Earth Station. A station located either on the earth's surface or within the major portion of earth's atmosphere and 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 § 2.1
Where a term or definition appears in this part of the Commission's Rules, it shall be the definitive term or definition and shall prevail throughout the Commission's Rules.