Vostok 3 cover with special Baku postmark, August 11, 1962.
Vostok 3 cover with special Kiev postmark, August 11, 1962.
Vostok 4 was launched a day after Vostok 3 on August 12, 1962, with cosmonaut Pavel Popovich on board - the first time that more than one manned spacecraft were in orbit at the same time.
Vostok 4 launch with special Nikolaiev postmark, August 12, 1962.
Vostok 4 launch with special Simferopol postmark, August 12, 1962.
Vostok 4 cover with special Kiev postmark, August 15, 1962.
Vostok 3 and 4 special Vinnitsa postmark, August 15, 1962.
Vostok 3 and 4 special Lvov postmark, August 15, 1962.