China's first domestically built polar icebreaker, Xuelong 2, embarked on sea trials on Friday after 45 days of maintenance, preparing for the country's 11th Arctic expedition scheduled for July. Xuelong 2 completed maintenance at the Jiangnan Shipyard in east China's Shanghai Municipality. Another Chinese icebreaker, Xuelong, is also under maintenance in Shanghai and is set to leave the shipyard at the end of July.