John Turner/U.S. Air ForceIt is a little-known mission within the United States Air Force that operates almost entirely underground, shrouded in secrecy – and is critical to national security.Those tasked with the job are known as missileers. Their work requires them to be on alert 24/7, and they are responsible for the maintenance, security and operation of the United States’ arsenal of Minuteman III nuclear intercontinental ballistic missiles. Their mission is one component of the U.S. nuclear "triad," which includes land, air and sea-based nuclear weapons.The weapons are monitored by the missileers who operate in what are known as "launch control centers," or LCCs, attached to three Air Force bases: F.E. Warren in Wyoming, Malmstrom in Montana and Minot in North Dakota. LCCs are essentially trailer-sized capsules positioned far beneath the earth’s surface, protected from threats and surveillance.Now, a mysterious threat has potentially emerged, which has pr