 |
| A Vostok 5 launch cover postmarked in Donetsk with a hand cancel on June 14, 1963. |
Vostok 5 was the fifth crewed mission of the Soviet Vostok program and a major step toward longer-duration human spaceflight. It launched from Baikonur Cosmodrome on June 14, 1963, carrying cosmonaut Valery Bykovsky. The spacecraft remained in orbit for 4 days, 23 hours and 7 minutes, completing 81 Earth orbits before landing on June 19.
 |
| A Vostok 5 launch cover postmarked in Liepaja with a hand cancel on June 14, 1963. |
The mission had originally been planned to last eight days, but several factors affected the flight plan. There was concern about increased solar activity, while the spacecraft was inserted into a lower-than-planned orbit. The lower orbit increased concerns about orbital decay during a very long mission, and the planned duration was subsequently shortened.
 |
| A cover from "Kiev Society of Collectors" commemorating the Vostok 5 spaceflight, postmarked with a red Kiev special hand cancel dated June 15, 1963, signed by Gherman Titov and Valery Bykovsky. |
Vostok 5 was particularly important because it formed a paired mission with Vostok 6. Two days after Bykovsky's launch, Valentina Tereshkova launched aboard Vostok 6 on June 16. The two spacecraft operated simultaneously and established radio communications with one another. They came within approximately 5 km (3 miles) of each other, although they were not capable of docking. This was the second Soviet pair of simultaneous crewed spacecraft, following Vostok 3 and Vostok 4 in August 1962.
 |
| A cover from "Poltava City Society of Collectors" commemorating the Vostok 5 spaceflight, postmarked in Poltava with a hand cancel on June 15, 1963. |
After nearly five days in orbit, Bykovsky returned to Earth on June 19, 1963. He landed in Kazakhstan, shortly after Tereshkova's Vostok 6 landing. His total flight time was approximately 119 hours 6 minutes, and he completed 81 orbits. Vostok 5 established a new record for the longest solo human spaceflight, a record that remained significant until later American and Soviet missions extended human endurance in space.
 |
| A postcard featuring a portrait of Valery Bykovsky, postmarked with a black Moscow special hand cancel, signed by Valery Bykovsky |
 |
| A cover commemorating the Vostok 5 & 6 spaceflights featuring a portrait of Valery Bykovsky, postmarked with a black Moscow special hand cancel. |
