Back in the Cold War years, the Soviet nuclear threat compelled the Strategic Air Command to keep an EC-135 command-post plane airborne continuously — for 29 years.

SAC called the plane “Looking Glass,” because its communications systems mirrored the ones on the ground at SAC’s Offutt Air Force Base headquarters. A general officer on board could launch nuclear weapons even if the Pentagon, the White House and SAC had all been incinerated in a Russian first strike.

https://omaha.com/news/local/rep-don-bacon-wants-to-bring-24-7-looking-glass-back-to-offutt/article_cb3d623c-ac2a-11ee-b224-7bd2b728b6d1.html