The significant leap forward in lunar exploration began with the development of the ability to launch spacecraft. In this chapter, we will review the different types of spacecraft that were involved in the study of the moon, either by circling it or by landing on its surface
The closest astronomical body to us is the Earth's Moon. Its diameter is 3480 km and its distance from us is 384,000 km. Due to its proximity to the Earth, the Moon shows only one side of it. The inclination of the moon in relation to its path of movement sometimes makes it possible to see part of its poles, so that in fact a little more than half of its surface can be seen. With eye observation you can see, albeit in a rough way, its outline. An in-depth study of the moon began to develop from a time when telescopes were developed and each improvement in them increased their resolution, which made it possible to distinguish more details from its surface, up to the ability of geological research. It should not be forgotten that naturally the research was reduced to its visible side. The significant leap forward in lunar exploration began with the development of the ability to launch spacecraft.
An overview of spacecraft directed to the moon
Since launching rockets began to be developed and as a result launching spacecraft, it became possible for the first time to launch spacecraft towards the moon. Because of the close proximity of the moon, the number of launches to it is greater than those launched to other planets in the solar system. A distinction must be made between unmanned flights and manned flights, and the latter have so far been the pinnacle of lunar exploration. Humans landed and operated on another world. For those who landed on it, they experienced experiences that no human before had, viewing Earth from another planet. The experience they experienced was something that was completely new and so was its intensity. Those huge expanses that anyone who travels on the ground of the earth sees when he crosses deserts and oceans or he sees from the heights of a mountain, are dwarfed compared to what an astronaut on the moon sees. All those spaces become something that is small and fragile.
Exploration of the moon using spacecraft began to develop during the Cold War between the United States and the Soviet Union. They were the only powers that had the ability to launch spacecraft to the moon. This had far-reaching strategic implications. Those who can launch spaceships, using the same launch missiles are also able to launch bombs, including nuclear weapons, anywhere on the planet. Only in the last decade more countries began to enter this field of research. They are all from Asia and the reference is to India, China and Japan, although the launch rate of these countries is minor. Once every few years they launch a spacecraft, during the Cold War every few months a spacecraft would go to the moon. A total of 111 unmanned spacecraft and 9 manned spacecraft were launched to the moon. These are recent, launched by the United States. Such a scope of launches has not been directed to any other body in the solar system.
Both the United States and the Soviet Union strove to land a man on the moon, a mission in which the Americans were very successful and the Russians failed. The two powers each operated in a different way of working. The Americans worked with the method of series, where each series of spacecraft is intended for a different purpose. The first series was of Pioneer spacecrafts designed to pass by the moon and make a first survey of it. The second series was of the Ranger spacecraft, debris spacecraft designed to hit the lunar surface and during their movement transmitted photographs of its surface with increasing resolution as they approached it. The third series was of the Serviar spacecraft that landed on the ground and two of them for the first time performed a chemical analysis of the soil. Another series was of the Lunar Orbiter spacecraft that entered orbit around him. The last two series were launched alternately, once a Serviar spacecraft and once a Lunar Orbiter spacecraft. Only after that came the manned flights as part of the Apollo program.
The Russians launched a smaller number of spacecraft to the moon. They did not work according to the technique of the American series, but each time a different type of spaceship, although they also operated spaceships for fly-by flights, entering orbit and then landing. Actually there were two series, each of which was under a different name. One series was the Luna spacecraft which included the types of spacecraft mentioned. In total, there were officially 24 Luna spacecraft, the second series would have received the name Zond. These are actually manned Soyuz model spacecraft that were converted to unmanned spacecraft as part of preparations to send a man to the moon. There were a total of 5 spacecraft of this model. The pinnacle of the Russian lunar space program were the Luna 16, Luna 20, and Luna 24 spacecrafts that returned samples from the lunar soil and the Lunakhod (Luna 17) and Lunakhod 2 (Lonkhod 21) spacecrafts which were ground vehicles to be operated from Earth.
