A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals.
In the aerospace context, relay refers to a device or system that receives a signal or message from one source and then retransmits it to another destination. This allows for the transmission of signals or messages over long distances, or through areas where direct communication is not possible.
One example of relay in the aerospace context is the use of communication satellites that act as relays to transmit signals between ground stations or other satellites. These satellites receive a signal from a ground station or other satellite, amplify the signal, and then retransmit it to another destination.
Another example is the use of relay aircraft, which are aircraft that are equipped with communication equipment and are used to relay signals between ground stations or other aircraft. These aircraft act as a link between two or more ground stations or aircraft that are out of direct communication range.
Additionally, relays are also used in the aerospace industry to extend the range of ground-based sensors, cameras and other systems, allowing them to cover larger areas and increase the amount of data gathered. They are also used to extend the coverage of communication networks for aircraft, drones, and other vehicles, allowing them to operate in remote or hard-to-reach areas.