Magnetic Attitude Control Development and Simulation for a 3U Cube Satellite

Abstract

SOCRATES and IMPRESS are two cubesats designed and built by the University of Minnesota's Small Satellite Team. These satellites have similar build and function by seeking to collect information from photons emitted from celestial objects in space. To do so, a cubesat form factor energy spectrometer, Cesium Iodide, Thalium-doped Incident Energy Spectrometer (CITIES), developed at the University of Minnesota is installed onto a 3U cubesat and operates in low-Earth orbit. For CITIES to collect this data, a reliable attitude determination and control system is important to maintain knowledge of the cubesat's position in orbit and keep the detector pointing towards the required celestial object. Based on a lenient attitude pointing requirement and strict energy budget, magnetic control was chosen as the method of actuation. In this thesis, the justification for and theory behind magnetic attitude control are presented. Operating conditions of the cubesats are briefed. Including a description of the types of controllers, how the controllers lie within the state machine architecture, and the concept of operations leading to the commands provided to the attitude controller. Finally, results from a Matlab simulation are presented using a proportional derivative (PD) controller. Results found indicate that given enough time, the magnetic control system stabilizes the cubesat towards its target.