I was a Flight Security Supervisor (FSS) for the Minuteman missiles at Grand Forks AFB, North Dakota, from May 1973 until December 1978. We had an incident around 1977, when strange lights took over our missiles. You may already have this data, so I won’t go into it deeper. I just wanted to confirm that these incidents were happening.
Satellite photo of Grand Forks, North Dakota (tageo.com)