Abstract “Projects of domestic cosmonautics. Artificial Earth satellites

An artificial Earth satellite is a spacecraft that revolves around the Earth while in a geocentric orbit. Initially, the word “sputnik” was used to refer to Soviet spacecraft, but in 1968-1969. The idea of ​​creating an international multilingual space dictionary was implemented, in which, by mutual agreement of the participating countries, the term “satellite” began to be applied to artificial Earth satellites launched in any country in the world.
According to international agreement, a spacecraft is considered a satellite if it has completed at least one revolution around the Earth. In order to launch a satellite into orbit, it is necessary to impart to it a speed equal to or greater than the first escape velocity. The flight altitude of a satellite can be different and ranges from several hundred to hundreds of thousands of kilometers.

The lowest altitude is determined by the presence of a rapid deceleration process in the upper layers of the atmosphere. The satellite's orbital period also depends on the altitude, which varies from
several hours to several days. They are used in scientific research and to solve applied problems. They are divided into military, meteorological, navigation, communications satellites, etc. There are also amateur radio satellites.

If the satellite on board has transmitting radio equipment, any measuring instruments, flash lamps used to send signals, then it is considered active. Passive artificial earth satellites are used to implement a number of scientific tasks and as observation objects from the earth's surface.

The mass of the satellite directly depends on the tasks that the launch object has to implement in near-Earth space, and can range from hundreds of grams to hundreds of tons.

Artificial satellites have a certain orientation in space depending on the assigned tasks. For example, vertical orientation is used for satellites whose main task is to observe objects on the Earth’s surface and in its atmosphere.

For astronomical research, satellites are oriented towards the celestial bodies being studied. It is possible to orient individual satellite elements, such as antennas, towards earthly receiving stations, and solar panels towards the Sun.

Satellite orientation systems are divided into passive (magnetic, aerodynamic, gravitational) and active (systems equipped with control elements).

The latter are used mainly on technically complex artificial satellites and spacecraft.

The world's first artificial satellite was Sputnik 1. It was launched on October 4, 1957 from the Baikonur Cosmodrome.

Leading scientists of the USSR of that time worked on the creation of this spacecraft, including the founder of practical cosmonautics S.P. Korolev, M.K. Tikhonravov, M.V. Keldysh and many others. The satellite was an aluminum sphere that had a diameter of 58 cm and a mass of 83.6 kg. At the top there were two antennas, each of which consisted of two pins and four antennas. The satellite was equipped with two radio transmitters with power supplies. The range of the transmitters was such that radio amateurs could track his movements. It completed 1,440 revolutions around the Earth in 92 days. During the flight, it became possible for the first time to determine the density of the upper atmosphere by changing the satellite's orbit; in addition, the first data on the propagation of radio signals in the ionosphere were obtained. Already on November 3, the second, biological, satellite of the Earth was launched, which on board, in addition to improved scientific equipment, delivered a living creature into orbit - the dog Laika. The total weight of the satellite was 508.3 kg. The satellite was equipped with thermal control and regeneration systems to maintain the conditions necessary for the life of the animal.

The first artificial satellite of the USSR for reconnaissance purposes was Zenit-2, which was launched into orbit on April 26, 1962. The equipment set included a capsule for dropping photographic material and various photo and radio reconnaissance equipment.

The United States became the second world power to discover outer space by launching its satellite, Explorer 1, on February 1, 1958 (according to some sources, January 31, 1958). The launch and development of the satellite was carried out by a team of specialists under the command of the former German engineer Wernher von Braun, the creator of the “weapon of retaliation” - the rocket known as the V-2. The satellite was launched using a Redstone ballistic rocket, which used a mixture of ethyl alcohol and hydrazine (N,H4) as fuel. The mass of the satellite was 8.3 kg, which is 10 times less than the Soviet satellite, however, Explorer 1 had a Geiger counter and an atmospheric particle sensor on board.
France became the third space power, launching the Asterix-1 satellite on November 26, 1965. Australia was the next power to earn the right to be called a space power, this happened on November 29, 1967, the satellite was called VRESAT-1. In 1970, two powers immediately joined the list of artificial Earth satellites - Japan (Osumi satellite) and China (China-1 satellite).

Spacecraft in all their diversity are both the pride and concern of humanity. Their creation was preceded by a centuries-old history of the development of science and technology. The space age, which allowed people to look at the world in which they live from the outside, has taken us to a new level of development. A rocket in space today is not a dream, but a matter of concern for highly qualified specialists who are faced with the task of improving existing technologies. What types of spacecraft are distinguished and how they differ from each other will be discussed in the article.

Definition

Spacecraft is a general name for any device designed to operate in space. There are several options for their classification. In the simplest case, spacecraft are divided into manned and automatic. The former, in turn, are divided into spaceships and stations. Different in their capabilities and purpose, they are similar in many respects in structure and equipment used.

