||SOHO is an ESA/NASA collaborative mission within ESA's `Solar Terrestrial Science Program' (STSP), and it is also part of ISTP (International Solar Terrestrial Physics Program). So far, SOHO represents the most comprehensive space mission devoted to the study of the sun and of the heliosphere. Within the collaborative mission, the functions are divided in the following way: ESA is responsible for S/C procurement, integration and testing; NASA provided the spacecraft launch and mission operations from GSFC. The following overall mission objectives are pursued:
Solar spectroscopy at soft X-ray and EUV wavelengths (study of the composition of the solar corona, of the structure and dynamics of the magnetic structures making up the corona, and of coronal holes, etc.)
Study of the structure and dynamics of the solar interior through the observation of minute oscillations on the sun's surface (helio-seismology).
Study of the solar wind and solar energetic particles, interaction with the Earth, plasma processes in both the solar and magnetospheric context.