It serves as a command center in the event that a command on earth is destroyed by an atomic impact.
On March 3, 1961, the United States Air Force (USAF) launched Operation Looking Glass. It is a code name for the fact that from then until today, there is always an American plane in the air to serve as a command center in the event that command on earth is destroyed by an atomic strike.
Initially, in the event of an increased risk of war, the pilot and co-pilot of the aircraft had to wear blindfolds. That is, in the event of a sudden nuclear flash, they would preserve at least one eye and continue flying. Today, instead, they wear special glasses that automatically darken in the event of a nuclear flash.
Used aircraft, the so-called Doomsday aircraft is of the Boeing E-6 Mercury type. The crew on board are capable of taking command of all US nuclear forces in case of need. It is even possible to communicate with nuclear submarines via a 4-kilometer antenna that the aircraft can pull out of its tail.