Definition of a Satellite
In aerospace and space exploration a satellite, also known as an artificial satellite, is a manmade object launched into space to orbit the Earth, moon, sun or other celestial body. Although the word satellite is now connected with the world of space exploration, it is actually quite an old word. Its origin can be traced to the Latin word satelles, meaning “one who escorts or follows after an important person.” This is also the original meaning of satellite in English. Because the moon can also be thought of as “escorts” of the planets they orbit, they also became known as satellites. The satellites in the modern day made by humans got their name because they, like the moon, orbit the earth.
The Sputnik 1 was the first artificial satellite was launched into orbit by Soviet Union in 1957. The Sputnik 1 was every simple in design, in comparison to modern day satellites. The Sputnik 1 was a small aluminum ball, about the size of a basketball, with four long antennas only weighed 183 pounds. The Sputnik was primarily designed to broadcast radio wave pulses to see how they react in the atmosphere. Modern satellites of today are much more complicated and are all built using the same basic platform. The main platform, called a bus, contains all the main systems, including the batteries, computers, and thrusters. Attached to the bus are the antennas, solar panels, and instruments like cameras, telescopes and communications equipment.
There are thousands of artificial satellites have been launched into orbit since 1957. These satellites have many different uses. Some satellites take pictures of the planet that help meteorologists predict weather and track hurricanes. Some take pictures of other planets, suns and distant galaxies to help scientists have a better understanding of earth and space. Most of our satellites are used communications, like sending television signals and phone calls across the world. There is also a group of 24...