High Accuracy Tracking of Space-Borne Non-Cooperative Targets

This dissertation is focussed on the subject of tracking non-cooperative targets, by the use of a vision based sensor. With the main goal of navigating a spacecraft or a rover. The main objective of the dissertation is to apply image processing methods to facilitate accurate and robust measurements for the spacecraft to navigate safely and autonomously towards the target. These methods are applied on three distinct study cases, which are based on the platform of the microASC instrument.
In relation to the Mars2020 rover, a structured light system is used to navigate the PIXL instrument towards the Martian surface, whose objective is to seek evidence of ancient life in the form of chemical biosignatures. The structured light is a subsystem of the PIXL instrument consisting of two active lasers and an imager. The structured light makes use of active triangulation to support a safe approach towards the surface and to enhance the PIXL instrument's capabilities with highly accurate distance measurements. Optical observations of planetary bodies and satellites are utilized to determine the inertial position of a spacecraft. A software module is developed, tested and verified by both ground based and in-ight observations, where the performanceover the complete operational envelope is characterized by simulations. The in-flight observations were captured onboard Juno, during the Earth flyby, by the microASC instrument, operating as an inertially controlled imager. The involvement in Juno's Earth Fly By operational team and processing of the captured data was recognized with two Group Achievement Awards from the National Aeronautics and Space Administration.
With today's advancement in autonomy, the focus is set on in-flight tracking of a non-cooperative artificial satellite with the end goal of capturing the target. The objective is to facilitate a sensor technology that enables fully autonomous relative navigation between a target and chaser. A novel method is designed, tested and verified to comply with the requirements for the final phase of a rendezvous scenario, applicable to servicing and sample return missions.