Study of energy efficient manoeuvring strategies for cubesats

Abstract

Space’s exploration has, for a long time, only been affordable by the main space agencies, supported by national governments, and big telecommunication companies due to the costs of launching machines. This is the reason why nanosatellites, also known as Cubesats, appeared as a solution for research and simulation in universities, being affordable and practical for their reduced uses. This thesis focuses on the study and design of the attitude control of a 1U CubeSat, in order to analyse the most energy efficient control strategies when using a combination of magnetorquers and reaction wheels. As this project is the continuation of a previous one, it is critical to understand how the previous model works and how has it been designed, to adapt and improve the existing model with additional actuators without interfering in the working mechanics and functionalities. The advantages that this project offers are, mainly, the usefulness in future uses for real tests and how simple it is to accurately reproduce manoeuvres using Simulink blocks, much easier when compared to what could be a standard satellite. For this analysis, simulations take into account three different low altitude orbits, assuming a constant disturbance torque. By using specific control algorithms for each operation, detumbling, Nadir-pointing and reaction wheels desaturation manoeuvers are performed. In addition, an energy balance is carried out with the used of and electrical system consisting of a battery, solar panels (installed on Cube- Sat faces as an energy source) and the actuators that will be consuming current from the battery if active