On the outside of Sputnik, four whip antennas were transmitting at shortwave frequencies above and below the current standard (27 MHz). Tracking stations on Earth picked up the radio signal and confirmed that the tiny satellite survived the launch and successfully entered a course around our planet. A month later, the Soviet Union launched Sputnik 2 into orbit. Inside the capsule was Laika the dog.
In December 1957, desperate to keep up with their Cold War opponents, American scientists attempted to put a satellite into orbit alongside the planet Vanguard. Unfortunately, the rocket crashed and burned out during the takeoff stage. Shortly thereafter, on January 31, 1958, the United States repeated the success of the USSR by adopting Wernher von Braun's plan to launch the Explorer-1 satellite with the U.S. rocket. Redstone. Explorer-1 carried cosmic ray detection tools and discovered in an experiment by James Van Allen of the University of Iowa that there were far fewer cosmic rays than expected. This led to the discovery of two toroidal zones (ultimately named after Van Allen) filled with charged particles trapped in the Earth's magnetic field.
Encouraged by these successes, several companies began developing and launching satellites in the 1960s. One of them was Hughes Aircraft, along with star engineer Harold Rosen. Rosen led the team that implemented Clark's idea of \u200b\u200ba communications satellite orbiting the Earth in such a way that it could reflect radio waves from one place to another. In 1961, NASA contracted Hughes to build a series of Syncom satellites (synchronous communications). In July 1963, Rosen and his colleagues saw Syncom-2 take off into space and enter a rough geosynchronous orbit. President Kennedy used new systemto speak with the Prime Minister of Nigeria in Africa. Soon, Syncom-3 took off, which could actually broadcast a television signal.
The era of satellites has begun.
What's the difference between satellite and space debris?
Technically, a satellite is any object that orbits a planet or lesser celestial body. Astronomers classify moons as natural satellites, and over the years they have compiled a list of hundreds of such objects orbiting the planets and dwarf planets of our solar system. For example, 67 moons of Jupiter were counted. And still.
Man-made objects such as Sputnik and Explorer can also be classified as satellites because, like moons, they revolve around the planet. Unfortunately, human activity has resulted in a huge amount of debris in Earth's orbit. All of these pieces and debris behave like large rockets - orbiting the planet at high speed in a circular or elliptical path. In the strict interpretation of the definition, each such object can be defined as a satellite. But astronomers, as a rule, consider as satellites those objects that perform useful function... Debris and other debris fall into the orbital debris category.
Orbital debris comes from many sources:
- The rocket explosion that produces the most junk.
- The astronaut relaxed his hand - if the astronaut repairs something in space and loses the wrench, he is lost forever. The key goes into orbit and flies at a speed of about 10 km / s. If it hits a person or a satellite, the results can be disastrous. Large objects like the ISS are a big target for space debris.
- Discarded items. Parts of launch containers, camera lens caps and so on.
NASA has launched a special satellite called LDEF to study the long-term effects of collisions with space debris. Over six years, the satellite's instruments have recorded about 20,000 collisions, some of which were caused by micrometeorites and others by orbital debris. NASA scientists continue to analyze LDEF data. But in Japan there is already a giant net for catching space debris.
What's inside an ordinary satellite?
Satellites come in many shapes and sizes and perform many different functions, but they are all basically the same. They all have a metal or composite frame and body, which English-speaking engineers call a bus, and Russians call a space platform. The space platform puts everything together and provides enough measures for the tools to survive launch.
All satellites have a power source (usually solar panels) and batteries. Arrays of solar cells allow you to charge batteries. Newer satellites include fuel cells. The energy of the satellites is very expensive and extremely limited. Nuclear batteries are commonly used to send space probes to other planets.
All satellites have an on-board computer to control and monitor various systems. They all have a radio and antenna. At a minimum, most satellites have a radio transmitter and a radio receiver, so the ground crew can query and monitor the satellite's status. Many satellites allow a lot of different things, from changing orbits to reprogramming computer system.
As you might expect, putting all these systems together is not an easy task. It takes years. It all starts with defining the purpose of the mission. Defining its parameters allows engineers to assemble the right tools and install them in the correct order. Once the specification is approved (and budget), the satellite assembly begins. It takes place in a clean room, in a sterile environment, which maintains the desired temperature and humidity and protects the satellite during development and assembly.
Artificial satellites are usually custom made. Some companies have developed modular satellites, that is, structures that can be assembled to fit additional elements to specification. For example, Boeing 601 satellites had two base modules - a chassis for transporting the propulsion subsystem, electronics and batteries; and a set of honeycomb shelves for storing equipment. This modularity allows engineers to assemble satellites from a blank, not from scratch.