Research Methods
As we have seen, different types of spacecraft were used to explore the moon. With the development of spacecraft and research equipment, research capabilities were improved. A more sophisticated utilization of spacecraft was also made, whether they were intended for the study of the moon directly or whether it was done using spacecraft that passed by it as part of their flight to other destinations in the solar system.
1. Transit flight - An example of the utilization of spacecraft for non-lunar purposes is the Galileo spacecraft, which on its way to Jupiter passed by the moon. During this transit, the Aitken Basin in the South Pole was photographed and it turned out to be darker than the Moon's plateaus (1).
2. Spacecraft cycle - In 2007, a fleet of 5 satellites was launched from the USA into orbit around the Earth into its magnetosphere to check geomagnetic storms. This fleet was named Themis (an acronym for History Time Events and Macroscal Interactions Substorms of). Two of these satellites received the names 2 P , P1 moved in the most distant orbits from the Earth. They were supposed to pass through the shadow of the earth. According to the original design, the power supply of the satellites was supposed to work in the dark for 3 hours (the time of transit through the shadow zone). For an unknown reason the trajectory of the spacecraft changed and as a result their stay time without light was extended to 8 hours. The satellites lost their power. It was clearly impossible to use them for their original research purposes. Since their fuel supply was still large, it was decided to take them out of their earthly orbit and into lunar orbit. In light of the change in their destination, they received a new name - Artemis (Acceleration, Reconnection, Turbulence, (and Electrodynamics of The Moon's Interaction with the Sun
On 25.8.2010 the satellite P1 - Artemis reached the Lagrange point 2 (on the hidden side of the moon). On 22.10 the 2P - Artemis satellite entered orbit to Grange 1 (on the visible side of the moon). This is the first time that these points have been investigated. Since they are located outside the Earth's magnetosphere, the solar wind can be tested in them. An approach has been opened to examine currents and storm clouds of the solar wind as they approach the Earth. Moreover, since the satellites are each on opposite sides of the Moon, it is possible to test solar wind storms on a scale that could not be done before. Other goals that the researchers set for themselves are:
- Investigating the moon's plasma wake (Moon's plasma wake) - a storm that is "cut" from the solar wind by the moon itself. Similar to the trail of water formed behind a racing boat.
– The investigation of the tail of the Earth's magnetosphere. Once a month when the moon is full the spacecraft pass through this tail to make various observations. The intention is to receive several renewed magnetic connections. These are explosions that occur in the tail of the magnetosphere that mimic solar flares on a smaller scale. This also has potential applied meanings.- Plasma waves in fusion chambers. It will be possible to use this knowledge for renewable energy. After 6 months of research, the orbit of the satellites was changed and their distance from the lunar surface was 100 km or even less. The intention was to test what the solar wind does to the rocks of the moon, places where there are no magnetic fields that can protect them. The route chosen for this purpose has a large eccentricity - 100-18,500 km (2). This route allows testing of two objectives, testing the Mascon (topic will be explained later) and testing the solar wind
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Investigating the Moon's core, soil composition and whether there are pockets of magnetism on its surface (3).
3.- Parallel measurements - these are measurements made from two or more observation points at least simultaneously. Such measurements were made by the LRO spacecraft (Lunar Reconnaissance Orbiter), the Hubble Space Telescope and telescopes in Hawaii, Arizona and New Mexico during the impact of the LCROSS spacecraft on the lunar surface. In each such observation, the focus of the observation was from several places - done from a different point of view and the result was a broader and more in-depth view of the studied area (4).
