Design and Development of a Custom-Build ADCS for METUCube Satellite


TUZCU G., Ergin İ. D., İlbağı M., Toy B., Gardezi A. A., Güngör Y., ...More

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.