Gravity influences many of the Earth’s dynamic processes, such as seismic activity and ocean circulation, which plays a crucial role in the world’s energy exchanges. GOCE’s ‘gravity-field map’ data are being used to advance knowledge of oceanography, solid Earth physics and geodesy, to analyse global sea-levels, and improve cliamate models and forecasts. Practical applications such as surveying also benefit.

This first global gravity model, based on only two months of GOCE data (November–December 2009), illustrates the excellent capacity of GOCE to map tiny variations in the Earth’s gravity field. © ESA - GOCE High Level Processing Facility

Orbiting the Earth at a particularly low altitude of just 250 kilometres in order to observe the strongest possible gravity-field signal, the entire GOCE satellite is in effect the mission’s primary sensor, its trajectory following and registering the irregular contours of the gravity field like a surfer riding the waves. Since it is vital that the measurements taken are of true gravity and not indications of any movement by the satellite, GOCE’s five-metre long body as designed by Astrium in Friedrichshafen is sleekly slim and aerodynamic, with a cross-sectional width of only one metre. The instruments and the satellite form a single composite gravity-measuring device, and there are no moving, mechanical parts anywhere inside the satellite to jeopardise the precision of the readings.

Astrium’s engineers in Friedrichshafen were responsible for the design and build of GOCE’s novel satellite platform © Astrium

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