This matches with what I heard from a former silo officer. I did a tour of the Atlas Missile Museum outside Tuscon, AZ, which holds the distinction of being one

This matches with what I heard from a former silo officer. I did a tour of the Atlas Missile Museum outside Tuscon, AZ, which holds the distinction of being one of the only fully intact but non-functional missile silos that you can visit. The tour itself, when I went, was given by an officer who used to be stationed at the silo when it was operational (being an Atlas, they were only in service for a short time), so I believe that was in the 50s. I asked him more or less this exact question, and here's how he explained it (and I remember it). They were on 2 week shifts, with 2 weeks on, 2 weeks off. When you enter the silo, you were ID'd over a camera on the outside, and only then would the officers being relieved unlock the door and let you in. If you got launch codes, you verified them with your partner (every place near the launch area was a 2 man zone), and then you both had to turn a key within a few seconds of each other. The keys were not within reach of each other. Once the launch sequence began, you basically powered everything down. Once the keys are turned, it is autonomous, and you basically aren't needed anymore. You didn't know if it was real, or if it was a test, and you were not aware of whether the missile would even launch or not. When it did launch, and it ended up being a test, you were notified more or less by the arrival of the next shift. As he put it, if the next shift didn't arrive, then you'd wait it out until you ran out of food, and then figure out what you would do. But he discussed the overall setup, and said he'd turned that key many times, as had all the other officers. The silo staff aren't going to know if its a legitimate launch or not, they are not trained to ask that question, and they are specifically conditioned in a way that leads me to believe that if an order came down, no matter how crazy, it would be executed by anyone who was outside of the decision hierarchy.