Yes, that is my guess too. On the other hand, I would be _extremely_ interested to see a real-time Prolog dialect used to control real-life space shuttles, that's totally my aesthetic. :) But I can't understand Russian, which makes it difficult to research.
My old German university's web server was written in prolog, so it's not completeley inconceivable for a spacecraft, but I'd like to see more evidence.