ESA GNC Conference Papers Repository
HERA GNC Subsystem - Preliminary Design
The HERA GNC subsystem is one of the most challenging subsystems of the HERA mission, as it implements state of the art autonomous vision-based technologies that will allow spacecraft operations very close to the binary asteroid system called Didymos. The main objective of the HERA mission is to investigate the efficiency of the kinetic impactor technique as possible solution for planetary defence. In order to achieve its goal, the spacecraft will navigate close to this system composed by two asteroids and characterised by an unpredictable environment of micro-gravity. The autonomous vision-based GNC of HERA has been designed in order to operate the spacecraft without ground intervention. In the first part of the mission, the autonomy will be limited to the spacecraft attitude in order not to lose the target from the field of view of the HERA payloads. Towards the end of the nominal operations, there will be an experimental phase where the GNC will be fully autonomous, also correcting the trajectory, in order to further reduce the distance and to increment the resolution of the data. The paper will report the different phases of the mission, focusing on the GNC modes and their usage. The most representative results of the analysis performed for the PDR of the subsystem will also be reported, in order to demonstrate the validity of the solution.