Yeah, it felt so wrong to see Lem up there. The fact that he was renowned in Soviet Union does not make him any Soviet. From what I've read of his works + his biography, he reminds me more of early US science-fiction writers than any of soviet ones.
Eastern European writers did contribute a sizeable bookshelf of writings about bright space communist future, until it began to turn sour. One lesser-known one who I remember from my childhood is Pavel Vezhinov's Death of Ajax.
UPD: Maybe we should use Eastern Bloc Science Fiction as a term?
One like Democracy and Republic and the literal translation is "Council".
So, you can surely be democratic outside of (hypothetical) Democratic Union, much like you may be soviet outside of USSR.