Provided are a non geostationary satellite orbit (NGSO) communication apparatus that extends an operation time using an ancillary territory component (ATC) and reduces a number of satellites, and an ATC and an operating method thereof. The NGSO communication apparatus extends an operation time using an ATC and reduces a number of satellites from a first ATC that communicates with a mobile earth station (MES), and a second ATC that communicates with the first ATC to relay data between the MES and the satellite when the first ATC is unable to communication with the satellite revolving along an orbit.