Flight Features

After launch, any spacecraft goes through three main stages: insertion into orbit, flight itself and landing. The first stage involves the device developing the speed necessary to enter outer space. In order to get into orbit, its value must be 7.9 km/s. Complete overcoming of gravity involves the development of a second equal to 11.2 km/s. This is exactly how a rocket moves in space when its target is remote areas of the Universe.

After liberation from attraction, the second stage follows. During an orbital flight, the movement of spacecraft occurs by inertia, due to the acceleration given to them. Finally, the landing stage involves reducing the speed of the ship, satellite or station to almost zero.

"Filling"

Each spacecraft is equipped with equipment that matches the tasks it is designed to solve. However, the main discrepancy is related to the so-called target equipment, which is necessary precisely for obtaining data and various scientific research. Otherwise, the equipment of the spacecraft is similar. It includes the following systems:

• energy supply - most often solar or radioisotope batteries, chemical batteries, and nuclear reactors supply spacecraft with the necessary energy;
• communication - carried out using a radio wave signal; at a significant distance from the Earth, accurate pointing of the antenna becomes especially important;
• life support - the system is typical for manned spacecraft, thanks to it it becomes possible for people to stay on board;
• orientation - like any other ships, space ships are equipped with equipment to constantly determine their own position in space;
• movement - spacecraft engines allow changes in flight speed, as well as in its direction.

Classification

One of the main criteria for dividing spacecraft into types is the operating mode that determines their capabilities. Based on this feature, devices are distinguished:

• located in a geocentric orbit, or artificial earth satellites;
• those whose purpose is to study remote areas of space - automatic interplanetary stations;
• used to deliver people or necessary cargo into the orbit of our planet, they are called spaceships, can be automatic or manned;
• created for people to stay in space for a long period - this is;
• engaged in the delivery of people and cargo from orbit to the surface of the planet, they are called descent;
• those capable of exploring the planet, directly located on its surface, and moving around it are planetary rovers.

Let's take a closer look at some types.

AES (artificial earth satellites)

The first devices launched into space were artificial Earth satellites. Physics and its laws make launching any such device into orbit a difficult task. Any device must overcome the gravity of the planet and then not fall on it. To do this, the satellite needs to move at or slightly faster. Above our planet, a conditional lower limit of the possible location of an artificial satellite is identified (passes at an altitude of 300 km). A closer placement will lead to a fairly rapid deceleration of the device in atmospheric conditions.

Initially, only launch vehicles could deliver artificial Earth satellites into orbit. Physics, however, does not stand still, and today new methods are being developed. Thus, one of the methods often used recently is launching from another satellite. There are plans to use other options.

The orbits of spacecraft revolving around the Earth can lie at different altitudes. Naturally, the time required for one lap also depends on this. Satellites, whose orbital period is equal to a day, are placed on the so-called It is considered the most valuable, since the devices located on it appear motionless to an earthly observer, which means there is no need to create mechanisms for rotating antennas.

AMS (automatic interplanetary stations)

Scientists obtain a huge amount of information about various objects of the Solar System using spacecraft sent beyond the geocentric orbit. AMS objects are planets, asteroids, comets, and even galaxies accessible for observation. The tasks posed to such devices require enormous knowledge and effort from engineers and researchers. AWS missions represent the embodiment of technological progress and are at the same time its stimulus.

Manned spacecraft

Devices created to deliver people to their intended destination and return them back are in no way inferior in technological terms to the described types. The Vostok-1, on which Yuri Gagarin made his flight, belongs to this type.

The most difficult task for the creators of a manned spacecraft is ensuring the safety of the crew during the return to Earth. Also an important part of such devices is the emergency rescue system, which may be necessary when the ship is launched into space using a launch vehicle.

Spacecraft, like all astronautics, are constantly being improved. Recently, the media have often seen reports about the activities of the Rosetta probe and the Philae lander. They embody all the latest achievements in the field of space shipbuilding, calculation of vehicle motion, and so on. The landing of the Philae probe on the comet is considered an event comparable to Gagarin's flight. The most interesting thing is that this is not the crown of humanity’s capabilities. New discoveries and achievements still await us in terms of both space exploration and the structure

