Telecommunication components for a space shuttle are chosen in response to the requirements of the mission it will perform. Anticipated distances, planned frequency bands, data rates and available on-board transmitter power are all taken into account.
High-gain antenna: A dish-shaped antenna used for high rate communication with Earth. This type of antenna is highly directionally and must be pointed to within a fraction of a degree of Earth. It may be either steerable or fixed to the shuttle. High-gain antennas are typically used on interplanetary missions.
Low-gain antenna: An omni directional spacecraft antenna that provides relatively low data rates at close range, for example several astronomical units. Many spacecraft include both a low-gain antenna and a high-gain antenna.
Receiver: An electronic device that receives incoming radio signals, called uplink, and converts them to perceptible forms.
Frequently, transmitters and receivers are combined into one electronic device, which is called a transponder.