Design and Development of a Custom-Build ADCS for METUCube Satellite
53rd IAF Student Conference at the 76th International Astronautical Congress, IAC 2025, Sydney, Australia, 29 September - 03 October 2025, pp.332-347, (Full Text)
- Publication Type: Conference Paper / Full Text
- Doi Number: 10.52202/083098-0030
- City: Sydney
- Country: Australia
- Page Numbers: pp.332-347
- Keywords: Attitude Determination and Control System (ADCS), CubeSat, Magnetorquers, Sun Sensor
- Middle East Technical University Affiliated: Yes
Abstract
METUCube is a 3U CubeSat developed by students at Middle East Technical University (METU), representing the university's first student-designed satellite. The mission aims at post-disaster monitoring and the evaluation of early warning systems, for which the satellite carries a multispectral and thermal imaging payload. Since high-quality imaging requires accurate pointing, this study focuses on the design and implementation of the Attitude Determination and Control System (ADCS) of METUCube. The ADCS integrates custom-developed Sun sensors, magnetorquers, and a star tracker, together with an ADCS computer that coordinates all subsystems. Commercial off-the-shelf (COTS) gyroscopes, magnetometers, and reaction wheels are used in the design of ADCS. The custom Sun sensor integrates photodiodes mounted on a pyramid structure, with the Sun vector estimated through a linear least squares algorithm. Magnetorquers are designed with iron cores for two axes and an air core for the third axis, controlled via pulse-width modulation. The developed star tracker combines a COTS image sensor, lens, and microprocessor, and executes the Quaternion Estimator (QUEST) algorithm onboard to provide an independent fine-pointing solution. ADCS algorithms, including estimation and control methods, are implemented in real time on the ADCS computer.