An/TVs 3 Searchlight – 20 kW Xenon Arc viewable from space
> Initially, NASA underestimated the electromechanical interference (EMI) projected by the light and the Apollo computers crashed when the beams were aimed at the rockets on the launch pads.Not wanting to ruin a good story, but I find this unlikely. If it were true I would think the military would be more interested in using them as weapons for electronic warfare than search lights. More likely the lights were interfering with radio links like telemetry or voice. Or maybe they were just not conforming to some EMI guidelines NASA was using at the time and were modified as a safety precaution.