Task: Testing an Attitude and Orbit Control System (AOCS)
The attitude and orbit control system (AOCS) of a satellite is to be tested in the laboratory. To achieve this, the conditions in orbit have to be simulated realistically on the ground. For this purpose, a suitable test system (SCOE, special check-out equipment) has to be set up as part of the overall electrical ground support equipment (EGSE).
Challenge: Realistic Simulation of the Space Environment
In order to simulate the conditions in orbit realistically, factors such as satellite attitude and position, the Earth's gravitational and magnetic field, friction with the residual atmosphere, solar wind, cosmic radiation, temperature fluctuations, etc. must be simulated in the laboratory. Since in this use case the SCOE is connected to either an engineering model or a flight model of the satellite, i.e., the SCOE is connected precisely to the hardware that will later fly into orbit, very strict requirements apply to all interfaces. The connection of the test system must not cause any damage to the system under test. To meet all these requirements, the SCOE must offer features such as galvanic isolation for all interfaces, continuous temperature measurement in the simulator, smoke detection, halogen-free cable insulation, and the usability of all components in the clean room.
Solution: AOCS SCOE Built on SCALEXIO
The SCALEXIO real-time system used as basis for the AOCS SCOE supports a wide range of emulation, stimulation, and sniffing interfaces (analog, digital, RS232, RS422, MIL-STD-1553, CAN, Ethernet, etc.) for either open-loop or closed-loop testing. On the SCALEXIO system, the dynamic models (satellite dynamics, Earth gravity and magnetic field, friction with the residual atmosphere, solar wind, cosmic rays, temperature variations) are computed. Using simulation models and the 3D animation software from dSPACE’s partner Astos Solutions, all test scenarios and their parameters can be graphically displayed and monitored for better clarity. The dSPACE SCALEXIO system also supports extensive test automation to enable efficient testing 24/7.
