The “Next Generation Gravity Mission”: challenges and consolidation of the system concepts and technological innovations

Following the success of GRACE and GOCE, the scientific communities and the space agencies have started to focus their attention towards the preparation of a future gravity mission, for the time being called Next Generation Gravity Mission (NGGM).Such a mission requires a quantum leap not only in the ranging sensor, such as that provided by laser interferometry in place of microwave sensing, but also a parallel improvement in the performance of the satellite subsystems dedicated to attitude and disturbance control, where the GOCE experience will be brought to bear.This paper focuses on the NGGM challenges, at mission and system levels, and on the main technological innovations needed to face them.The laser interferometry techniques and the metrology under development for achieving the precise pointing of the laser beams between the spacecraft are also described.In particular, an overview is given of the main results of the "Consolidation of the system concept for the Next Generation Gravity Mission" study, carried out for ESA by Thales Alenia Space in Italia [6].