Fully invested in its missions, OSUG is engaged in 28 national observation services (SNO) in connection with research carried out in its laboratories. The missions concern the near and far universe (planets, stars and galaxies), the outer envelopes (water, ice, atmosphere), and the internal ones of the globe (Internal Earth); they are divided into the three disciplinary sections: Astrophysics Astrophysics - Ocean, Atmosphere, Continental Surfaces & Interfaces - Solid Earth.
The OUSG is responsible for national observatory services, accredited by the Institute of Sciences of the Universe (INSU), which coordinates the academic observation services.
He is also a partner in international ground and space observations services for studying Earth and Universe systems dynamics. Some of these OSUG observation services are also labeled by the Ministry "ORE, Observatoire de Recherche en Environnement".