I think the Soviets did have so called space mines in orbit during the Cold War. They were bascially satellites that could move near an enemy satellite and explode. They were said to be nuclear powered which means they had a lot of power to be active for a long time. I don' t think the Russians have launched any new space mines since the end of the Cold War. The Americans and Chinese like to use anti satellite missiles. If a war in space did break out, the resulting debris could make manned space missions dangerous. That is why i don' t think there will be a war in space between humans. The Americans, Russians and the Chinese will want to continue with their manned space missions.