Satellites
Satellites are very important in communication. They are not a new idea, although they look different from the way they were first imagined.
Today’s communications satellites, known as comsats, are equipped to receive signals from Earth. The equipment then, boost them before sending them back to the ground. They must generate their own power and work reliably for many years in the harsh environment of space.
Satellites are carried into orbit by powerful rockets. They orbit Earth several hundreds miles up and travel at enormous speeds. A satellites in space travels so fast. It also has so much energy that it falls around the world without landing.
Satellites have changed the way people communicate because they are used to send phone calls, TV pictures and computer signals across the world. Nowadays, people use satellites to watch each other anywhere in the world. These are called spy satellites. Spy satellites can see objects on the ground which are smaller than a person.
Adopted from : Colin Uttley, Inside a Satellite, Connecticut, Grolier Educational, 2001.
