The European data relay system: present concept and future evolution

After briefly reviewing the users´ requirements and the results of traffic scenario simulations needed to size the system, the design of the European data relay system (DRS) (ground and space segment) is presented in detail. The interrelationship with the other data relay systems (NASA´s tracking and data relay satellite system (TDRSS) And the Japanese data relay and tracking satellite system (DRTSS)) is discussed together with the current status of systems interoperability. The evolution of DRS into a second generation, foreseen for operation at the beginning of next century, is outlined in terms of user scenario, improved spacecraft and system configurations, and technology developments needed