Satellite and its types pdf
File Name: satellite and its types .zip
A satellite is basically a self-contained communications system with the ability to receive signals from Earth and to retransmit those signals back with the use of a transponder —an integrated receiver and transmitter of radio signals. A satellite has to withstand the shock of being accelerated during launch up to the orbital velocity of 28, km 17, miles an hour and a hostile space environment where it can be subject to radiation and extreme temperatures for its projected operational life, which can last up to 20 years.
What is a Satellite?
We learned in the previous section that remote sensing instruments can be placed on a variety of platforms to view and image targets. Although ground-based and aircraft platforms may be used, satellites provide a great deal of the remote sensing imagery commonly used today. Satellites have several unique characteristics which make them particularly useful for remote sensing of the Earth's surface. The path followed by a satellite is referred to as its orbit. Satellite orbits are matched to the capability and objective of the sensor s they carry.
Types of orbits
Our understanding of orbits dates back to Johannes Kepler in the 17th century. An orbit is the curved path that an object in space such as a star, planet, moon, asteroid or spacecraft takes around another object due to gravity. Gravity causes objects in space that have mass to be attracted to other nearby objects. If this attraction brings them together with enough momentum, they can sometimes begin to orbit each other. Objects of similar mass orbit each other with neither object at the centre, whilst small objects orbit around larger objects. In our Solar System, the Moon orbits Earth, and Earth orbits the Sun, but that does not mean the larger object remains completely still. Because of gravity, Earth is pulled slightly from its centre by the Moon which is why tides form in our oceans and our Sun is pulled slightly from its centre by Earth and other planets.
In-depth details on the 3, satellites currently orbiting Earth, including their country of origin, purpose, and other operational details. Published Dec 8, Updated Jan 1, Assembled by experts at the Union of Concerned Scientists UCS , the Satellite Database is a listing of the more than 3, operational satellites currently in orbit around Earth. Our intent in producing the database is to create a research tool for specialists and non-specialists alike by collecting open-source information on operational satellites and presenting it in a format that can be easily manipulated for research and analysis. It is available as both a downloadable Excel file and in a tab-delimited text format. A version is also provided in which the "Name" column contains only the official name of the satellite in the case of government and military satellites, and the most commonly used name in the case of commercial and civil satellites.
World Space Week will celebrate the impact of satellites on humanity from Oct. Find out how to celebrate here and check out the history of satellites below! A satellite is an object in space that orbits or circles around a bigger object. There are two kinds of satellites: natural such as the moon orbiting the Earth or artificial such as the International Space Station orbiting the Earth. There are dozens upon dozens of natural satellites in the solar system, with almost every planet having at least one moon. Saturn, for example, has at least 53 natural satellites , and between and , it also had an artificial one — the Cassini spacecraft , which explored the ringed planet and its moons. Artificial satellites, however, did not become a reality until the midth century.
Satellite Characteristics: Orbits and Swaths
The satellite must be designed specifically to fulfill its role. There are nine different types of satellites i. Communications satellites are artificial satellites that relay receive signals from an earth station and then retransmit the signal to other earth stations. They commonly move in a geostationary orbit. A remote Sensing instrument collects information about an object.
One of the most important success factors today is quick and perfect communication. Such a communication is quite easy to ensure, when the communicators are near each other, but the difficulties arise as the distance increase. Already many years ago people used various means of communication between longer distances smoke signals, sounds, different colors flags and etc. The age of wire — based communication began after the A. Bell first time transmitted his voice in
In the context of spaceflight , a satellite is an object that has been intentionally placed into orbit. These objects are called artificial satellites to distinguish them from natural satellites such as Earth's Moon. On 4 October the Soviet Union launched the world's first artificial satellite, Sputnik 1. Since then, about 8, satellites from more than 40 countries have been launched.
Federal agencies have had challenges in acquiring new weather satellites, which could have led to a gap in weather satellite data and affected the accuracy of forecasts and extreme weather warnings. The United States relies on two complementary types of satellite systems for weather observations and forecasts:.