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Each set of hardware equipment of the INTELSAT V Attitude Determination and Control Subsystem (ADCS) is subjected to closed loop Dynamic Bench Tests (DBT). The test set-up comprises a three-axes dynamic motion simulator carrying sensor optical heads and associated signal processing electronics, earth and sun simulators for sensor stimulation, control electronics, TM/ТС simulator and a hybrid computer for the simulation of spacecraft dynamics, disturbance torque profiles and digital test data recording. The discussions to follow cover closed loop hardware test philosophy as compared to other test concepts, test procedure, dynamic bench test equipment and specifications, simulation software, test data recording and evaluation and examples of test results as obtained during flight model No. 1 ADCS testing.

In many applications, approximate results are often sufficient to achieve an acceptable behavior of a real–time system. Imprecise calculations could be necessary due to a transient overload situation caused by extraordinary events. To handle this exceptional work as well as the normal tasks, it is possible to reduce temporarily the computation time of the normal jobs by applying a more intelligent and flexible form of algorithms. In this paper, algorithm structures are presented, which are suitable to implement the mentioned methods. The basic idea is to offer multiple algorithm alternatives of different complexities for solving a problem. Then one can decide with the knowledge of the deadline and of the computation time which of the alternatives can be executed in time. These decisions will happen at runtime. To prove the applicability of the proposed methods on a real system, the theoretical considerations are devolved to a practical example consisting of a vehicle convoy. In this system, a normally realized control unit is substituted by an imprecisely working one. The effects of this action are described and analyzed with regard to the normal implementation. Therefore, a number of simulation results are presented. There exists also an experimental setup for verification in a real environment.