I worked with USAF nukes, though not on missiles. Training events and drills would have gone on all the time out in the field. Receiving and decoding messages, making preparatory steps, etc.
But I’d bet my butt that anything involving what looked to the crews like a real no-kidding launch order, would have taken place in a simulator back at the base, not out in the real lauch control facilities connected to real weapons. As noted above, the consequences of an error giving an actual launch would be too high to run that risk even with extremely low probability of it happening.
As to the mindset as asked by somebody above …
I was supposed to drop “tactical” nukes, not launch “strategic” ICBMs. At the moment of truth, it’s just a weapon, folks. It doesn’t kill people any deader than a sharp stick in the gut does.
Part of being a responsible military member is checking a large fraction of your personal judgment at the door. You *must *have the belief that the folks in charge (mostly) know what they’re doing. That’s true whether you’re a Private with a rifle, a Captain with a nuke gravity bomb, or a 3-star General with a dozen bases of nuke bombers under your command.
You all paid a lot of money (and still pay a lot of money) every year to have an effective coherent fighting force that does what it’s told to do in the manner it’s told to do it. Perforce, that can’t include a lot of second-guessing up & down the chain of command.
For normal combat, there are all sorts of legalities meant to ensure everybody is aware that you can’t just follow orders to slaughter a village. Everybody from 3-star to Private is 100% duty bound to retain some judgment and not blindly follow criminal orders.
But a properly authenticated launch order isn’t (by definition) criminal, and neither me nor my replacements today were/are in a position to second guess whatever decision process let things get this far.
At that point my job is to go do what damage I can to the enemy’s ability to kill us and our allies. And that’s exactly what I would have done to the best of my ability.
Yes, I am & was well aware of the strategic & geo-political firebreak between nuclear & non-nuclear combat. And that I would be part of taking humanity across that Rubicon. Still, my duty to do what I promised to do for your benefit (however convoluted) *must *outweigh any other concerns. People unable to compartmentailze the issue to that degree are not acceptable to occupy that role.