In the first part, we talked about the first flights to Venus - starting with Sputnik 7, followed by the Venera Monera 1 series and ending with Venera 6, which closed the sixties. The following flights were already more advanced and also included instruments for comprehensive chemical and geological research of the planet
In the first part, we talked about the first flights to Venus - starting with Sputnik 7, followed by the Venera Monera 1 series and ending with Venera 6, which closed the sixties. The following flights were already more advanced and also included instruments for comprehensive chemical and geological research of the planet
Venera 7
On August 17, 1970, Venera 7 was launched, the spacecraft is more sophisticated than its predecessors. Her weight is 1180 kg. After the previous failures to land spacecraft on Venus, the descent mechanism was completely changed. The lander is able to pass through the upper layers of the atmosphere much faster than its predecessors and it can withstand a pressure of G200 and a heat of 500 degrees. The parachute was also designed to withstand such a high temperature. After a journey of 120 days, on December 15, the spacecraft reached its destination. During the flight, more than 100 course corrections were made, 127 radio calls were made, which also made it possible to receive valuable information about the space itself and the activity of the instruments. The spacecraft traveled 320 million km.
The purpose of the flight was a comprehensive chemical and geological study of the planet. On December 2, at a distance of 1.3 million km from Venus, all the necessary preparations for the landing were made. At this distance, the cooling of the landing facility was started to 8 degrees below zero. The spacecraft has two instrument chambers, one designed to enter orbit around Venus and the other for landing. On December 15, the lander detached from the capsule and entered the atmosphere at a speed of 11.5 km per second. The temperature difference between the shock wave and the lander reached 11,000 degrees. The entry into the atmosphere was made in a jumping orbit. This is a gradual entry and while charting a spiral flight path that slows the flight speed to 201 meters per second. All the while, there was a G350 load landing. At this speed the parachutes were deployed and began transmitting data to Earth. Landing duration 35 minutes, 25 minutes less than expected.
During the flight, the spacecraft's instruments operated on electrical energy while being fed by solar energy. The devices included pressure gauges capable of withstanding pressures between 0.5 and 150 atmospheres. The thermometers are able to withstand temperatures of 25-540 degrees.
The parachutes were deployed at an altitude of 60 km and at a load of 0.7 atmospheres. The parachute can withstand a temperature of 530 degrees. Slowing down the landing speed allowed a thorough study of the lower layers of the atmosphere. Throughout the descent, the temperature rose gradually. The solid proof of the landing was that the power of the radio waves decreased 100 times. The reason for this probably lies in the sudden change in the direction of the transmitting antenna.
Venera 7 transmitted data to Earth for 23 minutes. It turned out that the prevailing temperature on the surface of Venus is 20 ± 475 degrees, the atmospheric pressure is 15 ± 90, the density of the atmosphere near the ground is 60 times greater than the Earth's atmosphere and the atmosphere contains 97% CO2 and 1% water vapor. During the flight, from December 10, 1970, data on powerful solar flares was broadcast. The spacecraft carried with it a picture of Lenin and also the symbol of the hammer and sickle.
More of the topic in Hayadan:
- The first part of the series - Soviet missions to Venus in the sixties
- A review of the Soviet Union and Russia's space program
Venera 8
On March 27, 1972, Venera 8 was launched. The spacecraft was launched from a terrestrial parking orbit that is 193.6 - 240 km from the ground. The angle of inclination is 51.77 degrees and the duration of the lap is 88.79 minutes. The weight of the spacecraft is 1180 kg. Venera 8 is designed to continue the research done by its predecessors and they are:
- A Landing Landing on the surface of the ground.
- B. Transmission of data on the atmosphere, atmospheric pressure, temperature, hydrogen concentration and dust content.
- third. Measuring the flow of solar plasma to the planet.
- d. Chemical analyzes of the atmosphere. Check if it has sulfur, bromine, iodine and mercury. The Russian researchers assumed that on the ground and in several layers of the atmosphere there are metals such as zinc and lead in a liquid phase, and they tried to prove this hypothesis.
- God. Measuring the chemical composition of Venus soil and the nature of the rocks.
- and. Measuring light conditions on the ground.
- G. Measuring interstellar space during the spacecraft's flight.
The Russian space scientists called the Jedrell Bank Observatory in England and asked the astronomers instead to receive the spacecraft's transmissions and transmit them to them. The request was answered positively.
