from Earth to pass by Venus; Venera 3 was the first probe to land on Venus. The later Venera craft (9-14) were made of both a lander and an orbiter. Venera 13 and 14 were twins, designed to take advantage of the 1981 launch opportunity, and Venera 15 and 16 were twins, designed to take advantage of the 1983 launch opportunity.

Also called Venus 1 and Gamma Venera
Launched February 12, 1961 at 2:09:00 UTC
Orbital Mass: 643.5 kg

Venera 1 was the first spacecraft to fly by Venus. The probe consisted of a cylindrical body topped by a dome, totaling 2 m in height. Two solar panels extended radially from the cylinder. A large (over 2 m diameter) high-gain net antenna was used to receive signals from the ground. This antenna was attached to the cylinder. A long antenna arm was used to transmit signals to Earth. The probe was equipped with scientific instruments including a magnetometer attached to the end of a 2 m boom, ion traps, micrometeorite detectors, and cosmic radiation counters. The dome contained a pressurized sphere which carried a Soviet pennant and was designed to float on the putative Venus oceans after the intended Venus impact. Venera 1 had no on-board propulsion systems. Temperature control was achieved with thermal shutters.

Venera 1 was launched along with an Earth orbiting launch platform (Tyazheliy Sputnik 5 (61-003C)) with a SL-6/A-2-e launcher. From a 229x282 km orbit, the Venera 1 automatic interplanetary station was launched from the platform towards Venus with the fourth stage Zond rocket. On February 19, 7 days after launch at a distance of about two million km from Earth, contact with the spacecraft was lost. On May 19 and 20, 1961, Venera 1 passed within 100,000 km of Venus and entered a heliocentric orbit.

Also called Venus 2
Launched November 12, 1965 at 5:02:00 UTC
Orbital Mass: 963 kg

Venera 2 was launched from a Tyazheliy Sputnik (65-091B) towards Venus and carried a TV system and scientific instruments. On February 27, 1966, the spacecraft passed Venus at a distance of 24,000 km and entered a heliocentric orbit. The spacecraft system had ceased to operate before the planet was reached and returned no data.

Also called Venus 3
Launched November 16, 1965 at 4:19:00 UTC
Orbital Mass: 960 kg

Venera 3 was launched from a Tyazheliy Sputnik (65-092B) towards Venus. The mission of this spacecraft was to land on the surface. The entry body contained a radio communication system, scientific instruments, electrical power sources, and medallions bearing the coat of arms of the USSR. The station impacted Venus on March 1, 1966, making Venera 3 the first spacecraft to impact on the surface of another planet. However, the communications systems had failed before planetary data could be returned.

Also called Venus 4
Launched June 12, 1967 at 2:40:00 UTC
Orbital Mass: 1106 kg

Venera 4 was launched from a Tyazheliy Sputnik (67-058B) towards Venus with the announced mission of direct atmospheric studies. On October 18, 1967, the spacecraft entered the Venusian atmosphere and released two thermometers, a barometer, a radio altimeter, and atmospheric density gauge, 11 gas analyzers, and two radio transmitters operating in the DM waveband. The main bus, which had carried the capsule to Venus, carried a magnetometer, cosmic ray detectors, hydrogen and oxygen indicators, and charged particle traps. Signals were returned by the spacecraft, which braked and then deployed a parachute system after entering the Venusian atmosphere, until it reached an altitude of 24.96 km.

Also called Venus 5
Launched January 5, 1969 at 6:28:00 UTC
Orbital Mass: 1130 kg

Venera 5 was launched from a Tyazheliy Sputnik (69-001C) towards Venus to obtain atmospheric data. The spacecraft was very similar to Venera 4 although it was of a stronger design. When the atmosphere of Venus was approached, a capsule weighing 405 kg and containing scientific instruments was jettisoned from the main spacecraft. During satellite descent towards the surface of Venus, a parachute opened to slow the entry rate. For 53 min on May 16, 1969, while the capsule was suspended from the parachute, data from the Venusian atmosphere were returned. The spacecraft also carried a medallion bearing the coat of arms of the USSR and a bas-relief of V.I. Lenin to the night side of Venus.

Also called Venus 6
Launched January 10, 1969 at 5:52:00 UTC
Orbital Mass: 1130 kg

Venera 6 was launched from a Tyazheliy Sputnik (69-002C) towards Venus to obtain atmospheric data. The spacecraft was very similar to Venera 4 although it was of a stronger design. When the atmosphere of Venus was approached, a capsule weighing 405 kg was jettisoned from the main spacecraft. This capsule contained scientific instruments. During descent towards the surface of Venus, a parachute opened to slow the entry rate. For 51 min on May 17, 1969, while the capsule was suspended from the parachute, data from the Venusian atmosphere were returned. The spacecraft also carried a medallion bearing the coat of arms of the USSR and a bas-relief of V.I. Lenin to the night side of Venus.

