From the late 1950s to approximately the mid-1970s, the USSR carried out a program of studying the moon through automatic interplanetary stations. As part of one of the stages of this long-term program, remotely-controlled mobile research probes of the E-8 series worked on the surface of the Earth's satellite for several months in 1970-71, and also in 1973. The whole world knows them as Soviet moon rovers.
Stages of the lunar program of the USSR
The devices with which the study of the moon and the surrounding space was carried out, it is customary to divide into three generations. Automatic stations belonging to the first generation had the task of delivering the probe to the Earth’s satellite, as well as circling it and photographing the reverse side with the transfer of images to Earth. The second-generation devices were intended for soft landing, and, in addition, for launching an artificial satellite into the lunar orbit, photographing the surface of the moon from its side and working out communication systems with the Earth.
The third generation of stations (E-8 series) was created already for a deeper study of our nearest space neighbor. Within its framework, mobile devices controlled from the Earth — lunar rovers, as well as a heavy moon satellite E-8 LS and stations E-8-5 with a return vehicle designed to deliver soil from the Earth’s satellite were designed.
A series of interplanetary stations E-8
Since 1960, OKB-1 (now the Energia Corporation) considered the creation of a self-propelled lunar machine. In 1965, the work on the design of interplanetary stations was entrusted to the design bureau of the Machine-Building Plant (since 1971 - NPO). Lavochkin, led by G.N. Babakin, who in 1967 prepared documentation on his own version of the apparatus. In particular, the chassis design was completely redesigned. Instead of the previously proposed caterpillars, the designers equipped the Soviet moon rovers with eight driving wheels 200 mm wide and 510 mm in diameter each.
The station of the E-8 series consisted of two modules: the KT landing missile stage and, in fact, the 8EL lunar rover. Delivery to the moon was to be carried out by a Proton-K booster rocket, equipped with a booster D.
Construction and equipment of the movable probe
Lunokhod is a sealed container. This is the instrument compartment mounted on a self-propelled wheeled chassis. The lid of the container is equipped with 180 W solar cells for recharging the buffer battery. The chassis has a set of sensors, with the help of which the soil properties, passability were evaluated and the distance covered was recorded. The lowering ninth wheel, freely rolling and not slipping, also served this purpose.
Instrument filling included radio complex equipment, automation units for remote control, systems providing power supply and thermoregulation, television systems and scientific instruments: spectrometer, X-ray telescope, radiometric equipment.
Soviet lunar rovers were equipped with two navigation cameras in the front of the hull and four panoramic telephoto cameras.
The main tasks of the device
The devices of the E-8 series were designed to solve such applied problems as:
- working out the remote control of a mobile probe;
- the study of the lunar surface in terms of its suitability for moving automatic transport;
- testing and testing of the basic transport system for the moon;
- study of radiation conditions on the way to the Earth satellite and on its surface;
- in the long term - a survey of the main and reserve areas for the landing of the manned spacecraft and support for the expedition at some stages, in particular, during landing or in the event of an emergency on the moon.
Was the Soviet lunar rover suitable for serving as a transport for the astronaut? The program of a manned expedition provided for the creation of such a machine. However, due to the closure of the project, this was not carried out.
Lunokhods carried out a scientific program to study the chemical composition and physical characteristics of the soil, as well as to study the distribution and intensity of x-ray radiation from various space sources. For laser ranging from the Earth, an angular reflector created in France was installed on board the machines.
Device management
The following elements were included in the system providing control of lunar rovers:
- a set of equipment on board the unit itself;
- the ground complex NIP-10, located in the Crimea, in the village of Shkolnoye, where the space communications equipment and the control unit of the unit with control panels for crew members and the telemetry processing room were located.
There, near Simferopol, a lunodrome was set up - a training ground for crews, arranged taking into account the data received from Luna-9 and Luna-13.
Two crews were formed, each with five members: commander, navigator, driver, flight engineer and operator of a directional antenna. The eleventh member of the management group was the backup driver and operator.
Not a single Soviet lunar rover on the far side of the moon was ever due to the difficulties associated with the organization of communications and control. Also, the landing of manned ships was planned only on the visible side.
Lunokhod-0
In total, four self-propelled lunar vehicles were built. The very first of them did not achieve the goal, since at launch on February 19, 1969, a launch rocket crashed, which ended in 53 seconds of an explosion.
