ESA GNC Conference Papers Repository

The Terma T1 Star Tracker Qualification Test Results and New Developments
Peter Davidsen, Ole Mikkelsen, Jan Storbank Pedersen, Carsten Gjevert Petersen, Preben Bohn, Karl Kaas, Johan De Claville Christiansen
Presented at:
Virtual Conference 2021
Full paper:

The design and qualification of the Terma T1 star tracker Electronics Unit (EU) and associated software supported by ESA GSTP has been completed with key results presented in this paper: - EU environmental test campaign - Software tests comprising acquisition and tracking robustness with and without heavy transient radiation events - Software tests verifying autonomous update and robust use of a full sensor dark current map - Software tests verifying overall dynamic attitude accuracy - Test using proton irradiated Faintstar-2 sensor - Results from night sky testing - Qualification campaign results from the first T1 STR flight model production including a new 26 deg SEA baffle In addition, some new STR key components have been developed, expanding the suitability of the T1 product towards the nano- and micro satellite marked. Design and test results obtained with these new developments during an ARTES study will be presented: - A new 18 mm aperture aspheric optics designed to operate with a very compact baffle - A miniature COTS computer integrated in the Optical Head was developed in partnership with Space Inventor. The computer fits within an envelope of only 57x57x9 mm3 and has been integrated together with the T1 Faintstar-2 PCB forming a very compact star tracker assigned the model name T3 - A 37.5 deg SEA straylight baffle designed for the new optics, allowing the complete T3 STR including EU to be contained within 60 x 60 x 100 mm, addressing the CubeSat marked The algorithmic part of the star tracker software has been enclosed in a separate Star Tracker Library (STRLib). The paper will present how this library can be used for hosting star tracker software on an AOCS OBC using a time-space partitioning based software architecture. A prototype star tracker software, which can be integrated in a dedicated star tracker partition, has been developed as part of an ARTES study and tested on an evaluation Zedboard.