Venera

As part of the Venera mission (Russian Венера ) were launched 1961-1983 by the Soviet Union several space probes to Venus. Occasionally, there is also the spelling " Wenera " (see transcription of the Cyrillic alphabet ). In addition to the designated space probes there were a number of false starts, which were reported in the case of reaching Earth orbit as satellites Sputnik and the cosmos deck name. In addition, as part of the Zond program were made a flight ( Zond 1) in the direction of Venus and other non- successful launches.

• 7.1 Notes and references

Missions

First generation

In the Start window, 1961, the Soviet Union was planning to launch two probes toward Venus. For a long time we suspected that the probes had a small landing capsule on board, which was supposed to land on Venus and was designed in an ocean (whose presence was suspected on Venus ) to swim. This assumption was nourished by the entrainment of Soviet emblems like the Lunik probes. Today we know that the probes brought with them no Lander, but instead probably should try a hard impact on the surface of Venus.

• Sputnik 7 was launched on 4 February 1961. The probe failed due to the failure of the upper stage of the Molniya launcher not orbit. The probe was in orbit together with the upper stage of the rocket ( which was not separated ) a mass of 6843 kg.
• Venera 1 was launched on February 12, 1961 and left orbit. However, the contact with the probe already on February 19, 1961 broke in 2 million kilometers from the Earth. The silent probe flew on May 20, 1961 passed into 100,000 km of Venus, which she was the first object created by man that came into the vicinity of Venus. The probe weighed 643.5 kg.

Since the Molniya rocket used to launch was still unproven, it has started 1962 the same three probes. For two of these three probes and a landing for a flyby of Venus was planned. The mass of the probes was approximately 890 kg each. The probes were from the project 2- MV, in which developed a common bus for a Mars or Venus probe. This bus could then either carry a landing capsule or an instrument package.

• Sputnik 19 Sputnik 20 Sputnik 21 and started on August and September 1st and September 12th, 1962 25, but came because of the failure of the launch vehicle, no more than the Earth's orbit.

Sputnik Sputnik 19 and 20 were rovers, Sputnik 21, however, a flyby probe. Technical details were not released, but because of the common bus should the structure have been identical with Mars 1.

" Venera 2" and "Cosmos 96" were flyby probes, " Venera 3" should release a lander, which should then land on the planet's surface: In 1965, again different probe pairs were sent on their way. Although only " Venera 2" and " Venera 3" partially successful work, presented the 1966 yet the Soviet breakthrough to Venus represents the United States was the Soviet Union, but already discovered it: your first successful Venus flyby was held by Mariner 2 on December 14, 1962.

The bus of the probes was identical to the one of Zond 1 Zond 3 was planned to a common bus for probes to Mars and Venus. While the Venus probes were incorporated into the Venera program, you have the Mars probes never started except one. Instead, they were launched as Zond 1 Zond 3 up. The Zond program was generally for interplanetary probes whose true nature of the Soviet Union did not want to divulge.

The flyby probes contributed with different spectrometer and a camera system, which should make recordings during flyby. The lander should spend a longer time on the surface and was equipped with solar panels to. He had meteorological sensors and instruments to study the atmosphere.

• Venera 2 launched on 12 November 1965. 963 kg spacecraft flew on 27 February 1966 in 24,000 km Distance to Venus over the connection but stopped short before the flyby, so that you will not get any data. This was caused by overheating of the probe.
• Venera 3, launched on 16 November 1965, at its flyby of Venus on March 1, 1966 for the same reason no contact with the ground station, but automatically unlatched the probe their landing probe, but in the atmosphere of Venus burned up partially and hard hit on the surface. She was thus the first object created by man, which landed on the surface of Venus. The total mass of the probe was 960 kg.
• Cosmos 96 remained after its launch on November 23, 1965 in Earth orbit. The probe was probably " Venera 3" identical.

