Luna spacecraft to the moon (B)

On September 12, 1970 Luna 16 was launched to the moon. Its launcher was more powerful than the one that launched Luna 9 and Luna 13.

Luna 16
On September 12, 1970 Luna 16 was launched to the moon. Its launcher was more powerful than the one that launched Luna 9 and Luna 13.
The goals of the flight were:
1. Land on the moon, collect soil samples and return to Earth.
2. Do a scientific study of the moon and its surroundings.

The structure of the spaceship
The spaceship consists of two parts, the landing pad which was named "Cosmodrome" and the launch vehicle. The landing vehicle serves as a launch vehicle for the takeoff vehicle. This part of the spaceship has four short legs at the bottom with plates at the ends. Therefore, the landing is connected to a 35 cm long electric excavator that reaches up to a distance of 0.9 meters from the spacecraft. The pedestal engine is used for landing and necessary track corrections. A spherical container is attached to the launch vehicle. In each place for sampling, a parachute, an instrument compartment, accumulators, parachutes and two gas tanks.

the course of the flight
The spacecraft was launched into a circular parking orbit around the Earth, which is 212.2 km from the ground and has an inclination angle of 51 degrees and 36 minutes. 70 minutes after launch, the launcher's third stage engine was activated and moved the spacecraft into a lunar flight path. For September 13, two lane corrections were planned and only one was carried out. In this repair, the spacecraft rotated around its three axes, and the landing gear motor was activated for 6.4 seconds. A deviation of one meter from the flight path would have moved the spacecraft 3,000 km away from the moon.
On September 17, Luna 16 entered an orbit around the moon that is 110 km from the ground, the inclination angle is 70 degrees and the duration of the orbit is 119 minutes. After that, the spaceship was transferred to an elliptical orbit with a distance from the ground of 15-110 km and an inclination angle of 71 degrees. The Praslanion point is near the place in the Sea of ​​Fertility where the spacecraft is supposed to land and collect soil samples. The flight route was changed for the third time to 15-106 km.
The landing was on September 20 in the Sea of ​​Fertility and was done in three stages:

1. First the engines were turned on to take the spacecraft out of orbit. Since radio signals travel the distance from Earth to the Moon in 1.3 seconds, in the time period in which the spaceship travels two kilometers, the central coordination and computer system on Earth is useless. At this point, the spacecraft's instruments went into action. A radio altimeter that transmits signals returned from the surface of the moon, received by the receiver of the spacecraft, based on this the computer measured the height of the spacecraft from the ground. The spacecraft's engine stopped working, the spacecraft descended to the ground in an orbit with great curvature towards the moon. At an altitude of 16 km, the engine was started again.
2. At an altitude of 600 meters precise braking was applied, altitude, horizontal speed and vertical speed were continuously measured and the thrust of the engine was corrected accordingly.
3. At a height of 20 meters the speed of the spaceship was nine km. At the same time, the main engine stopped working and two tiny braking engines were activated. According to the altimeter signal, the activity of these engines was stopped at a height of two meters.

landing
Luna 16 landed at E '18 0 50 - S '54 0 0, 1.5 km from the landing site. Until the landing, the control center had contact with the spacecraft 68 times. After landing, the radio equipment in the spacecraft was activated. Every part is thoroughly tested. The next step was to determine the spacecraft's position relative to its three axes, which is of great importance in taking off from the moon. Excellent images broadcast during the landing showed that the spacecraft functioned successfully. The spacecraft's systems were designed to be able to work at a temperature of 150 degrees. The spacecraft landed when it was night at the landing site. It was necessary to adapt the systems to the new situation.

The weight of the soil samples collected by Luna 16 was 100 grams and they represent material consisting of sticky grains and parts of mountain minerals. The samples were taken in one drilling. The excavator drilled a hole 35 cm deep and 4 cm wide. A solid layer of rock did not allow the drill to take samples from a greater depth. During the flight the excavator is locked. On the moon it opens. According to a signal from Israel, the teleport cameras helped the lunar explorers choose the best excavation site.

The excavator turned 180 degrees towards the ground. A small cover was moved aside, another horizontal correction was made and the excavator touched the ground. After the excavator picked up the sample, it made a 180 degree turn, this time upwards and put the samples into a container that was closed with an automatic hammer blow. At the end of the work, the excavator was moved down again to allow the launching of the take-off vehicle.

