The Benefits of Spaceflight and Space Exploration

The Benefits of Spaceflight and Space Exploration — page 7
as space debris More than five hundred of the operational satellites were launched by the United States Most satellites orbit Earth in low Earth orbit LEO between one hun dred and one thousand miles 160 km and 1,600 km above Earth or geostationary orbit GEO 22,236 miles 35,786 km above Earth PHONING HOME AND TUNING IN The major application of artificial satellites in the modern world is to provide long-distance communication links In addition to launching the space age Sputnik 1 ushered in a new era in communications technology For its first twenty-two days in orbit before its battery ran down the satellite transmitted signals back to Earth In 1962 the United States launched Telstar 1 the first satellite capable of two-way communication It transmitted live television images between the United States and Europe as well as the first phone call transmitted by satellite A satellite consists of three main components The communications system receives a signal from Earth ampli fies the signal and retransmits it back to Earth where it can be received over a wide geographic area The propulsion system includes the rockets that propel the satellite and is capable of adjusting the satellite’s position in space Finally solar panels provide power to the satellite A communica tions satellite can function for up to twenty years Many communications satellites operate in GEO meaning that they are fixed over one specific location 8 the BenefIts of spaCeflIght and spaCe exploratIon