A look at the Minuteman III

The Air Force's nuclear missiles have stood ready for war on short notice for more than 50 years.

Americans tend to assume the missiles are safe, but ¿Do they remember they exist? Let us look, in brief, at the Minuteman III missiles and their mission

The Air Force operates just one type of land-based nuclear missile, the Minuteman III. It is a class of weapon known as an intercontinental ballistic missile, or ICBM. The U.S. has 450 of these missiles, each with a single nuclear warhead attached. The missiles are guided to a target by a self-contained navigation system that uses motion and rotation sensors to track and update the missile's position and orientation.

Each Minuteman 3 missile is based in its own underground silo "hardened" with concrete to withstand an enemy nuclear strike. At the heart of the silo are the men and women who command the missiles. They are called missileers and are junior officers - lieutenants and captains, typically ages 22 to 27. Two missileers operate an underground launch control center, which is responsible for 10 missiles. The missileers do 24-hour "alert" shifts, then hand off to a replacement crew. Because the missiles are meant to be ready for combat on short notice, the launch capsules are manned without interruption, 365 days a year.

There are three Air Force ICBM bases: Malmstrom in Montana, F.E. Warren in Wyoming and Minot in North Dakota. Each base operates 150 missiles, divided into three squadrons of 50 missiles each. The force is commanded by a two-star general who heads the 20th Air Force. He answers to a three-star general at Air Force Global Strike Command at Barksdale Air Force Base in Louisiana who is responsible not only for the ICBMs but also for the B-2 and B-52 bombers that have a nuclear mission as well.

Minuteman III missiles are the third generation of Minuteman missiles. The first generation went into service in October 1962 during the Cuban missile crisis. The Minuteman II became operational in 1966, and the current version was declared operational at Minot in December 1970, according to an official Air Force history of the ICBM. No ICBM has ever been launched other than for testing. The Obama administration has decided to take 50 of the 450 Minuteman 3 missiles off active duty by February 2018, but it is committed to preserving their role as part of the "triad" of strategic nuclear forces, along with bombers and nuclear-armed submarines.