The European Space Agency’s satellite GOCE (Gravity Field and Steady-State Ocean Circulation Explorer ) has been called the most beautiful satellite to be launched (Monday from Plesetsk Cosmodrome in north-west Russia, if all goes well).

GOCE needs a low orbit to accomplish its mission, which is to map “fantasically small” variations in the Earth’s gravity.

The arrow shape and fins are necessary to keep the spacecraft stable as it flies through the wisps of air still present at an altitude just under 270km. This orbit is much lower than for most Earth observation missions but will be essential if Goce is to sense the very subtle gravity anomalies that exist across the planet.

The satellite will also fine-tune its altitude with an ion engine, which accelerates charged xenon atoms through nozzles at the rear of the craft.

The data will inform a multitude of science disciplines:

• understanding how the mass of ocean waters circulate, moving heat around the planet, will assist climate prediction
• a better knowledge of the way mass is distributed inside the Earth will be useful to those who study geo-hazards such as volcanoes and earthquakes
• and because gravity defines what is meant by “up”, “down” and “level”, the new data can underpin a truly universal system to compare heights the world over

This first of at least six projected  missions is being launched by a modified ICBM. Glad to see one of those things get put to good use.

[Image: NASA]