From May to August 1961, he trained to fly on spacecraft "Vostok-2" in a group of astronauts, followed (between September and November 1961) with training to fly "Vostok-3".
He commanded the space flight Vostok 4 () in 1962[REF] which, along with Andrian Nikolayev on Vostok 3, was the first time that more than one manned spacecraft were in orbit at the same time.