Artificial satellites of the Earth: All about satellites. How many artificial earth satellites are there

Artificial satellites can be called both spacecraft built specifically for orbiting the Earth, and various objects - fragments of satellites, upper stages, non-functioning vehicles, nodes of the last stages, which are space debris. Most often, satellites are called guided or automatic spacecraft, but other structures, such as orbital stations, are also.

All these objects, not even manned, are orbiting the Earth. In total, more than sixteen thousand different artificial objects rotate in near-Earth orbit, but only about 850 of them are functioning. It is impossible to determine the exact one, as it is constantly changing - some debris in low orbits gradually descends and falls, burning up in the atmosphere.

Most of the satellites belong to the United States, the second place in their number is occupied by Russia, and China, Great Britain, Canada, Italy are also in the first places in this list.

The purpose of satellites can be different: these are meteorological stations, navigational instruments, biosatellites, warships. If earlier, at the dawn of the development of the space age, only government organizations could launch them, today there are satellites of private companies and even individuals, since the cost of this procedure has become more affordable and amounts to several thousand dollars. This explains the huge number of different objects moving in the orbit of the Earth.

The most notable satellites

The first artificial satellite was launched in 1957 by the USSR, it was named "Sputnik-1", it became well-established and was even borrowed by many other languages, including English. The following year, the United States launched its own - Explorer-1.

Then followed the launch of the UK, Italy, Canada, France. Today, several dozen countries around the world have their own satellites in orbit.

One of the largest projects in the history of the space age was the launch of the ISS, an international space station with research purposes. Its control is carried out by the Russian and American segments, Danish, Canadian, Norwegian, French, Japanese, German and other astronauts also take part in the work of the station.

In 2009, the largest artificial satellite, Terrestar-1, an American project of a telecommunications organization, was launched into orbit. It has a huge mass - almost seven tons. Its purpose is to provide communications for most of North America.

The only natural satellite of the Earth is the Moon. Some scientists mistakenly assign a similar status to other space objects, but over time, such theories lose their credibility. The French astronomer Petit believed that in addition to the Moon, our planet also has other satellite formations. As them, the scientist cites fireballs - meteors, characterized by high brightness, large dimensions. These bolides revolve around the planet in elliptical orbital routes. The most famous of them is the fireball, which was discovered by an astronomer in 1846. But after 5 years, a refutation of the theory of the French scientist appeared. It was put forward by Le Verrier.

Another theory about the existence of other EES was put forward by Waltemat, whose calculations claimed that there is another prototype of the Moon, rotating around the planet and making one revolution around it in 119 days. However, he did not receive a real status.

The moon is the only natural earth satellite, but many scientists distinguish quasi-satellites. This is due to the fact that the Moon is not the only satellite formation located near the planet. Various asteroids may also be in orbital space. Various media and popular science publications call such bodies second moons. However, such asteroids do not revolve around the planet, but around the Sun. One of the clearest examples of such objects is the asteroid Kruitni, which crosses the orbital routes not only of our planet, but also of Mars and Venus.

Another group of celestial bodies has been singled out, which can be called natural earthly satellites, but they are not, called Trojans. Trojan asteroids move along the orbital route along which our planet rotates. At certain moments, they can outrun or catch up with it. Today, the presence of only 1 such asteroid is officially recorded: TK7, which is 60 degrees ahead of the planet.

An ordinary optical illusion can suggest the existence of other satellite bodies. In certain situations, you can become an eyewitness to the phenomenon when a second false moon appears in the sky. Such an optical illusion appears only when the object emits a sufficiently bright light. A halo appears around the luminous spot. A second false object appears due to the fact that the lunar rays begin to refract in the crystalline ice formations of cirrostratus clouds. This action ensures the appearance of bright luminous objects on both sides of the Moon ball.

This illusion quickly disappears. The false moon is called parselena and is just an ordinary play of light rays.

Despite a zealous search for other satellite existences, all plausible theories about their presence have been refuted. All asteroids, meteors, one way or another crossing the orbital line, cannot be considered as EES. It is also impossible to give such a status to emerging optical illusions.

This video tells about the satellites of the Earth and what will happen in orbit.

Artificial terrestrial satellite objects are called spacecraft that are put on an orbital route and rotate in a geocentric orbit. They are necessary for the elimination of applied and scientific problems, the study of near-Earth space.

