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For thousands of years, a person has been looking at, but on a whim he sees only one side of it. In all ages, pundits have been building hypotheses, and science fiction writers, until recently, have painted vivid pictures of the life of the “Selenites”. But as soon as the right tool was in the hands, humanity did not fail to look at the "dark side" of the moon.
The first attempts to photograph Selena, like all the first space missions in general, were of the pronounced nature of the "space race" between the USA and the USSR. In August-September 1958, the Americans were the first to attempt to photograph the surface of the Moon at close range, sending the first small and imperfect Pioneer probes into space.
All those involved in this event were able to contribute to their asset another “undoubted victory in space”: the Soviet Union was ahead of the United States for the sixth time, launching after the first satellite, the first animal in space, the first heavy automatic laboratory on, the first artificial planet and the first hit to neighboring heavenly body the first object that was able to photograph the side of our natural satellite, forever hidden from direct human gaze. Meanwhile, the success of "Luna-3" was not only propaganda. Behind him were solid scientific and engineering developments in areas such as ballistics, control systems, optics, telecommunications, not to mention rocketry.
A planned miracle
Undoubtedly, the most difficult task was the calculation of the flight path. Since photographing the lunar surface was supposed to be performed during a passive ballistic flyby (the means of active trajectory correction had not yet been mastered), the calculation and subsequent implementation of the trajectory had to be carried out with the highest accuracy. The choice of flight pattern was influenced by many factors. Among them, the main requirements were the requirements for the necessary orientation, illumination and distance from the lunar surface at the time of shooting, the energy capabilities of the launch vehicle and geographical position starting places. In addition, the shape of the trajectory was supposed to provide a “reset” of information at the moment when the station was at a small distance from the Earth: it was required to receive the maximum amount of information from the territory of the Soviet Union in the shortest possible time.
The flight scheme envisaged a flight around the Moon along a highly elongated elliptical trajectory, the apogee of which was near the boundary of the Earth's sphere of action. If no additional measures had been taken, the station would have returned to the Earth and burned up in the atmosphere already at the end of the first orbit, and any long-term studies of the space between the Moon and the Earth would have become impossible. The fact is that, although the rocket almost informed Luna-3 of the second space velocity in magnitude (approximately 11.14-11.15 km / s), the direction of the vector was far from horizontal. As a result, without taking into account external perturbations from the Moon and and an unclosed elliptical trajectory was obtained. This trouble was due to the fact that the carrier rocket under development, when starting from the territory of the USSR, could not give the AMS a second space velocity for flying to the Moon, placing the vector strictly horizontally. By the way, the limited mass of the payload was an additional nuisance: the gravitational losses were too great with a direct acceleration scheme.
The situation could be corrected by a launch to the Moon from an intermediate orbit of the Earth. But he required a double activation of the engine of the last stage. Alas, the Soviet rocket scientists did not yet have such an opportunity. In 1959, a beautiful solution was found by ballistics, who proposed to “correct” the trajectory with the help of ... the Moon itself - due to its gravitational field. The trajectory was calculated in such a way that at some point, when the station was already moving quite slowly, the Moon's sphere of action "bumped" into it. At the same time, lunar gravity significantly changed the AMS orbit, which eventually became artificial satellite Earth. Thus, in this mission, for the first time, a gravitational maneuver was used, as a result of which Luna-3, instead of the prescribed week, existed in space for six months, until April 20, 1960.
Lunar Yenisei
Photographs of the Moon were made at a specially chosen moment. It did not coincide with the point of closest approach to the Moon: the main requirement was to ensure the orientation of the AMS in such a way as to capture on film as much of the invisible side of our celestial neighbor as possible in the conditions of necessary illumination. The station's attitude control system included optical and gyro sensors, logical electronic devices, and control motors. It was turned on by a signal from the Earth at the moment when the AMS was lying on the Moon-Sun line, that is, when the Earth's natural satellite was in the full moon phase in relation to Luna-3.
