In the space business, there is typically a quite long period from the design and development of new technologies to their commercial use. Even comprehensive tests on ground cannot replace long-lasting experiments and tests in space. Such IOV (In Orbit Verification) activities provide the scientific basis for the introduction and application of new technologies and the necessary heritage for commercial satellite programs. The Heinrich-Hertz mission of a geostationary communication satellite with a planned life time of 15 years lead by the German Space Administration (DLR) establishes a valuable basis to verify new technologies scientifically in orbit over a long period of time and to gain heritage regarding their performance in space [1]. In addition, research institutes and the industry are enabled to perform numerous scientific and technological experiments over the full life time of 15 years. With this approach of the mission, the German Space Administration offers to the German satellite industry an outstanding advantage and gain in knowledge for the development of new communication technologies and their applications. The launch of the satellite is envisaged for 2016. The technical feasibility of the overall program was successfully demonstrated within a Phase A study. The major tasks for the payload responsible during Phase A have been: (1) survey and assessment of all proposed IOV-technologies, (2) development of a payload concept for the scientific-technical verification of the IOV-technologies.

The architecture of an experimental payload with on‐board processing capabilities is described. Since the system is proposed as an experimental one it operates with only four beams in the 20/30 GHz frequency band. Special emphasis is put on the design of the switch and its associated control. The switch operates in a synchronous circuit‐switching manner and provides a throughput of 131 Mb/s. To derive the requirements for the on‐board controller, a process model is established. This model shows that an implementation in a finite state machine will not give enough flexibility. Therefore a microprocessor system is proposed for the controller.