During the excavation, data on the temperature of various parts of the spacecraft were transmitted to Israel and radiation was measured. At the same time, computers on Earth were busy calculating the appropriate time for launch, the thrust force needed for this and the duration of the engine's operation. This information is captured in the spacecraft's computer.

the mirror
On September 21, after spending 26.5 hours on the moon, the launch vehicle was launched to Earth. Clouds of dust rose on the surface of the moon during the landing and during the launch. When the engine reached a speed of 975 km/h they stopped the engine. Luna 16 flew to Israel on a ballistic trajectory. The flight path was so perfect that no path corrections were necessary. The lander continued to transmit data on the moon's temperatures and radiation. The batteries of the instruments provided nuclear energy so that the research instruments on the landing pad were not affected at all by the extreme temperatures of the moon.

On September 24, the spacecraft arrived in Israel. The launch vehicle was released from the sample tank and is now moving with the power of its batteries. After three hours and 20 minutes the container penetrated the upper layers of the atmosphere at a speed of 11 km/h. A load of 350 g acted on the tank. A special device at the bottom of the tank softened this load and protected the devices in this way. The temperature on the heat shield rose to 1,000 degrees.

From now until landing, the flight was monitored by the spacecraft's computer. When the temperature and pressure reached their peak, the pressure gauge activated a small chute. The parachute opened at an altitude of 14.5 km and at a speed of 300 meters per second it was fully retired. The parachute broke off at an altitude of 11 km. According to a signal from the barometer, another parachute opens. The landing was 80 km south of Djakastan. The tank was located by helicopters, and taken to the Soviet Academy of Sciences for examination. The flight itself to Earth was smooth and no path corrections had to be made.

The absorption laboratory

In the Russian Academy of Sciences, laboratories equipped with appropriate instruments were prepared for the study of lunar models. Before the container with the sample is transported there, it is placed in a special chamber for radiation tests and perfect sterilization of the outer sheath (sterilization is done before launch). The absorption chamber is equipped with mechanical arms capable of transferring the sample. The sample is studied and weighed in this chamber, cut into parts and these are transferred to special laboratories.

The moment the container is placed in the chamber, the pressure in the chamber is reduced to prevent contact between the sample and elements from the Earth's atmosphere. To further reduce the risk of sample contamination, the chamber is filled with helium, a gas that does not react with other elements. To prevent the infiltration of air from the outside, the pressure in the chamber is raised again. The purpose of these measures is twofold. Protection of terrestrial organisms from pollution and vice versa.

Sterilized mechanical arms open the container and take the sample out. It is covered with a thin layer of gray dust. The metal arms are operated very carefully. They gently transfer the sample to a transparent ball, and keep the original shape of the sample, in order to learn about the cross section of the surface of the lunar surface at the landing site. In this mode the sample is studied and photographed through optical glass portholes. The photographs are colored but in different lighting intensities and at all possible angles. The samples after the sample distribution are submitted to toxicological, biological, radiation, chemical, thermo-physical and other tests.

the findings of the test

The sample as a whole has a dark gray color reminiscent of gray cement and its shade changes depending on the lighting. No lunar bacteria were found in it. The sample can be divided into six areas of grains of different sizes. The first two zones along the length of the sample are made of very fine grains. The following areas at a depth ranging from 15 to 33 cm are made of grains of different sizes, usually up to a diameter of 3 mm and a little more than that. The last two centimeters contain large grains with fragments of the hard rock layer where the drill stopped. The average density of the grains is 2 grams per cubic meter. Although there is no water in the sample, it resembles fine sand. He stuck to the sides of the ball.

About 70 chemical elements are found in the sample, including some short-lived radioactive isotopes. Basalt-like stones, feldspar stones, pyroxene, olivine, plagioclase, illument, metallic iron and glass-like spheres are also found in it.
The grains can be classified into two types:

1. Volcanic grains similar to terrestrial basalt and surprisingly found as fresh as newly formed basalt shards. The particles have an angular shape.
2. Fine grains formed due to temperature changes, radiation, meteorite bombardment and more, therefore they appear on or near the ground. in which the most changes apply, where the irregular forms are found. The surface of the grains contains metal balls and glass balls. The Russian lunar explorers called them "cosmic balls". The color of the vitreous balls is greenish, dark yellow and transition colors. They were formed at high temperatures and ejected from the craters.

minerals