Comparative study of space segments for the provision of future operational data relay satellite services

Data relay satellite (DRS) user requirements are identified in terms of required data rate, mission time, availability, and location of DRS and ground station(s). Time dependent mission scenarios are presented. The payload design is screened against constraints stemming from the user satellites. User availability requirements are translated into reliability requirements for payload and service module. European systems cost effectiveness is assessed, and alternative implementation and replenishment strategies are developed considering dedicated, combined, and functionally shared configurations for three payload categories. The resulting satellite systems are defined and a satellite/launcher matrix given for the space segment implementation alternatives. Planning and cost estimates are provided for comparison with minimum costs resulting for a system consisting of satellites of the TV-SAT/L-SAT class with combined payloads.