High Quality Content by WIKIPEDIA articles! Vostok 4 (Russian: -4, Orient 4 or East 4) was a mission in the Soviet space program. It was launched a day after Vostok 3 with cosmonaut Pavel Popovich on board - 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. The mission went largely as planned, despite a malfunction with the Vostok's life-support systems that meant that cabin temperature dropped down to 10 °C (50 °F). The flight was terminated early after a misunderstanding by ground control, who believed that Popovich had given them a codeword asking to be brought back ahead of schedule.