The nation’s only heavy icebreaker departed Seattle Sunday for a four-month mission to Antarctica as part of Operation Deep Freeze, the annual Joint Task Force Support to resupply the National Science Foundation outpost there. The crew of Coast Guard Cutter Polar Star from Coast Guard Base Seattle will head to McMurdo Sound in support the U.S. Antarctic Program and the National Science Foundation. This mission will require the cutter’s crew to break through more 12 miles of ice in McMurdo Sound, sometimes as much as 10 feet in thickness, to resupply McMurdo Science Station. For more than 50 years, Coast Guard icebreakers have deployed to Antarctica in support of Operation Deep Freeze. This deployment will mark the second Antarctic mission a Coast Guard icebreaker has performed since 2007. Operation Deep Freeze is unlike any other U.S. military operation. It is one of the military’s most difficult peacetime missions due to the harsh Antarctic environment. The U.S. military is uniquely equipped and trained to operate in such an austere environment. Polar Star is a 399-foot polar class icebreaker with a 140-person crew and was commissioned in January 1976.