This Master’s Thesis presents the definition of a navigation strategies for the Space Rider Observer Cube (SROC) mission, conceived to demonstrate autonomous rendezvous and docking technologies for small satellites. Originally designed to operate with the Space Rider vehicle, the mission was re-scoped: the target platform was replaced by a cooperative 12U CubeSat, enabling a fully symmetric proximity operations scenario between two identical spacecraft. In this framework, the thesis focuses on the design and validation of a navigation algorithm capable of accurately estimating the relative pose (position and velocity) between the two vehicles during proximity and docking maneuvers. The work includes a complete redefinition of the mission’s Sensor Suite, comprising two Narrow Field of View and one Wide Field of View optical cameras, LIDAR, Relative GNSS, and Intersatellite Link sensors, together with an analysis of their performance and the derivation of noise models for covariance tuning.