January 27, 2010: The U.S. Air Force test program for its Minuteman III ICBMs has been interrupted by a "mechanical problem" that will delay the next test seven months. The missile, selected at random from those stored in Midwest silos, was brought to Vandenberg Air Force Base in California, placed in a silo there, and readied for firing into the Pacific. But during the installation of the missile in the silo, a problem was encountered. The air force won't say what exactly the problems is, or if it is something common to other Minuteman missiles.

This kind of testing is not as realistic as what the Russians do, which is to just pick a missile at random, remove the nuclear warhead and replace it with one full of monitoring and radio equipment, and then fire it. The U.S. can't do that because American silos are surrounded by inhabited areas. Thus if the missile ran into trouble, and had to be destroyed (all such missiles are equipped with explosives for this, that can be set off by remote control), the debris could come down on people. The Russian silos are in more isolated areas, and Russians are more tolerant of their government showering them with missile debris. 

American ICBM tests are different in other ways. For example, a test three years ago was unique because for the first time, the test silo had the 105 ton doors closed, and then blown open just before launch. Repairing the doors is expensive, so the doors are usually kept open during preparations for the test, and plastic sheeting spread over the open silo to keep rain out. But a previous test was screwed up by a heavy rain, that flooded, and damaged, the silo despite the plastic sheeting. Another first for the test three years ago was the use of GPS guidance in the test warhead.

The tests are a form of quality control, and the current problems are actually beneficial. The test preparation process often uncovers problems that would cause the missiles to fail if used in a combat situation.