Last episode in the series describing the history of the Luna program from the seventies
Luna 18
On September 2, 1971, Luna 18 was launched. This spacecraft continued the research of its predecessors and he studied the moon and its surroundings. The purpose of the flight was to land in the Sea of Fertility, in a mountainous area of great scientific importance. Lunar researchers hoped to find here the original foundation rock of the moon in its original arrangement. On September 7, the spacecraft entered lunar orbit at an altitude of 100 km from the ground and an inclination angle of 35 degrees. Luna 18 circled the moon 54 times.
At the end of the last lap, on September 11, the spacecraft began maneuvers for its landing. The landing attempt was unsuccessful and the spacecraft crashed on the moon. She disappeared in the Apollonius Mountains. Contact with it is cut off immediately after activating the braking motor. Russian space scientists speculated that the landing failed due to topographical difficulties. The prevailing opinion as to the cause of the failure was that Luna 18 crashed on the edge of a sharp cliff or deteriorated on a slope.
Luna 19
On September 28, 1971 Luna 19 was launched to the moon. The purpose of the flight was to study the moon and its environment and in particular the effect of its moons, the moon's gravity and interstellar magnetic fields. On October 3, the spacecraft entered a lunar orbit that is 140 km from the ground, the angle of inclination is 40 degrees and the duration of the orbit is 122 minutes. On October 6, the route was lowered to 127 km and the lap lasted 121 minutes. Maneuvers made on November 26 resulted in changing the shape of the orbit to an elliptical one. The distance from the ground was 77-385 km and the duration of the lap was 121 minutes. The angle of inclination remained the same angle.
Among the measuring devices were panoramic television cameras. The spacecraft observed ten powerful solar flares. The lunar radiation was compared with similar measurements made with the Mars spacecraft Mars 2, Mars 3, the Venus spacecraft Venera 8, Venera 7 and the satellites Prognosis 1 and Prognosis 2. Towards the end of October 1972 Luna 19 finished its mission. She made many television photographs of selected sites and tested possibilities of using orbital panoramas for navigation purposes. Plasma observed by Luna 19 near the moon was explained as an interaction between light coming from space and the surface of the moon.
Luna 20
Luna 14 was launched on February 1972, 20. The spacecraft was to explore the surface of the moon and its surroundings, land on it and return to Israel with soil samples. The spacecraft was launched into a stationary Earth orbit and from there aimed at the moon. In its national route, its distance from the ground was 190.5-237 km, the angle of inclination 51.51 degrees and the duration of the lap 88.73 minutes. On February 18, the spacecraft entered lunar orbit. The track was circular and its distance from the ground is 100 km, the angle of inclination is 65 degrees and the duration of the lap is 118 minutes. On February 19, the track was changed to elliptical. The distance from the ground was 21-100 km.
After selecting the site, the spacecraft landed. A panoramic photo telemetry camera transmitted to Israel photographs from which a gray cloud-like structure was selected for sampling. The landing took place on February 21 after 40 laps, and was done in three stages: first, the spacecraft's engine was turned on for four minutes and 27 seconds, which lowered the height of the spacecraft to a distance of 760 meters from the ground. In the second stage, at this height, a navigation engine was activated that guided the spacecraft towards landing. In the third stage, Luna 20 landed at N' 53 0 3 - E ' 55 0 56 where Luna 18 should have landed. In total, the landing lasted six minutes. The landing place is a strait with large craters.
The spacecraft stayed on the surface of the moon for 27.5 hours. During this time she photographed and examined it. Taking the soil samples was done with the help of a mechanical arm. Due to unexpected hardness of the rock, the arm worked in stages and breaks. The drill slowed down at a depth of 10 cm. In order to cool down, it was decided to temporarily stop its operation. Then he drilled another five cm. The drill is a rotary hammer type wrapped in an insulator against heat (the Luna 16 drill overheated) and is capable of picking up soft and hard samples. The samples were placed in a container and on February 23 it was sent to Israel. On February 25, the tank landed in Central Asia, on an island in the Karaggunir River, southwest of Dazkazgan in Kazakhstan. A blizzard raging at the landing site did not make it easy to locate the tank.
In the first tests, the hypothesis of the lunar researchers that these samples are a million years older than the moon was confirmed. They resemble ashes. Their color is light gray and some of them are 4-6 mm in diameter. As in previous samples, glass balls were also found in them.
