SOHO (Solar and Heliospheric Observatory) is a project of international cooperation between ESA and NASA. The SOHO mission is included in ESA's Horizon 2000 Programme as a cornerstone called the Solar-Terrestial Science Programme. ESA's part has been the planning and building of the SOHO spacecraft and NASA's task includes the launch and operation. SOHO is the first cooperative programme in which the overall mission responsibility rests with ESA.
Design studies for SOHO began in 1984 and the main development work in May 1991. More than 250 scientists from 39 institutes and fourteen European nations and USA have had a major involvement in SOHO's experiments.