Due to the data accumulated in previous flights, the shape of the lander was changed. It is much like an ice box. A few days before landing, the spacecraft's instruments were frozen so that they could withstand the high temperature during entry into the atmosphere. Indeed, the temperature inside the lander dropped to 12 degrees below zero. The lander was also equipped with special parachutes and heat shields capable of withstanding a temperature of 500 degrees.
Landing weight 495 kg. The spacecraft contains a gamma radiation detector to measure the chemical composition of the soil, a photometer, an additional transmission antenna for emergencies, the hammer and sickle symbol and a photo of Lenin.
After a journey of 300 million km for 117 days, on July 22 the lander detached from the spacecraft, entered the atmosphere, deployed its parachutes and landed. The landing was 2896 km from the Venera 7 landing site. The lander transmitted data for 50 minutes and stopped working. During the landing the Earth was relatively low to the horizon of Venus, so that the illumination of the Sun could be measured. Since the landing took place during the morning time of Venus, the sun was a little high above the horizon of the landing site.
the landing course
The descent to the ground began with the disconnection of the lander when the initial speed is 41,696 km/h. When the lander stabilized, the aerodynamic braking slowed the speed to 900 km/h. During this time, the lander must withstand a load of 350 g. After the lander passed the 70 km altitude line, a height where the clouds are found, the telemetry was activated and the data was transmitted to Earth. At the same time the altimeter also started working and the parachute deployed. In the final stage, the main parachute was disconnected. The landing was on the bright side of Venus where it could be seen from Earth, making it possible to communicate with it.
Findings
The chemical composition of the planet's soil at the landing site is similar to that of the Earth, and radioactive elements such as potassium (4%), uranium (4% 10X 2.1) and thorium (% -4 10X 6.5) were found in the same ratio in which they are found in many volcanic rocks on Earth . In earlier geological periods Venus was probably hotter and the material in it softened and flowed in it. At this time the heavy elements were drawn towards the center (the core) while the light ones with the radioactive elements rose to the surface from the crust of the star. The density of the soil at the landing site is 1.5 g/cmXNUMX. The material from which the ground at the landing site is made is very similar to the earthly granite rocks. The soil is probably crunchy and crumbly.
The atmosphere contains 97% CO2, 2% nitrogen and less than 1% oxygen. The water vapor has a concentration of less than 1%. Close to the clouds there is ammonia in a concentration of 0.1% - 0.01%. Less than 2% of the sunlight that penetrates through the cloud cover reaches the star and hits the ground and is scattered everywhere by endless amounts of CO2 and softens any shadow or color contrast.
And candle 8 landed on the light side, and candle 7 on the dark side. According to the data of the two spacecraft it was determined that there is no noticeable difference between day and night, the ground does not cool down. During the long night the greenhouse effect of the atmosphere prevents the heat from escaping. The temperature measured at the landing site reached 475 degrees and the atmospheric pressure reached 90 atmospheres. At an altitude of 48 km the wind speed is 176 km/h and near the ground 6.4 km/h. These values confirmed observations from Earth which assumed that the atmosphere moves in the direction of its movement around itself. The wind moves from the dark side to the light side.
Venera 9, Venera 10
On June 8, 1975, the USSR began the next phase in the study of the planet Venus, launching two spacecraft - Venera 9 and Venera 10. They were launched at different times. The first was launched on June 8 and the second on June 14. They were launched from a national runway. The launcher is SL-13 Proton. The goal is to better withstand the planet's climate. The decision to launch the two spacecraft one after the other came to increase the amount of new information about Venus and also allow for a cross examination of the findings, to obtain more complete data about Venus and to ensure the reliability of the information. During the flight, the spacecraft must collect information about magnetic fields in space, the solar wind and interstellar ultraviolet radiation.
The structure of the spacecraft
These spaceships are a new model and their equipment is much more perfect than their predecessors. The weight of each spacecraft is 4.3 tons. Each spaceship is made of two parts - a hull and a lander.
the circle
Each hyphen has two parts. The upper part is cylindrical and contains the fuel tanks, and the lower part is equipped with various systems and measuring devices. The spacecraft engine is attached to this part. On both sides of the spaceship are two solar collectors equipped with cooling systems to regulate the temperature. The compass has three antennas, one parabolic connecting Venus to the Earth and located between the solar collectors. The other two antennas are spiral and multi-channel for the link between the spacecraft and the Earth and for the link between the lander and the compass. In order to be able to make observations already in the upper layers of the atmosphere, the ratio between the mass and the contact area between the spacecraft and the lander was reduced. The reference system is three-dimensional and the reference parameters are the Earth, the Sun and the North Star.
