I think Ivan Yefremov's books are some of the best in this genre, both very Communist and well-written ;) Looks like Amazon sells some English translations.

I also highly recommend Strugatsky brothers -- they are by far most prominent Russian sci-fi writers. While they were not eager promoters of Communism -- in fact, they were at odds with the regime -- I believe many of their books fit the Space Communism label. Try Noon: 22nd Century (Полдень. XXII век) or Far Rainbow (Далёкая Радуга). In their later works, they became concerned about societal changes being brought by technological advances and painted more grim future, e.g. in The Ugly Swans (Гадкие лебеди) or The Doomed City (Град обреченный)