Well, I'm a Russian and I really don't know, because I was born in Russia not in the Soviet Union )
Oh, I googled and in one minute realized, that I had read a book by Kir Bulychev, it was really good. Also, Aelita by Alexey Tolstoy is considered to be the main book of the early Soviet space travel period. Also, Ivan Efremov and Alexander Belyaev.
If you can read basic Russian, here is the link for you about the brief history of soviet space literature. Authors are in bold :) http://www.mirf.ru/book/sovetskaya-kosmicheskaya-fantastika
Enjoy :)