Artificial Earth satellites (satellite)

spacecraft launched into orbit around the Earth and designed to solve scientific and applied problems. The launch of the first satellite, which became the first artificial celestial body created by man, was carried out in the USSR on October 4, 1957 and was the result of achievements in the field of rocketry, electronics, automatic control, computer technology, celestial mechanics and other branches of science and technology. With the help of this satellite, the density of the upper atmosphere was measured for the first time (by changes in its orbit), the features of the propagation of radio signals in the ionosphere were studied, theoretical calculations and basic technical solutions related to launching the satellite into orbit were tested. On February 1, 1958, the first American satellite, Explorer-1, was launched into orbit, and a little later, other countries also launched independent satellites: November 26, 1965 - France (satellite A-1), November 29, 1967 - Australia (VRSAT-1). 1"), February 11, 1970 - Japan ("Osumi"), April 24, 1970 - China ("China-1"), October 28, 1971 - Great Britain ("Prospero"). Some satellites, manufactured in Canada, France, Italy, Great Britain and other countries, have been launched (since 1962) using American launch vehicles. International cooperation has become widespread in the practice of space research. Thus, within the framework of scientific and technical cooperation between socialist countries, a number of satellites have been launched. The first of them, Intercosmos-1, was launched into orbit on October 14, 1969. In total, by 1973, over 1,300 satellites of various types were launched, including about 600 Soviet and over 700 American and other countries, including manned spacecraft-satellites and orbital stations with crew.

General information about satellites. In accordance with international agreement, a spacecraft is called a satellite if it has completed at least one revolution around the Earth. Otherwise, it is considered a rocket probe taking measurements along a ballistic trajectory and is not registered as a satellite. Depending on the tasks solved with the help of artificial satellites, they are divided into research and applied ones. If a satellite is equipped with radio transmitters, some kind of measuring equipment, flash lamps for sending light signals, etc., it is called active. Passive satellites are usually intended for observations from the earth's surface when solving certain scientific problems (such satellites include balloon satellites reaching several tens in diameter). Research satellites are used to study the Earth, celestial bodies, and outer space. These include, in particular, geophysical satellites (See Geophysical satellite), Geodetic satellites, orbital astronomical observatories, etc. Application satellites are Communications satellites and meteorological satellites (See Meteorological satellite), satellites for the study of earth resources, navigation satellites (See Navigation satellite), satellites for technical purposes (for studying the effects of space conditions on materials, for testing and testing on-board systems), etc. AES intended for human flight are called manned satellites. Satellites in an equatorial orbit lying near the equatorial plane are called equatorial, satellites in a polar (or subpolar) orbit passing near the Earth's poles are called polar. Satellites launched into a circular equatorial orbit at a distance of 35860 km from the Earth’s surface, and moving in a direction coinciding with the direction of the Earth’s rotation, “hang” motionless over one point on the Earth’s surface; such satellites are called stationary. The last stages of launch vehicles, nose fairings and some other parts separated from the satellite during launch into orbits represent secondary orbital objects; they are not usually called satellites, although they orbit the Earth and in some cases serve as objects of observation for scientific purposes.

In accordance with the international system of registration of space objects (satellites, space probes (See Space probes), etc.) within the framework of the international organization COSPAR in 1957-1962, space objects were designated by the year of launch with the addition of a letter of the Greek alphabet corresponding to the serial number of the launch in a given year , and an Arabic numeral - the number of an orbital object depending on its brightness or degree of scientific significance. So, 1957α2 is the designation of the first Soviet satellite, launched in 1957; 1957α1 - designation of the last stage of the launch vehicle of this satellite (the launch vehicle was brighter). As the number of launches increased, starting from January 1, 1963, space objects began to be designated by the year of launch, the serial number of the launch in a given year, and a capital letter of the Latin alphabet (sometimes also replaced by a serial number). Thus, the Intercosmos-1 satellite has the designation: 1969 88A or 1969 088 01. In national space research programs, satellite series often also have their own names: “Cosmos” (USSR), “Explorer” (USA), “Diadem” (France) ) etc. Abroad, the word “satellite” until 1969 was used only in relation to Soviet satellites. In 1968-69, during the preparation of the international multilingual astronautical dictionary, an agreement was reached according to which the term “satellite” was applied to satellites launched in any country.

In accordance with the variety of scientific and applied problems solved with the help of satellites, satellites can have different sizes, weights, design designs, and the composition of on-board equipment. For example, the mass of the smallest satellite (from the EPC series) is only 0.7 kg; The Soviet satellite "Proton-4" had a mass of about 17 T. The mass of the Salyut orbital station with the Soyuz spacecraft docked to it was over 25 T. The largest payload mass launched into orbit by an artificial satellite was about 135 T(American Apollo spacecraft with the last stage of the launch vehicle). There are automatic satellites (research and applied), in which the operation of all instruments and systems is controlled by commands coming either from the Earth or from an on-board software device, manned satellites and orbital stations with a crew.

