On 5 October 1960 an early-warning system warned the North American Aerospace Defence Command (NORAD) of a massive Soviet nuclear missile strike approaching the United States. What happened is that a fault in a computer system had removed two zeros from the radar's ranging components, detecting the missile attack at 4 000km (2,500 miles) away. The radar was actually detecting a reflection from the moon, located 400 000km (250,000 miles) away.
Nuclear bomb - man's worst invention
On 3 June 1980 a massive Soviet missile attack was again registered by computers. 100 nuclear-armed B-52s were immediately put on alert. A computer fault was detected in time, but three days later the same error occurred and again the bombers were put on alert. The problem was later traced to the failure of an integrated circuit in a computer, which was producing random digits representing the number of missiles detected.
On 10 January 1984, Warren Air Force Base in Cheyenne, Wyoming, recorded a message that one of its Minuteman III intercontinental ballistic missiles was about to launch from its silo due to a computer malfunction. To prevent the possible launch, an armoured car was parked on top of the silo.