The four areas in which space technology finds application are:
1. It is used for making long distance communications.
2. It is used for continuous weather monitoring and weather forecasting on the earth.
3. It is used for collection of information about other planets and outer space.
4. It is also used to study the world resources from outer space.
Working of communication satellite:
A communication satellite is space-craft circling high above the earth. A communication satellite has an amplifier and a transmitter which work with solar energy. A network of transmitting and receiving ground stations is set up throughout the country. The extremely short wavelength T.V. wave, radio waves and radio telephone waves carrying the messages are beamed up to the satellite from one of the ground stations.
The satellite amplifies these electromagnetic communication signals and then transmits the amplified signals to all far flung ground stations. These ground stations have receivers which reconvert the signals obtained from satellites into radio/TV programmes, telephone conversations etc. Thus a communication satellite in the sky acts as a relay station, amplifying and retransmitting radio, T.V. and radio-telephone signals.