Everyone went from feudal backwater to something else in that era. The US was poorer than Argentina per capita. That’s not really saying that much. It’s also not saying that much because of course if you have a strong central authority you can divert resources from more valuable production toward national pride vanity projects like a space travel. What really matters is how productive your economy is, how much it can produce for its society, and on that front the US defeated the Soviet Union soundly.
I have nothing against a space program, I just don’t see that as a very strong indicator of the success of a society.