To solve some scientific and applied problems, it is necessary that the satellite be oriented in a certain way in space, and the type of orientation is determined mainly by the purpose of the satellite or the features of the equipment installed on it. Thus, satellites intended for observing objects on the surface and in the Earth’s atmosphere have an orbital orientation, in which one of the axes is constantly directed vertically; Satellites for astronomical research are oriented towards celestial objects: stars, the Sun. Upon command from the Earth or according to a given program, the orientation can change. In some cases, not the entire satellite is oriented, but only its individual elements, for example, highly directional antennas - towards ground points, solar panels - towards the Sun. In order for the direction of a certain axis of the satellite to remain unchanged in space, it is given a rotation around this axis. For orientation, gravitational, aerodynamic, and magnetic systems are also used - the so-called passive orientation systems, and systems equipped with reactive or inertial control elements (usually on complex satellites and spacecraft) - active orientation systems. AES that have jet engines for maneuvering, trajectory correction, or deorbiting are equipped with motion control systems, an integral part of which is the attitude control system.

The power supply for the on-board equipment of most satellites is provided by solar panels, the panels of which are oriented perpendicular to the direction of the sun's rays or are located so that some of them are illuminated by the Sun at any position relative to the satellite (the so-called omnidirectional solar panels). Solar batteries ensure long-term operation of on-board equipment (up to several years). AES designed for limited periods of operation (up to 2-3 weeks) uses electrochemical current sources - batteries, fuel cells. Some satellites have isotope generators of electrical energy on board. The thermal regime of satellites, necessary for the operation of their on-board equipment, is maintained by thermal control systems.

In artificial satellites, which are characterized by significant heat generation from their equipment, and spacecraft, systems with a liquid heat transfer circuit are used; on satellites with low heat generation, equipment in some cases is limited to passive means of thermal regulation (selection of an external surface with a suitable optical coefficient, thermal insulation of individual elements).

The transmission of scientific and other information from satellites to Earth is carried out using radio telemetry systems (often having on-board storage devices for recording information during periods of satellite flight outside the radio visibility zones of ground points).

Manned satellites and some automatic satellites have descent vehicles for returning the crew, individual instruments, films, and experimental animals to Earth.

Movement of satellites. AES are launched into orbit using automatic controlled multi-stage launch vehicles, which move from the launch to a certain calculated point in space thanks to the thrust developed by jet engines. This path, called the trajectory of launching an artificial satellite into orbit, or the active part of the rocket’s movement, usually ranges from several hundred to two to three thousand km. km. The rocket starts, moving vertically upward, and passes through the densest layers of the earth's atmosphere at a relatively low speed (which reduces energy costs to overcome atmospheric resistance). As the rocket rises, it gradually turns around, and the direction of its movement becomes close to horizontal. On this almost horizontal segment, the rocket's thrust is not spent on overcoming the braking effect of the Earth's gravitational forces and atmospheric resistance, but mainly on increasing speed. After the rocket reaches the design speed (in magnitude and direction) at the end of the active section, the operation of the jet engines stops; This is the so-called point of launching the satellite into orbit. The launched spacecraft, which carries the last stage of the rocket, automatically separates from it and begins its movement in a certain orbit relative to the Earth, becoming an artificial celestial body. Its movement is subject to passive forces (gravity of the Earth, as well as the Moon, Sun and other planets, resistance of the Earth’s atmosphere, etc.) and active (control) forces if special jet engines are installed on board the spacecraft. The type of initial orbit of an satellite relative to the Earth depends entirely on its position and speed at the end of the active phase of motion (at the moment the satellite enters orbit) and is calculated mathematically using the methods of celestial mechanics. If this speed is equal to or exceeds (but not more than 1.4 times) the first cosmic speed (See Cosmic velocities) (about 8 km/sec near the Earth's surface), and its direction does not deviate much from the horizontal, then the spacecraft enters the orbit of the Earth's satellite. The point at which the satellite enters orbit in this case is located near the perigee of the orbit. Orbital entry is also possible at other points of the orbit, for example, near the apogee, but since in this case the satellite’s orbit is located below the launch point, the launch point itself should be located quite high, and the speed at the end of the active segment should be somewhat less than the circular one.

To a first approximation, the orbit of an satellite is an ellipse with a focus at the center of the Earth (in a particular case, a circle), maintaining a constant position in space. Movement in such an orbit is called unperturbed and corresponds to the assumptions that the Earth attracts according to Newton’s law as a ball with a spherical density distribution and that only the Earth’s gravitational force acts on the satellite.

Factors such as the resistance of the earth's atmosphere, the compression of the earth, the pressure of solar radiation, the attraction of the moon and the sun, cause deviations from undisturbed motion. The study of these deviations makes it possible to obtain new data about the properties of the Earth's atmosphere and the Earth's gravitational field. Due to atmospheric resistance, satellites moving in orbits with perigee at an altitude of several hundred km, gradually decrease and, falling into relatively dense layers of the atmosphere at an altitude of 120-130 km and below, they collapse and burn; they therefore have a limited lifespan. For example, when the first Soviet satellite entered orbit, it was at an altitude of about 228 km above the Earth's surface and had an almost horizontal speed of about 7.97 km/sec. The semimajor axis of its elliptical orbit (i.e., the average distance from the center of the Earth) was about 6950 km, period 96.17 min, and the least and most distant points of the orbit (perigee and apogee) were located at altitudes of about 228 and 947 km respectively. The satellite existed until January 4, 1958, when, due to disturbances in its orbit, it entered the dense layers of the atmosphere.

