Design and Testing of a Low-Budget 2-in-1 Star Tracker and Sun Sensor for CubeSats

Abstract

Satellites are becoming smaller and therefore their attitude sensors must reduce in size as well. However, in order to maintain 3-axis attitude determination, a combination of several sensor types is required. Moreover, the availability of these sensors is mostly dependent on the lighting conditions and slew rate of the spacecraft. In this thesis, a prototype low-budget 2-in-1 star tracker and Sun sensor was designed with similar performance but reduced technical budgets compared to a typical combination of COTS attitude sensors on CubeSats. The design can be used in both sunlight and eclipse, while stable pointing and while tumbling and it takes up less volume on a satellite. Future designs should focus on reducing solving times and power consumption by creating a dedicated microcontroller and a more optimized star tracker algorithm. Alternatively, a different CMOS chip with lower power consumption should be selected or the use of a satellite's central computing unit needs to be considered.