Relative navigation systems based on monocular cameras are currently under active investigation for their capability to deliver fast pose solutions under low power and mass requirements. Cameras depend on the passive collection of radiation, making their performance highly dependent on illumination conditions and image background. In the presence of undesirable lighting conditions, their performance may decrease significantly. This thesis aims to assess the performance of a guidance system given these challenges of vision-based pose estimation systems. A number of representative undesirable scenarios was defined, and the behaviour of the GNC system, specifically guidance, was evaluated for these scenarios. This work formulated mitigation strategies, required on multiple occasions. Furthermore, the largest source of error was found to be due to the prediction of the target attitude dynamics and a new method was developed to improve this prediction. Finally, the design of trajectories with optimal lighting conditions was explored, resulting in the design of a rendezvous trajectory with favourable lighting conditions.