How are satellites launched into orbit?
Today, all satellites are being launched into orbit on a rocket. Many transport them in the cargo department.
Most satellite launches launch a rocket straight upward, allowing it to travel faster through the thick atmosphere and minimize fuel consumption. After the rocket takes off, the rocket's control mechanism uses an inertial guidance system to calculate the necessary adjustments to the rocket nozzle to achieve the desired tilt.
After the rocket exits into thin air, at an altitude of about 193 kilometers, the navigation system releases small rackets, which is enough to flip the rocket into a horizontal position. A satellite is then released. Small rockets are fired again and provide the difference in distance between the rocket and the satellite.
Orbital speed and altitude
The rocket must pick up a speed of 40 320 kilometers per hour to completely escape from Earth's gravity and fly into space. The space velocity is much higher than the satellite needs in orbit. They do not avoid Earth's gravity, but are in a state of balance. Orbital speed is the speed required to maintain a balance between gravitational attraction and the inertial motion of the satellite. This is approximately 27,359 kilometers per hour at an altitude of 242 kilometers. Without gravity, inertia would carry the satellite into space. Even with gravity, if the satellite moves too fast, it will be blown into space. If the satellite moves too slowly, gravity will pull it back towards Earth.
The orbital speed of a satellite depends on its height above the Earth. The closer to Earth, the faster the speed. At an altitude of 200 kilometers, the orbital speed is 27,400 kilometers per hour. To maintain its orbit at an altitude of 35,786 kilometers, the satellite must rotate at a speed of 11,300 kilometers per hour. This orbital speed allows the satellite to fly once every 24 hours. Since the earth also rotates 24 hours, the satellite at 35,786 kilometers is in a fixed position relative to the earth's surface. This position is called geostationary. Geostationary orbit is ideal for weather and communication satellites.
In general, the higher the orbit, the longer the satellite can stay in it. At low altitude, the satellite is in the earth's atmosphere, which creates drag. At high altitude, there is practically no resistance, and a satellite, like the moon, can be in orbit for centuries.
Types of satellites
On earth, all satellites look similar - shiny boxes or cylinders decorated with wings from solar panels... But in space, these clumsy machines behave very differently depending on flight path, altitude and orientation. As a result, satellites are difficult to classify. One approach is to determine the orbit of the spacecraft relative to the planet (usually the Earth). Recall that there are two main orbits: circular and elliptical. Some satellites start out in an ellipse and then enter a circular orbit. Others follow an elliptical path known as the Lightning orbit. These objects, as a rule, circle from north to south through the poles of the Earth and complete a full circle in 12 hours.
Polar-orbiting satellites also pass through the poles with each revolution, although their orbits are less elliptical. The polar orbits remain fixed in space while the Earth rotates. As a result, most of the Earth passes under a satellite in polar orbit. Because polar orbits provide excellent coverage of the planet, they are used for mapping and photography. Forecasters also rely on global network polar satellites that fly around our balloon in 12 hours.
You can also classify satellites by their height above the earth's surface. Based on this schema, there are three categories:
- Low Earth Orbit (LEO) - LEO satellites cover an area of \u200b\u200bspace from 180 to 2000 kilometers above the Earth. Satellites that move close to the Earth's surface are ideal for observing, military, and weather gathering.
- Medium Earth Orbit (MEO) - These satellites fly from 2,000 to 36,000 km above the Earth. GPS navigation satellites work well at this altitude. The approximate orbital speed is 13,900 km / h.
- Geostationary (geosynchronous) orbit - geostationary satellites move around the Earth at an altitude of more than 36,000 km and at the same rotational speed as the planet. Therefore, satellites in this orbit are always positioned to the same place on Earth. Many geostationary satellites fly around the equator, which has created a lot of "traffic jams" in this region of space. Several hundred television, communications, and weather satellites use geostationary orbit.
Finally, you can think of satellites in the sense where they "search". Most objects sent into space over the past few decades look at the Earth. These satellites have cameras and equipment that can see our world in different wavelengths of light, allowing you to enjoy the spectacular ultraviolet and infrared colors of our planet. Fewer satellites turn their gaze to space, where they observe stars, planets and galaxies, as well as scan objects like asteroids and comets that may collide with Earth.