4.- Tiny spaceships - these are spaceships launched from spaceships orbiting the moon. The Americans were the first to do so. These launches were made from Apollo, Apollo 15 and Apollo 16 spacecraft. These spacecraft are 35 cm in diameter, 79 cm high and weigh 36 kg each (5). The first spacecraft - PFS-1 was launched from Apollo 15 and the second spacecraft 2 PFS - was launched from Apollo 16. These spacecraft moved at a distance of 89-122 km from the ground. During their flight they experienced a very strange phenomenon. 2 - PFS changed its course for two and a half weeks. The height of its orbit from the ground was reduced to 10 km. After that her course changed again. The spacecraft climbed to a height of 48 km, but not for long. On May 25.5.1972, 35, after 1 days of flight, it crashed. The moon does not have an atmosphere that can exert atmospheric drag and cause the spacecraft to crash. After an in-depth study, they came to the conclusion that on the moon there are mass concentrations of mascons (mass concentrations) that have greater attraction fields than their surroundings and that affected the orbits of the tiny spacecraft. This was also the fate of the PFS-86 spacecraft after operating for a year and a half. "frozen orbits" have been identified in which spacecraft can move in orbits whose distance from the ground is stable. They are possible when the inclination angle of the trajectories is 76°, 56°, 27°, 1°. The angle of inclination of PFS-28 was 2°, which allowed for a long lifespan and the angle of inclination of 11-PFS was 6°. Any spacecraft moving in non-iced orbits needs to make orbit corrections to maintain a stable distance from the ground (XNUMX).
The Japanese equipped the Kaguya spacecraft that they launched to the moon on September 14.9.2007, 50 with two tiny spacecraft weighing 7 kg each. One spacecraft was named RSAT and the other VARD (2400). Each has a different route. The RSAT was put into an orbit that is 800 km from the ground and the ARD's orbit is 8 km from the ground (XNUMX).
5.- Rask spacecrafts - Rask spacecrafts are spacecrafts designed to hit the surface of the moon and learn from it various details about the surface and interior of the moon. Spaceships of this type as we have seen were the Ranger spaceships. A continuation of this were the Apollo spacecraft that left on research equipment including seismographs to examine earthquakes. As soon as the astronauts finished their work, they took off towards the mother spacecraft that was in lunar orbit, connected to it and the lander, which no longer had any purpose, was disconnected and directed towards the lunar surface with the goal of crashing it. The rays of these impacts were picked up by the seismographs and transmitted to Earth.
This idea for utilizing a spacecraft that has finished its mission found its place in the European spacecraft 1 - SMART that entered orbit around the moon on 15.4.2004. Upon completion of her work program on September 3.9.2006, 10, she was intended to crash on his land. The entire course of the flight towards this impact was monitored by telescopes from Earth, the flashes that followed the impact were observed in infrared. This work plan was done in cooperation with the Americans in preparation for the launch of the American spacecraft LRO (31.7.1999). This technique was also used in the American Prospector Lunar spacecraft which finished its work on 161. The chosen crash site was near the South Pole. The thought that faced the planners of the operation was that this impact would release large amounts of water vapor that could be observed both from space and from Earth. A positive detection of water or hydroxyls (OH) will be proof of the existence of water in the polar regions. The weight of the spacecraft was no more than 2 kg (since all the fuel stock had already been used). The collision was with the force of a vehicle weighing 1760 tons moving at a speed of more than 10 km/h (XNUMX).
A spacecraft that was planned to crash on the moon is the LCROSS spacecraft (Lunar Crater Observation and Sensing Satellite) which was attached to the LRO spacecraft that was put into orbit around the moon at a distance of 50 km from the ground. The goals of the spacecraft were a better understanding of the geology of the moon, preparations for the resumption of manned flights to the moon and finding potential landing sites, to examine the condition of the landing sites of the Apollo spacecraft, to examine the Sea of Tranquility where Apollo 11 landed, to examine previously launched spacecraft Such as locating the place where the Russian Lonkhod 1 finished its work, checking what happened to the American lander Survivor 4 which in 1967 stopped transmitting data near landing, checking what happened to the Russian spacecraft Luna 15 which was supposed to land on the moon and return soil samples. Shortly before the launch of Apollo 11, Luna 15 did not meet its mission because it crashed, to examine the rim of the Cone Crater where the Apollo 14 pilots were supposed to reach, but due to fatigue they had to return to the lander (11,12).
