During the Cold War, both the Soviet Union and the United States quietly explored plans for permanent moon bases, military outposts, and even detonating a nuclear device on the lunar surface.

In the early 1960s, the Soviet Union quietly pursued Project Zvezda, an ambitious plan to build a concealed, self sufficient moon base before the United States. Declassified designs and failed rockets ...

I sometimes wonder where we would be now, as a species, had the Soviet Union not collapsed and continued its space race with the United States. Would we have already colonized other planets by now, or ...