>According to my college professor, in the 1950's US engineers didn't bother to check russian publications on any subject, because they, just like you, thought that they were ignorant peasants that had nothing to contribute. Therefore they were completely ignorant about Lyapunov's developments. The thing is that Lyapunov's stability was a key advantage that allowed the soviets to beat the US in launching the first satellite into orbit. Only then, Kalman and others began to read their papers.
Oh dear, Ruzzist bovine faces on slashdot, color me surprised.
Tsiolkovski's stuff was ahead of time, but rather trivial physics that, nowadays, can be done by schoolchildren..
Did you decide to mention Lyapunov because Tsiolkovski was not ethnic Russian? Oh well. Anyway, what Lyapunov did was in a generic math field, not specific to space. He got noticed and published abroad. Hardly "unknown".
USSR has managed to win the "first man in space" race only when US tried to suppress von Braun.
It was behind before that event, as well as after.