The departure of the first artificial assistant is dated October 4, 1957. It was launched on the territory of the USSR. The sent satellite gave humanity the opportunity to obtain measurement data on the density of the upper atmospheric layers, establish the reliability of the calculations made in theory, and confirm the feasibility of the main technical solutions used for the launch. The satellite also provided an opportunity to examine the characteristics of the transmission of a radio signal through the ionosphere.

The American first-born satellite was launched on February 1, 1958. After some time, other powers also launched their research vehicles:

• France;
• Australia;
• Great Britain;
• Japan.

AES registration occurs only after the device makes a complete revolution around the planet, otherwise it will be registered in the registry as a rocket probe.

Types, movement of artificial satellites of the Earth

AES acquires the status of active only on condition that it is equipped with radio transmitters, flash lamps that give light signals. Also, various measuring equipment should be located on it. Based on the purpose of artificial SZ, all devices are divided into applied and research. The latter type is necessary to ensure research activities aimed at celestial bodies, the globe and outer space. This group includes geodetic and geophysical devices, as well as astronomical observatories located in orbit. The applied type is formed by communication, navigation devices, as well as devices that provide meteorological land-resource, technical study. There are other satellites designed for human flight. They are called satellite ships with the possibility of piloting. When the body is located in a polar orbit, it is called - polar, if on the equator - equatorial. There are also stationary satellites, with the possibility of sending to the equatorial orbital route. Their movement coincides with the earth's rotation, which is why they are motionless over a specific planetary point.

An Earth satellite is any object that follows a curved path around a planet. The Moon is the original, natural satellite of the Earth, and there are many artificial satellites, usually in close orbit to the Earth. The path a satellite travels is an orbit that sometimes takes the form of a circle.

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To understand why satellites move in this way, we must return to our friend Newton. Newton suggested that a gravitational force exists between any two objects in the universe. If not for this force, a satellite moving near the planet would continue to move at the same speed and in the same direction - in a straight line. However, this rectilinear inertial path of the satellite is balanced by a strong gravitational attraction directed towards the center of the planet.

Orbits of artificial earth satellites

Sometimes the orbit of an artificial Earth satellite looks like an ellipse, a squashed circle that moves around two points known as foci. The same basic laws of motion apply, except that the planet is in one of the foci. As a result, the net force applied to the satellite is not uniform throughout the orbit, and the satellite's speed is constantly changing. It moves fastest when it's closest to Earth - a point known as perigee - and slowest when it's farthest from Earth - a point known as apogee.

There are many different satellite orbits of the Earth. The ones that get the most attention are the geostationary orbits as they are stationary over a specific point on the Earth.

The orbit chosen for an artificial satellite depends on its application. For example, direct broadcast television uses the geostationary orbit. Many communications satellites also use the geostationary orbit. Other satellite systems, such as satellite phones, may use low earth orbits.

Similarly, satellite systems used for navigation, such as Navstar or Global Positioning (GPS), occupy a relatively low Earth orbit. There are also many other types of satellites. From meteorological satellites to research satellites. Each of them will have its own type of orbit depending on its application.

The actual chosen orbit of an Earth satellite will depend on factors including its function and the area in which it is intended to serve. In some cases, an Earth satellite orbit can be as long as 100 miles (160 km) for a LEO, while others can reach over 22,000 miles (36,000 km) as in the case of a GEO-orbit GEO.

The first artificial earth satellite

The first artificial earth satellite was launched on October 4, 1957 by the Soviet Union and was the first artificial satellite in history.

Sputnik 1 was the first of several satellites launched by the Soviet Union in the Sputnik program, most of which were successful. Sputnik 2 followed the second satellite in orbit, as well as the first one, to carry an animal on board, a bitch named Laika. The first failure was Sputnik 3.

The first earth satellite had an approximate mass of 83 kg, had two radio transmitters (20.007 and 40.002 MHz) and orbited the Earth at a distance of 938 km from its apogee and 214 km at its perigee. Radio signal analysis was used to obtain information about the electron density in the ionosphere. Temperature and pressure were coded for the duration of the radio signals it emitted, indicating that the satellite was not perforated by a meteorite.

