Buttoning the Mountain:

Airmen of the 21st Space Wing’s 721st Mission Support Group at Cheyenne Mountain AFS, Colo., recently practiced “button-up” procedures—closing the mountain’s monstrous blast doors. “The blast doors are three-and-a-half feet thick, weigh 25 tons, and are normally closed by a hydraulic pump in 30 to 45 seconds,” says 1st Lt. Jeff Crepeau, 721st MSG executive officer. With muscle power alone, they can be closed in 4.5 minutes.