Also called Venus 7
Launched August 17, 1970 at 5:38:00 UTC
Orbital Mass: 1180 kg

Venera 7 was launched from a Tyazheliy Sputnik in an Earth parking orbit towards Venus to study the Venusian atmosphere and other phenomena of the planet. Venera 7 entered the atmosphere of Venus on December 15, 1970, and a landing capsule was jettisoned. After aerodynamic braking, a parachute system was deployed. The capsule antenna was extended, and signals were returned for 35 min. Another 23 min of very weak signals were received after the spacecraft landed on Venus. The capsule was the first human-made object to return data after landing on another planet.

Also called Venus 8
Launched March 27, 1972 at 4:15:01 UTC
Orbital Mass: 1180 kg

Venera 8 was a Venus atmospheric probe. Its instrumentation included temperature, pressure, and light sensors as well as radio transmitters. The spacecraft took 117 days to reach Venus, entering the atmosphere on July 22, 1972. Descent speed was reduced from 41,696 km/hr to about 900 km/hr by aerobraking. The 2.5 meter diameter parachute opened at an altitude of 60 km, and a refrigeration system was used to cool the interior components. Venera 8 transmitted data during the descent and continued to send back data for 50 minutes after landing. The probe confirmed the earlier data on the high Venus surface temperature and pressure returned by Venera 7, and also measured the light level as being suitable for surface photography, finding it to be similar to the amount of light on Earth on an overcast day.

Also called Venus 9
Launched June 8, 1975 at 2:38:00 UTC
Launch mass: 4936 kg total, including 2015 kg lander and 2300 kg orbiter

The orbiter part of this mission was to act as a communications relay for the lander and to explore cloud layers and atmospheric parameters. The orbiter's instruments included a French 3500 Å UV photometer, a 4000-7000 Å photo-polarimeter, a 1.5-3 µm infrared spectrometer, and a 8-30 µm infrared radiometer. The orbiter also carried a magnetometer and charged particle traps. Some reports indicated a camera system was also aboard. 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 m sphere which held the landers.

On October 20, 1975, the lander part of this craft was separated from the orbiter, and landing was made with the sun near zenith at 05:13 UT on October 22. 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 53 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 from the Venera 10 landing site. Preliminary results indicated:

clouds 30-40 km thick with bases at 30-35 km altitude
atmospheric constituents including HCl, HF, Br, and I
surface pressure about 90 (Earth) atmospheres
surface temperature 485 °C
light levels comparable to those at Earth mid-latitudes on a cloudy summer day
successful TV photography showing shadows, no apparent dust in the air, and a variety of 30-40 cm rocks which were not eroded

Also called Venus 10
Launched June 14, 1975 at 3:00:31 UTC
Launch mass: 5033 kg total, including 2015 kg lander and 2300 kg orbiter

The orbiter part of this mission was to serve as a communications relay for the lander and to explore cloud layers and atmospheric parameters. The instruments included a French 3500 Å UV photometer, a 4000-7000 Å photo-polarimeter, a 1.5-3 µm infrared spectrometer, and a 8-30 µm infrared radiometer. The orbiter also carried a magnetometer and charged particle traps. Some reports indicated a camera system was also aboard. 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 m sphere which held the landers.

On October 23, 1975, the lander was separated from the orbiter, and landing was made with the sun near zenith, at 05:17 UT, 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:

profile of altitude (km)/pressure (Earth atmospheres)/temperature (°C) of 42/3.3/158, 15/37/363, and 0/92/465
successful TV photography showing large pancake rocks with lava or other weathered rocks in between
surface wind speed of 3.5 m/s

Launched September 9, 1978 at 3:25:39 UTC
Orbital Mass: 4940 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. The flight platform had instruments to study solar-wind composition, gamma-ray bursts, ultraviolet radiation, and the electron density of the ionosphere of Venus. The lander probe carried instruments to study the characteristics and composition of the atmosphere of Venus.

Venera 11 was launched into a 177x205 km, 51.5° 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 platform was equipped with 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.

The Venera 11 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. Separating from its flight platform on December 23, 1978 it 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 December 25 after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s. Information was transmitted to the flight platform for re-transmittal to Earth until it moved out of range.

It is unknown whether the lander carried an imaging system. No mention of it occurs in the Soviet literature examined by NASA. Two other experiments on the lander did fail, and their failure was acknowledged by the Soviets. Some U.S. literature on the subject notes that the imaging system "failed" but did return some data. 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. Results reported included evidence of lightning and thunder, a high Ar36/Ar40 ratio, and the discovery of carbon monoxide at low altitudes.

Launched September 14, 1978 at 2:25:13 UTC
Orbital Mass: 4940 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. The flight platform had instruments to study solar wind composition, gamma-ray bursts, ultraviolet radiation, and the electron density of the ionosphere of Venus. The lander probe carried instruments to study the characteristics and composition of the atmosphere of Venus.

