Reading John Wyndham's Retro Hugo nominated story, "The Sleepers of Mars", I was startled to see that his cosmonauts knew of only seven Soviet Republics (in a story published in 1938 and set in 1981). When the USSR broke up in 1991, there were fifteen of them. What, I wondered, had Wyndham done with the other eight?
Four were easy enough. In 1938, most of what is now Moldova was part of Romania (with what's now Transdniestria part of the Ukrainian SSR), and the three Baltic states were enjoying a precarious independence (incidentally, they've now been independent again for longer than they were between the World Wars).
However, Wyndham was actually a little out of date with regard to the other four. There had indeed been only seven Soviet Republics up until the new Soviet Constitution of December 1936. But from then on, the former Transcaucasian SSR was split into the Georgian, Armenian and Azerbaijan SSR's; and the Kyrgyz and Kazakh SSR's were split off from the RSFSR (now the Russian Federation). The Uzbek and Turkmen SSR's had been constituents of the Soviet Union since 1924, and the Tajik SSR was split off from the Uzbek SSR in 1926. His cosmonauts should have made Mars the twelfth republic to be attached to the Soviet Union, not the eighth.
It's a slightly surprising slip from Wyndham. It would be odd to write a story set 43 years in our future about, for instance, making Mars the fifty-third state of the US, or the thirty-fifth of the European Union, without checking how many states there are in that entity at the moment and deciding how many you thought there might be in 2057. Perhaps the story was written before December 1936; or perhaps (I guess most likely) the news of the new Soviet internal arrangements hadn't seeped very far into popular discourse by the time he wrote the story in 1937.