An equipment failure disrupted communication between 50 nuclear missiles and the launch control center at Warren Air Force Base in Wyoming over the weekend, although the Air Force never lost the ability to launch the missiles.
Air Force spokesman Lt. Col. Todd Vician said the break occurred early Saturday and lasted less than one hour. The White House was briefed about the failure Tuesday morning.
There was no evidence of foul play, officials said Tuesday.
The Minuteman III intercontinental ballistic missiles are part of the 319th Missile Squadron stockpiled at Warren Air Force Base near Cheyenne, where 150 ICBMs are located. The failure affected 50 of them, or one-ninth of the U.S. arsenal. ICBMs at Air Force bases in Montana and North Dakota were not affected.
The equipment failure disrupted "communication between the control center and the missiles, but during that time they were still able to monitor the security of the affected missiles," Vician said. "The missiles were always protected. We have multiple redundancies and security features, and control features."
The launch control center computers communicate through an underground cable, but Vician could not confirm the cable was the source of the problem.
Vician said base personnel inspected all 50 missile sites and found no evidence of damage.
One military official, who spoke on condition of anonymity because he was not authorized to discuss the incident publicly, said the equipment in the launch control center has been the subject of unspecified communications problems in the past.
The White House referred questions to the Pentagon.
The failure was first reported by The Atlantic on the magazine's website.
The communications failure is the latest in a series of nuclear mishaps that have plagued the Air Force in recent years.
In August 2007, an Air Force B-52 bomber was mistakenly armed with six nuclear-tipped cruise missiles and flown from Minot Air Force Base, N.D., to Barksdale Air Force Base, La. At the time, the pilot and crew were unaware they had nuclear arms aboard.
Then, in March 2008, the Pentagon disclosed the mistaken shipment to Taiwan of four electrical fuses for ballistic missile warheads and launched a broad investigation into the military's handling of nuclear related materials.
An internal report asserted that slippage in the Air Force's nuclear standards was a problem that has been identified but not effectively addressed for more than a decade. Those findings led to Defense Secretary Robert Gates' decision to fire Air Force Secretary Michael Wynne and Gen. Michael Moseley, the Air Force chief of staff.