The orientation system stopped the erratic rotation that the probe received when it separated from the last stage of the carrier. Then the sensors found the Sun and oriented the probe to the luminary, accordingly directing the lenses of the photographic equipment to the Moon. The shooting was carried out at shutter speeds of 1/200, 1/400, 1/600 and 1/800 with a device with two lenses that had focal lengths of 200 and 500 mm. The distance from the center of the Moon was 65200−68400 km. By the way, the launch time of the AMS, the flight path and the shooting time were chosen so that the photographs captured some part of the surface of our satellite, visible from the Earth. This was necessary to “bind” the images to already known lunar objects. Approximately 70% of the captured surface was on the far side of the Moon, and the remainder was the western edge of the lunar hemisphere as observed from Earth. In addition, the presence of fragments of the visible side of the Moon confirmed the authenticity of the images - at the time cold war and unbridled propaganda was not superfluous.
For filming at the All-Union Scientific Research Institute of Television Technology (VNIIT, Leningrad), a special Yenisei photo-television equipment was created. The moon was filmed by a film camera, the exposed film was processed automatically on board the station. The resulting frames were scanned by a television camera that could operate in "slow" and "fast" modes. The latter served to transmit images from a station near the Earth (at a distance of 40,000 - 50,000 km), the former - at large distances. To receive the signals transmitted by the AMS, two types of ground equipment served: "Yenisei-I" for the "fast" and "Yenisei-II" for the "slow" transmission mode. Receiving ground complexes were made both in stationary and in automobile versions.
In the "fast" mode, the horizontal scanning frequency was 50 Hz, and the full frame transmission time was 15 s. In the "slow" mode, the line duration was 1.25 s, and the frame transmission time reached half an hour. The resolution is approximately 1000 elements per line.
For photographing, we used “trophy” film ASh (“American balls”) 35 mm wide, the history of which is worth dwelling on separately. As you know, in the middle and in the second half of the 1950s, American reconnaissance balloons with photographic equipment flew over the Soviet Union in flocks. Some of them were shot down or simply landed on the territory of our country. One way or another, at the Academy named after A.F. Mozhaisky, with whom VNIIT collaborated, turned out to be American equipment and film. And when it turned out that not a single domestic film meets the requirements for photographing the Moon, they remembered the film from the “balloons”. According to the memoirs of veterans of those events, the film was secretly cut, perforated and ... used on Luna-3, secretly from the authorities. So the rival in the space race unwittingly helped the Soviet triumph.
To control the quality of the received frames, test marks were applied to the film in advance, some of which appeared on Earth. Another part of the signs, copies of which were kept on Earth, appeared on board the station.
Seas and circuses
For many reasons, the quality of the obtained images was mediocre, but it turned out to be sufficient for understanding the morphology of the invisible side of the Moon. In particular, it was revealed that the "dark side" is more mountainous, and there are very few "seas" on it. Apart from the Marginal Sea, the Smith Sea, the South Sea starting on the visible side, and the Dream Sea, no other "reservoirs" have been identified, except for the surfaces of large cirques.
The scientific result of the mission was important, but not the only one. Soviet scientists and engineers were able to test the three-stage booster by studying the dynamics of its design. It is also important that the launch took place exactly at the estimated time, and the station's flight path was maintained with high precision. For the first time sessions of deep space communication were held. The flight of Luna-3 laid the foundations for the Soviet school of creating interplanetary probes and marked its first major success.
No, today is not another memorable date related to any achievement in space exploration. Recently, the history of the Luna-1 apparatus was published on Habré, in connection with which it is worth remembering, probably, one of the most famous spacecraft - Luna-3.
The fact is that it was this Soviet spacecraft that took pictures of the far side of the moon. It happened on October 7, 1959, at 6:30 am (Moscow time).
