Ground-based low altitude hovering technique of Hayabusa2

The asteroid explorer Hayabusa2 carries multiple rovers and separates them to land on an asteroid surface. One of these rovers, called MASCOT, was developed under the international cooperation between the Deutsches Zentrum für Luft- und Raumfahrt and the Centre National d’Etudes Spatiales. This rover was designed to be separated to land and perform several missions on an asteroid surface. To support these missions, the mother ship Hayabusa2 must separate this rover at a low altitude of approximately 50 m and hover at approximately 3 km after separation to achieve are liable communication link with MASCOT. Because the on-board guidance, navigation, and control (GNC) does not have an autonomous hovering function, this hovering operation is performed by ground-based control. This paper introduces the GNC operation scheme for this hovering operation and reports on its flight results.