Notable satellites
Until recently, satellites remained exotic and top-secret devices that were used mainly for military purposes for navigation and espionage. Now they have become an integral part of our daily life. Thanks to them, we find out the weather forecast (although forecasters, oh, how often they are mistaken). We watch TV and work with the Internet also thanks to satellites. The GPS in our cars and smartphones allows you to get to the right place. Is it worth talking about the invaluable contribution of the Hubble telescope and the work of astronauts on the ISS?
However, there are real heroes of the orbit. Let's get to know them.
- Landsat satellites have been photographing the Earth since the early 1970s, and they hold the record for observing the Earth's surface. Landsat-1, known at the time as ERTS (Earth Resources Technology Satellite), was launched on July 23, 1972. It carried two main instruments: a camera and a multispectral scanner built by the Hughes Aircraft Company and capable of recording data in green, red, and two infrared spectra. The satellite made such gorgeous images and was considered so successful that a whole series followed. NASA launched the last Landsat-8 in February 2013. This craft flew two Earth-observing sensors, the Operational Land Imager and the Thermal Infrared Sensor, collecting multispectral images of coastal regions, polar ice, islands and continents.
- Geostationary Operational Environmental Satellites (GOES) orbit the Earth in geostationary orbit, each responsible for a fixed portion of the globe. This allows satellites to closely observe the atmosphere and detect changes in weather conditions that can lead to tornadoes, hurricanes, floods and thunderstorms. Satellites are also used to estimate the amount of precipitation and snow accumulation, measure the extent of snow cover and track the movements of sea and lake ice. Since 1974, 15 GOES satellites have been launched into orbit, but at the same time only two GOES "West" and GOES "East" satellites are observing the weather.
- Jason-1 and Jason-2 have played a key role in the long-term analysis of Earth's oceans. NASA launched Jason-1 in December 2001 to replace the NASA / CNES Topex / Poseidon satellite, which has been operating on Earth since 1992. For nearly thirteen years, Jason-1 has measured sea level, wind speed and wave height in more than 95% of Earth's ice-free oceans. NASA officially retired Jason-1 on July 3, 2013. In 2008, Jason-2 entered orbit. It carried high-precision instruments that made it possible to measure the distance from the satellite to the ocean surface with an accuracy of several centimeters. This data, in addition to being valuable to oceanographers, provides a broad insight into the behavior of global climate patterns.
How much do satellites cost?
After Sputnik and Explorer, satellites have become larger and more complex. Take TerreStar-1, a commercial satellite that was supposed to provide mobile data transmission in North America for smartphones and similar devices. Launched in 2009, the TerreStar-1 weighed 6,910 kilograms. And when fully deployed, it revealed an 18-meter antenna and massive solar panels with a 32-meter wingspan.
Building such a complex machine requires a ton of resources, so historically only government departments and corporations with deep pockets could enter the satellite business. Much of the cost of a satellite lies in hardware - transponders, computers, and cameras. A typical meteorological satellite costs about $ 290 million. The spy satellite will cost $ 100 million more. Add to this the cost of maintaining and repairing satellites. Companies have to pay for satellite bandwidth in the same way that phone owners pay for cellular communication... Sometimes it costs more than $ 1.5 million a year.
Others important factor is the startup cost. Launching a single satellite into space can cost anywhere from $ 10 million to $ 400 million, depending on the vehicle. The Pegasus XL rocket can lift 443 kilograms into low Earth orbit for $ 13.5 million. Launching a heavy satellite will require more lift. The Ariane 5G rocket could launch an 18,000-kilogram satellite into low orbit for $ 165 million.
Despite the costs and risks associated with building, launching and operating satellites, some companies have managed to build an entire business out of it. Take Boeing, for example. In 2012, the company delivered about 10 satellites into space and received orders for more than seven years, generating nearly $ 32 billion in revenue.
The future of satellites
Almost fifty years after the launch of Sputnik, satellites, like budgets, are growing and getting stronger. The United States, for example, has spent nearly $ 200 billion since the beginning of the military satellite program and now, despite all this, has a fleet of aging vehicles awaiting replacement. Many experts fear that the construction and deployment of large satellites simply cannot subsist on taxpayer money. The solution that could turn everything upside down remains private companies like SpaceX, and others that clearly will not suffer bureaucratic stagnation like NASA, NRO and NOAA.
Another solution is to reduce the size and complexity of the satellites. Scientists from Caltech and Stanford University have been working on a new type of satellite, CubeSat, since 1999, based on building blocks with a face of 10 centimeters. Each cube contains ready-made components and can be combined with other cubes to increase efficiency and reduce load. By standardizing design and reducing the cost of building each satellite from scratch, a single CubeSat can cost as little as $ 100,000.
