Design of a Guidance, Navigation and Control System for a Smart On-Orbit Servicer Mission (SOOS-1)

<p>  </p> <p>This thesis presents the preliminary design, implementation, and simulation of a monocular visionbased autonomous Guidance, Navigation, and Control system for Smart On-Orbit Servicing missions targeting defunct satellites in geostationary and graveyard orbits. First, a YOLOv8 object detection model was trained to identify satellite components and tested on a synthetic video frames simulated to model video captured by a monocular camera. These detections were then fed into a depth estimation process using the MiDaS neural network, which generates per-pixel depth maps. Depth readings are extracted from bounding box centers and, together with image coordinates, are used to estimate the relative 3D pose of the target satellite.</p> <p>To address noise and fluctuations from individual frame detections, a Savitzky-Golay filter is applied to smooth the estimated trajectory over time. Using Two-Line Element orbital data, the simulation initializes five defunct satellite targets and a chaser spacecraft 2 kilometers below each target’s orbit. The Hill-Clohessy-Wiltshire equations are employed for modeling the relative dynamics between the chaser and target satellites. A proportional-derivative controller is implemented in the Hill frame to autonomously steer the chaser into a rendezvous with the target, achieving relative positions within 5 meters and final velocity errors below 0.05 m/s.</p> <p>Across all five targets, rendezvous was successfully achieved, with maneuver durations ranging from 48,500 to 49,100 seconds. The object detection model reached a mean average precision (mAP) of 97%, while Z-depth outputs ranged from 17 to 21 meters in the test video, validating the feasibility of monocular-based pose estimation. Although the system lacks ground-truth validation for absolute depth, results show promising accuracy in visual tracking and dynamic control. This work contributes a software-level feasibility for SOOS missions, with potential for additional hardware testing and conducting ground truth testing.</p>