A satellite communication system comprising: a plurality of satellite communication ground apparatuses (200a, 200b) to decode data encoded by an error-detecting code received over a downlink channel, and request retransmission on the data in which an error has been detected by the decoding over an uplink channel to a non-geostationary satellite, wherein the satellite communication ground apparatuses (200a, 200b) are interconnected by a terrestrial channel, wherein the satellite communication ground apparatuses (200a, 200b) are configured to transfer decoded data or an error notification from one to another by the terrestrial channel; and the non-geostationary satellite to emit radio waves on the downlink channel to transmit the data encoded by the non-geostationary satellite to the satellite communication ground apparatuses (200a, 200b) by the downlink channel, and retransmit the data that the non-geostationary satellite has been requested to retransmit to the satellite communication ground apparatuses (200a, 200b) or to one of the satellite communication ground apparatuses (200a, 200b), in a time period during which the non-geostationary satellite moves in a predetermined specific location in a satellite orbit, wherein the time period during which the non-geostationary satellite performs retransmission is between a time when one of the satellite communication ground apparatuses that has first entered an irradiation area of radio waves on the downlink channel is outside the irradiation area and a time when all of the plurality of satellite communication ground apparatuses is outside the irradiation area. a plurality of satellite communication ground apparatuses (200a, 200b) to decode data encoded by an error-detecting code received over a downlink channel, and request retransmission on the data in which an error has been detected by the decoding over an uplink channel to a non-geostationary satellite, wherein the satellite communication ground apparatuses (200a, 200b) are interconnected by a terrestrial channel, wherein the satellite communication ground apparatuses (200a, 200b) are configured to transfer decoded data or an error notification from one to another by the terrestrial channel; and the non-geostationary satellite to emit radio waves on the downlink channel to transmit the data encoded by the non-geostationary satellite to the satellite communication ground apparatuses (200a, 200b) by the downlink channel, and retransmit the data that the non-geostationary satellite has been requested to retransmit to the satellite communication ground apparatuses (200a, 200b) or to one of the satellite communication ground apparatuses (200a, 200b), in a time period during which the non-geostationary satellite moves in a predetermined specific location in a satellite orbit, wherein the time period during which the non-geostationary satellite performs retransmission is between a time when one of the satellite communication ground apparatuses that has first entered an irradiation area of radio waves on the downlink channel is outside the irradiation area and a time when all of the plurality of satellite communication ground apparatuses is outside the irradiation area.