March launch planned for ESA's gravity mission   The GOCE satellite undergoing testing at the Russian Plesetsk Cosmodrome in August 2008   Over its lifetime of about 20 months, GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) will map global variations in the gravity field with extreme detail and provide a unique model of the geoid, which is crucial for understanding ocean circulation, sea-level change and ice dynamics – all of which are affected by climate change.   The GOCE gradiometer contains three pairs of proof masses positioned at the outer ends of three 50 cm long orthogonal arms. Because of their different position in the gravitational field they all experience the gravitational acceleration of the Earth slightly differently. The three axes of the gradiometer allow the simultaneous measurement of six independent but complementary components of the gravity field. Release date: 3 December 2009