A Chinese icebreaker has completed its passage though the arctic Northern Sea Route, marking the first such voyage by a Chinese vessel, officials said. The icebreaker Xuelong, or Snow Dragon, traveled through five marginal seas of the Arctic Ocean: the Chukchi, the East Siberian, the Laptev, the Kaka and the Barents, China\'s state-run Xinhua News Agency reported. The voyage enabled scientists to conduct arctic research on the Atlantic sector of the arctic and also opened up a transportation ocean route linking Asia and Europe, expedition leader Yang Huigen said. The Xuelong, capable of breaking through ice 4 feet thick, is expected to cover 17,000 nautical miles in 90 days before it returns to Shanghai on Sept. 29, officials said. The expedition is planning to conduct further research in the Norwegian Sea and the Greenland Sea, they said.