The first earth satellite was an aluminum sphere 58 cm in diameter, with four long and thin antennas ranging in length from 2.4 to 2.9 m. The antennas looked like long mustaches. The spacecraft received information about the density of the upper atmosphere and the propagation of radio waves in the ionosphere. Instruments and sources of electrical power were housed in a capsule which also included radio transmitters operating at 20.007 and 40.002 MHz (about 15 and 7.5 m at wavelength), emissions were made in alternative groups of 0.3 s duration. The telemetry grounding included data on the temperature inside and on the surface of the sphere.

Because the sphere was filled with pressurized nitrogen, Sputnik 1 had its first opportunity to detect meteorites, although it did not. The loss of pressure inside, due to penetration to the outer surface, was reflected in the temperature data.

Types of artificial satellites

Artificial satellites come in many shapes, sizes, and roles.

• weather satellites help meteorologists predict the weather or see what is happening at the moment. A good example is the geostationary operational environmental satellite (GOES). These earth satellites typically contain cameras that can return photographs of the earth's weather, either from fixed geostationary positions or from polar orbits.
• Communications satellites allow you to transmit telephone and information conversations via satellite. Typical communications satellites include Telstar and Intelsat. The most important feature of a communications satellite is the transponder, a radio receiver that receives a conversation on one frequency and then amplifies it and retransmits it back to Earth on a different frequency. A satellite usually contains hundreds or thousands of transponders. Communication satellites are usually geosynchronous.
• Broadcast satellites transmit television signals from one point to another (similar to communication satellites).
• scientific satellites, such as the Hubble Space Telescope, carry out all sorts of scientific missions. They look at everything from sunspots to gamma rays.
• Navigation satellites help ships and planes navigate. The most famous are the GPS NAVSTAR satellites.
• Rescue satellites respond to radio interference signals.
• Earth observation satellites are checking the planet for changes in everything from temperature, forest plantations, to ice cover. The most famous are the Landsat series.
• Military satellites The Earths are in orbit, but much of the actual position information remains secret. Satellites can include encrypted communications relaying, nuclear monitoring, observation of enemy movements, early warning of missile launches, eavesdropping on ground radio links, radar imaging and photography (essentially using large telescopes that photograph areas of military interest).

Earth from an artificial satellite in real time

Images of the earth from an artificial satellite, broadcast in real time by NASA from the International Space Station. The images are captured by four high-definition cold-sealed cameras, making us feel closer to space than ever before.

The experiment (HDEV) aboard the ISS was activated on April 30, 2014. It is installed on the external cargo mechanism of the Columbus module of the European Space Agency. This experiment involves several high-definition video cameras that are enclosed in a case.

Advice; put the player in HD and full screen. There are times when the screen will be black, this can be for two reasons: the station passes through the orbit zone, where it is at night, the orbit lasts approximately 90 minutes. Or the screen goes dark when the cameras change.

How many satellites are in Earth orbit 2018?

According to the United Nations Office for Outer Space Affairs (UNOOSA) Index of Objects Launched into Outer Space, there are currently about 4,256 satellites in Earth orbit, up 4.39% from last year.

221 satellites were launched in 2015, the second highest in a single year, although it is below the record number of 240 launched in 2014. The increase in the number of satellites orbiting the Earth is less than the number launched last year because satellites have a limited lifespan. Large communications satellites are 15 years or more, while small satellites such as the CubeSat can only expect a lifetime of 3-6 months.

How many of these orbiting Earth satellites are operational?

The Union of Scientists (UCS) is clarifying which of these orbiting satellites are working, and it's not as many as you think! There are currently only 1,419 operational Earth satellites—only about one-third of the total number in orbit. This means that there is a lot of useless metal around the planet! That's why there's a lot of interest from companies looking to capture and return space debris using methods like space nets, slingshots or solar sails.

What are all these satellites doing?

According to UCS data, the main targets of operational satellites are:

• Communications - 713 satellites
• Earth observation/science - 374 satellites
• Technology demonstration/development using 160 satellites
• Navigation & GPS - 105 satellites
• Space Science - 67 satellites

It should be noted that some satellites have multiple targets.

Who owns the earth's satellites?

It is interesting to note that there are four main types of users in the UCS database, although 17% of the satellites are owned by a few users.

