The Solar Orbiter project, is part of ESA's program Cosmic Vision 2015–2025 which is the current cycle of ESA's long-term planning for space science missions.

Solar Orbiter's mission is to address the central question of heliophysics: "How does the Sun create and control the heliosphere?" This, in turn, is a fundamental part of the second science question of ESA's Cosmic Vision: "How does the solar system work?"
Solar Orbiter is specifically designed to identify the origins and causes of the solar wind, the heliospheric magnetic field, solar energetic particles, transient interplanetary disturbances, and even the Sun's magnetic field itself.

By approaching as close as 62 solar radii, Solar Orbiter will view the solar atmosphere with high spatial resolution and combine this with measurements made in-situ. Over the extended mission periods Solar Orbiter will deliver images and data that will cover the polar regions and the side of the Sun not visible from Earth.

Solar Orbiter will coordinate its scientific mission with NASA's Solar Probe Plus within the joint HELEX programme (Heliophysics Explorers) to maximise their combined science return.

Solar Orbiter is an ESA satellite launched by NASA (which also receives the scientific data through its DSN network) and which instruments have been conceived and realized by European and american scientists.

French scientists are Principal Investigator for one of the ten instruments (RWP) and have greatly contributed to several others (SWA, STIX, EUI, SO/PHI, SPICE).