Key Points:
<aside> đŸ’¡ A satellite is a manmade object put into orbit around a celestial body for the purpose of transmitting or collecting information
</aside>
<aside> đŸ’¡ Earth-orbiting satellites function as self-contained communications systems and possess the capability to utilize a transponder (an integrated receiver and transmitter of radio signals)
</aside>
By definition, an artificial satellite is a manmade object put into orbit around a celestial body for the purpose of transmitting or collecting information. The satellite technology being analyzed in this research are Earth-orbiting satellites, which function as self-contained communications systems, possessing the capability to utilize a transponder, referring to an integrated receiver and transmitter of radio signals, to receive communication signals from Earth’s surface and subsequently retransmit those signals. Such satellites must be lightweight but durable enough to withstand the rapid acceleration during launch, and operate in a hostile space environment, exposed to radiation and extreme temperatures. The projected operational life for a satellite is around 20 years.
A video on the functions and mechanisms of satellites
A video on the functions and mechanisms of satellites
For satellites to operate, they must orbit either the low Earth orbit (LEO, positioned at an altitude between 160 km and 1,600 km), medium Earth orbit (MEO, 10,000 to 20,000 km), and geostationary or geosynchronous orbit (GEO, 35,786 km). GEO satellites remain in one spot along with the Earth’s rotation and thus, only three GEO satellites are sufficient to provide global coverage, compared to the required 20 or more satellites from LEO and 10 or more from MEO. One drawback of GEO satellites, however, is the delay of approximately 0.22 second for signals to travel between Earth and the satellite, causing problems for telecommunication applications. Hence, GEO satellites are usually used for broadcasting and data applications, whereas most mobile and voice services use LEO or MEO satellites.
Map of different orbits and their corresponding representative satellites
Source:
https://www.britannica.com/technology/satellite-communication/How-satellites-work
https://spaceforscience.wordpress.com/2015/08/20/about-orbits/