Okay, just to go full conspiracy theorist on you for a second:
The USSR could’ve covered USA’s ass on this because their own achievements were fake too, and they didn’t want it to come out
I don’t have any evidence for this, nor do I believe it myself, but just playing devil’s advocate here
That doesnt work in the long term unless you kill everyone that knows about it. Its a weak plan at best.
Oh that’s definitely true, but that could be said for literally every conspiracy theory, ever.
My comment was working on the assumption that you already believe in conspiracy theories, and was meant to explain how one could then rationalize this particular one