After more than four years mapping Earth’s gravity with unrivalled precision, GOCE’s mission is nearing its end and the satellite will soon reenter our atmosphere. The Gravity field and steady-state Ocean Circulation Explorer – GOCE – has been orbiting Earth since March 2009 at the lowest altitude of any research satellite.
With a sleek, aerodynamic design responsible for it being dubbed the ‘Ferrari of space’, GOCE has mapped variations in Earth’s gravity with extreme detail.
The result is a unique model of the ‘geoid’, which is essentially a virtual surface where water does not flow from one point to another.
In mid-October, the mission will come to a natural end when it runs out of fuel and the satellite begins its descent towards Earth from a height of about 224 km.
While most of GOCE will disintegrate in the atmosphere, several parts might reach Earth’s surface.
When and where these parts might land cannot yet be predicted, but the affected area will be narrowed down closer to the time of reentry. Reentry is expected to happen about three weeks after the fuel is depleted.
Taking into account that two thirds of Earth are covered by oceans and vast areas are thinly populated, the danger to life or property is very low.
About 40 tonnes of manmade space debris reach the ground per year, but the spread and size mean the risk of an individual being struck is lower than being hit by a meteorite.
An international campaign is monitoring the descent, involving the Inter-Agency Space Debris Coordination Committee. The situation is being continuously watched by ESA’s Space Debris Office, which will issue reentry predictions and risk assessments.
ESA will keep its Member States and the relevant safety authorities permanently updated.