Luna 21 and the lunar rover Lonchod 2
On January 8, 1973, Luna 21 was launched carrying the Lunkhod 2 lunar rover nearby. On January 9, a minor correction was made to the flight path. On January 12, the spacecraft entered a lunar orbit that is 90-100 km from the ground. The duration of the entire lap is 118 minutes and the angle of inclination is 60 degrees. The Preslanion was later reduced to 16 km. On the 41st lap on January 16, the spacecraft landed in the La Moniere Crater, in the Sea of Tranquility, 170 km from the landing site of Apollo 17. Lohnud 2 carried the Soviet flag with a picture of Lenin and the inscription "50 years of the Soviet Union". During the flight to the moon, false telemetry signals almost failed the flight.
The Lonkhod structure
The weight of the vehicle is 850 kg. The increase in weight compared to that of Lunchod 1 is due to improvements in the instruments and the installation of new research instruments. Control and communication have been improved. One of the panoramic television cameras was mounted in the center of the vehicle. The result - the quality of the footage has improved and the broadcast time to Israel is shortened. Shortening the transmission time allowed for better control of the vehicle. A corner laser reflector made in France continued the studies carried out with the same device that was in Longhud 1. The other goals carried out with this device are to measure the altitude lines of the moon more precisely and to test a theory that states that there is land migration on the moon similar to that on Earth. Another instrument is a space photometer for visible and ultraviolet light. This device is designed to measure the light radiation in different areas of the sky, observe the milky way and the edge of the galaxy where the solar system is located and find the light source of the zodiac and its relationship with the sun's corona. They also hoped to determine using the photometer if there are traces of cosmic dust in the "atmosphere" of the moon. The importance of these measurements is to test the feasibility of a plan to establish an observatory on the moon.
Lohnod 2 has a greater maneuverability than Lohnod 1. Its greater travel range allowed the examination of magnetic changes of the lunar rocks and the moon as a whole along a long travel path. The speed of the vehicle is twice that of Lonkhod 1. The internal temperature of the vehicle ranges from 12 degrees to 32 degrees and the pressure from 1.01 to 1.09 atmospheres. The vehicle is guided in its tours by a laser. This device is also used to measure the illumination of the moon in visible and ultraviolet light.
landing place
The La Moniere Crater was chosen as a landing site because it is located in a transitional area between the "continent" and the "sea" and in that area there is a 16 km long tectonic fault. Another task assigned to the vehicle is to explore the surface of the moon in the area between the ancient plateaus and the young plateaus filled with basalt-like lava. Researchers from the Russian Academy of Sciences and the American Space Agency hoped that the findings of this flight and the Apollo 17 flight would complement each other. An accurate description of the landing site was given to the US space agency so that they could benefit from the laser device. A French team that was at the observatory on Mount Lek (an observatory belonging to the University of Texas-McDonald, USA) managed on January 26 to contact the reflector with the help of a powerful laser beam. The returned signals could be compared with the reflectors placed by Apollo 11, Apollo 14 and Apollo 15.
Landing
The landing in its final stages was carried out at a speed of two meters per second. The landing was so perfect that only one leg needed shock absorbers. A careful examination of the ground after landing showed that it remained stable and did not feel any shocks during the landing. This is to be credited to the spacecraft's engine, which has shown extremely high reliability. A surveillance ship in the Atlantic warned of a malfunction near landing - one of the legs did not open at all. It turned out to be a false alarm. There was also concern that the power supply to the lander would be impaired because the plate, on which the solar collectors are located, was open during the flight to the moon.
The first lunar day, from January 16 to 26
January 16 - The first two and a half hours were dedicated to a comprehensive inspection of the lunar rover, the lander and first tests of the landing site. After a short drive, the vehicle was parked for 48 hours to charge the batteries. The first photographs showed that the vehicle was on a smooth plane between two small craters and in front of it at a distance of six kilometers are the low peaks of the Taurus Mountains.
January 17 - the vehicle's activity was stopped for two hours to charge the batteries and perform another and final inspection of the vehicle. For this purpose, the vehicle was driven towards the landing. On this trip, a disaster almost occurred. The angle of impact of the sun's rays made it difficult to determine distances. The vehicle approached to a distance of four meters from the lander and there was a fear of a collision between the two bodies. It was the resourcefulness of the car drivers that prevented the collision. They managed to turn the vehicle in another direction.
