> What I'm saying that writers were clearly forbidden by the communist powers to look towards west.
That's highly debatable, and it most certainly depended on the writers. I can speak for Romania (from where I'm from), where the works of Faulkner or Hemingway were held in very high esteem starting with the early 1960s, when translation of most of the stuff they were famous for started to be translated. The same goes for most of the Anglo (and Western) literature. Yes, in the second half of the '80s stuff was less rosy in that domain, but that mostly because of the self-imposed austerity we were going through, almost nothing of note was getting published anymore, with rare exceptions (such as a wonderful translation of Proust in 1987-1988, something like that).
I can confirm that it was the same for the USSR. There was a "blessed" corpus of Western authors, and this actually did include a lot of sci-fi as well.
Asimov is one prominent case because the translators had to figure out how to deal with his obviously Jewish name at the time when that became a red flag. This is why it's traditionally transcribed phonetically as Айзек rather than the more straightforward Исаак.
Isaac Asimov was born in Petrovichi, Russia. There should be an obvious Russian transcription of his originally Russian name. Азимов for the family name, according to Wikipedia.
So it existed but was changed when being translated back, for political / antisemitic reasons?
That's the thing - "Isaac" is not a Russian name, but rather a Russian Jewish name, and is normally spelled "Исаак" (and pronounced something like ee-saah-k), which is indeed exactly how it was spelled in his birth certificate. It is also a very recognizably Jewish name - e.g. it would often be used in Russian political jokes on the subject.
And then you have USSR with its periodic antisemitic campaigns. The relevant one here is the one that started under Brezhnev in late 1960s, which is also when sci-fi in general became more popular in the USSR prompting more translations. So, publishing an author whose first name is Isaac would immediately draw attention from the censors. Seeing how anything Western was already on shaky grounds - sci-fi being allowed in the first place because it would often critique contemporary Western societies - translators played it safe by transcribing the American English pronunciation of "Isaac" into Russian, which made it Айзек (Ayzek). Which helpfully looks nothing like Исаак (Isaak), and doesn't "sound" Jewish at all to Russian ears.
This translation stuck, and it's how he is commonly known in Russian to this day.