A trio of satellites to study Earth's magnetic field was launched into a polar orbit atop a Russian rocket , the European Space Agency reported. The three-satellite Swarm constellation is designed to provide insights into the complex workings of the magnetic shield that protects the biosphere from charged particles and cosmic radiation, the ESA said in a release from its Paris headquarters. The Rockot launcher lifted off from the Plesetsk spaceport in northern Russia at 7:02 a.m. EST Thursday, releasing the three satellites into orbit 90 minutes later at 300 miles altitude. Contact was established with the trio minutes later through the Kiruna station in Sweden and the Svalbard station in Norway, ESA officials said. "Swarm is about to fill a gap in our view of the Earth system and in our monitoring of global change issues," Volker Liebig, ESA's director for Earth observation, said. "It will help us to better understand the field that protects us from the particles and radiation coming from the sun."