January 18 - the vehicle's activity was resumed. Lunchod 2 traveled a short distance and no damage to the ground was found following the landing. First chemical tests of the regolith in the Rifma instrument (RIFMA) showed that the soil composition is similar to the results of Lonkhod 1. The soil texture is coarser than that found by Lonkhod 1, and the density of craters and rock blocks is greater. After a six-hour break, the vehicle was driven to the southeast, to the landing site. In total he traveled 1,148 meters. Its distance as the crow flies from the landing is 1,050 meters.
January 20 - the vehicle traveled XNUMX km and discovered crunchy soil mixed with earth.
On the moonlit night the temperature reached 183 degrees below zero. During the day, the moon's sky shines 13-15 times more than that of the earth. Driving the car up the Taurus Mountains as "heavy traffic". The drivers underwent medical and hearing and vision tests before each trip. They were connected to sensors as if they themselves were on the moon.
The second lunar day, from February 9 to 22
On February 11, the vehicle traveled a distance of 1,636 meters. On February 17, he moved three kilometers south of the landing site and reached a crater with a diameter of two kilometers located on the slopes of the Taurus. On the 22nd, the activity of the solar collectors was stopped for the lunar night and the vehicle was parked.
On this day, the vehicle traveled a distance of 11,067 meters and it slid over slopes whose angle is 25 degrees. In one case, the vehicle's wheels deflated (became flat) temporarily when it was moving on an unstable rock. During its journey towards the Taurus Mountains, the vehicle performed magnetic measurements. He moved slowly down the mountain slope. In 80% of the vehicle's movement, the distribution of the wheels was measured. From a height of 400 meters, the second bank of the La Moniere crater and the main peaks of the mountain located 5-6 km away were photographed. The vehicle also took a continuous photo of the Earth when it appeared as a "thin sickle" in the sky.
The third lunar day, from March 9 to 22
On March 9, the vehicle "Woke Up" filled the batteries of the solar collectors and on the 11th it set off looking for interesting views for panoramic stereoscopic photography. The vehicle launched five stereoscopic views of the surface and examined the magnetism of the lunar rocks. The chemical composition of the soil, the radiation conditions and the intensity of the light in the moon's sky. On the 17th the vehicle traveled 2,230 meters and the next day 3,130 meters. Until March 19.3, Lonkhod 2 covered a distance of 17.68 km.
The fourth lunar day, from April 7 to 20
On April 10, the vehicle traveled a distance of two kilometers and tested the chemical composition of the soil in a large tectonic fault that passed that day. The fracture is 16 km long, 300-400 meters wide, 30-50 meters deep and is parallel to the Taurus Mountains. The vehicle moved carefully along the western edge of the fault and then moved along the eastern slope. It turned out to be a solid basaltic rock that was cracked by tectonic forces.
The night before, the vehicle was parked two kilometers from the fracture and then driven at speed up to a distance of 200 meters from it. The trip was towards sunrise, but the vehicle did not immediately begin its observations. The sun was at too low an angle and dangerous to operate near the fault. It was necessary to wait until the angle increased.
By April 19, the vehicle had traveled 31 km. It turned out that the ground in the tour area includes large areas of lying and exposed rocks and the regolith covers the rest of the areas up to a depth of 5-30 meters. The exposed rocks greatly increase the speed of the vehicle while in the remaining areas the wheels stick to the regolith.
The fifth lunar day, from May 5 to 18
On May 9, the vehicle moved away from the tectonic fault. This time it was moving in a northeasterly direction. On June 3, it was announced that Lonkhod 2 had finished its work plan. He traveled 37 km and transmitted 80,000 television photographs and 86 panoramic photographs from the surface. The lunar rover discovered that the ground is covered with a layer of dust particles that scatters sunlight and Earth's light. Data were also obtained on the structure of the lunar soil down to a depth of hundreds of kilometers.
From measurements made by Lunchod 2 in lunar orbit (before landing), on the surface of the moon and on the Earth, it became clear that on the visible side the surface is 9.5 km lower from the center and on the hidden side it is 13 km higher (these measurements are made relative to the center of the moon). Lunar conditions are not always good for space observation. The radiation of the sun after its sunset is 15-XNUMX times greater than expected than what exists on Earth. It was suggested that a large amount of dust particles scatters the solar radiation. This radiation makes the lunar day inconvenient for astronomical observations from the ground.
