Final Autonomous Descent Based on Target Marker Tracking

This paper describes the navigation, guidance, and control for the final descent phase of the Hayabusa spacecraft, a technology demonstrator aiming at the sample and return from an asteroid. To cancel the relative horizontal velocity with respect to the asteroid surface, an artificial landmark named "Target Marker" was used. The design and in-flight data of Target Marker tracking are shown in the paper, together with autonomous control scheme of the spacecraft.