In the Age of IT(Information Technology) communication is an easy aspect because of the invention of Television, Telephone, mobile phone, wireless, fax, email, internet.

Satellite tv channels play a good role in conveying news about motherland to people who living in abroad. Satellites take a essential part in communication. A communication satellite is an artificial vehicle. It is erected into orbit around the Earth so as to carry out and pass over communications on the earth.

It has such an electronic system that relay telephone talk, television programme, high speed digital data and fax. It can interlink any number of stations which are within the limit of its antenna beams. Microwaves by which it can be transmitted are a form of electro magnetic radiation of shorter wave length.

Arthur C. Clarke who is the first British Engineer proposed the issue of wireless world about the operation of a satellite system for the purpose of communications. He acts like a bridge between scientific world and entertainment field. He is both scientist and scientific fiction author.

Dr. John. R. Pierce who was an American Engineer, implemented active repeater satellite programme. He took important role in America's ECHO I  Satellite.

SCORE was the first satellite for communications. It was launched on December 18, 1958. The first electronic active repeater satellite was launched on September 4, 1960. Solar Cells were used to operate the first satellite. Solar panels collects energy from sun and that is useful in orbit.

Various types of satellites are there depens on it's usage.

Weather satellites

TIROS, COSMOS and GOES  are the examples of weather satellites. That  generally have some cameras and sent photos about Earth's Weather. That aids to meteorologists for predict weather conditions.

Scientific satellites

Scientific satellites are used for scientific inventions such as finding sun spots, gamma rays. Hubble Space Telescope is the example for scientific satellite.

Navigational satellites

This type of satellites are used for navigation of aero planes and ships. GPS NAVSTAR is the example for Navigational satellites.

Rescue satellites

These are respond to radio distress signals.

Earth observation satellites

That observes the changes of any planet such as temperature, ice-sheet coverage. LANDSAT is the example of this type of satellite.

Military satellites

Encrypted communications, nuclear monitoring, eavesdropping on radio links, radar imaging are works of this type of satellites. Observing enemy movements and warning are the duties of this satellites.

Communications satellites

This satellites contains hundreds or thousands of transponders.  Transponders used for convert one frequency level into another level.

Broadcast satellites

That is used for broadcasting television signals from one point to another point. It is similar to communication satellites.