A spacecraft simulation environment with a complete command chain has been established at the Institute of Space Systems. It consists of an on-board computer development board, a real-time spacecraft simulator, a mission control system and a flight/test-procedure execution engine. Furthermore a 3D visualization facility is included. The small satellite FLP is simulated in this environment, which enables control algorithms and on-board software testing before spacecraft hardware is available. The elements of this command chain are all applied industrial systems,sponsored by several companies. Both students and industry benefit from this cooperation. Students get trained on real industrial tools and the space industry has an improved access to qualified graduates. The illustration outlines the general architecture of such an infrastructure.

The real-time simulator is the heart of this environment and has been sponsored by EADS Astrium. The on-board software is run on an FPGA development board representing the on-board computer. Die Bordrechnersoftware läuft auf einem FPGA Entwicklungsboard, dass den Bordrechner repräsentiert. This board is connected to the real-time simulator. Both the simulator and the on-board software on the development board can be commanded by an ESA mission control system, SCOS-2000. This type of system will later be used in the ground station of the Institute. Spacecraft test and later flight procedures can be edited and automatically executed by means of the procedure execution engine MOIS. This system has been sponsored by Rhea and enables test automation. Finally the spacecraft is visualized as 3D object representing its current simulated flight conditions. The open-source software Celestia is used for this purpose. The complete setup is depicted below.

The developed FLP component models are currently verified by comparing results with specific simulation tools like ESATAN-TMS and Matlab/Simulink. The spacecraft simulation environment turns out to be very precise. One of the next steps is to analyze simulator performance on various real-time linux operation systems and to select one of them. A spacewire interface card will be installed upon this system in order to connect the Flying Laptop on-board computer to the simulation environment at the second half of this year. This configuration is called System Testbed and enables extensive on-board software testing. Thesis topics are available in several fields of activity. Please contact Michael Fritz.