Akademik Veri Yönetim Sistemi
76th International Astronautical Congress (IAC), Sydney, Avustralya, 29 Eylül - 03 Ekim 2025, ss.1-16, (Tam Metin Bildiri)
METUCube is a 3U CubeSat developed by students at Middle East Technical University (METU), marking the university’s first student-designed satellite. The primary mission objectives of METUCube are post-disaster monitoring and the evaluation of early warning systems. To fulfill these objectives, the satellite is equipped with a multispectral and thermal camera as its primary payload. Since the satellite carries an optical imager as its payload, precise attitude pointing is essential. This study presents the development of an Attitude Determination and Control System (ADCS) for the satellite. The ADCS module includes custom-designed sun sensor, magnetorquers, star tracker, and an ADCS computer that integrates all sensors and actuators. Additionally, commercial off-the-shelf (COTS) gyroscope, magnetometer, and reaction wheels are used. The ADCS is designed to achieve a pointing accuracy better than 0.1 degrees to ensure stable imaging performance for the optical payload. The developed sun sensor consists of COTS photodiodes positioned at different angles on a pyramid structure, with the sun vector estimated using the linear least squares algorithm. The magnetorquers are designed with iron cores for two axes and an air core for the third axis, controlled by changing the input voltage based on Pulse Width Modulation method. Furthermore, the developed star tracker incorporates a COTS image sensor, lens, and microprocessor. It independently executes the Quaternion Estimator (QUEST) algorithm to provide an attitude solution for fine pointing. This paper first presents the details for the design and development of the ADCS. Additionally, we discuss the developed algorithms and their implementations within the ADCS providing insights into their effectiveness in achieving the desired pointing accuracy. To evaluate the performance of both the designed system and the algorithms, hardware in the loop (HIL) tests are conducted and the results are analyzed.