The €330m (£265m) project aims to provide an extremely accurate map of the planet's gravitational field. Its main mission is to help climate scientists improve their predictions by enabling them to produce a more precise picture of the ocean currents.
By comparing the surface shape of the oceans with the undulations in the gravitational field, scientists can arrive at a more accurate picture of the oceans' currents - the flows that transport vast amounts of heat around the planet and so have a profound impact on the global climate.
The satellite will complete a map of the gravitational field once every 70 days and stay in operation for about 18 months.
Read more at - 'Gravity-mapping satellite will help predict climate change'