The orbit into which the satellite is launched immediately after the booster phase of the launch vehicle is sometimes only intermediate. In this case, there are jet engines on board the satellite, which are turned on at certain moments for a short time upon command from the Earth, imparting additional speed to the satellite. As a result, the satellite moves to another orbit. Automatic interplanetary stations are usually launched first into the orbit of the Earth's satellite, and then transferred directly to the flight path to the Moon or planets.

Satellite observations. Control of the movement of satellites and secondary orbital objects is carried out by observing them from special ground stations. Based on the results of such observations, the elements of satellite orbits are refined and ephemeris are calculated for upcoming observations, including for solving various scientific and applied problems. Based on the observation equipment used, satellites are divided into optical, radio, and laser; according to their ultimate goal - to positional (determining directions on satellites) and rangefinding observations, measurements of angular and spatial velocity.

The simplest positional observations are visual (optical), carried out using visual optical instruments and making it possible to determine the celestial coordinates of the satellite with an accuracy of several minutes of arc. To solve scientific problems, photographic observations are carried out using satellite cameras (See Satellite camera), providing accuracy of determinations up to 1-2 "in position and 0.001 sec by time. Optical observations are possible only when the satellite is illuminated by sunlight (the exception is geodetic satellites equipped with pulsed light sources; they can also be observed while in the earth’s shadow), the sky above the station is sufficiently dark and the weather is favorable for observations. These conditions significantly limit the possibility of optical observations. Less dependent on such conditions are the radiotechnical methods of observing satellites, which are the main methods of observing satellites during the operation of the special radio systems installed on them. Such observations involve receiving and analyzing radio signals that are either generated by the satellite's onboard radio transmitters or sent from the Earth and relayed by the satellite. Comparison of the phases of signals received on several (at least three) spaced antennas allows one to determine the position of the satellite on the celestial sphere. The accuracy of such observations is about 3" in position and about 0.001 sec by time. Measuring the Doppler frequency shift (see Doppler effect) of radio signals makes it possible to determine the relative speed of the satellite, the minimum distance to it during the observed passage and the moment in time when the satellite was at this distance; observations carried out simultaneously from three points make it possible to calculate the angular velocities of the satellite.

Rangefinding observations are carried out by measuring the time interval between sending a radio signal from the Earth and receiving it after retransmission by the onboard radio responder of the satellite. The most accurate measurements of distances to satellites are provided by laser rangefinders (accuracy up to 1-2 Depending on the tasks solved with the help of artificial satellites, they are divided into research and applied ones. If a satellite is equipped with radio transmitters, some kind of measuring equipment, flash lamps for sending light signals, etc., it is called active. Passive satellites are usually intended for observations from the earth's surface when solving certain scientific problems (such satellites include balloon satellites reaching several tens in diameter and higher). For radio engineering observations of passive space objects, radar systems are used.

Research satellites. The equipment installed on board the satellite, as well as satellite observations from ground stations, make it possible to conduct a variety of geophysical, astronomical, geodetic and other studies. The orbits of such satellites are varied - from almost circular at an altitude of 200-300 km to elongated ellipticals with an apogee height of up to 500 thousand. km. Research satellites include the first Soviet satellites, Soviet satellites of the Elektron, Proton, Kosmos series, American satellites of the Avangard, Explorer, OGO, OSO, OAO series (orbital geophysical , solar, astronomical observatories); English satellite “Ariel”, French satellite “Diadem”, etc. Research satellites make up about half of all launched satellites.

Using scientific instruments installed on satellites, the neutral and ionic composition of the upper atmosphere, its pressure and temperature, as well as changes in these parameters are studied. The electron concentration in the ionosphere and its variations are studied both using on-board equipment and by observing the passage of radio signals from on-board radio beacons through the ionosphere. Using ionosondes, the structure of the upper part of the ionosphere (above the main maximum of electron density) and changes in electron density depending on geomagnetic latitude, time of day, etc. were studied in detail. All results of atmospheric research obtained using satellites are important and reliable experimental material for understanding the mechanisms of atmospheric processes and for solving such practical issues as forecasting radio communications, forecasting the state of the upper atmosphere, etc.

