This is the last Titan Missle. It was part of the US, mutually assured destruction strategy to prevent the USSR from launching a first nuclear strike. This sort of thing only works if the enemy knows how good your ability to respond to a first strike really is so the US, while nominally acting like it was keeping the details a secret, let the Russian spies get the information about how our system worked. Even though the Russians had many more ICBMs than we did, and hugely more powerful nuclear weapons, they knew from their spies that we had enough clout to destroy them even if they did strike first.
The second picture is a re-entry vehicle that would house a thermonuclear weapon. The third picture is an entire Titan missle inside the last remaining Titan silo. It's been rendered inoperable according to the terms of the nuclear disarmament treaty, and any Russian can come here to take the tour to see that it's inoperable because the extremely heavy silo cover has been cemented stuck in the half open position. The last picture is the control room. That's where they'd have launched the missle from if they'd ever gotten the launch order from the President.
This museum is around 15 miles south of Tucson, AZ.
