Minuteman facilities were designed to withstand the nuclear environments produced by a near miss from an attacking warhead detonation. The operation of the Minuteman depended on a second strike capability. This means that the system must be able to function even after exposure to a hostile nuclear environment. The design of the silo and its support facilities reflect this hardened design in many ways, including the steel launch tube liner that provided electromagnetic shielding and prevented damage to the missile from surface erosion and from flying chips of concrete at launch.
Before we visit the silo, make a perimeter scan inside the fence. The United States Air Force called this 1.6 acres of gravel, concrete, and steel a “Priority Area”. This was one of ten sites under command of Delta-01, and when all systems were functioning properly, this site was unmanned. With solid fuel technology, the missile could lie dormant for weeks, months, or (theoretically) even years with limited maintenance and upkeep. Launch Officers at Delta-01 monitored these sites remotely via multiple sensors and miles of underground cables. Minuteman was America’s quickest-responding ICBM. From the moment the capsule received a valid launch order—and completed a checklist-guided key-turn procedure—it could take as little as one minute for the missile to fire.
Only when the missile or its silo needed maintenance, or when its intrusion detectors noted an alarm, was Delta-09 ever manned. As so complex a system as Minuteman aged, this became more frequent. Daily, five or more missile sites of the 150 total in the Wing required scheduled repairs of some kind. That’s when Minuteman’s three interdependent support organizations—Operations, Maintenance, and Security—worked in close harmony to secure sites and get them back on-line for constant alert.
Let’s now head to the glass enclosure over the silo itself.