CCCP Lunar Program - Lunokhod-2 medal.
Jan. 8, 2021
48 years ago, on January 8, 1973, the automatic station Luna-21 was launched from the Baikonur cosmodrome using the Proton-K launch vehicle. The flight to the Moon and the braking procedures were carried out normally, and on January 16, 1973, the automated probe Luna-21 landed on the eastern edge of the Sea of Clarity, inside the Lemonnier crater. The landing of the station took place only 3 meters from the edge of the crater with a diameter of about 40 meters, located inside the Lemonnier crater.
After inspecting the terrain, a command was issued from the Earth's television image, and at 4:14 pm Lunokhod-2 left the landing stage on the lunar surface and began to carry out a program of scientific and technical research and experiments. Thanks to the experience gained while flying the first lunar rover, the average speed of Lunokhod-2 was significantly higher than the average speed of its predecessor: 340 meters per hour against 140 meters, and the distance covered on a lunar day reached 16.5 km.
On the second lunar day, February 12, 1973, the lunar rover reached the nearest projection of the coastline of the Gulf of Lemonnier, explored the foothills of the Taurus Mountains, examined a large crater with a diameter of 2 km. On the third and fourth lunar days (from March 10 to March 23 and from April 10 to April 22) Lunokhod-2 conducted research in the southern part of Lemonnier crater. The route along which the apparatus moved at the same time began on the mainland, crossed the pre-continental hilly area, passed along the southern coast of the crater and ended 2.5 km from a large tectonic fault located in the eastern part of Lemonnier crater.
The total distance covered by the spacecraft in 4 lunar days was 36 km 200 m. When the spacecraft moved across the lunar surface, studies of the physicochemical and magnetic properties of the lunar soil were carried out, 93 panoramas were obtained, of which 18 stereo panoramas when the lunar rover moved 30–100 cm Sessions of laser ranging were also carried out using a French corner reflector and a laser signal photodetector. During the shooting, stereoscopic images of the most interesting features of the relief were obtained, allowing a detailed study of their structure.
On the fifth lunar day, May 9, 1973, the lunar rover, trying to get out of the crater, “scooped up” dust from the crater wall with a plate of the solar battery. This would not have happened if one of the cameras was located in the back. As a result, dust adhered to both the solar panel and the radiator-cooler. Due to the dusting of the solar battery, the charging current fell, and due to the fact that the dust got on the radiator, the thermal regime was violated: during the day, the temperature in the compartment rose to + 47 ° С. The last time telemetry information was received from Lunokhod-2 on May 10, 1973.
During the operation of the complex of the automatic station "Luna-21" and "Lunokhod-2", a large complex of scientific research was carried out on the lunar surface:
- The RIFMA-M device, which was used to measure the chemical composition of the lunar soil, recorded changes in the chemical composition of the surface, associated mainly with the differences in rocks in the “sea” and “continental” regions;
- As a result of magnetic measurements carried out continuously during movement and at stops using the SG-70A magnetometer, an inhomogeneity of the magnetic field on the lunar surface was recorded, which indicates the processes of induction of currents in the moon under the influence of changing interplanetary fields;
- Regular laser-ranging measurements of the distances to the Lunokhod-2 reflector, which were carried out at the telescope of the Crimean Astrophysical Observatory for several months, gave the statistical accuracy of determining the distance between the pulse source and the reflector mounted on the Moon +40 cm;
- During lunar days, continuous measurements of the intensity of corpuscular radiation of solar and galactic origin were carried out from the self-propelled vehicle. At the same time, the radiation situation in the region of the Moon was calm;
- An astronomical experiment carried out on board Lunokhod-2 using an astrophotometer to determine the luminosity of the lunar sky in the visible and ultraviolet regions of the spectrum, showed that the luminosity of the lunar sky is much higher than scientists expected. This result indicated that the Moon is surrounded by a layer of dust particles that strongly scatter sunlight and the reflected light of the Earth.
ROSCOSMOS Press Release: https://www.roscosmos.ru/29793/
Related articles:
Half a century on the Moon
https://orbiterchspacenews.blogspot.com/2020/11/half-century-on-moon.html
Lunokhod-1 - 50 years old
https://orbiterchspacenews.blogspot.com/2020/11/lunokhod-1-50-years-old.html
Lunokhod-1 first on the surface of the Earth satellite
https://orbiterchspacenews.blogspot.com/2015/11/lunokhod-1-first-on-surface-of-earth.html
Images, Text, Credits: ROSCOSMOS/Orbiter.ch Aerospace/Roland Berga.
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