ESTCube-2 attitude and orbit control system design

Abstract

This thesis presents the design and analysis of the attitude and orbit control system for the ESTCube-2 CubeSat. The objective of the system is to spin up the satellite to high angular rates, perform accurate pointing and should also be able to operate outside of the Earth’s magnetic influences, for example in a Lunar orbit. For this thesis various requirements for the subsystem and payloads of the nanosatellite have been gathered. From these requirements the design drivers for the attitude and orbit control system are identified. Additionally the thesis analyses the ESTCube-1 nanosatellite attitude determination and control performance and presents the lessons learned, which provides input to the design of the ESTCube-2 nanosatellite. Based on the requirements a set of actuators and sensors are presented that fulfil the various ESTCube-2 mission objectives. The thesis also covers the attitude estimation process. This is done by describing the data generation from the simulation environment and the different potential algorithms to be used for sensor fusion. A sensor fusion algorithm for nanosatellite attitude determination is proposed and the first implementation was made to work on the ESTCube-2 microcontroller. Initial results for the algorithm are described and the future improvements are identified.