Mission to Map Earth’s Magnetic Field Readies for Takeoff
A satellite trio is set to unravel the mysteries of our planet’s inner dynamo, and could reveal mineral and ore deposits

Quirin Schiermeier & Nature magazine

A trio of European satellites is being readied for launch tomorrow from Russia’s Plesetsk spaceport to study Earth’s magnetic field in unprecedented detail. The $296-million mission, known as Swarm, will map the magnetosphere for at least four years.

Mission managers with the European Space Agency (ESA) are awaiting the launch—postponed twice owing to problems with the Russian rocket’s upper stage—with anxiety. In 2009, a Rockot carried two ESA Earth-observation satellites—GOCE (Gravity field and steady-state Ocean Circulation Explorer) and SMOS (Soil Moisture and Ocean Salinity)—safely into orbit. But in 2005, ESA’s ice-observing CryoSat satellite crashed into the Arctic Ocean after a Rockot vehicle failed to reach orbit.At 12.02 gmt, a Russian Rockot launcher is scheduled to take off, lifting the three identical satellites into polar orbits. If all goes according to plan, two of the spacecraft will orbit the planet side-by-side at an initial altitude of 450 kilometers. The third satellite will fly 70 kilometers higher, and at a slightly different inclination.