Csoportos űrrepülés, 1962. VIII. 11-15. Budapest, első nap, 1962.IX.4.

Vostok 3 and Vostok 4 joint spaceflight, Hungarian FDC, 1962.

Vostok 4 (with cosmonaut Pavel Popovich on board) was launched a day after Vostok 3 (with cosmonaut Andrian Nikolayev aboard) — the first time that more than one manned spacecraft were in orbit at the same time. The two Vostok capsules came within 6.5 km (4.0 mi) of one another and ship-to-ship radio contact was established.