Novel testbed architectures for small satellites attitude control and pointing stabilisation systems

The space sector has undergone a paradigm shift over the last two decades, from large and costly satellites developed by a few nations and major companies to small satellites developed by a wide range of actors. This new approach, often referred to as newspace, is planned to play an increasingly important role in the upcoming years. CubeSats are an example of these new small satellites and enable low-cost missions for a wide range of fields. Their performance and reliability are however limited, with many missions experiencing in-flight issues or failure. Among other factors, the teams’lack of experience and the oversight of functional system level testing have been identified as the leading causes of the low success rate. The Attitude Determination and Control System is one of the critical subsystems on board a satellite, on which the missions success depends. It is, however, a subsystem difficult to test “like you fly” as it requires free rotational motion in a low torque environment with sensor stimulus. Attitude testing facilities for CubeSats exist but are limited in terms of simulation capabilities, lack flexibility in hosting different CubeSat sizes and present disturbance torque levels orders of magnitude higher than those in space. To address this gap, a new facility has been developed for the European Space Agency (ESA) and has been installed at the European Space Research and Technology Centre (ESTEC). The new facility can be used to provide a verification & validation tool that can truly support a ‘test-as-you-fly’ philosophy. The development of part of this facility is described in this thesis. Just as reliability remains a challenge for small satellites, their performance is also limited compared to that of traditional large spacecraft, even though attitude control and payload pointing requirements are becoming increasingly demanding.