Earth station. A station located either on the Earth's surface or within the major portion of the Earth's atmosphere intended for communication:
(1) With one or more space stations; or
(2) With one or more stations of the same kind by means of one or more reflecting satellites or other objects in space. (RR)
47 CFR § 25.103
Terms with definitions including the (RR) designation are defined in the same way in 2.1 of this chapter and in the Radio Regulations of the International Telecommunication Union.