|This cover was produced by Kniga with a backdated 3 November 1957 Moscow postmark.|
Sputnik 2 detected the Earth's outer radiation belt in the far northern latitudes, but the significance of the elevated radiation was not realized. In Australia, Professor Harry Messel intercepted the signals but the Soviets would not provide the code and the Australians would not send the data. In 1958, with Sputnik 3, they began to cooperate and confirmed the findings of the US satellites Explorer 1, 3, and 4.
|Set of four Sputnik 2 stamps were issued.|