• 94 satellites registered by civilians: they are usually educational institutions, although there are other national organizations. 46% of these satellites have a goal of developing technologies such as earth and space science. Surveillance account for another 43%.
• 579 are owned by commercial users: commercial organizations and government organizations that want to sell the data they collect. 84% of these satellites are focused on communications and global positioning services; of the remaining 12% are Earth observation satellites.
• 401 satellites are owned by government users: mainly national space organizations, but also other national and international bodies. 40% of them are communications and global positioning satellites; another 38% is focused on Earth observation. Of the rest, the development of space science and technology is 12% and 10%, respectively.
• 345 satellites belong to the military: communications, Earth observation and global positioning systems are again concentrated here, with 89% of the satellites having one of these three purposes.

How many satellites do countries have

According to UNOOSA, about 65 countries have launched satellites, although the UCS database only has 57 countries registered using satellites and some satellites are listed with joint/multinational operators. The biggest:

• USA with 576 satellites
• China with 181 satellites
• Russia with 140 satellites
• The UK is listed as having 41 satellites, plus participates in an additional 36 satellites held by the European Space Agency.

Remember when you look!
The next time you look at the night sky, remember that between you and the stars there are about two million kilograms of metal surrounding the Earth!

Have you ever wondered how many satellites revolve around the Earth?

The first artificial satellite was launched into earth orbit on October 4, 1957. Over the years of space exploration, several thousand flying objects have accumulated in near-Earth space.

Flies over our heads 16 800 artificial objects, among them 6,000 satellites, the rest are considered space debris - these are boosters and debris. There are fewer active devices - about 850 .

AMSAT OSCAR-7, launched into orbit on November 15, 1974, is considered the longest-lived among satellites. This small device (its weight is 28.8 kilograms) is intended for amateur radio communications. The largest object in orbit is the International Space Station (ISS). Its mass is about 450 tons.

Satellites that provide communication for cellular operators (Beeline, MTS and Megafon) are placed in two types of orbits: low and geostationary.

At a low altitude, 780 kilometers from the Earth, is the Iridium global communication system used by mobile operators. The idea of ​​its creation was proposed in the 1980s by Motorola. The name of the system is due to the chemical element iridium: it should have included 77 devices, which is equal to the atomic number of iridium. Now Iridium has 66 satellites.

The geostationary orbit is located at an altitude of 35,786 kilometers above the equator. It is more profitable to place communication satellites on it, since you do not need to constantly direct the antenna - the devices rotate with the Earth and are always above the same point. There are 178 satellites at the geostationary station. The largest group in Russia belongs to the Federal State Unitary Enterprise "Space Communications": 9 satellites of the "Express" series provide television and radio broadcasting, mobile, as well as government and presidential communications, and the Internet. Meteorological and observation satellites are also placed in geostationary orbit. Meteorological satellites record changes in the atmosphere, "observers" determine the degree of ripening of grain, the degree of drought, and so on.

Working satellites / failed / junk

As usual, click to enlarge

For the first time, scientists started talking about large-scale space pollution in the 1980s, when the concentration of debris in Earth's orbit reached such a density that ballistics needed to work hard to safely place one or another satellite among it. The situation has only worsened in the last decade. “The amount of debris in near-Earth space is so great that it poses a real danger to automatic stations operating there. In the near future, the difficulties will grow like a snowball,” believes Alexander Bagrov, senior researcher at the Research Institute of Astronomy of the Russian Academy of Sciences. He has very serious reasons for this.

Junkyard in the sky - trouble on Earth

First of all, objects in orbit suffer from space debris, of course. “Ground observation services sometimes record collisions of space debris particles with each other, which is why their number multiplies exponentially,” says the chairman of the commission on space debris problems of the Russian Academy of Sciences, deputy director of the Institute of Applied Mathematics. Keldysha Ephraim Akim. - Small fractions are no less dangerous than large ones. Just imagine a large-caliber bullet moving at a speed of 8-10 km/s. When such a particle hits an active spacecraft, the impact force is simply monstrous. No ship can withstand such a collision. If an impact occurs, a cloud of debris in orbit will spread in all directions in just a couple of weeks, threatening to destroy other neighbors as well.”

And although the probability of destroying orbiting satellites with space debris is still extremely small, there have already been unpleasant incidents, including with passenger spacecraft and orbital stations.

