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Introduction
A satellite is an object that orbits the sun, the earth, or any other massive body. When it comes to satellites, there are two basic categories of classification: natural and man-made.
Planets, moons, and comets are examples of natural satellites. There are 67 natural satellites orbiting Jupiter. The moon, the earth’s only permanent natural satellite, is responsible for the sea’s tides. Other objects (such as asteroids) can occasionally reach the earth’s orbit and serve as natural satellites for a period of time.
Aside from these, the planet has a slew of man-made satellites in orbit that are utilised for a variety of communications and data gathering purposes. An artificial satellite, as the name implies, is one that is sent into space by humans and follows the orbit of natural satellites.
They can collect data faster than sensors that can be utilised at ground level since they have such a vast view field. Apart from that, clouds, dust, and other obscurities do not hinder their view into space beyond Earth, allowing satellites to view space much more efficiently than telescopes on Earth.
Currently, the earth is orbited by about 2,500 man-made satellites. The majority of these are Russian in origin. Given their size, you might wonder why none of these satellites collide with one another. It’s entirely possible that this will happen. Although great care is taken to launch satellites in precise orbits to avoid collisions, these orbits can change. Many international organisations have been established to avert such catastrophes. A handful of Russian and American spacecraft did, however, collide for the first time in 2009!
The satellites are launched with a specific goal in mind for a variety of applications, including communications, scientific research, weather forecasting, and intelligence. Once in orbit, all types of satellites obey the same physics principles and are guided by the same mathematical formulae.
Different Types of Satellite
Artificial satellites are classified into two types based on their intended use. Geostationary satellites and polar satellites are the two types. Satellites come in a variety of shapes and sizes.
- Geostationary Satellite: These satellites are launched into orbit around 35,800 kilometres above the earth’s surface. They revolve in the same direction as the earth, and one revolution of one of these satellites corresponds to one day on the planet (roughly 24 hours). As seen from Earth, this means that these satellites will appear to be in the same place at all times. As a result, satellites are referred to as “geostationary.” These satellites are utilised for weather-related applications as well as communication satellites.
- Polar satellites orbit the planet in a north-south direction, as opposed to east-west like geostationary satellites do. They’re particularly handy in situations where a single day’s field vision of the entire globe is required. This is simple to do because the entire earth shifts beneath them. They’re employed in weather applications when it’s possible to predict weather and climate-related disasters in a short amount of time. They serve as relay stations as well.
Satellite of the Polar Regions
In 1998, the International Space Station (ISS) was launched into space. It is a livable artificial satellite that can occasionally be observed on clear nights. It serves as a laboratory, observatory, and landing base for any future missions.
Geostationary Orbit
An object in such an orbit has an orbital period equal to Earth’s rotational period, one sidereal day, it appears immobile and fixed in the sky to ground observers. In the 1940s, science fiction writer Arthur C. Clarke popularised the concept of a geostationary orbit as a way to revolutionise telecommunications, and the first satellite to be placed in this orbit was launched in 1963.
Geostationary orbits are used by communications satellites so that Earth-based satellite antennas (located on Earth) do not have to spin to follow them and may be directed continually at the position in the sky where they are located. Weather satellites and navigation satellites are also put in this orbit for real-time monitoring and data collection, as well as a known calibration point to improve GPS accuracy.
Geostationary satellites are launched into a slot above a certain point on the Earth’s surface through a transient orbit. To avoid collisions, modern defunct satellites are placed in a higher graveyard orbit, which requires considerable stationkeeping to maintain its position.
Conclusion
Geostationary satellite communications are advantageous because they can be seen from a wide portion of the earth’s surface, stretching 81 degrees in both latitude and longitude. They look to be stationary in the sky, thus ground stations don’t need to have mobile antennas.
