After Vietnam, the US Army decided that visible spectrum searchlights were a liability, since shedding white light on a battlefield provided illumination for both friendly forces and enemy combatants in equal measure. Modern night vision technologies made it possible for US military forces to function without artificial lighting and this gave them a huge advantage over enemies who did not have such technologies. By the late 1970’s, many AN/TVS 3’s were taken out of service and placed on the surplus market. Most of the remaining searchlights were sent to NASA to illuminate Apollo rockets on the launch pads at Kennedy Space Center. 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. Engineers solved the problem by using hardware store chicken wire to build “Faraday cages” that disrupted the harmful emissions.
via: AN/TVS 3 Searchlight