Venera 12 was launched into a 177x205 km, 51.5° inclination Earth orbit from which it was propelled into a 3.5 month Venus transfer orbit which involved two mid-course corrections, on September 21 and December 14. After ejection of the lander probe on December 19, 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 its own measurements on interplanetary space. The platform was equipped with 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.

The Venera 12 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. Separating from its flight platform on December 19, 1978, it 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 06:30 Moscow time on December 21 after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s. Information was transmitted to the flight platform for re-transmittal to earth. until it moved out of range.

Launched October 30, 1981 at 6:04:00 UTC
Orbital Mass: 760 kg lander

Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched five days apart. The Venera 13 mission consisted of a bus (81-106A) and an attached descent craft (81-106D). After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on March 1, 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 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.

The Venera 13 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 design was similar to the earlier Venera 9-12 landers. It carried instruments to take chemical and isotopic measurements, monitor the spectrum of scattered sunlight, and record electric discharges during its descent phase through the Venusian atmosphere. The spacecraft utilized a camera system, an X-ray fluorescence spectrometer, a screw drill and surface sampler, a dynamic penetrometer, and a seismometer to conduct investigations on the surface.

After entering the atmosphere, a parachute was deployed. At an altitude of 47 km the parachute was released and simple aerobraking was used the rest of the way to the surface. Venera 13 landed about 950 km northeast of Venera 14 at 7° 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 °C and a pressure of about .05 atmospheres. The composition of the sample determined by the X-ray fluorescence 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 °C and a pressure of 84 Earth atmospheres. The descent vehicle transmitted data to the bus, which acted as a data relay as it flew by Venus.

Launched November 4, 1965 at 5:31:00 UTC
Orbital Mass: 760 kg lander

Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart. The Venera 14 mission consisted of a bus (81-110A) and an attached descent craft (81-110D). After launch and a four month cruise to Venus, the descent vehicle separated and plunged into the Venus atmosphere on March 5, 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 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.

The Venera 14 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 design was similar to the earlier Venera 9-12 landers. It carried instruments to take chemical and isotopic measurements, monitor the spectrum of scattered sunlight, and record electric discharges during its descent phase through the Venusian atmosphere. The spacecraft utilized a camera system, an X-ray fluorescence spectrometer, a screw drill and surface sampler, a dynamic penetrometer, and a seismometer to conduct investigations on the surface.

After entering the atmosphere, a parachute was deployed. At an altitude of about 50 km the parachute was released and simple aerobraking 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° 15 min S by 310 E on a basaltic plain. 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 °C and a pressure of about .05 atmospheres. The composition of the sample was determined by the X-ray fluorescence 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 °C and a pressure of 94 Earth atmospheres. The descent vehicle transmitted data to the bus, which acted as a data relay as it flew by Venus.

Launched June 2, 1983 at 2:38:39 UTC
Orbital Mass: 4000 kg

Venera 15 was part of a two spacecraft mission (along with Venera 16) designed to use 8 cm band side-looking radar mappers to study the surface properties of Venus. The two spacecraft were inserted into Venus orbit a day apart with their orbital planes shifted by an angle of approximately 4° relative to one another. This made it possible to reimage an area if necessary. Each spacecraft was in a nearly polar orbit with a periapsis at 62 N latitude. Together, the two spacecraft imaged the area from the north pole down to about 30° N latitude over the 8 months of mapping operations.

The Venera 15 and 16 spacecraft were identical and were based on modifications to the the orbiter portions of the Venera 9 and 14 probes. Each spacecraft consisted of a 5 m long cylinder with a 6 m diameter, 1.4 m tall parabolic dish antenna for the synthetic aperture radar (SAR) at one end. A 1 m diameter parabolic dish antenna for the radio altimeter was also located at this end. The electrical axis of the radio altimeter antenna was lined up with the axis of the cylinder. The electrical axis of the SAR deviated from the spacecraft axis by 10°. During imaging, the radio altimeter would be lined up with the center of the planet (local vertical) and the SAR would be looking off to the side at 10°. A bulge at the opposite end of the cylinder held fuel tanks and propulsion units. Two square solar arrays extended like wings from the sides of the cylinder. A 2.6 m radio dish antenna for communications was also attached to the side of the cylinder.

Launched June 7, 1983 at 2:32:00 UTC
Orbital Mass: 4000 kg

Venera 16 was part of a two spacecraft mission (along with Venera 15) designed to use 8 cm band side-looking radar mappers to study the surface properties of Venus. The two spacecraft were inserted into Venus orbit a day apart with their orbital planes shifted by an angle of approximately 4° relative to one another. This made it possible to reimage an area if necessary. Each spacecraft was in a nearly polar orbit with a periapsis at 62 N latitude. Together, the two spacecraft imaged the area from the north pole down to about 30° N latitude over the 8 months of mapping operations. In June 1984, Venus was at superior conjunction and passed behind the sun as seen from Earth. No transmissions were possible, so the orbit of Venera 16 was rotated back 20° at this time to map the areas missed during this period.