In April 2013 NASA decided to test this simple principle and three CubeSats powered by commercial smartphones. The goal was to put the microsatellites into orbit for a short time and take some pictures with phones. The agency is now planning to deploy an extensive network of such satellites.
Whether large or small, satellites of the future must be able to communicate efficiently with ground stations. Historically, NASA has relied on radio frequency communications, but RF has reached its limit as the demand for more power has arisen. To overcome this obstacle, NASA scientists are developing a two-way communication system based on lasers instead of radio waves. On October 18, 2013, scientists first launched a laser beam to transmit data from the Moon to Earth (at a distance of 384,633 kilometers) and achieved a record transfer rate of 622 megabits per second.
Modern human life is already unthinkable without artificial earth satellites, because with their help we monitor the weather and make its forecast, satellites provide a person with long-distance communication, with the help of satellites, a person conducts unique various studies in space, which is basically impossible on Earth. ... But the history of the life of the companion is not yet 60 years old. The first artificial Earth satellite was launched in the USSR on October 4, 1957, exactly 56 years ago. At the moment, a huge number of different satellites fly around our planet in different orbits, doing different work. So which satellites serve a person?
Satellites that provide communication are probably the most popular type of satellite operation and, so to speak, the most obvious, because at high altitudes the signals received and emitted by the satellite can be received at points on the Earth that are at a considerable distance from each other. With the help of communication satellites, we watch TV programs, talk on the phone, go to the Internet.
Satellites providing navigation on the ground. Surely, many have heard of GPS navigation with which a person can determine the location of certain objects with great accuracy. This is the job that navigator satellites do. With the help of GPS-navigators built into mobile phones, PDAs and car computers, anyone can determine their location and plan routes taking into account road signs, search for houses and streets they need on the map, etc.
The next most popular satellite is the meteorological satellite, which monitors changes in the earth's weather and studies the climate of our planet. It is thanks to meteorological satellites that forecasters make up their own weather forecasts.
Of course, the military could not miss such a gorgeous opportunity to spy on each other from space. As they say, I sit high, I look far away. Spy satellites are able to take high-definition photographs of objects on Earth, listen to communications systems, carry out surveillance, and so on.
The satellites are also irreplaceable helpers for scientists in their scientific research. Research satellites study the Earth's magnetic field, radiation conditions, they are used by geodesists, cartographers and other specialists. A special type of research satellites are biosatellites, on which scientists conduct their experiments, solve various technical problems astronautics, etc.
And, of course, in their research, satellites are used by astronomers who can observe distant galaxies and other space objects from space, while the earth's atmosphere does not distort signals received from space. One of the most famous astronomical satellites is the famous Hubble Telescope.
Telecommunication satellites are usually placed in geostationary orbit (GEO). which is a circular orbit with an altitude of 35,786 kilometers above the Earth's equator and follows the direction of the Earth's rotation. The object in GEO has an orbital period equal to the period of rotation, therefore, to ground observers, it appears stationary and occupies a fixed position in the sky.
Satellites in GEO allow continuous communicationby transmitting radio frequency signals from fixed antennas. These signals are not very different from those used in broadcast terrestrial television transmissions and are usually 3-50 times higher in frequency. The signal received by the satellite is amplified and transmitted back to Earth, making it possible to establish communication between points located thousands of kilometers apart.
A special feature that makes geostationary satellites extremely attractive is their ability to transmit information... The relayed signal can be received by antennas anywhere in a satellite's coverage area, comparable to the size of a country, region, continent, or even the entire hemisphere. Anyone who has a small antenna 40-50 cm in diameter can become a direct satellite user.
A satellite operating in a geostationary orbit does not need any engine and its stay in Earth's orbit can last for many years. Friction from the thin upper atmosphere will eventually slow it down and cause it to sink lower and lower, and eventually burn up in the lower atmosphere.
If a satellite is launched with more fuel, it travels faster and has a larger orbital radius. A large orbit means that the satellite's angular motion around the Earth is slower. As an example, the Moon, located 380,000 km from Earth, has an orbital period of 28 days.
Low Earth Orbit (LEO) satellites, such as many scientific and observing satellites, operate at much lower altitudes: they make a complete circle around the Earth in about 90 minutes at altitudes of several hundred kilometers.
Telecommunication satellites can also be on LEO, being visible from anywhere for 10-20 minutes. To guarantee the continuity of information transmission, in this case, it will be necessary to deploy dozens of satellites.
