Soviet space exploration history on Soviet stamps

The history of Soviet space exploration has been well documented on the country's stamps. These include not only the notable accomplishments in space flight, including mankind's first satellite, Sputnik 1, first animal in space (the dog Laika on Sputnik 2), first human in space and Earth orbit (cosmonaut Yuri Gagarin on Vostok 1), the first woman in space (Valentina Tereshkova on Vostok 6), first Moon impact (1959) and unmanned landing, first space station, and first interplanetary probe but also more general astronomical observation.