The device lost during the accident received the code name "Lunokhod-0".
Lunokhod-1
The next probe of this type was launched as part of the Luna-17 station on November 10, 1970. On November 17, she landed in the western region of the Sea of ​​Rains. Having descended from the landing platform of the station, the first Soviet lunar rover began its work on the moon.
The mass of the car was 756 kg, dimensions - 4.42 m in length (with an open solar panel), 2.15 m in width and 1.92 m in height. When moving, it left a track 1.60 m wide. Moving along the satellite’s surface was carried out for 11 lunar days. With the onset of moonlit night, the lid of the case closed, and the device was waiting for the day to come in a stationary state.
A few words about what the first Soviet lunar rover discovered on the moon and what it achieved. He worked three times longer than planned - until September 14, 1971, examined an area of ​​80 thousand square meters and walked a total of 10.54 km. More than 20 thousand television images and over 200 panoramas of the moon were transmitted to Earth. Physico-mechanical tests of the soil were performed more than 500 times, and its chemical composition was studied at 25 points. Laser location using a corner reflector, performed by Soviet and French scientists, made it possible to determine the distance to the Earth's satellite with an accuracy of 3 meters.
Lunokhod-2
The launch of the next station of the E-8 series (Luna-21) took place on January 8, 1973. The device safely landed in the Sea of ​​Clarity on January 16. There were no fundamental differences from the previous Lunokhod-2 probe, but some improvements to its design were made taking into account the wishes of the operator-drivers.
In particular, a third navigation camera was installed on it at the height of human growth, which greatly facilitated the control of the machine. Some changes also affected the instrumentation, and the mass of the device was already 836 kg.
Pictures from the Soviet lunar rover number two were already received in the amount of more than 80 thousand. In addition, he broadcast 86 television panoramas. In a rather difficult terrain, the self-propelled probe functioned for 5 lunar days (4 months), covered 39.1 km, studied in detail the soil and rock outcrops of the moon. The distance to our natural satellite this time has been determined with an accuracy of 40 cm.
To the question of finding moon rovers
In 2010, the first Soviet lunar rover and the second were found in the images obtained by the American LRO orbital probe LRO. In connection with these events, information was spread about the allegedly “lost” Soviet scientists, and now the “found” devices. Specialists working in the lunar program of the USSR emphasize that the devices were never lost. Their coordinates were known with precision achievable for that time. The Lunokhod-1 was photographed by the Apollo 15 crew from a low orbit, and the Luna 21 landing site was photographed by the Apollo 17 astronauts, and these images were used to navigate the second spacecraft.
As for the photos taken by the LRO station, they, thanks to the high resolution (0.5 meters per pixel), played a significant role in determining the coordinates of the places where the Soviet moon rovers remained forever, stopping their work. This refinement is also important because in 2005, in connection with the creation of a new unified selenodetic network, the coordinate reference of the Earth’s satellite surface was updated.
Lunokhod-3
In 1977, the next self-propelled probe was supposed to go to the moon. He was distinguished by serious improvements to the navigation system. However, constructed in 1975, fully equipped with equipment and tested, the third Soviet lunar rover on the Moon never visited. In the lunar race, as in other space programs, the initial priority was political and economic, rather than purely scientific motives. By the way, real scientific and technological development is generally inseparable from the economy.
After 1972, the United States actually closed its program. The last Soviet station, Luna-24, visited the Earth’s satellite in 1976, delivering soil samples from it. What happened to the last device? "Lunokhod-3" took a place among the exhibits of the museum of NPO them. Lavochkina, where he remains to this day.
The role of moon rovers in the development of space
Designed by Soviet scientists and engineers, the first ever mobile probes, controlled from the Earth, made a huge contribution to the technology of creating automatic interplanetary stations. They demonstrated the great potential and prospects of planet rovers in research, and in the future, perhaps, in the development of other planets.
Soviet lunar rovers proved the suitability of such machines for long-term operation, the ability to comprehensively study quite vast areas, in contrast to stationary vehicles. Now self-propelled probes - of course, a necessary tool for planetology. It should be remembered that the "moon tractors" are the ancestors of the high-tech current, equipped with on-board computers and modern automatic equipment of units, as well as machines that have yet to leave ruts on the surface of other planets.