Satellites can be used for communication and are classified by their orbit - low earth orbit (LEO), medium earth orbit (MEO), and geostationary earth orbit (GEO). GEOs orbit at an altitude of about 23,000 miles above the equator and appear stationary, making them well-suited for broadcasting. Early communication satellites experimented with reflecting signals off passive objects while modern satellites are active. Positioning, stability, power supply, and operating in the harsh space environment pose ongoing challenges for satellite design and operation.

1. Satellite communications Introduction