The US Coast Guard's Polar Star, the nation's sole heavy icebreaker, has arrived in Unalaska for the first time since 2013. The ship is preparing to patrol Alaska's Arctic waters, including the maritime boundary line separating the US and Russia, to assert maritime sovereignty and security in the far north. The ship arrived with 136 crew members for a pit stop 30 days into a months-long deployment to the Arctic. The mission is not only about national security and securing US economic interests, but also about doing environmental research. The ship's first winter Arctic deployment since 1982 is expected to help train the future generation of Arctic sailors and mission leaders. The Polar Star was expected to leave Unalaska's Port of Dutch Harbor on Thursday, Jan. 7, and complete its mission and return to Seattle by the end of February.