GOLF and VIRGO will perform long and uninterrupted series of oscillations measurements of the full solar disk, respectively in velocity and in the irradiance domain. In this way, information will be obtained about the solar nucleus. SOI/MDI will measure oscillations on the surface of the Sun with high angular resolution. This will permit to obtain precise information about the Sun's convection zone - the outer layer of the solar interior.
SUMER, CDS, EIT, UVCS, and LASCO constitute a combination of telescopes, spectrometers and coronagraphs that will observe the hot atmosphere of the Sun, the corona, extending far above the visible surface. SUMER, CDS and EIT will observe the inner corona. UVCS and LASCO will observe both inner and outer corona. They will obtain measurements of the temperature, density, composition and velocity in the corona, and will follow the evolution of the structures with high resolution.
CELIAS, COSTEP and ERNE will analyze in situ the charge state and isotopic composition of ions in the solar wind, and the charge and isotopic composition of energetic particles generated by the Sun. SWAN will make maps of the hydrogen density in the heliosphere from ten solar diameters. It uses telescopes sensitive to a particular wavelength of hydrogen, allowing the large-scale structure of the solar wind streams to be measured.