Smart attitude control components for small satellites

With increasing mission capabilities for small satellites, the demand for accurate and reliable attitude control components for this satellite class is rising. This paper presents Astround Feinwerktechnik Adlershof GmbH (AFW) attitude control components including the reaction wheel family, starting from RW1 for Cubesats to the RW260 with up to 12 Nms angular momentum. The performance of the RW90 and the gyro system on the TET-1 satellite mission is discussed and lessons learned derived from observations of the components behavior are presented. Most of AFWs attitude control components are smart components, meaning that they have data processing capabilities. They have a digital interface and can also provide telemetry information and include software models that model and control disturbing influences like temperature gradients or friction. Smart sensors will filter their measurements, so that their performance is increased. The smart components are easy to integrate, time saving and require a less complex attitude control software on board the satellite. With smart components, a modular satellite is possible, where integration and on board software development time is greatly reduced. The required software for the component is developed by the manufacturer; therefore it is especially adapted to the physical properties of the smart component and thus tends to enhance the precision and reliability of the component much more than software developed by the satellite design team.