Important dates in this lesson:
1945: First atomic bombs dropped on Hiroshima and Nagasaki (by USA)
1949: USSR makes its own atomic bomb
China becomes a communist state
1953: Stalin dies. His successor is Nikita Khrushchev
1957: first satellite (Sputnik) sent into orbit (by USSR)
1961: first man in space: Yuri Gagarin (USSR)
Bay of Pigs invasion
1962: Cuban Missile Crisis
1969: first man on the moon: Neil Armstrong (USA)