Originally Posted By: wagga
The sites are concrete as in mortar, although a lot of slide rules (a weapon of math instruction) were used in the making of the events. In fact, they used roomfuls of Computers.

so now we know it was probably built in the 1950s or 1960s, but we kinda already knew that from looking. The use of NASA- grade computer rooms of IBM 360s or whatever suggests some sort of macroscientific study, maybe like timing of cosmic rays zapping through the Earth, or some such.