Two lenses (focal lengths of 200 and 500 mm) managed to capture about half of the surface of the Moon (with 2/3 of the images being the far side of the Moon) from a distance of about 67,000 km. It is worth noting that the shooting was carried out with a shutter speed of 1/200, 1/400, 1/600 and 1/800. The images were developed directly on board the apparatus by combat robots, after which the images were transmitted using a specific photo-television system to Earth. The system was called "Yenisei", and the shooting was carried out by a traveling beam camera, with direct data transmission to the Earth. Images were taken at a temporary point in the Crimea (Mount Koshka). There was also a reserve point located in Kamchatka.
This is such a difficult path the device has done in order to reach the point that is optimal for taking pictures.
Only 17 “scanned” images were transmitted to Earth, after which communication with the spacecraft was lost. Well, a little later, six months later, the device burned down (planned) in the Earth's atmosphere, with all the images and equipment.
Here is an interesting point - the shooting was carried out not on Soviet, but on American film, which was found in American equipment (as far as you can understand, the equipment was removed from American reconnaissance balloons that conducted aerial photography of the territories of the USSR. The devices either landed themselves, as a result of a failure / breakdown , or they were shot down). So, the domestic film, as it turned out, did not meet the technical requirements for shooting the Moon, so foreign "spy" film 35 mm wide was used (secretly from the authorities).
Unfortunately, the level of noise during data transmission was very high, so these photos cannot be called high-quality. But it was they who added a lot of data to the information about the Moon, and also allowed the USSR to get the right to name the newly discovered objects on the far side of the Moon.
By the way, the pictures taken by Luna-3 can be seen on the NASA website (yes, NASA),
No, today is not another memorable date related to any achievement in space exploration. Recently, the history of the Luna-1 apparatus was published on Habré, in connection with which it is worth remembering, probably, one of the most famous spacecraft - Luna-3.
The fact is that it was this Soviet spacecraft that took pictures of the far side of the moon. It happened on October 7, 1959, at 6:30 am (Moscow time).
Two lenses (focal lengths of 200 and 500 mm) managed to capture about half of the surface of the Moon (with 2/3 of the images being the far side of the Moon) from a distance of about 67,000 km. It is worth noting that the shooting was carried out with a shutter speed of 1/200, 1/400, 1/600 and 1/800. The images were developed directly on board the apparatus by combat robots, after which the images were transmitted using a specific photo-television system to Earth. The system was called "Yenisei", and the shooting was carried out by a traveling beam camera, with direct data transmission to the Earth. Images were taken at a temporary point in the Crimea (Mount Koshka). There was also a reserve point located in Kamchatka.
This is such a difficult path the device has done in order to reach the point that is optimal for taking pictures.
Only 17 “scanned” images were transmitted to Earth, after which communication with the spacecraft was lost. Well, a little later, six months later, the device burned down (planned) in the Earth's atmosphere, with all the images and equipment.
Here is an interesting point - the shooting was carried out not on Soviet, but on American film, which was found in American equipment (as far as you can understand, the equipment was removed from American reconnaissance balloons that conducted aerial photography of the territories of the USSR. The devices either landed themselves, as a result of a failure / breakdown , or they were shot down). So, the domestic film, as it turned out, did not meet the technical requirements for shooting the Moon, so foreign "spy" film 35 mm wide was used (secretly from the authorities).
Unfortunately, the level of noise during data transmission was very high, so these photos cannot be called high-quality. But it was they who added a lot of data to the information about the Moon, and also allowed the USSR to get the right to name the newly discovered objects on the far side of the Moon.
By the way, the pictures taken by Luna-3 can be seen on the NASA website (yes, NASA),
In the exploration of the moon is open new chapter: China's Chang'e-4 space probe landed safely on the far side of the moon on its first attempt.
According to the Chinese space agency, at 10:26 am Beijing time (02:26 GMT), the device touched the lunar surface in the region of one of largest craters throughout the solar system - the South Pole - Aitken Basin.
"This is an important milestone in Chinese space exploration," said Wu Weiren, chief designer of China's lunar program.
The probe delivered equipment to the Moon, with the help of which a number of experiments and studies will be carried out.
The first pictures from the satellite have already been sent to Earth and published by Chinese state media.