With the help of satellites, the Earth's radiation belts have been discovered and studied. Along with space probes, satellites made it possible to study the structure of the Earth’s magnetosphere (See Earth’s magnetosphere) and the nature of the solar wind flow around it, as well as the characteristics of the solar wind itself (See Solar wind) (flux density and particle energy, the magnitude and nature of the “frozen” magnetic field ) and other solar radiation inaccessible to ground-based observations - ultraviolet and x-rays, which is of great interest from the point of view of understanding solar-terrestrial connections. Some applied satellites also provide data valuable for scientific research. Thus, the results of observations carried out on meteorological satellites are widely used for various geophysical studies.

The results of satellite observations make it possible to determine with high accuracy disturbances in satellite orbits, changes in the density of the upper atmosphere (due to various manifestations of solar activity), laws of atmospheric circulation, the structure of the Earth’s gravitational field, etc. Specially organized positional and rangefinding synchronous observations of satellites (simultaneously from several stations) by satellite geodesy methods (See Satellite geodesy) allow for geodetic reference of points remote by thousands km from each other, study the movement of continents, etc.

Applied satellites. Applied satellites include satellites launched to solve certain technical, economic, and military problems.

Communication satellites are used to provide television broadcasts, radiotelephone, telegraph and other types of communication between ground stations located from each other at distances of up to 10-15 thousand. km. The onboard radio equipment of such satellites receives signals from ground-based radio stations, amplifies them and relays them to other ground-based radio stations. Communications satellites are launched into high orbits (up to 40 thousand). km). Satellites of this type include the Soviet satellite « Lightning » , American satellite "Sincom", satellite "Intelsat", etc. Communication satellites launched into stationary orbits are constantly located above certain areas of the earth's surface.

Meteorological satellites are designed for regular transmission to ground stations of television images of the cloudy, snow and ice covers of the Earth, information about the thermal radiation of the earth's surface and clouds, etc. Satellites of this type are launched into orbits close to circular, with an altitude of 500-600 km up to 1200-1500 km; The viewing range from them reaches 2-3 thousand. km. Meteorological satellites include some Soviet satellites of the Cosmos series, Meteor satellites, and American satellites Tiros, ESSA, and Nimbus. Experiments are being conducted on global meteorological observations from altitudes reaching 40 thousand. km(Soviet satellite "Molniya-1", American satellite "ATS").

Satellites for studying the Earth's natural resources are extremely promising from the point of view of application in the national economy. Along with meteorological, oceanographic and hydrological observations, such satellites make it possible to obtain operational information necessary for geology, agriculture, fisheries, forestry, and environmental pollution control. The results obtained using satellites and manned spacecraft, on the one hand, and control measurements from cylinders and aircraft, on the other, show the prospects for the development of this area of ​​research.

Navigation satellites, the functioning of which is supported by a special ground-based support system, are used for the navigation of sea ships, including submarines. The ship, receiving radio signals and determining its position relative to the satellite, the coordinates of which in orbit at each moment are known with high accuracy, establishes its location. Examples of navigation satellites are the American satellites Transit and Navsat.

Manned satellites. Manned satellites and manned orbital stations are the most complex and advanced artificial satellites. They are, as a rule, designed to solve a wide range of problems, primarily for conducting complex scientific research, testing space technology, studying the Earth’s natural resources, etc. The first launch of a manned satellite was carried out on April 12, 1961: on the Soviet spacecraft-satellite “ Vostok » Pilot-cosmonaut Yu. A. Gagarin flew around the Earth in an orbit with an apogee altitude of 327 km. On February 20, 1962, the first American spacecraft entered orbit with astronaut J. Glenn on board. A new step in the exploration of outer space with the help of manned satellites was the flight of the Soviet orbital station "Salyut", on which in June 1971 the crew consisting of G. T. Dobrovolsky, V. N. Volkov and V. I. Patsaev carried out a wide program of scientific and technical , biomedical and other research.

N. P. Erpylev, M. T. Kroshkin, Yu. A. Ryabov, E. F. Ryazanov.

AES "Cosmos"

“Cosmos” is the name of a series of Soviet artificial Earth satellites for scientific, technical and other research in near-Earth space. The Cosmos satellite launch program includes the study of cosmic rays, the Earth's radiation belt and the ionosphere, the propagation of radio waves and other radiation in the Earth's atmosphere, solar activity and solar radiation in various parts of the spectrum, testing of spacecraft components and elucidation of the influence of meteoric matter on the structural elements of the spacecraft , studying the influence of weightlessness and other cosmic factors on biological objects, etc. Such a broad research program and, consequently, a large number of launches confronted engineers and designers with the task of limiting unification of the design of the service systems of the Cosmos artificial satellites. The solution to this problem made it possible to carry out some launch programs using a single body, a standard composition of service systems, a common control circuit for on-board equipment, a unified power supply system and a number of other unified systems and devices. This made serial production of Cosmos and component systems possible, simplified preparations for satellite launches, and significantly reduced the cost of scientific research.