Each hyphen has two purposes. A technical one, to maintain contact between the Earth and between it and to serve as a satellite relay station between it and the lander as long as the latter is functioning. The second goal is scientific and long-term, to study Venus and its environment. Among the objectives set before the spacecraft, it had to perform an analysis of the upper atmosphere, its chemical composition and physical properties, optical and radio-telescopic observations, such as investigating the structure of the clouds and their upper surface area. The latter is done with ultraviolet means. The orbiter must measure its gravity and magnetic field and the effect of the solar wind on the plasma in the upper atmosphere.
landed
Compared to previous spacecraft, each lander is inside two heat shields in the form of half spheres. The diameter of such a shield is 3 meters and its advantage is that it allows greater exposure of the research instruments compared to the previous landings. These shields can withstand a load of g350 and a temperature of thousands of degrees. The shields are disconnected shortly after entering the atmosphere.
At the bottom of the lander is a landing ring and its role is to monitor the correct landing speed rate. Attached to it are aerodynamic stops in the form of an inverted umbrella and a multi-channel cylindrical antenna. The ring is connected to the landing gear by shock absorbers. In the lander there is a device that ensures that it stands on the ground at an angle of 90 degrees and a telephotometer that is used as an insulating material (pure gold is found in it) and its melting point is 1063 degrees.
Until now, they assumed that the cloud cover did not allow light to penetrate the ground, and to illuminate the landing site at the bottom of the lander, lighting sources were installed. The range of the power systems, transmitters and antennas is 1500 km. The communication system is new and its capacity is 64 times greater than that of the previous spacecraft. The lander is equipped with a modern parachute system and is made according to a French design.
Each lander has a cooling system that aims to allow a longer life time on the surface of Venus. The planned lifetime is 30 minutes. A few days before landing, a cooling system is activated that lowers the temperature inside to 10 below zero. The temperature begins to rise gradually from the moment of landing up to 59 degrees above zero. At this moment the lander stops working. Each lander is stamped with the hammer and sickle symbol and a medal engraved with the shape of the spacecraft.
the purposes of the research:
A. photograph the surface of the ground with the help of panoramic television cameras.
B. Do a physical analysis of the soil such as density, the nature of the rocks and the intensity of illumination by the sun. Density is measured by a density meter placed on the ground upon landing.
third. measure the wind speed.
d. Measure the temperature and atmospheric pressure at the landing site.
God. Check the atmosphere at all stages of the descent to the ground - chemical and physical properties, illumination, atmospheric pressure and temperature, the structure of the clouds and their chemical composition.
Landing
The landing begins with the lowering of the temperature of the spacecraft's systems to 10 degrees below zero. The next step is to detach the lander from the makpet. The landing takes place two days later with the entry of the lander into the atmosphere. To ensure the landing, the lander must enter the atmosphere at an angle of 20 degrees while passing through a "narrow corridor" that is 20 km wide. The speed of entry into the atmosphere is 10.7 kilometers per second. Air resistance slows down the speed gradually up to 250 meters per second. In the eighth minute after entering the atmosphere, the spaceship's distance from the ground is 60 km. According to an electrical signal, the first of three parachutes deploys and removes its upper heat shield from the lander. The second chute removes the lower shield. At an altitude of 58 km, its third main dome-shaped parachute is deployed. At an altitude of 50 km, the last parachute disengages and the second braking phase begins by the aerodynamic stops in the landing ring. This braking system is superior to parachutes as it allows a faster landing. This prevents premature heating of the landing systems. The speed is only slightly higher than that achieved by parachutes. The landing speed is 6.8 meters per second. Shock brakes soften the landing. The landing lasts 75 minutes during which atmospheric measurements are made.
The maximum speed possible in the last stages of entering the atmosphere (the speed depends on the strength of the toroidal landing mechanism) was designed so as not to damage too much the life of the lander. The soil measurement begins immediately with the exposure of the camera lenses and the deployment of the soil testing system.
תקשורת
To make the most of the short life of the landers, their flight path was designed so that both the orbiters and the landers would approach each other on the other side of the planet. This arrangement brought the orbiters to an ideal position where information from the landers would be received for two hours from the moment they enter the atmosphere. From here the information is transmitted to the control center.
