Evaluation of the SpaceWire-D network and architecture through HAYABUSA2 optical navigation system: Missions and Applications, Short paper

We developed a hard real-time optical navigation system based on SpaceWire-D draft standard for HAYABUSA2 asteroid probe. HAYABUSA2 accomplished its primary mission successfully in the vicinity of asteroid Ryugu in November 2019. It brought back samples of Ryugu on December 6th, 2020 to the Earth. Digital Electronics and Optical Navigation Camera (DE-ONC) was used for scientific observation as well as for optical navigation using real-time image recognition. Thanks to the integrated architecture referring to SpaceWire-D we were able to analyze deterministic onboard networks to fulfill the timeliness and latency requirement. Image tracking functions were successfully performed during autonomous and automatic touch-down onto the surface of Ryugu. No feature points were missed, and they were tracked continuously within limited latency using radiation hardened devices. We report the evaluation result of the design approach in this paper.