Cosmos satellites are launched into circular and elliptical orbits, the altitude range of which is from 140 (Cosmos-244) to 60,600 km (Cosmos-159) and a wide range of orbital inclinations from 0.1° (Cosmos-775). up to 98° (“Cosmos-1484”) allows the delivery of scientific equipment to almost all areas of near-Earth space. The orbital periods of the Cosmos satellites range from 87.3 minutes (Cosmos-244) to 24 hours 2 minutes (Cosmos-775). The active operation time of the Cosmos satellite depends on the scientific launch programs, orbital parameters and operating resources of the onboard systems. For example, Cosmos-27 was in orbit for 1 day, and Cosmos-80, according to calculations, will exist for 10 thousand years.

The orientation of the artificial Earth satellites “Cosmos” depends on the nature of the research being carried out. To solve such problems as meteorological experiments, studying the spectrum of radiation leaving the Earth, etc., satellites with orientation relative to the Earth are used. When studying the processes occurring on the Sun, modifications of “Cosmos” are used with orientation towards the Sun. Satellite orientation systems are different - jet (rocket engines), inertial (flywheel rotating inside the satellite) and others. The greatest orientation accuracy is achieved by combined systems. Information transmission is carried out mainly in the ranges of 20, 30 and 90 MHz. Some satellites are equipped with TV communications.

In accordance with the tasks being solved, a number of satellites of the Cosmos series have a descent capsule for returning scientific equipment and experimental objects to Earth (Cosmos-4, -110, -605, -782″ and others). The capsule's descent from orbit is ensured by a braking propulsion system with preliminary orientation of the satellite. Subsequently, the capsule is slowed down in dense layers of the atmosphere due to aerodynamic force, and at a certain altitude the parachute system is activated.

On the satellites Kosmos-4, -7, -137, -208, -230, -669” and others, a program of research into primary cosmic rays and the Earth’s radiation belt was carried out, including measurements to ensure radiation safety during manned flights (for example, on "Cosmos-7" during the flight of the spacecraft "Vostok-3, -4"). The flights “Cosmos-135” and “Cosmos-163” finally dispelled the long-standing assumption about the existence of a dust cloud around the Earth. Artificial satellites "Cosmos" are widely used to solve national economic problems. For example, “Study of the distribution and formation of cloud systems in the Earth’s atmosphere” is one of the items in the Cosmos satellite launch program. Work in this direction, as well as the accumulated experience in operating the Kosmos-14, -122, -144, -156, -184, -206 satellites and others led to the creation of the Meteor meteorological satellites, and then the Meteor meteorological space system " Cosmos satellites are used for navigation, geodesy and more.

A significant number of experiments on these satellites relate to the study of the upper atmosphere, ionosphere, Earth radiation and other geophysical phenomena (for example, the study of the distribution of water vapor in the mesosphere - on Cosmos-45, -65, the study of the passage of ultra-long radio waves through the ionosphere - on Cosmos -142", observation of thermal radio emission from the Earth's surface and study of the earth's atmosphere using its own radio and submillimeter radiation - on Kosmos-243, -669; mass spectrometric experiments - on Kosmos-274). On the Cosmos-166, -230 satellites, studies of X-ray radiation from the Sun were carried out, including during solar flares, on Cosmos-215, the scattering of Lyman-alpha radiation in the geocorona was studied (8 small telescopes were installed on the satellite), on "Cosmos-142" carried out a study of the dependence of the intensity of cosmic radio emission on a number of factors. On some Cosmos satellites experiments were carried out to study meteor particles (Cosmos-135 and others). On the Cosmos-140, -656 and other satellites, tests were carried out of a superconducting magnetic system with a field strength of up to 1.6 MA/m, which can be used to analyze charged particles with energies up to several GeV. On the same satellites, studies of liquid helium, which was in a supercritical state, were carried out. The Kosmos-84, -90 satellites had isotope generators as part of their power supply systems. An on-board quantum molecular generator was installed on the Cosmos-97 satellite, experiments with which made it possible to increase the accuracy of the ground-space unified time system, the sensitivity of receiving equipment and the stability of the frequency of radio waves of transmitters by several orders of magnitude.