The two probes 1967 were further developed models of " Venera 3" and " Cosmos 96". " Venera 4 " was the first fully successful Venus mission of the Soviet Union, although it did not reach the surface of Venus because the high pressure of the atmosphere of Venus was known only inadequate. Nevertheless, the probe worked over the entire scheduled time and could provide important data about the atmosphere of Venus.

• Venera 4 was launched on June 12, 1967. Transfer probe separated on October 18, 1967, to the Venus a lander from which to 24.96 km in height successfully transferred 96 minutes long data until the batteries failed (they were scheduled a battery life of 100 minutes). Since the atmospheric pressure was estimated to be low, the probe for the descent took longer, and therefore could not reach the surface of the planned operation. The last measurement data showed a temperature of 270 ° C and a pressure of 22 bar at 25 km above the surface. The total mass of the probe was 1106 kg.
• Cosmos 167 was born on June 17, 1967 does not go beyond Earth orbit. The probe was identical to " Venera 4".

1969 succeeded for the first time a double launch of the Soviet Union to Venus. The two probes were similar to the successful " Venera 4", but had been put on a slightly higher outside pressure of 25 bar drop pods. However, this was not sufficient, so that the two probes do not soil the Venus reached intact. Had improved to the parachute system, so that the probes are now reached rapidly by the atmosphere; also the battery capacity has been increased. However, both probes are considered to be successful because they delivered as planned - while descending on a parachute hanging - data on the atmosphere. The mass of the probes in each case was 1130 kg, with 405 kg accounted for the lander.

• Venera 5 was launched on January 5, 1969 and continued on May 16, 1969, lander from. With this lander could for 53 minutes contact be maintained above the surface of Venus until it was crushed by atmospheric pressure up to a height of 18 kilometers.
• Venera 6 launched on January 10, 1969, placed the lander on May 17, 1969. Contact with the lander was 51 minutes long up to 10 km altitude.

With " Venera 7 ", the lander could withstand a pressure of 180 bar, the Soviet Union achieved a decisive breakthrough. It was the first successful landing on an alien planet at all. The total mass of the probe was 1180 kg. A weak signal could be received for 23 minutes from the surface, then broke off the landing capsule. The instrumental equipment to Venera 6 included numerous experiments to study the atmosphere at Venera 4, now had to be kept to a thermometer and a barometer, since the increased shielding of the landing capsule required a lot of weight.

• Venera 7 began the flight to Venus on August 17, 1970. Landing probe " Venera 7" led on 15 December 1970, the first successful landing on Venus. The descent to the surface took 35 minutes, with data on the atmosphere have been transferred. After landing, could be received by the surface 23 minutes data.

• Cosmos 359 reached on August 22, 1970 due to a malfunction of the upper stage of the launcher no transfer orbit to Venus. Probably the probe was similar to the " Venera 7".

The two probes, which were launched in 1972, which from 1970 were similar. Now that you know the ground pressure of 90 bar, you could reduce the shielding of the capsule again and carry more experiments. A radio altimeter allowed to record the movement of the probe over the ground, and thus to create a height profile. A device according pointed ammonia chemically, another examined the size and distribution of aerosols in the atmosphere. A gamma-ray spectrometer to the specific soil, the concentration of the elements potassium, uranium and thorium. Another task was to measure the light levels on the surface of Venus to prepare the next equipped with cameras missions. Therefore, the probes had to land on the day side of Venus, after all the current landing tests were carried out on the night side. The total mass of the probes in each case was 1180 kg, the rovers each weighing 495 kg and contained the following instruments: temperature, pressure and light sensors, as well as an altimeter, a gamma-ray spectrometer and a gas analyzer. Since the 180 bar designed " Venera 7" previously reported only a pressure of 90 bar at the bottom, this landing capsule was now designed for 120 bar external pressure.

