Abstract
Since the beginning of space history new innovative ideas have been driving space scientists to develop state of the art systems to get their satellites further into space, enable them to handle huge amounts of data connecting the Earth’s continents, produce imagery with sufficiently high detail to help governments and companies to plan, protect and develop their interests. These systems, or more accurately satellite subsystems, are the building blocks of complicated machines which the current modem world relies upon heavily for now and the future. This study presents the successful attempt to develop a new multi purpose actuator part of a very important satellite system, the ADCS (Attitude Determination and Control System). The ADCS is a very crucial subsystem for every spacecraft as it provides the necessary control, very often determining the possible capabilities of each mission. Focused on small Earth Observation (EO) satellites, a highly agile ADCS can greatly increase the satellite’s performance by capturing more images during a single orbital pass, while enabling new types of images to be captured such as stereoscopic ones. A new actuator TW-ECMG (Twin Energy Control Moment Gyro) is developed to further improve the current state of the art by increasing the satellite’s power efficiency, attitude control capabilities, attitude resolution, along with considerable mass savings. While decreasing development costs, launch costs, development time and spacecraft complexity the new TW-ECMG actuator can also be used as an energy storage device. The thesis will start by a detailed reference to the current state of the art introducing the reader to the basic principles behind attitude control, followed by the development steps of a range of air-bearing platforms which are used to test the newly developed TW-ECMG, a cluster of four TW-ECMGs and an additional new actuator, the Modular Control Moment Gyro (M-CMG). The entire hardware development process is described accompanied with extended hardware and software simulations developed using CAD and MATLAB software packages. As the actuator has been developed with the potential of storing energy in its flywheels a chapter has been dedicated to test this principle by combining the ADCS with the power subsystem to create a demonstration of a Combined Energy and Attitude Control System which is called for sort CEACS. Although none of these systems have been used as part of an actual satellite mission to date, they clearly demonstrate the capabilities of such technologies and the substantial benefits it can offer to any spacecraft that will employ them. With some further improvement and the integration of these systems, current small satellite platforms can become more capable than ever before.