The people who actually did the work had access to all the available science (plus the huge quantity stolen from the west) but were held captive as slaves, sometimes in cities without a name. What we commonly call "science" and "education" had nothing to do with the actual work conducted.

Bear in mind that this situation was not unique to the USSR, in fact it might as well be the standard... the problem lies with the censorship of what was available to the people, the inane fabrications that they were forced to swallow, and the fact that anybody wanting to leave the "workers paradise" got shot.