Since direct communication with the probe is not possible, all forwarded images and data are first transmitted to the relay satellite and only then get to Earth.
For the first time in history
Chang'e-4 is a Chinese automatic interplanetary station for the study of the moon and outer space. It consists of a stationary lunar station and a lunar rover.
It has built in:
- video camera;
- geological radar for studying the lunar soil;
- infrared spectrometer for the study of minerals;
- impact tester solar wind to the surface of the moon.
This is the first landing on the far side of the moon in history and a huge step in the study and exploration of space.
On board the lunar rover, in a sealed container, there are seeds of potatoes, rapeseed, plants of Tal's arabidopsis, and silkworm larvae. Scientists will check whether a biosystem can exist in such conditions.
AT last years many flights were made to the Earth's satellite. Most missions were limited to orbit, some flew past.
The last landing on the moon with a crew on board was made by spaceship Apollo 17 in 1972.
The far side of the Moon is often called dark, but in reality it is that part of the lunar surface that is not visible from Earth. The moon and the earth rotate synchronously, so the surface of only one of the hemispheres of the satellite is visible from the earth.
There are more craters and denser soil on the far side of the Moon.
China's plans for space
China aspires to become one of the leading space powers along with the US and Russia.
In 2017, Beijing announced the preparation of a manned expedition to the moon. Next year, China plans to start building its own space station and complete it by 2022.
The BBC correspondent in Beijing, John Sadworth, notes that before the successful landing of the Chang'e-4, almost nothing was known about the preparations for this mission.
China in 2003 became the third country after the USSR and the USA to independently launch a man into space.
First picture of the far side of the moon
Postage stamp issued to commemorate the event
Photomosaic of the far side of the Moon, compiled on the basis of photographs transmitted by the Zond-3 spacecraft
1 . The far side of the Moon is not visible from Earth. The period of revolution of the Moon around the Earth is equal to the period of its own rotation around its axis, therefore, it always faces the Earth with one side.
2. The famous words "dark side of the Moon" are a figurative expression. The reverse side of the Moon is not at all dark: all sides of the Earth's natural satellite are illuminated by the Sun equally.
3. For the first time, the far side of the Moon was photographed by the Soviet AMS Luna-3, launched on October 4, 1959 by the Vostok-L launch vehicle. On October 7, 1959, during a photographic session, almost half of the surface of the Moon was photographed with two lenses (one third in the marginal zone, two thirds on the reverse side, invisible from Earth). The images - after developing the film on board - were transmitted by a photo-television system to Earth. The signal was received by the Simeiz Observatory in the Crimea.
4. Successful image transmission was achieved by only one method - shooting a traveling beam camera on film. However, the signal quality was poor and the noise levels were high.
5. Nevertheless, based on the materials obtained, in 1960 the first ever map of the far side of the Moon was prepared, containing hundreds of surface details. Following this, together with the Institute. Sternberg and TsNIIGAiK, the first globe of the Moon was prepared with an image of 2/3 of the surface of the reverse, invisible from the Earth, hemisphere. On August 22, 1961, the International Astronomical Union officially approved the names of the details of the relief of the far side of the Moon, given by Soviet scientists.
6. The main differences between the far side of the Moon and the one visible from the Earth are the predominance of the continental relief on it over the seas and the abundance of craters. There are only two seas here: the Sea of Moscow and the Sea of Dreams. However, in the list of the largest lunar craters in terms of diameter, the first nine are located precisely on the far side of the Moon.
7. Subsequently, the USSR carried out several more launches under the same program, but they were all unsuccessful. High-quality images of the far side of the Moon were obtained by the Zond-3 station, launched on July 18, 1965.
8. Despite the poor quality, the images obtained by the Luna-3 AMS provided Soviet Union priority in naming objects on the lunar surface. Craters and circuses of Giordano Bruno, Jules Verne, Hertz, Kurchatov, Lobachevsky, Maxwell, Mendeleev, Pasteur, Popov, Sklodowska-Curie, Zu Chongzhi, Edison and others appeared on the map.