Medical and biological experiments were carried out on a number of Cosmos satellites, which made it possible to determine the degree of influence of space flight factors on the functional state of biological objects - from unicellular algae, plants and their seeds (Cosmos-92, -44, -109) to dogs and other animals (“Cosmos-110, -782, -936”). Studying the results of these studies in conjunction with data from medical observations of the human body in space helps to develop the most favorable modes of work, rest, and nutrition for astronauts, to create the necessary equipment for the spacecraft, and for the crews of the spacecraft - clothing and food. On Cosmos-690, studies were carried out on the effect of radiation on living organisms, and to simulate powerful solar flares on board the satellite, a radiation source (cesium-137) with an activity of 1.2-1014 dispersion/s was used. A centrifuge with a diameter of 60 cm was installed on the Cosmos-782 satellite, with the help of which the possibility of creating art, gravity and its effect on biological objects were studied. On a number of biological satellites (for example, Kosmos-605, -690 and others)

Some Kosmos satellites have been tested as unmanned spacecraft. During the joint flight of the Kosmos-186 and Kosmos-188 satellites in October 1967, for the first time in the world, automatic rendezvous and docking in orbit were made; After undocking, their autonomous flight continued and the descent vehicles landed on the territory of the USSR. In April 1968, automatic docking in orbit was carried out during the flights of Kosmos-212 and Kosmos-213 - both satellites (descent vehicles) also landed on the territory of the USSR. In June 1981, in order to test the onboard systems of the new spacecraft, the Kosmos-1267 satellite docked with the Salyut-6 orbital station. Until July 29, 1982, the orbital station and the artificial satellite were in a docked state. On the Cosmos series satellites, individual systems were tested and the equipment of many other spacecraft was tested. Thus, on “Cosmos-41” some design elements of the Molniya communication satellites were tested, which, in combination with specially created receiving, transmitting and antenna devices at earth stations, now form a permanent system of long-distance space communications, “Cosmos-1000” performed navigation tasks . Separate components of the lunar rover were tested on the Cosmos satellites.

Practical international cooperation between socialist countries in the study of outer space began with the launches of the artificial Earth satellites “Cosmos”. The main task of the Cosmos-261 satellite, launched in December 1968, was to conduct a complex experiment, including direct measurements on the satellite, in particular, the characteristics of electrons and protons that cause auroras, and variations in the density of the upper atmosphere during these auroras, and ground-based studies of auroras . Scientific institutes and observatories of the People's Republic of Belarus, Hungary, the German Democratic Republic, Poland, the Socialist Republic, the USSR and Czechoslovakia took part in this work. Specialists from France, the USA and other countries also participated in experiments on satellites of this series.

Earth satellites "Cosmos" have been launched since 1962 using launch vehicles "Cosmos", "Soyuz", "Proton" and others, capable of delivering payloads weighing up to several tons into orbit. Until 1964, Kosmos satellites were also launched into orbit by the Vostok launch vehicle. On January 1, 1984, 1521 artificial Earth satellites “Cosmos” were launched.

Volcanic chain (photo from space)

Mount Fuji in Japan (photo from space)

Olympic Village in Vancouver (photo from space)

Typhoon (photo from space)

If you admired the starry sky for a long time, then, of course, you saw a moving bright star. But in fact it was a satellite - a spacecraft that people specially launched into space orbit.

The first artificial Earth satellite was launched by the Soviet Union in 1957. This was a huge event for the whole world, and this day is considered the beginning of the space age of mankind. Currently, about six thousand satellites, all different in weight and shape, revolve around the Earth. In 56 years they have learned a lot.

For example, a communications satellite helps you watch TV shows. How does this happen? A satellite flies over a television station. The transmission begins, and the television station transmits the “picture” to the satellite, and he, as in a relay race, passes it on to another satellite, which is already flying over another place on the globe. The second satellite transmits the image to the third, which returns the “picture” back to Earth, to a television station located thousands of kilometers from the first. Thus, residents of Moscow and Vladivostok can watch TV programs simultaneously. Using the same principle, communication satellites help conduct telephone conversations and connect computers with each other.

Satellites also monitor the weather. Such a satellite flies high, storms, storms, thunderstorms, notices all atmospheric disturbances and transmits them to Earth. But on Earth, weather forecasters process the information and know what weather is expected.

Navigation satellites help ships navigate, because the GPS navigation system helps determine, in any weather,
Where are they located. Using GPS navigators built into mobile phones and car computers, you can determine your location and find the desired houses and streets on the map.

There are also reconnaissance satellites. They photograph the Earth, and geologists use photographs to determine where on our planet there are rich deposits of oil, gas, and other minerals.

Research satellites help in scientific research. Astronomical - explore the planets of the solar system, galaxies and other space objects.

Why don't satellites fall?

If you throw a stone, it will fly, gradually sinking lower and lower until it hits the ground. If you throw a stone harder, it will fall further. As you know, the Earth is round. Is it possible to throw a stone so hard that it circles the Earth? It turns out that it is possible. You just need high speed - almost eight kilometers per second - this is thirty times faster than an airplane. And this must be done outside the atmosphere, otherwise friction with the air will greatly interfere. But if you manage to do this, the stone will fly around the Earth on its own without stopping.

Satellites are launched on rockets that fly upward from the surface of the Earth. Having risen, the rocket turns and begins to accelerate along a side orbit. It is the lateral motion that keeps satellites from falling to Earth. They fly around it, just like our invented stone!