• Venera 8 launched on 27 March 1972. Landing probe appeared on 22 July 1972 at 08:37 UTC in the atmosphere of Venus. The entry velocity of 41,696 km / h was reduced by the deceleration to 900 km / h and then opened in 60 km altitude of 2.5 m large parachute. During the descent data has been transferred. The probe landed at 09:32 UTC on the day side of Venus and discovered that it was on the surface of the planet was as bright as on a cloudy day on Earth, with a visibility of about one kilometer. This was known that taking pictures on the surface of Venus is possible. The probe was a total of 50 minutes on the data, although only 11 seconds of data are sent from the surface.
• Cosmos 482 was on March 31, 1972 due to failure of the launcher back into the orbit.

Second generation

All previous Venera probes were launched with Molniya rocket and were limited to a mass of about 1,180 kg. But now you had the much stronger Proton rocket available that could carry about 5000 kg toward Venus. This far more demanding missions were possible, which is why you worked on the new heavy Venera probes.

After the launch window was missed in 1973, was started in 1975 " Venera 9" and " Venera 10 ", each consisting of an orbiter and a lander. For the first time flew the mother probes not on planets over, but beat a highly eccentric orbit. The two ( excluding fuel) 2,300 kg orbiter exact measurements the planet and delivered the first radar measurements, since the surface of Venus is not visible because of the completely made ​​of clouds atmosphere. The Soviet Union worked with these two missions together with France. The Lander these missions were housed in 2.4 m large balls and each weighing 1560 kg. We used different techniques to increase the life span on the 475 ° C hot surface; For example, the pre-cooling of the entire Landers to -10 degrees Celsius, and the carrying of packages with lithium nitrate trihydrate, a salt that melts at 30 degrees Celsius and it absorbs heat. For the first time contained the Lander cameras, provided the low-resolution images of the surface of Venus. These were the first full images of the surface of an alien planet at all. In addition, the Lander possessed a boom on which by X-ray fluorescence spectrometer, the composition of the surface was determined.

• Venera 9 was launched on 8 June 1975, swung into orbit around Venus on 20 October 1975. The lander landed on the same day at 32 ° North and 291 ° East and transmitted data for 53 minutes and for the first few images of the surface to Earth. The probe weighed at the start of 4936 kg.
• Venera 10 was launched on June 14, 1975, Venus reached on October 25, 1975, and the Lander ( landing point 16 ° North and 291 ° East ) worked as 63 minutes on the surface. They also provided data and images of the planet's surface. The probe weighed at the start of 5033 kg.

As it turned out later, the end of transmission was not caused by the failure of the Lander, but seen from the lander from the orbiter since disappeared behind the horizon and you could then no longer receive data. The Venera -9 orbiter worked until 22 March 1976. Both orbiter studied the Venus atmosphere with cameras and spectrometers. Further experiments were interplanetary space and the search for gamma-ray bursts.

The 1978 launched " Venera 11" and " Venera 12" the Soviet Union then returned back to the ancient art back: The flyby spacecraft flew past the planet and put down a lander. This allowed a longer contact with the lander. Both probes could - because the lining of the camera could not solve - transmit only data, but no pictures. The probe weighed at the start of each 4940 kg. At both flyby probes France and Austria also participated.

• Venera 11 left Earth on September 9, 1978, flew on 25 December 1978 at the Venus over. They put down a lander, which occurred at 11.2 km / s in the atmosphere and about an hour later touched down s with 7-8 m / on the surface. Lander the transmitted data from the surface of 95 minutes, but some tools had malfunction.
• Venera 12 was launched on 14 September 1978 but reached the probe to the planet on the 21st December 1978. The lander then transferred for 110 minutes data before the flyby spacecraft left the radio range.

The probe " Venera 13" and " Venera 14" each consisted of a flyby stage and a lander. The probes sent in contrast to their predecessors, again images of the surface of the earth. The images of the surface were this time created with high-resolution color cameras. In addition, the Lander possessed sophisticated analysis systems that withdrawals soil samples and examined the inside of the probe with an X-ray fluorescence spectrometer. The Lander each weighing 760 kg. The two parent probes were also used more to maneuver tests for later Vega mission, as well as observations of the sun and were fitted to a magnetometer and detectors for cosmic rays, gamma rays and particle detectors.

