Satellites have been in existence since the emergence of planetary bodies. Most planets have their satellites, but these are all-natural, created by the cosmic effect of the universe, or God as religious individuals call it. These natural satellites are huge, capable of harbouring entire civilizations and of spherical shape. Thanks to the effect of gravity in space. They rotate around their host planets, through an orbit. Though it would be fascinating to discuss these natural satellites, let’s leave that part to the astronomers. Our major focus would be the artificial satellites, what they are, and their various purposes. So let’s move on.
Let’s start from the most obvious question.
What is the satellite?
A satellite is a spherical heavenly body rotating freely around a bigger body in space, through a fixed part way called an orbit. An example of this is clearly the relationship between the Earth and its singular moon. Satellites could be more than one, it just depends on the planetary body in question. This ferries us to our main event.
What is an artificial satellite?
The first thing one would most likely bear in mind is that these artificial satellites are totally man-made and could be any shape, unlike their spherical natural counterparts. An artificial satellite would be best defined as a man-made object, placed in orbit, rotating around the Earth to fulfil a specific purpose beneficial to man.
Artificial satellites can be placed in orbit according to their functions, and these functions determine the altitudes they achieve in space. Generally, altitudes are grouped in three variations. The LEO (Low Earth Orbit), the Middle Earth Orbit, and GEO (Geostationary Orbit). Artificial satellites vary in sizes. In fact, their designs are based on taxes they were launched to perform. Some satellites are as small as basketball balls, while others could be as large as buildings. Huge satellites are known to reach as much as 7 meters in length with light energy trapping structures extending almost 50 meters. It’s quite huge but like a pin compared to the moon.
These are low altitude satellites that rotate around the earth at a distance of roughly 200-2000 kilometres away from the Earth’s surface. They are known to make a complete orbit in about 90 minutes, the time it takes a football match to be complete. Most satellites within this distance limit need to be closer to Earth for specific reasons.
For instance, satellites that take pictures of the Earth’s surface are designed to maintain this distance in order to get a clear shot. The International Space Station, orbits within this range, as this provides it with an optimum region to perform experiments in space and at the same time, reduce the fuel cost and travel distance required to deliver cargo to the station. Talk of killing two birds with one stone.
The middle Earth orbiters
These satellites are designed to maintain a middle-range altitude about 20,000 kilometres away from the Earth’s surface. These satellites are usually placed in this orbit to maintain a 12 hours rotation around the Earth. They are usually unmanned and relay all information acquired, to the stations on the Earth below. A good example of these would be a GPS satellite.
These satellites are most distant of all. They maintain a distance of roughly 36,000 kilometres
above the Earth’s surface. These artificial satellites were designed to achieve a complete orbital part in 24 hours. A satellite like this was designed to focus on a particular spot or region it was designed to observe.
Parts Of A Satellite
Like every machine put together, whether in space or on Earth, the artificial satellites have various regions which are designed to perform specific duties and help the satellite function properly. We would like to begin from….
As the name suggests, this is the powerhouse of a satellite. Artificial satellites make use of nuclear reactors or light panels as this is highly economical to keep a body functional for such a long time. These power cores provide the energy source required to keep all systems functioning
Is more or less the beacon of communication between the satellites and the base on Earth. All information gathered by artificial satellites, use this medium to engage communication with Earth through various streams of waves.
Altitude control systems
These are systems made up of tiny rockets, particle, and light sensors too, which are useful in re-adjusting the altitude distance of a satellite and determining its direction after it has been placed in orbit. Once placed in orbit, a satellite has no need for rocket propulsion anymore, it rotates freely around the Earth due to gravity. But sometimes the need to adjust orbit occurs, this is where altitude adjustment rockets crawl in.
Thermal control system
Space is a near-vacuum, with nothing to absorb heat from the region around the satellites. Continuous light rays from the sun and heat from system operations, channels enormous heat energy. Therefore, heat monitoring, radiation, and reflective systems are designed in the satellite to help regulate heat and prevent destruction.
Information collecting system
Artificial satellites were mounted for the purpose of space research and studies. To fulfill this aim, it should be fused with structures that make this possible. Long scan and high focus cameras working simultaneously with particle detectors make this a possibility. The information is then stored in a database and relayed back to Earth.
Satellites And Their Functions
Artificial satellites have been really useful in helping us understand space and the world beyond. As of today, thousands of satellites belonging to various countries orbit Earth and play major roles in research and space discoveries. We can’t touch all, but we will list a few.
International space station
This is a space station where countries of the world conduct experiments in space and monitor some astronomical occurrences. It is the biggest satellite in space, as large as a family house
with solar panels roughly the size of a football field.
These are satellites that make a transmission, for television, radios, cellphones, and the internet possible. They are GEO satellites.
Weather satellites measure cloud changes from space and use those details to determine the weather of a geographical region. They of two types. The GEO and LEO weather satellites.
These are GPS satellites, and they are usually made up of a total of 24 satellites. They maintain the middle Earth orbit, at a distance of 20 kilometres from Earth’s surface. The difference in time for signals received by four satellites determines the point of a GPS receiver on Earth.
These are satellites with good telescopic and photographic capabilities. An example of this would be the Hubble space telescope with the ability to take clear photos of distant solar systems and even galaxies. They orbit within the low Earth orbit.