At Thule Air Base, Greenland, 695 miles north of the Arctic Circle, the ice has broken, and the once-yearly resupply and construction season has begun on half-century old dormitories. With the Summer's ice thaw, the base's port is accessible to supply ships for a short three month window.      Airmen and Guardians at Thule-balance the responsibilities that come with a vital missile warning and missile defense mission with the mental resiliency required to sustain minus 12-degrees average winter temperatures in total darkness, or days at a time indoors during deadly snowstorms between September and May that give little warning before a mandatory shelter-in-place.        "We've got to keep the lights on and got to keep the mission on, and nobody wants to freeze to death in the winter." Installation Commander and 821st Space Base Group Commander U.S. Air Force Col. Heather L. McGee told Air Force Magazine by phone from Thule in the final week of her command.  McGee's role as instalation commander includes supporting the missile defense and space surveillance missions of the 12th Space Warning Squadron-and the tracking station operated by the 23rd Space Operations Squadron, Detachment 1.                        Service members pass their personal time achieving personal and professional goals.  Many have trained for triathlons and ironman competitions or completed advanced degrees online.  Every day are different social events and intramural sports coupled with access to a state-od-the-art gymnasium, pool, and a new hockey rink.  Summer temperatures ranging from the 30s to 50s encourage service members to get outdoors for "Thule Trippin," activities that include running, hiking nearby Mount Dundas, and riding all-terrain vehicles.    "The Base was built in 1951, so some of these buildings have been around since then," Col. McGee said.    Perhaps one of the most important changes that happened during McGee's tenure was the beta test by the Air Force Research Laboratory-to install satellite internet by accessing the polar-orbiting low Earth orbit (LEO) Satellites of the OneWeb Constellation.    The radar looks out over the North Pole and provides the initial ground-based warning if any potential missile attacks were to be launched from Russia.  The Thule radar would confirm data gathered by Space-Based Infrared System (SBIRS) Satellites that would first detect a missile launch.  "People here are passionate about what they do. They're dedicated.  It takes a very resilient Airman or Guardian to be up here, and the people that are here are truly knocking it out of the park," Col. McGee said.