The Coast Guard Cutter Polar Star, with 75,000 horsepower and its 13,500-ton weight, is guided by its crew to break through Antarctic ice en route to the National Science Foundation's McMurdo Station, Jan. 15, 2017. The ship, which was designed more than 40 years ago, remains the world's most powerful non-nuclear icebreaker. (U.S. Coast Guard photo by Chief Petty Officer David Mosley)