Concept for the First Earth Explorer Core Mission GOCE - February 2001. The Gravity Field and Steady-State Ocean Circulation Mission GOCE is intended to advance research in the fields of steady-state ocean circulation, physics of the Earth's interior and levelling systems (based on GPS). It will also provide the unique data set required to formulate global and regional models of the Earth's gravity field and the geoid (its reference equipotential surface) to high spatial resolution and accuracy. (Image: Alenia Spazio)