bearings. Propeller issues continued through 1977-1988, leading Coast Guard to invoke the warranty clause of the Lockheed Shipbuilding and Construction Company.Polar Star has supported National Science Foundation and United States Antarctic Program objectives in the Antarctic, breaking a channel through the fast ice to resupply the McMurdo Station in the Ross Sea and the close quarter ice escorts of Military Sealift Command resupply ships through the channel in support of Operation Deep Freeze, which deliver food, fuel, and other goods to the station annually. Polar Star is the only ship in the United States' fleet capable of breaking the fast ice in McMurdo Sound. Polar Star also delivered inspectors from the U. S. Antarctic Inspection team to foreign outposts for the purpose of Antarctic Treaty Inspections. Arctic deployments for occurred, including the annual resupply of Thule Air Base, Greenland, as well as science and power projection based operations referred to as Arctic East Summer (AES), Arctic West Summer (AWS), and Arctic West Winter (AWW). In the 1997-1998 season, the ship supported the New Zealand Antarctic Research Programme. In February 1998 Polar Star received a report from the Greewave that they were disabled and adrift off Cape Adare. Arriving on scene the next day Polar Star took the Greewave in tow and proceeded on a 12-day 1515 mile transit to Lyttelton, New Zealand. This was the first visit by a military vessel of the United States to New Zealand in 13 years. Reserve status — Overhaul The ship was placed in reserve, or "Commission-Special" status, in 2006 and stationed in Seattle. A 26 February 2008 report by the Congressional Research Service estimated a US$400 million cost for a 25-year service life extension refit for Polar Star, a US$56 million cost for an 8 to 10-year service life extension refit or US$8.2 million cost for a single season service life extension refit. This caretaker status required a reduced crew of 44 to keep the ship ready for a possible return to the ice. In 2009, the NSF announced that they would end funding for maintaining the ship. The ship was reactivated for overhaul, which took four years and was completed by Seattle's Vigor Industrial shipyard (formerly Todd Pacific shipyard), at a cost of US$57 million. Polar Star was back in operation in late 2013, and assigned to Antarctic operations as part of Operation Deep Freeze in early 2014 for the first time