1950s-70s USA and Russia philatelic covers that are related to the early satellites development, manned and unmanned spaceflights to the moon.
1967-08-01 USA Lunar Orbiter 5
The final in the Lunar Orbiter series, Lunar Orbiter 5, was launched on 1 August 1967, and after nearly 90 hours and travelled 255,000 miles (410,000 km) of flight, it entered into orbit. Its missions were to continue detailed photography of more than 40 preselected sites on the near side of the moon and to cover the unphotographed regions along the western equator on the far side. Upon completion of the Lunar Orbiter 5 mission, over 99% of the moon's surface had been mapped (with data from all previous missions combined). The mission ended on January 31, 1968.