Contractors conduct work on the hull of the Coast Guard Cutter Polar Star from the floor of the dry dock where the cutter is undergoing depot-level maintenance in Vallejo, Calif., in preparation for the cutter’s future polar region patrol, April 16, 2018. The crew of Polar Star overcame several engineering challenges during their recent Antarctic deployment including two instances requiring significant damage control efforts in order for the crew to complete their mission. U.S. Coast Guard photo by Petty Officer 1st Class Matthew S. Masaschi.