On June 14th, the U.S. Air Force successfully completed a quality control test on its fleet of 500 Minuteman III missiles. One of the missiles was fired about 7,600 kilometers away, towards the central Pacific, and the three test warheads (their nuclear weapons replaced with tracking instruments) landed, where they were supposed to, near the Marshall Islands.
The Minuteman third stage, that now contains three 440 pound nuclear weapons, is being replaced with the more capable one from the more recent, but now retired. Peacekeeper ICBM. The Minuteman III is 70 feet long, 5.5 feet in diameter and weighs 32 tons. The Peacekeeper is being taken out of service because not many (only 50) were put into service before the Cold War ended, and disarmament treaties outlawed some of its features.
The Minuteman III is expected to remain in service until 2020, at which point it will be replaced by a new missile design. Current disarmament treaties have the United States reducing nuclear warheads to fewer than 2,200 in the next few years.