Ball Aerospace Star Tracker Achieves High Tracking Accuracy for a Moving Star Field

Star trackers are traditionally a key component in spacecraft attitude control systems. Ball Aerospace has designed, developed and delivered the High Accuracy Star Tracker (HAST). The HAST achieves 0.2 arcsec total error (1σ) performance on each tracked star moving between 0.07 and 1.0 degrees/second. HAST maintains track on stars moving 0 to 4 degrees/second. Multiple star tracking further enhances the accuracy. This paper describes HAST and examines measured performance. Performance is assessed according to the three dominant error sources: 1) boresight alignment bias, 2) transit dependent bias, and 3) random measurement. The performance measurement techniques are described along with delivered product test results.