Angles-only relative navigation in low earth orbit

Rendezvous in orbit has recently regained considerable attention, as it is required to enable on-orbit servicing or active debris removal activities. The pressing need for the realization of suchmissions falls within the more general societal attempt to make human activities more sustainable, avoiding wasting valuable resources and ensuring that the environment remains clean after exploitation. Despite the technical heritage of decades of experience, space rendezvous faces, with these new prospects, additional challenges due to the possible noncooperative nature of the target of the rendezvous. A successful and safe approach has to be ensured with limited relative navigation capabilities while reducing the overall mission costs. This quest for cost-effectiveness is indeed required to eventually reach an economically viable large-scale solution able to mitigate the threat posed by the evergrowing population of orbiting space debris.
This dissertation demonstrates that the first part of a rendezvous to a noncooperative object, starting from large separations of several tens of kilometers down to a few hundred meters, can be safely and reliably performed using line-of-sight navigation and solely relying on a single spaceborne camera. More specifically, this research shows that it is possible to use a simple, low-cost, computationally-light and autonomous camerabased embedded navigation system to perform the far-to mid-range approach, thus greatly reducing the necessary onboard equipment and the operational costs. In order to demonstrate this assertion, the dissertation is articulated around three Research Questions:
How to design a reliable and accurate spaceborne real-time angles-only relative
navigation system? How does it behave under real conditions? How can future anglesonly relative navigation systems be improved?