The SOlar and Heliospheric Observatory (SOHO) is a project of international cooperation between ESA and NASA. and was launched in December 1995. The Charge, Element, and Isotope Analysis System (CELIAS) is designed to study the composition of the solar wind (SW) and of solar and interplanetary energetic particles.

CELIAS is a joint effort of five hardware institutions under the direction of the Max-Planck-Institut für Extraterrestrische Physik, MPE (prelaunch), the University of Bern, UoB (postlaunch), and now the University of Kiel (CAU). The CAU involvement in SOHO/CELIAS is supported by the German Space Agency, DLR, under contract 50 OC 1103.