In 1983, the crew of the infamous Challenger shuttle discovered a small impact mark on the windshield of their ship from a foreign object. The crater was only 2.5 mm deep and the same width, but made NASA engineers very worried. After the spacecraft landed, experts carefully examined the damage and came to the conclusion that the cause of the collision was a microparticle of paint that had peeled off from some other spacecraft. The Soviet orbital station Salyut-7 also suffered from space debris, the surface of which was literally dotted with microscopic craters from collision with debris particles. To prevent the possibility of such incidents in the future, the Mir station and the ISS that replaced it were equipped with screens that protected the habitable modules from collisions with small debris. However, this did not help either. In June 1999, the then uninhabited ISS had every chance of colliding with a fragment of the upper stage of one of the rockets, which had been orbiting the Earth for many years. Fortunately, the specialists of the Russian Mission Control Center (MCC) managed to correct its orbit in time, and the fragment flew past at a distance of 6.5 km. In 2001, the ISS had to take a special maneuver to avoid colliding with a seven-kilogram instrument lost during a spacewalk by American astronauts. Since then, the station has been dodging space debris with enviable regularity, several times a year.

Space debris is also dangerous for earthlings far from outer space, falling on their heads in the truest sense of the word. In 1978, the taiga regions in northern Canada were hit by the fall of the Soviet satellite Kosmos-594. A year later, the wreckage of the American space station Skylab scattered over the desert regions of Australia.

In 1964, during the unsuccessful launch of a US navigation satellite with nuclear power sources on board, radioactive materials scattered over the Indian Ocean. Everyone remembers the situation with the Mir station, which was flooded in the Pacific Ocean. Then tens of thousands of inhabitants of the island states had a uniform mass psychosis. People were terribly afraid that the “Russian hulk” would fall right on their heads. But for the inhabitants of the Altai Territory, this nightmare has become a reality. It is over this region of Russia that the flight paths of missiles launched from Baikonur lie, and it is here that the wreckage of the first stages with the remnants of highly toxic fuel falls.

But what is space debris? Where does it come from?

Who is littering here?

“The situation is developing paradoxically,” says Alexander Bagrov. “The more we launch vehicles into space, the less usable it becomes.” Indeed, according to Russian experts, there are currently more than 10 thousand aircraft and Earth satellites in space, while only 6% of them are functioning. Spacecraft fail with enviable regularity, and as a result, the density of space debris in orbit increases by 4% annually. Currently, about 70-150 thousand objects ranging in size from 1 to 10 cm revolve around our planet, millions of particles less than 1 cm in diameter. “And if in low orbits, up to about 400 km, debris slows down on the upper layers of the atmosphere and eventually falls to Earth, then in geostationary orbits it can rotate indefinitely,” Alexander Bagrov continues.

The upper stages of rockets, with the help of which satellites are launched into geostationary orbits, also contribute to the increase in space debris. About 5-10% of the fuel remains in their tanks, which is very volatile and easily turns into steam, which often leads to powerful explosions. After several years of being in space, the spent rocket stages shatter into pieces, scattering shrapnel of small fragments around them. In recent years, 182 such fireworks have been recorded in near-Earth space. Just one recent explosion of the stage of an Indian launch vehicle resulted in the formation of 300 large debris and countless small, but no less dangerous objects. The first victims have already been.

In July 1996, at an altitude of about 660 km, a French satellite collided with a fragment of the third stage of the French Arian rocket, launched much earlier. The relative speed at the time of the collision was about 15 km/s, or about 50,000 km/h. The French ballisticians, who missed the approach of their own large object in orbit, then bit their elbows for a long time, and there was something. The incident did not end in a major international scandal just because both objects were of French origin. How to clear the orbit of space debris?

The space scavenger position is still open

“Unfortunately, at the moment there are no effective ways to destroy space debris,” said Efraim Akim. In his opinion, collecting debris with the help of American shuttles is insanely expensive, and the shuttles have been laid up for several years now. It is even more insane to burn space debris with a laser, as the molten metal, as it cools, will turn into a deadly "shrapnel" that will spread in orbit, further polluting space. Replacing multi-stage rockets with reusable systems is also not yet possible, they are too expensive. “Of course, it is good to launch and pick up satellites using flying saucers. At any moment, it took off, hooked it and sat back on Earth, - Ephraim Akim laughs. - Alas, humanity does not have such technical devices. Until they appear, we must by all means prevent further pollution of space, otherwise in the future, due to the danger of encountering space debris, its development will turn into a very risky undertaking.

