Portland State Aerospace Society (PSAS) is a student-led organization behind Oresat0, Oregon’s first, fully open source cube satellite platform. Future versions of the cube satellite, are to come equipped with Attitude Control and Determination System allowing the satellite to determine its relative orientation in Low Earth Orbit (LEO).
One key input to an ACDS is provided by means of a CMOS image sensor/camera subsystem, which uses the relative orientation of known and cataloged stars to determine the satellite’s orientation.
As part of this internship, we built, tested, and debugged the various aspects of subsystems including Camera Linux Kernel Module and firmware, the CAN (controller area network) application interface, and the image processing front end. Images of stars taken under low light and variable conditions were transformed into relative position estimates. The opensource star tracking software (Open Star Tracker) was configured with Hipparcos and Tycho catalogs were used to generate the best estimate for the right ascension and declination of the satellite in a manner allowing the satellite to query and listen for latest orientation updates. The algorithms and subsystem were field tested at Oregon Museum of Science and Industry (OMSI) Planetarium, Pacific Northwest Regional Observatory, and Pine Mountain Observatory in Oregon to prove the functioning and accuracy of the subsystem.