Venera 9
June 8 - launch.
October 20 - the lander was detached from the Mekpet.
October 22 - the Mekapet entered a flight path that brought it to a minimum distance of 1300 km from the planet on its hidden side. At this distance the spacecraft's engine was activated and it entered orbit around Venus. An hour later the lander touched the ground of the star. The landing was perfect even though a heavy fog covered the entire planet. Venera 9 landed in the highest place 2.65 km from its surroundings. She landed on a 30 degree slope between sharp rock fragments on a gravel surface. The temperature was 465 degrees, the pressure 86 atmospheres and the wind speed very low. Venera 9 transmitted data to Israel for 53 minutes. The first images were broadcast 15 minutes after landing. Dr. Boris Rob, the director of the supervising team, announced that he was surprised by the unexpected clarity and sharpness of the images. In the photographs you see a mass of large rocks - a typical type of young rock. The diameter of the rocks is 0.3-1 meter. Venera traveled 300 million km in 156 days.
October 26 - The Mikpet began surveying the clouds of Venus in ultraviolet in coordination with Venera 10. The width of the photographed strip is 1200 km.
November 4 - Venera 9 was transferred to a high eccentric orbit 1300 - 112,000 km and cycle time 48 hours and 13 minutes. The measurements made by the spacecraft are identical to those of Venera 10 and were carried out simultaneously:
A. photographing the clouds. Their structure and temperature profile, measuring their radiation by spectrometer, radiometer and photopolarimeter.
B. Studying the upper atmosphere and near space to determine their composition, transmitting radio waves to measure the density of ions and electrons and directly measuring the height of the latter by trapping the ions.
3. Measuring the magnetic field of the star, particles from the solar wind and gravimetric anomalies of Venus.
Venera 10
June 14 - launch.
October 23 - the lander was cut off.
October 25 - The Mekapet entered a flight path that brought it to a minimum distance of 1400 km from the face of the star, on its hidden side. At this distance the spacecraft's engine was activated and it entered orbit around Venus. Venera 10 landed at a distance of 2,200 km from Venera 9. The landing took place in a flat area. The temperature was 465 degrees, the atmospheric pressure 92 atmospheres and the wind speed 3.5 meters per second. Data was broadcast to Israel for 65 minutes. The images are similar to those taken from Venera 9 and yet differ considerably from them. The landscape is older. You can clearly see an ancient volcano with many smooth rocks on its surface. It seems that the landscape is like molten rock.
October 26 - The Mikpet began surveying the clouds of Venus in ultraviolet in coordination with Venera 9. The width of the photographed strip is 1,200 km.
November 4 - Venera 10 was transferred to a high eccentric orbit 1400-114,000 km and the cycle time 49 hours and 23 minutes. Its measurements are similar to those of Venera 9 and were performed simultaneously with it.
The course of work of the circles
From October 22 to November 21, the flight controllers made contact 75 times with dashcams, which transmitted information about the upper atmosphere to Israel and photographed the cloud layers.
January 23, 1976 - after three months, the Mikapets still continued to work. Venera 9 performed 47 laps. Venera 10 performed 46 laps.
March 22, 1976 - until this day, Venera 9 and Venera 10 completed 75 and 71 laps respectively. Although their research program ended, they continued to transmit data to Israel about the clouds, the upper atmosphere and the interaction of the latter with the solar wind.
findings
1. Atmosphere
The images broadcast to Israel show that Venus is much brighter than expected. The horizon line can be clearly seen at a distance of 200-300 meters, which proves that the atmosphere does not break the light rays as was believed until this flight. The unexpected brightness gives room for the assumption that the clouds of the star Venus are much more dispersed than thought. The panoramic photographs covering an area at an angle of 140-160 degrees clearly show what is described as a curved horizon line, distinguishing between the bright sky and the dark ground.
You can clearly see in the photographs the sharp contrasts between light and shadow like a photograph of the rocks of the star. This phenomenon contradicted the Or between the Arabs hypothesis. It was believed that Venus is always illuminated by the gray light of sunset, which is close to nebulae.
The upper limit of the cloud layer is at an altitude of 65 km and its base starts at an altitude of 30-35 km from the ground. The cloud layers are probably different from each other. The upper layers probably contain concentrated sulfuric acid mixed with hydrochloric and hydrofluoric acid. The clouds are highly homogeneous and not fragile. They are more permeable to light than the clouds of the land.
