Performance Testing a New Medium Accuracy Star Tracker

At Ball Aerospace, we have developed the advanced CT-2020 star tracker featuring a new state of the art CMOS detector with exceptional radiation tolerance and performance suitable for spacecraft in any orbital regime. Performance testing has verified the CT-2020 can achieve single head accuracies of better than 1.5 arc-second autonomous attitude output in the cross axes (total error), while also allowing for customer driven “directed search” mode for even higher accuracy performance. A qualification unit was tested to and met the qualification requirements of the Space and Missile Systems Center Standard SMC-S-016. Thermo-mechanical stability testing verified that the innovative lens design and detector package mount is stable over launch and on-orbit environments. Stray light performance verified the CT-2020 lightshade, which is coated with Surrey NanoSystems's Vantablack, provides a Sun exclusion angle of less than 33 degrees. The coating allows for less light shade baffles which minimizes the star tracker's size and weight. Software testing verified the user can export full frame data from the image sensor while simultaneously tracking stars at full accuracy. Low angular rate bright star testing correlated very well with high fidelity models and the design unit showed exceptional calibration performance in Ball's state of the art flight proven test systems. Results of the qualification units performance testing and SMC-S-016 testing will be discussed in the paper.