The LCROSS spacecraft at the time of launch was connected to the LRO spacecraft and on the other side to the last stage of the Atlas 5 Centaur launch vehicle and weighing 826 kg. It was equipped with 5 cameras, 3 spectrometers and a photometer designed to take pictures of the flash created during the impact on the moon. The entire equipment is designed to provide information regarding the material blown at the time of impact. The assumption of the work was that it would be possible to observe water ice and the plume that would be created by the LCROSS, based on the findings of chemical traces that were discovered inside craters that are permanently located in Alta. The total weight of the spacecraft and the upper stage of the launch vehicle is 2.2. Ton and impact speed 8950 km/h (13). The impact was in a crater near the South Pole and these findings were compared to those of the Japanese lunar crater Kaguya. It was possible to map an area whose dimensions are 500 X 400 km. Contrary to what they had hoped, no flashes of light were observed at the time of the impact (15, 14).
6. Structure flight - it is about two spaceships designed to orbit the moon with a fixed distance between them. These spacecraft were named GRAIL-A and GRAIL-B (Gravity Recovery and Interior Laboratory). This is a mission that was planned to last 9 months. The intention is to measure the internal structure of the moon from the crust to the core and to better understand its thermal evolution In order to save fuel during the flight to the moon, a special flight path was chosen for the two spacecraft and the duration of the flight was 3.5 months. During the flight, small changes were gradually made to the flight path. For comparison, a normal flight to the moon lasts only 65 hours, such as the Apollo flights (16).
GRAIL-A was launched on 8.9.2011 and GRAIL-B was launched a few days later and despite this the flight paths were planned so that they would land on the moon at the same time. GRAIL-A entered a lunar orbit with a large eccentricity whose extreme points are 8363 X 90 km and the orbit time is 115 hours (16). This is also the lap time of GRAIL-B. During their movement around the moon, a series of maneuvers were performed so that in March 2012 their orbit was polar and circular and its distance from the ground was 55 km (17). On March 8.3.2012, 74, the scientific activity of the spacecraft began and the distance between them varies between 224-100 km. In their flight, the spacecraft passed over craters, craters, mountain ranges, basins and other geological formations. Small changes were expected in their flight path and by analyzing these changes it was possible to determine explosive masses inside the moon and thus learn about hidden geological structures that are under the surface and also learn about the nature of the nucleus, measuring the inside of the moon and mapping its gravity. The effectiveness of the measurements was 1000-18 times greater than these of previous studies. During their flight, the distance between them is regularly monitored. Starting from the moment when the first of the two spacecraft passes over Mescon or an area where gravity is greater, its speed is slightly accelerated, so that the distance between the spacecraft increases. From the moment the second spaceship passes over this place, the distance between them decreases again. It is these differences that give the ability to measure the gravitational field of the moon (XNUMX).
7. Photo overlap - the Clementine spaceship transmitted over a million photographs of the moon to Earth with a resolution of 400 meters per pixel. Although the individual photographs, each photograph by itself, cover a smaller area and are less detailed than those of the Lunar Orbiter and Apollo spacecraft, as a whole they constitute a rich source of information whose research can enable the discovery of various formations and anomalies. As soon as you find an unusual and unusual anomaly phenomenon identified by other researchers, other photographs of the same phenomenon taken at other illumination angles of the sun and/or in other perspectives are scanned. A combination of these images creates a three-dimensional image. Analyzing the spatial relationships of everything in the images can provide new insights (19).
8. Mapping - The LRO spacecraft was designed to orbit the moon for a year at a distance of 50 km from the ground. Her work plan was to map the surface of the earth using 20D photographs and high resolutions at different wavelengths. As part of this activity, the deepest craters are mapped, regions that are regularly illuminated by the sun and regions that are regularly shadowed are examined to provide a better understanding of the effect of the moon's radiation on people (XNUMX).
9 Spacecraft excitation - the Russian Lonkhod 1 off-road vehicle, from which no signal has been heard for 40 years, was detected by the LRO spacecraft. On 22.4.2010/1/21, laser signals were transmitted to it from the Apache Point Observatory, New Mexico. The signal was received by Lonkhod XNUMX and sent back. It was clearly picked up. The high strength of the signals sent by the SUV made it possible to make measurements in visible light (XNUMX).
And this is what they knew about the moon before the Apollo missions
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