The proposed idea comes mainly within the framework of new concepts identification and development for future satellite gravity missions, in continuation of previously launched space missions CHAMP, GRACE, GOCE, GRACE-FO and ongoing and prospective studies like NGGM. We focus here more particularly on the inertial sensors that complete or form the payload of such satellites. The clearly identified instruments for space accelerometry are based on the electrostatic technology developed for many years and that offer a high level of performance and naturally a high degree of maturity for space applications. On the other hand, a new generation of quantum sensors based on cold atom interferometry is emerging and seems very promising in this context. These atomic instruments have already demonstrated on ground impressive results and should benefit from their full potential only in space where the microgravity environment allows long interaction times. These two technologies seem in some aspects very complementary and a hybrid sensor bringing together all their assets could be the opportunity to take a big step in this context of gravity space missions. We propose here a research work on a unique hybrid lab prototype to assess the potential of this original concept and to study experimentally solutions to mitigate the detrimental impact of satellite rotation on the atomic signal. In this configuration, the quantum sensor will also benefit from innovation compared to state-of-the-art cold atom interferometers since several atomic species (87Rb, 85Rb and 133Cs) would be manipulated simultaneously, offering new perspectives that should improve current performances of atomic inertial sensors such as to benefit from continuous measurements without deadtimes. The multi-species character of the instrument gives it also a great potential for applications on ground in the field of fundamental physics as well as in the more applied fields of navigation and geophysics.