• Venera 13 was launched on 30 October 1981, flew on 1 March 1982 at the Venus over. The lander transmitted by " Venera 13" ( were scheduled 32 minutes ) for 127 minutes of data and images from the surface ( landing site at 7.5 ° South and 303 ° East ) at an external temperature of 457 ° C and an atmospheric pressure of 84 bar
• Venera 14 was launched on 4 November 1981 and reached Venus on 3 March 1982. The lander survived 57 minutes on the surface ( landing location 13.3 ° South and 310 ° East ) at an external temperature of 465 ° C and an atmospheric pressure of 94 bar and provided data and images.

" Venera 15" and " Venera 16" were the first to no longer Lander from, but continued the work of " Venera 9" and " Venera 10 " away. Both probes were identical and were based on modified flight platforms of " Venera 9 " to " Venera 14". They consisted of a 5 m long cylinder and a 1.4 -meter parabolic antenna with a diameter of 6 m for the Synthetic Aperture Radar ( SAR), which was housed at one end of the cylinder. A 1 m wide parabolic antenna for the radio altimeter was also located at this end of the probe. A buckle at the opposite end of the cylinder bore of fuel tanks and propulsion systems. To power were two solar panels available. A 2.6 m wide antenna was mounted on the side of the cylinder, was used to communicate with the Earth. The probes each weighing 4000 kg.

Overall, the probes were able to detect about 30 % of the surface with its Synthetic Aperture Radar (SAR ), by means of which you could see under the dense clouds of Venus. The maps produced by " Venera 15" and " Venera 16" had a resolution of 1 up to 2 km and were about 30 times more detailed than the Pioneer Venus 1 Both probes showed in their elliptical orbit only the northern hemisphere to about 30 degrees capture north latitude. This represents about 25 percent of the surface of Venus. However, six years later, launched U.S. Magellan probe created global maps of Venus at a resolution of about 100 meters, which put the Soviet achievements in the shade. At the missions " Venera 15" and " Venera 16 " France and the German Democratic Republic were involved with instruments.

• Venera 15 was launched on 2 June 1983 Venus. The probe reached on 10 October 1983 an orbit and mapped the planet by the year 1984 with Synthetic Aperture Radar.
• Venera 16 left Earth June 7, 1983 and began mapping the planet on October 14, 1983. Contact with " Venera 16 " ended on 12 July 1984.

Later missions

From 1984 to 1986 there were two further Soviet missions, Vega 1 and 2, both were able to complete their missions successfully.

Venera D

Venera D is a proposed Venus lander, developed by Lavochkin and should start about 2016. Current (2006) plans to go from a 1,700 -pound ( 8120 kg in orbit ) spacecraft, which will consist of an orbiter, a lander and a number of smaller balloons. The original design from 2003 contained only the lander, which should be launched in 2013.

" Venera D" is expected to be launched from a Sojus-2/Fregat-Rakete. The lander with a mass of 1.100 kg is to be able to survive on the surface of Venus for a month and take about 10-11 kg instruments. The orbiter will weigh about 600 kg and carry 40 kg scientific payload. The focus of the mission should be in the study of the atmosphere and seismic activity.

Summary

The exploration of Venus is one of the highlights and brilliant achievements of Soviet space exploration. In 1966 the Soviet Union with the first landing on another planet achieved initial partial success, 1970, the final breakthrough. After 1972, the technology was so far advanced that no mission failed. In 1975, the Soviet Union sent the first orbiter, which began with the radar mapping of the planet. The mapping of the planet was not completed by the Soviet Union.

Nevertheless, the Venus was the mid-1980s explored as so well that the Soviet Union turned to other targets. By the end of the 20th century there was only one more Venus mission, Magellan of the United States, which completed the mapping of the planet.

In the new millennium there is renewed efforts to explore Venus, namely primarily of Europe with the successful probe Venus Express and Japan with Akatsuki, but which missed the Venus orbit on their first attempt. Russia also wants to participate with the Venera -D mission.