Some of these aren't conspiracy theories. The Soyuz 1 pilot knew he was going to die and, well, he did. The 1960 R-16 rocket explosion at the Baikonur Cosmodro

Some of these aren't conspiracy theories. The Soyuz 1 pilot knew he was going to die and, well, he did. The 1960 R-16 rocket explosion at the Baikonur Cosmodrome killed something like 200 ground crew. This was covered up for decades and only officially acknowledged as the USSR was beginning to fall apart in 1989. https://en.wikipedia.org/wiki/Nedelin_catastrophe https://en.wikipedia.org/wiki/Nedelin_catastrophe I also believe the Polyus anti-satellite weapon platform intended to militarize space was a secret to the West until it failed to achieve orbit: https://en.wikipedia.org/wiki/Polyus_%28spacecraft%29 https://en.wikipedia.org/wiki/Polyus_%28spacecraft%29 Pretty much every space mission in the USSR was a secret. The West would detect a launch, or sometimes be told in advance a launch was happening to lower nuclear tensions, and then days later we'd see in Pravda what mission it was.