Abstract: A space-based server network architecture (1) which permits on demand transfer of mission and control data between client satellites (14) in an orbit about earth and an earth station (20, 22, 24, 26) irrespective of the location of the client satellite (14) relative to the earth station (20, 22, 24, 26). The architecture includes a plurality of server satellites (10) located spaced apart in a earth orbit above the orbit of the client satellites (14). The server satellites (10) provide substantially total world-wide communications coverage to and connectivity with designated and authorized earth stations (20, 22, 24, 26) and the plurality of client satellites (14).