The only thing that scientists can offer so far is a thorough mapping of the space dump. But even here everything is not so simple. “Today, only two states in the world are able to effectively track the behavior of space debris,” said Nikolai Ivanov, chief ballistician of the MCC. It is easy to guess that this is Russia and the United States, which, by the way, are also the main "pollutants" of space. “We, like in America, have unique ground-based systems that make it possible to detect pieces up to several centimeters in diameter in low orbits, but it is also necessary to jointly develop measures to neutralize them. It would be nice to create an international tracking system, unite object catalogs, develop a common collision risk warning system, only in this case it is possible to really secure flights,” Nikolay Ivanov continues. “In order for there to be no accidents on space roads, it is necessary to develop international rules for space traffic,” Ephraim Akim echoes him. The first steps in this direction have already been taken.

Space traffic rules

“Several international commissions, including those under the auspices of the UN, are involved in preventing further pollution of outer space,” says Alexander Alferov, Scientific Secretary of the Space Council of the Russian Academy of Sciences. - True, they are faced with the sluggishness of a number of agencies that prefer to weigh everything very carefully before going for cooperation. The fact is that many satellites belong to the military departments and it is very difficult to obtain complete information about them. The commercial side of the issue cannot be discounted either.” However, the privatization of space plays into the hands of those who stand up for its purity. “Space is gradually turning into a zone for investing capital, and businessmen have always been interested in the issues of risk insurance and compensation for losses as a result of various force majeure circumstances,” Alexander Bagrov believes. - It will not be possible to achieve this without developing uniform legal norms. For example, who should be responsible if an old lifeless satellite or upper stage of a rocket launched by one state rams an automatic station belonging to another country? So far, there is no answer to this question, although such precedents have already taken place. And although private space companies are only taking their first steps, the very fact of their birth prompted the development of common international rules. “Currently, new requirements for space technology are being intensively developed, satellite operation zones are being determined and methods for burying obsolete vehicles are being discussed,” says Efraim Akim.

One of the first real achievements in the fight against space debris was the development of new international standards for artificial earth satellites. Now they must have reserve fuel reserves on board in order to take the vehicles to specially designated areas of near-Earth orbits or send them to the Earth after the expiration of the service life. It is also desirable to equip the satellites with additional control systems capable of, in the event of damage to the apparatus by debris particles, to remove it from working orbits. It is assumed that the "cemeteries of satellites" will be located 200-300 km above the zone of geostationary orbits. “Of course, the introduction of new standards is going very slowly,” admits Efraim Akim, “because they are associated with significant costs. The change in satellite design entails an additional multi-million dollar investment that not all aerospace corporations like. But these measures are simply indispensable at the moment, and everyone understands this.”

Another important step is the introduction into the international rules for the use of outer space of the requirement to equip rocket upper stages with fuel drain systems. Once in space, after the completion of the maneuver, the control electronics must open the valves and throw out excess fuel. Unfortunately, this is sometimes not enough. Due to the characteristics of the fuel and the impossibility of completely throwing it out of the tanks, even “empty” tanks explode. This means that measures must be taken to improve the design of space rockets.

To date, space debris has been well studied. As scientists note, it is distributed in orbits in layers, like the filling of a pie. This is directly related to the functional load on a particular orbit. The more convenient it is, the more satellites work on it. After some time, some of them turn into lifeless scrap metal, polluting the space where their life has recently passed.

The first debris belt is located at an altitude of 850-1200 km from the Earth's surface. It is here that a huge number of meteorological, military, scientific satellites and probes move. The second pollution belt lies in the region of geostationary orbits (over 30,000 km). Now there are about 800 objects from different countries. Every year 20-30 new stations join them

According to the Russian Academy of Sciences, about 85% of space debris is accounted for by large parts of rockets and upper stages, with the help of which artificial Earth satellites are put into orbit, as well as the spent satellites themselves.

Another 12% of debris is structural elements that are separated during the launch of satellites and their operation. Everything else is small fractions and fragments resulting from their collision

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