Vostok 5 (Russian: Восток-5, Orient 5 or East 5) was a joint mission of the Soviet space program together with Vostok 6; as with the previous pair of Vostok 3 and Vostok 4 the two Vostok spacecraft came close to one another in orbit and established a radio link.

Several delays plagued the prelaunch preparations of Vostok 5, the biggest being concern over elevated solar flare activity. At this early phase, it was not well understood what effects this might have on the spacecraft and its passenger, so the planned launch date of 11 June was postponed a few days. On the 14th, Bykovsky was strapped into the capsule awaiting liftoff when further delays occurred. A gyroscope in the Blok E stage malfunctioned and needed to be replaced, but this would mean removing the propellants from the booster, taking it down from the pad back to the vehicle assembly building, and delaying the launch another several days. It was decided to take the calculated risk of simply doing the repair work on the fully fueled launch vehicle. A replacement gyroscope was quickly installed and liftoff took place at 2:59 PM Moscow time. One last minor problem popped up when a pad umbilical failed to disconnect, but as soon as the booster began lifting, it was yanked out. The launch proceeded without any difficulties, although the Blok E stage slightly underperformed and put the spacecraft into a lower-than-intended orbit at 108x137 miles (175x222 kilometers) versus the normal 112x146 miles (181x235 kilometers).

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