Stalin’s eldest son died as a Nazi prisoner of war during WWII, after Stalin refused multiple offers to exchange him for German prisoners held by the Soviets.
When the Soviet Union were occupying Afghanistan there was an Afghan Cosmonaut who became a Hero of the Soviet Union.
In 1978 a man was shot in the head by a proton beam and amazingly lived.
There’s an island in Kazakhstan/Uzbekistan that was used as a test site and is now riddled with anthrax, smallpox, plague, etc.
Devyatayev was a soviet pilot who was captured by the Nazis in 1944 and managed to steal a German airplane from a heavily guarded Nazi military base. On his return to the USSR his plane was shot at, and was then labeled as a spy because his story was so unbelievable.