Luna 22
On May 29, 1974, Luna 22 was launched towards the moon to study it and its surroundings. On June 2, it entered orbit around it. The route is 220 km, the inclination angle is 19 degrees and 35 minutes. And the cycle time is 2 hours and 10 minutes. On June 9, the route was changed to 25-244 km so that resolution would be possible during the television filming of the selected photo sites, the investigation of the relief of the moon's surface by a radio altimeter and the testing of the chemical composition of the soil by a gamma radiation detector.
On the 13th with the completion of photographing the moon and measuring it closely. The route was changed to 299-189 km. At this height, the goal was to measure the magnetic field of the moon, the flux of meteorites, the energy intensity of solar radiation, plasma concentrations and cosmic radiation on November 11. The orbit was 171-1437 km, the angle of inclination 19 degrees and 33 minutes and the duration of the trip was three hours and 12 minutes. On August 24, 1975, the Parasol was lowered to 30 km to take better photographs of a certain site using a mechanical optical device and television. This site has been scanned in detail and systematically several times. At the end of the filming, the route was elevated and it was 100-1,286 km, the angle of inclination was 21 degrees and the duration of the lap was three hours.
Luna 22 worked for 15 months. It transmitted data on the chemical composition of the lunar rocks based on the measurement of their radiation and magnetic field. It measured the energy bursts of cosmic radiation from the sun and long radio waves transmitted from the planet Jupiter and photographed the surface of the moon. Much attention was paid to the magnetic field of the moon and the anomalies of the field which were discovered during previous flights. The results of Luna 22's measurements were matched with Luna 19's findings to verify with greater precision the gravimetric differences between the northern and southern hemispheres of the moon.
Luna 23
Luna 29 was launched on October 1974, 23. The goals of the flight were to explore the moon and its surroundings, to take soil samples from a depth of 2.5 meters, to check the normal functioning of the spacecraft and to achieve continuous contact with the control center. The spacecraft was launched from a terrestrial parking orbit. On November 2, the spacecraft entered lunar orbit. The route is 94-104 km and the inclination angle is 138 degrees.
On November 4, a first maneuver was performed and the next day a second maneuver and the route was set at 105-17 km. After 53 laps, Luna 13 landed in rough terrain in the south of the Sea of Crisis near - W 0 56.5 - N 0 13.5. The landing was not perfect. Luna 23 was badly damaged and was unable to complete its mission. Following the unsuccessful landing, the work plan was changed. The spacecraft worked for three days, and on November 10, contact with it was lost.
Luna 24
On August 9, 1976, Luna 24 was launched into orbit around the Earth and from there towards the Moon. The main purpose of the flight was to continue the scientific research of the moon and the space around it. The launch was made using the -12 SL Proton launcher. On November 8, a correction was made to the flight path. On August 14, 104 hours and 7 minutes after launch, the spacecraft entered lunar orbit at a distance of 115 km from the ground, the inclination angle was 12 degrees and the duration of the orbit was two hours. On August 16 and 17, the route was changed to 12 - 120 km.
On August 18, Luna 24 landed at the southeastern end of the Sea of Crisis at the point E' 12 0 62 - N 45 0 12. After the braking engines were activated, the landing lasted six minutes. Immediately afterwards, the spacecraft's systems and the spacecraft's condition in relation to the ground were checked. The soil was tested and a sample was taken from a depth of two meters. The sample was taken in one excavation and placed in a chamber that was then hermetically closed. The drilling tools were also checked after excavation. All these operations lasted 22 hours and 50 minutes until August 19. On this day, Luna 24 went back to Earth. The return route to Israel is close to the one planned.
After a flight of 84 and a half hours on August 22, Luna 24 landed 200 km east of Surgut in Western Siberia. The tank's parachutes were deployed at an altitude of 15 km. The operation was defined as "a new success of Soviet science and Soviet technology in lunar exploration." Luna 24 had a rotating drill capable of lifting light and heavy rocks at the same time, so the structure of the specimen was preserved in its natural form as much as possible. It turned out that the sample was more complex than those brought before it. The sample was tested in two stages. In the first stage, which lasted four to five days, she was photographed, and her description was investigated. Next came chemical analyses.
The findings showed that the color of the sample is silver gray with brown stripes. It is similar to the sample of Luna 16 but its grains are larger, its color is lighter. The size of the grains is five mm and it is powdery for a sample with a mini-initiative structure. You can see this in the continuous sediments at the bottom.
