Artificial Satellites – Concept, use, types and operation

We explain what artificial satellites are, what they are for, how they work and what types exist. Also, natural satellites.

artificial satellite
Artificial satellites are machines that orbit the planet.

What is an artificial satellite?

In astronomy, satellites are the objects that orbit the planets. These can be natural satellites, composed of rocks, minerals and other elements, like our Moon; or they can be artificial satellites, that is, man-made machines orbiting planet Earth.

Artificial satellites are an important part of our lives, allowing us various daily and scientific tasks. For example, they fulfill various telecommunications functions. On the other hand, fragments of them that constitute the so-called “space junk”.

The first to be put into orbit was Sputnik 1, thrown into the atmosphere by the former Soviet Union in 1957. Thus was formally inaugurated the so-called “Space Race”, an extension of the Cold War (1947-1991) between the United States and the USSR in the astronomical scientific field.

The first satellite was followed by Sputnik 2 and 3. In the second, the first living being to orbit the planet was boarded (and to die in orbit, since no plans were made for its return): a Russian stray dog ​​named Laika. Since then, many countries have put hundreds of artificial satellites into orbit.

Artificial satellites have a useful life, after which they cease to function. In some cases they remain in orbit, gradually deteriorating until they become space junk, part of the metallic fragments that surround our planet. In other cases, they succumb to gravity and disintegrate when rubbing against the atmosphere.

Types of artificial satellites

artificial satellite guys military spy
Reconnaissance satellites are used for military and security purposes.

Broadly speaking, artificial satellites are classified into two:

  • Observation satellites. For astronomical or geolocation tasks,
  • Telecommunications satellites.

However, according to its specific function, several subtypes can be distinguished:

  • Communications satellites. Employees in telephony, radio, television, etc.
  • Meteorological satellites. In constant observation of the climate, atmospheric conditions and other important details of cartography without military purposes.
  • Navigation satellites. Necessary for geolocation and GPS.
  • Reconnaissance satellites. Also called spy satellites, they are used for military or intelligence purposes.
  • Astronomical satellites. They serve as orbiting telescopes to observe regions of outer space without intrusion from the atmosphere.
  • Space stations. Structures of greater size and complexity than simple satellites, which allow human beings to live in space and conduct scientific experiments there.

What are artificial satellites for?

artificial satellite what is meteorology for
Satellites allow us to observe phenomena such as hurricanes in a more global way.

Earlier we talked about the specific functions of satellites, that is, the tasks to which they can dedicate their resources. However, the essential function of satellites can be explained by the interest of human beings to have a better view of our planet and outer space, than from the ground.

This allows not only a more global perspective of the planet, which is key in a world of globalized economy and interests, but also to be able to overcome the distortions of the earth’s atmosphere and keep an eye out.

On the other hand, satellites have been thought of as artifacts of war since its inception, since they could be equipped with extra-atmospheric weapons that allow them to attack rivals from unattainable positions on the border with space.

Likewise, thinking of less destructive purposes, the design and construction of solar energy capturing satellites have been proposed, which could serve as gigantic solar panels in space and supply constant and almost free energy to the Earth.

How do artificial satellites work?

Artificial satellites must be put into orbit by some kind of space launch, which once the region of the desired atmosphere is reached, abandons the artifact forever. Although there are hundreds of possible orbits, generally the satellites are located in three types of trajectories:

  • Low Earth Orbit (Low Earth Orbit). Between 700 and 1400 km high, with an orbital period of 80 to 150 minutes.
  • Mean Earth orbit (Medium Earth Orbit). Between 9000 and 20,000 km of altitude, with an orbital period of 10 to 14 hours.
  • Earth’s high orbit (High Earth Orbit). At a height of 37,786 km above the Earth’s equator, with a 24-hour orbital period over the same place on the planet.

Once in orbit, the satellites deploy their solar panels, which allow them to capture energy from the Sun to send and receive information and instructions from Earth, using microwave antennas for the latter.

Earth’s artificial satellites

Currently, our planet is being orbited by more than 5,600 artificial satellites of a different nature, as well as by 21,000 satellite fragments of more than 10 centimeters, some 500,000 of around one centimeter and more than one billion particles in size to one centimeter.

All of the latter make up the so-called “space junk” and represent a real danger for future space missions and future satellites. This space junk ranges from astronaut gloves to broken telescopes and disused ship fragments, nuts, bolts, fragments of matter, etc.

Through the website all satellites and space debris on the planet can be observed in real time.

Natural satellites

natural artificial satellite saturn rings
Saturn’s rings are made up of numerous natural satellites.

Unlike the artificial satellites, the natural ones were born together with the astronomical body that they orbit (generally planets) or got caught in their orbit as a consequence of some kind of cosmic or astronomical phenomenon.

The most obvious case of natural satellites is our Moon, but there are many more on other planets in the Solar System. Some are similar in size and shape to ours, and others consist of rocks of various shapes or groups of asteroids that form “rings” around the planet, as happens with Saturn.

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