We explain what artificial satellites are and the types of satellites that exist. In addition, we explain what their general characteristics and functions are.
Artificial satellites are ships sent into space to obtain information.
What are artificial satellites?
Artificial satellites are objects that humans manufacture and launch into outer space with the aim of orbiting a celestial body (a planet) or a natural satellite (for example, the moon). They differ from natural satellites, which are celestial bodies that orbit a planet.
The purpose of these satellites is to obtain certain useful information about the celestial body or natural satellite they observe. Satellites orbiting the planet Earth are used to improve telecommunications.as they emit signals and enable the operation of telephones, the Internet and digital television. They are also used to generate weather reports and obtain information about the Earth’s surface.
Satellites are launched into space and They must pass through the Earth’s atmosphere and orbit a celestial body., which is usually Earth. Once there, they must follow a specific route depending on their objective. The satellites have an energy recharge that allows them to extend their useful life. However, after power depletion, the satellite is discarded in outer space as space debris.
See also: Asteroid belt
The first artificial satellite and the space race
The first satellite was manufactured by the Soviet Union.
The first space satellite It was sent in October 1957 by the Soviet Union and was called Sputnik I. Its objective was to collect information about the highest layers of the atmosphere.
This occurred within the framework of The space race that began in the mid-1950s, between the United States and the Soviet Union, which aimed at space exploration with the development of satellites and sending humans into space. The United States managed to send its first artificial satellite, called Explorer Iin 1958 and had as one of its greatest successes the discovery of the Van Allen belts.
Later other countries managed to place artificial satellites in Earth’s orbit. It is believed that there are currently almost 5,000 satellites orbiting the Earth. and more than half are already inactive and constitute so-called space junk.
Due to scientific development and the necessary financial support, few countries in the world sent satellites into space. Those leading the list of shipments are: Russia, the United States, France, Japan and China.
Characteristics of artificial satellites
Satellites do not have flashing lights or make noise.
The main characteristics of artificial satellites are:
- They are created by humans.. Satellites are launched for a specific purpose that varies depending on each case.
- They usually orbit planet Earth. Most of the satellites that are built are used to obtain information about planet Earth or fulfill certain purposes that contribute to human and social development.
- They can be spherical, cylindrical or conical.. Inside they have highly delicate and sensitive materials.
- They can be observed from EarthThe most suitable times are two hours before sunrise and two hours after sunset.
- They can be scientific or applied.Scientific satellites are used to study space, radiation or planets, while applied satellites have a specific function on Earth, such as meteorological observation, military espionage or telecommunications.
- They are made up of certain fundamental parts. Satellites are made up of: solar panels, which absorb solar energy and convert it into electrical energy (in some cases they can be made up of batteries); antennas, which are responsible for transmitting and receiving information; a control center, which processes the stored information, and a camera or mechanism that collects information.
- They must have a route or path to followWhen a satellite follows a path around a planet, it is called an orbit. If this orbit is elliptical, it will have a furthest point, which is called the “apogee,” and a closest point, which is called the “perigee.”
- They can be active or inactive. Satellites have a certain useful life, so after a while, or due to certain factors, they become obsolete. In some cases they remain in Earth’s orbit as space debris, but in others they can re-enter the atmosphere, where they disintegrate and return to Earth.
- They are launched in a rocket. In order to place a satellite that orbits the Earth, a powerful driving mechanism is required, since the satellite must reach a speed of 8 km per second. For this, it is necessary to build a rocket that has the satellite inside, which will be dropped once the desired location is reached.
Types of satellites
Solar power satellites redirect their energy toward homes.
Satellites can be classified according to two main criteria:
According to its purpose:
- Communication satellites. They are satellites that help transmit the signals necessary for telecommunications. They usually transmit television and radio signals from one point to another. The first satellite of this type was the Telstar 1.
- Weather satellites. They are satellites used to assess, measure and predict Earth’s weather conditions. The first satellite of this type was the Shots-1released in 1960.
- Navigation satellites. These are satellites that are used to know the precise and exact position of something or someone on Earth. They are, for example, those used by the GPS, Galileo and GLONASS systems.
- Reconnaissance satellitesThey are better known as spy satellites and are used in the military or intelligence services.
- Astronomical satellites. They are satellites that are manufactured to observe galaxies, planets, asteroids or other astronomical objects.
- Solar power satellitesThey are satellites that serve as a power source. They receive energy from the sun and redirect it to antennas in homes on Earth.
According to the type of orbit:
- Low Earth OrbitThey are satellites located at a short distance from the Earth’s surface, between 700 and 1400 km, and their orbital period is between 80 and 150 minutes.
- Medium Earth orbit or intermediate circular orbitThey are satellites located between 9,000 and 20,000 km and their orbital period can be between 10 and 14 hours.
- Geostationary orbit. They are satellites that are 35,786 km away above the equator. These satellites always remain over the same place on Earth, that is, they do not rotate.
space junk
A satellite can disintegrate and enter the atmosphere.
After its useful life or the collection of necessary data, an artificial satellite can remain orbiting a celestial body without any use. Therefore, it is said to become space junk.
Space debris is often a risk for spacecraft that are launched from Earth into space, because these loose satellite remains can damage or destroy them.
If the satellite is at a low altitude, it can disintegrate and enter the Earth’s atmosphere in portions.
Importance of artificial satellites
Artificial satellites that manage to position themselves in Earth’s orbit are fundamental for the development of the human species and life in society. They are used both in the field of scientific research and development, as well as in telecommunications and meteorology.
On the one hand, satellites are used for scientific research since many of them are sent into space with the aim of explore other planets or bodies and detect meteoritesThey also allow us to observe life on Earth and study phenomena such as deforestation, different types of relief, sea levels, pollution, and explore inhospitable regions or those that are difficult for humans to access.
Satellites are essential for obtaining useful information, such as climate data at a specific point on the planet or information needed to create maps. They are also responsible for development of GPS type technology which allows us to know the almost exact position of any object on the Earth’s surface.
Artificial satellites are of great importance in the field of telecommunications because transmit messages and information from one point on the planet to anotherCommunication satellites send and receive signals that enable the development of technologies and media such as television, radio, cell phones and the Internet.
natural satellites
Unlike artificial satellites, which are created by humans, natural satellites are those that They exist naturally in space.
Natural satellites are celestial bodies (objects located in space) that orbit a planet (although bodies that orbit other celestial bodies are also often called satellites). The most recognized case of a natural satellite is the Moon, which is the only natural satellite that orbits planet Earth. In many cases the term moon is often used as a synonym for a natural satellite.
Other natural satellites are: the four main satellites of Jupiter: Io, Europa, Ganymede and Callisto; the largest satellite of Saturn: Titan; the two satellites of Mars: Deimos and Phobos; and the main satellites of Uranus: Titania, Miranda, Ariel, Umbriel and Oberon.
Follow with:
References:
- “Components of a satellite” at Space Foundation.
- “What is a satellite?” at NASA.
- “How satellites work” in Britannica.
- “Sputnik, the first satellite that launched the space race between the USSR and the United States 60 years ago” on BBC.