What if Star Trackers Were Navigation Cameras?

Navigation cameras and star trackers are widely used sensors in current space missions. Although both rely on similar hardware components and process images to extract information, they serve distinct purposes. Navigation cameras support vision-based navigation by estimating a vehicle’s state relative to the observed environment, while star trackers are designed exclusively for precise inertial attitude estimation. This work explores the feasibility of repurposing a high-TRL Leonardo star tracker for navigation tasks. Vision-based navigation algorithms were adapted to account for the hardware, optical, and software constraints of the star tracker, including detector readout and image blurring. Feasibility was evaluated through numerical simulations, processor-in-the-loop, and hardware-in-the-loop testing, assessing both navigation performance and computational load.