The Solar Oscillations Investigation is an international project to study the interior
structure and dynamics of the Sun. The SOI program was responsible for design and
fabrication, and now for operation, of the Michelson Doppler Imager (MDI) instrument
on board the Solar and Heliospheric Observatory (SOHO) spacecraft, launched on
December 2, 1995. The SOI Science Team includes over 60 scientists from around the world.
In addition, SOI is building an archive of helioseismology data from several other solar
projects.
