In the 1960s, while the world watched Saturn V rockets rise under the banner of Apollo, the Air Force was developing the manned orbiting laboratory, a military space station designed for reconnaissance of America's enemies and other orbital operations.
And then in June of 1969, exactly one month before the Apollo mission reached the moon for the first time, the manned orbiting laboratory was canceled.
Advances in automated spy satellites made human observers redundant. Vietnam was draining resources. The Apollo program was imminent. So the classified space program was folded.