Telecommunications systems on LEO may require 48, 66, 77, 80 or even 288 satellites to provide the required services. Several of these systems have been deployed to provide connectivity for mobile terminals. They use relatively low frequencies (1.5-2.5 GHz), which are in the same range as the frequencies used in mobile networks with GSM. The fact that for of this type satellites do not require any expensive transmitting and receiving devices - plus for them: no careful tracking of the satellite is needed in this case. In addition, the low altitude minimizes signal transit time delay and requires less transmitter power to establish communications.
A satellite of the Earth is any object that moves in a curved path around a planet. The moon is original natural satellite Earth, and there are many artificial satellites, usually in close orbit to Earth. The satellite's path is an orbit, which sometimes takes the form of a circle.
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To understand why the satellites move in this way, we must return to our friend Newton. exists between any two objects in the universe. If it were 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 the 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 focus. 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 is closest to Earth - a point known as perigee - and slowest when it is farthest from Earth - a point known as apogee.
There are many different satellite orbits for the Earth. The ones that receive the most attention are geostationary orbits, as they are stationary over a specific point on the Earth.
The orbit chosen for the artificial satellite depends on its application. For example, a geostationary orbit is used for live broadcast television. Many communications satellites also use geostationary orbit. Other satellite systems, such as satellite phones, can 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 their own own type orbits 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, the Earth satellite's orbit can reach 100 miles (160 km) for LEO, while others can reach over 22,000 miles (36,000 km), as in the case of the GEO-orbiting GEO orbit.
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. Satellite 2 followed a second satellite in orbit and also 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. Analysis of radio signals was used to obtain information on the concentration of electrons in the ionosphere. Temperature and pressure were encoded 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 whiskers. The spacecraft received information about the density of the upper atmosphere and the propagation of radio waves in the ionosphere. The devices and sources of electrical energy were placed in the capsule, which also included radio transmitters operating at 20.007 and 40.002 MHz (about 15 and 7.5 m at a wavelength), emissions were made in alternative groups of 0.3 s duration. Telemetry grounding included temperature data inside and on the surface of the sphere.
Since the sphere was filled with nitrogen under pressure, Sputnik 1 had its first opportunity to detect meteorites, although it did not. The loss of pressure inside, due to penetration on the outside surface, was reflected in the temperature data.
Types of artificial satellites
Artificial satellites are different types, shapes, sizes and play different roles.
- Weather satellites help meteorologists predict the weather or see what is happening at the moment. A good example is a geostationary operational environmental satellite (GOES). These earth satellites usually contain cameras that can return photographs of the earth's weather, either from fixed geostationary positions or from polar orbits.
- Communication satellites allow the transmission of telephone and informational conversations via satellite. Typical communications satellites include Telstar and Intelsat. The most important feature of a communications satellite is a transponder - a radio receiver that picks up a conversation on one frequency, then amplifies it and re-transmits 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 satellitessuch as the Hubble Space Telescope carry out all kinds of scientific missions. They look at everything from sunspots to gamma rays.
- Navigation satellites help ships and planes navigate. The most famous satellites are GPS NAVSTAR.
- Rescue satellites react to radio interference signals.
- Earth observation satellites they check the planet for changes in everything: from temperature, afforestation, to ice cover. The most famous are the Landsat series.
- Military satellites The earths are in orbit, but most of the actual position information remains classified. Satellites can include encrypted communication relaying, nuclear monitoring, surveillance of enemy movements, early warning of missile launches, eavesdropping of ground radio links, radar imaging, and photography (using essentially large telescopes that photograph militarily interesting areas).
Earth from artificial satellite in real time
Satellite imagery of the earth, broadcast in real time by NASA from the International Space Station. Images are captured by four cameras high resolutionisolated from cold temperatures, allowing us to feel closer to space than ever before.
Experiment (HDEV) aboard the ISS was activated on April 30, 2014. It is mounted on the external cargo vehicle of the European Space Agency's Columbus module. This experiment involves several high definition video cameras that are enclosed in a housing.
Council; place the player in HD and full screen. There are times when the screen will be black, this may 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 gets dark when the cameras are changed.
How many satellites are in Earth's 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 orbiting the Earth, up 4.39% from last year.
221 satellites were launched in 2015, the second largest in one year, though below the record 240 launched in 2014. The increase in the number of satellites orbiting the Earth is less than the number launched last year, as satellites have a limited lifespan. Large communication satellites are 15 or more years old, while small satellites such as CubeSat can only count on a service life of 3-6 months.
