Watch 002 Operation Moon (1965) Official Trailer

KGB authorities abduct two criminals (Franco and Ciccio) who look exactly like missing spacemen and pretend they are the returning cosmonauts. They launch them in a rocket, so that they can land in public view, leading the populace to believe it was the original space craft that has returned. The two criminals look so much like the astronauts, they even fool the wives of the astronauts. Later however, the original spacecraft returns to Earth undamaged, and the plan goes all to pieces. In the end, Franco and Ciccio stay in Russia and the real astronauts relocate to Italy.