1962-08-11 USSR Vostok 3

Vostok 3 cover with special Kiev postmark, August 11, 1962.
Vostok 3 was launched on August 11, 1962, carried cosmonaut Andrian Nikolayev for a near fours days spaceflight in order to determine the ability of the human body to function in conditions of weightlessness and test the endurance of the Vostok 3KA spacecraft over longer flights. Cosmonaut Andriyan Nikolayev orbited the Earth 64 times in Vostok 3 over nearly four days in space, August 11–15, 1962, a feat which would not be matched by NASA until the Gemini program (1965–1966). Pavel Popovich was launched on Vostok 4 on August 12, and made 48 Earth orbits. The two capsules were launched on trajectories that brought the spacecraft within approximately 6.5 km (4.0 mi) of each another. They also communicated with each other via radio, the first ship-to-ship communications in space. These missions marked the first time that more than one crewed spacecraft was in orbit at the same time, giving Soviet mission controllers the opportunity to learn to manage this scenario.

Vostok 3 cover with special Baku postmark, August 11, 1962.
Vostok 3 cover with Penza postmark, August 11, 1962.
Andrian Nikolayev post card.
(Reference from Vostok 3 and 4)