The environment near the ground is hostile and the high temperatures evaporate various substances. It is very possible that future spacecraft will find iodine and bromide vapors.
The gray light (pale and strange light that shines on the dark side) is made up of bands of radiation whose intensity rises steeply at the poles. The analysis of the phenomenon showed that this glare was created in a relatively narrow strip, probably at a high altitude.
2. Geology
There is no evidence of the presence of craters seen in radar images (note, the article was written in the 70s. In later measurements from spacecraft that circled Venus, craters are also visible, although their number is smaller). The star is sloped with huge rocks, some of which are as wide as a meter or more. Many of the rocks have very sharp edges, a fact that suggests that they are geologically young. In one of the photographs you see a field of rocks - rocks similar to those found in new lunar craters or in new formations on Earth. The age of rocks of this type is estimated on the surface of the moon to be tens of millions of years and on Earth to be tens of thousands.
The presence of rocks on the surface of Venus is amazing. From data transmitted to Israel by previous Venera spacecraft it was understood that only light winds blow on the surface of the ground. That is why it is amazing how rocks can be present in these meteorological conditions. The appearance of the rocks ranges from granite to volcanic rocks. It is very possible that they originate from earthquakes and volcanic eruptions. At their core, the rocks are very young and this gives grounds for believing that Venus is a geologically living planet and that the processes shaping these bodies are in progress. These new findings dispelled the belief that the planet's soil is shaped like earthly sand dunes.
The density of the crust of Venus calculated according to the dimensions of Venus 10 is 2.8 g/cmXNUMX. This density corresponds to the basaltic structure that exists in a flat area.
3. Meteorology
At the top of the clouds the wind speed is 350 km/h and near the ground 1.7-1.9 km/h, however due to the high atmospheric pressure the wind force is 50-60 times greater.
4. Magnetic fields
Venus has no magnetic field of its own. In contrast, magnetic fields and a flux of charged particles were regularly measured near it.
Probe 1
The first of the Zonde 1 spacecraft series was launched to Venus. The launch was on April 2, 1964. Zonde 1 was an automatic space station. The spacecraft was put into a terrestrial parking orbit by a multi-stage launcher. The weight of the spacecraft is 950 kg. Navigation was relative to the stars. Close to Venus, contact with the spacecraft was lost and the operation failed. The spacecraft missed Venus by 99,779 km and entered orbit around the sun. During the flight, the interstellar plasma was measured and its state-of-the-art systems were tested.
Russian missions to Venus that were not officially reported
- August 25, 1962 - A spacecraft failed in its attempt to break free from the Earth's gravity.
- September 11, 1962 - A spacecraft failed in its attempt to break free from Earth's gravity.
- September 12, 1962 - A spacecraft failed in its attempt to free itself from the Earth's gravity.
- Cosmos 21 - launched on November 11, 1963 for engine testing. Failed in her attempt to break free from the Earth's gravity.
- Cosmos 27 - was launched on March 27, 1964 to a national parking orbit. It circled the earth in an orbit that is 192-237 km away. The duration of the lap is 88.7 minutes and the inclination angle is 64.8 degrees. The spacecraft failed in its attempt to free itself from Earth's gravity, entered the atmosphere and burned up.
- Cosmos 96 - was launched on November 23, 1965 to a terrestrial parking orbit that is 227-310 km from the ground, the duration of the orbit is 89.6 minutes and the angle of inclination is 49 degrees. Failed in her attempt to break free from the Earth's gravity.
- Cosmos 167 - launched on January 17.1.1967, XNUMX failed in its attempt to break free from the Earth's gravity.
- Cosmos 359 - launched on August 22, 1970 as part of the pair Venera 7 and Venera 8 (this is the original name of Cosmos 359). It was supposed to land on Venus but failed in its mission. The spaceship failed to break free from Earth's gravity and three months later burned up in the atmosphere. Her weight is 1189 kg.
- Cosmos 482 - was launched on March 31, 1972. Four days after the launch of Venera 8, it was launched into a terrestrial parking orbit that is 204 - 500 km from the ground, the duration of the orbit is 89.8 minutes and the angle of inclination is 51.2 degrees. After the first lap, the launcher's engines were activated to detach from the Earth's gravity. The attempt failed and the spacecraft entered a higher orbit which is 211.5-9744 km from the ground. The inclination angle is 52.22 degrees and the lap time is 201.44 minutes.
