The light was directly over my head, and no sound of a aircraft.While working for a defence contrator, I was part of a crew that was testing medium caliber ammunition on a US Army training center in central Wisconsin. I and another employee, and a government inspector were in a observation post above and behind the weapon used to test the ammunition. This test was conducted at night in order to see the tracer. We were firing and impacting about 5000 meters down range. To my surprise two lights appeared in the sky about 500 ft high and about 1500 meters down range. Thinking a aircraft had adccidently entered a forbidden airspace I called for a stop to all firing. The lights were lit for about 5 seconds, I telephoned range control to see if any aircraft were in the area, they said no. It was total quiet no sound of a plane. The two lights that were side by side looked about 30-50 feet apart, estimating from the distance from us. After about 10 minutes a light from above appeared on my right, just above the low clouds. This light was on for about 2 seconds, the light came on again, this time directly above us for about another 2 seconds, then a third time to the left of us. No sound of any kind could be heard.((NUFORC Note: Date is approximate. PD))