A relative navigation sensor for CubeSats based on retro-reflective markers

Over the last years, nanosatellites based on the CubeSat standard have been increasingly exploited by both academic institutions and commercial companies. The low cost and short development time of CubeSats make such miniature spacecraft interesting for a variety of applications. A particularly appealing future field of application for nanosatellites is On-Orbit Servicing of existing orbital assets. A number of mission concepts foresee the employment of miniature spacecraft to perform a variety of operations on orbital vehicles, ranging from inspection and monitoring to assembly and repairing. In this framework, the development of technologies that enable proximity navigation and/or docking between a nanosatellite chaser and a target object is of interest. In particular, miniaturized navigation sensors for the estimation of relative position and attitude of the involved vehicles are required. The work presented here focuses on the development of an IR-based relative navigation sensor compatible with CubeSat standard nanosatellites. The system estimates the relative pose and position of the target by taking images of the object, which is equipped with retro-reflecting fiducial markers illuminated by an array of IR LEDs on the chaser. The system architecture and operation are described, and preliminary laboratory test results are presented.