Astronomical-driven based TSC project for conceptual design and demonstration of a star tracker by using 0.7-meter optical telescope system

Thai Space Consortium (TSC) was originally a cooperation program by 13 leading Thailand research organizations that proposed to develop a microsatellite for a scientific mission; moreover, the aim of the TSC program includes sharing and enhancing an advanced engineering capacity in Thailand. Due to the National Astronomical Research Institute of Thailand (NARIT) being a part of the TSC contributor; therefore, the development of the star tracker is first promoted to be an astronomical-driven project through the eye of astronomical engineers. In practice, the knowledge of star trackers can apply to satellite attitude determination systems. It is the most precisely measured absolute three-axis orientation of a spacecraft when integrated with relative sensors. Therefore, in this work, the potential of using an 0.7-meter optical telescope-based for software experimentation as a function of stars pattern recognition and attitude determination algorithms according to the detected stars on astronomical images. The image is mapped to the guide star catalog to correct the magnification, shear, and rotation of the image sensor respective to the Cartesian coordinates as a function of astrometry engineering. The result of the method is a plate-constant that then corrects the positions of a target celestial body. An inertial measurement unit (IMU) was equipped with the telescope mounting to collect the local orientation of the telescope itself to demonstrate the results of attitude determination in both deterministic-TRIAD method and solving loss function based on Wahba's problem. The proposed system integration method can be performed with negligible attitude determination error compared to the IMU-baseline attitude sensor. This contribution will present some of the experimental results and plans for further measurement campaigns.