1950s-70s USA and Russia philatelic covers that are related to the early satellites development, manned and unmanned spaceflights to the moon.
1966-01-31 USSR Luna 9
Launched on 31 Jan 1966, Luna 9 became the first spacecraft to make a controlled landing onto the surface of another celestial body on 3 February 1966.
Luna 9 televised and transmitted across 250,000 miles (400,000 km) of space to earth, photographs of the surface, giving man a close-up look at its structure. Objects only a few inches in size showed up. It also conducted experiment to demonstrate that the bearing strength of the lunar ground was sufficient to hold a large spacecraft, and not destined to sink into layers of dust, as some astronomers had predicted. The communication with Luna 9 ended on 5 February 1966.