How many of these Earth orbiting satellites are in operation?
The Union of Scientists (UCS) is clarifying which of these orbiting satellites are working, and that's not as much as you might think! Currently, there are only 1,419 operational Earth satellites - only about one third of the total in orbit. This means there is a lot of useless metal around the planet! This is why there is a lot of interest from companies watching them capture and recover space debris using techniques such as space nets, slingshots or solar sails.
What are all these satellites doing?
According to UCS data, the main targets of operational satellites are:
- Communication - 713 satellites
- Earth observation / science - 374 satellites
- Technological 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 satellites of the Earth?
It is interesting to note that there are four main types of users in the UCS database, although 17% of satellites are owned by multiple users.
- 94 satellites registered by civilians: these are usually educational institutions, although there are other national organizations. 46% of these satellites have the goal of developing technologies such as earth and space science. Observation is 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% are 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 satellites serving one of these three targets.
How many satellites countries have
According to UNOOSA, about 65 countries have launched satellites, although there are only 57 countries registered using satellites in the UCS database and some satellites are listed with co-operative / 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!
In our VK group (vk.com/posterspbru), one of the users left such a playfully sarcastic comment:
- Monya, where are you looking?
- To the stars. Believe it or not, there are 8000 satellites!
- And sho, it became easier to breathe?
He gave us the idea of \u200b\u200bthis article.
Perhaps Moni's friend is right - in the literal sense of the word, satellites do not help people breathe. Although this is a controversial issue, because satellites are able to save from situations in which people can suffocate. Probably, many of us rarely think about how much satellites affect our lives.
Here are some of the applications that satellites provide us with.
1. Satellites send television signals to homes, but they are also the basis for cable and network TV. In other words, no satellites - no news, no broadcasts of sports matches, no Olympics in live etc. Satellites transmit signals from a central station, which generates programs for smaller stations, which transmit signals to local level... All direct connections are possible thanks to satellites.
2. Satellites provide telephone communications on airplanes and are often the only channel telephone connection for many rural areas and areas where telephone lines damaged by natural disasters. Satellites also provide the primary timing source for cell phones and pagers. In 1998, a satellite failure demonstrated this addiction - 80% of pagers in the United States temporarily fell silent, public national radio was unable to distribute its broadcasts to affiliates and only broadcast via a website, and a video picture was frozen on the CBS evening news and only broadcast audio.
3. Satellite navigation systems allow any user to navigate the terrain. GPS navigators are part modern world, whether they are used in private vehicles or for commercial or military purposes for navigation on land, at sea or in the air. And by the way, GPS navigation plays a decisive role in many situations, for example when a ship is heading for harbor in bad weather.
4. Satellites connect companies to suppliers, are the backbone for international video conferencing, provide instant credit card authorization and banking. Without a satellite in orbit, you will not be able to pay for goods in the hypermarket with your bank card.
5. Satellites provide meteorologists with weather data, with the help of which they monitor not only whether it will be cloudy or sunny today, but also for volcanic eruptions, hurricanes, gas leaks, and the like. Returning to the question of Mona and his friend, in some cases, satellites will help a person breathe, simply because they will warn him that a cloud of toxic gases is moving to the place where he is. Or a satellite can rescue him at sea or on land by transmitting a beacon signal to rescue services.
Sputniks are one of the main sources of data for climate change research. Satellites monitor ocean temperatures and currents. They can point out air pollution, help organize rescue operations in disaster regions, help locate people in remote areas, send distress signals, and more.
6. The satellite can detect groundwater and mineral springs, monitor the transfer of nutrients and pollutants from the earth to water sources, measure the temperature of the land and water, measure the growth of algae in the seas and erosion of the topsoil on land. They can effectively monitor large-scale infrastructures such as fuel pipelines that need to be checked for leaks using satellites rather than manual labor (which will take many hours). Satellite imagery is helping a variety of industries, and even you can take advantage of Google Earth thanks to satellites.
Satellites are of great importance to developing countries, as they provide their populations in remote regions with access to data, educational information, medical information, and the like. A person can get the right treatment only because their doctor consults with a more experienced companion colleague.
7. Space exploration is impossible without satellites. Telescopic satellites play a critical role in understanding many space phenomena.
Anthropogenic satellites orbiting the Earth greatly affect our modern lifealthough many do not realize it. To some extent, satellites help us breathe freely, providing us with data, timely assistance, and opportunities. Satellites make life safer, provide a host of modern amenities, and help broadcast entertainment and explore Earth and space.
