I Congreso de Postgrado fcfm: ingeniería, ciencias e innovación

102 Santiago, 10 al 12 de agosto, 2022 I NG E N I E R Í A A E ROE S PAC I A L 08 DEVELOPMENT, TEST, AND INTEGRATION OF AN ULTRA-LOW-COST STAR TRACKER IN THE NEW SUCHAI SATELLITE MISSIONS OF THE UNIVERSITY OF CHILE Samuel T. Gutiérrez¹*, César I. Fuentes², Marcos A. Díaz¹ ¹Space and Planetary Exploration Laboratory (SPEL), Electrical Engineering Department, Faculty of Physical and Mathematical Sciences, University of Chile, Santiago, Chile. ²Astronomy Department, Faculty of Physical and Mathematical Sciences, University of Chile, Santiago, Chile. *Email: samuel.gutierrez@ug.uchile.cl ABSTRACT Attitude estimation sensors contribute to increasing the capabilities of satellites in space, although they consti- tute a significant fraction of the budget of a satellite mission [1]. If the mission requires attitude determination with a precision of the order of arcminutes (or better), the cost skyrockets. This limits the capabilities of the satellite, especially if the mission budget is limited. To solve this problem, we developed SOST (SPEL - Open Star Tracker), a star tracker for CubeSat-type nanosatellites, capable of attitude determination at an ultra-low cost, achieving sub-arcminute precision (in the boresight direction) 97.3% of the time in almost 12 s of operation. Re- garding the hardware, the proposed platform is based on the Raspberry Pi family of microcomputers. In terms of software, SOST relies on free and open-source software widely used in the field of astronomy. Currently, the operation of a Raspberry Pi in space has been demonstrated [2], and the use of commercial off-the-shelf components (COTS) has been consolidated as a new area of research and testing for nanosatellites [3]. The development of SOST involved the creation of an algorithm based on robust astronomical tools and was tested with space images from the STEREO satellite from NASA. The proposed hardware with the algorithmwas extensively tested, ensuring its ability to work in space with performance according to the require- ments of the new space missions of the SPEL group: SUCHAI-2/3 and PlantSAT. In terms of hardware, the PC-104 standard was used to integrate SOST. Regarding software, the satellite f light software developed at SPEL was used. It was established requirements for the payload, and commands were developed to satisfy those require- ments. Finally, a series of experiments are proposed to evaluate the performance of SOST in space. ACKNOWLEDGMENT The authors thank CONICYT - Programa formación de capital humano avanzado (PFCHA)/Doctorado Nacional/2017-21171862. In addition, we would like to thank the entire human group that makes up SPEL for their constant support during this work. REFERENCES [1] C. C. Liebe. Accuracy performance of star trackers - A tutorial. IEEE Transactions on aerospace and electronic systems, 38(2):587–599, 2002. [2] BBC. Raspberry Pi computer looks down on Earth. Avail able: http://www.bbc.com/news/science-environment-49584941. [Online]. Accessed on: July 20, 2022. [3] Samuel Pedrotty, Ronney Lovelace, John Christian, Devin Renshaw, and Grace Quintero. Design and performance of an open-source star tracker algo rithm on commercial off-the-shelf cameras and computers. In 43rd Annual AAS Guidance, Navigation and Control Conference, 2020.