Two hours before take-off, the selected cosmonaut ascended to the top of the gantry in an elevator and climbed into the crew capsule through a round hatchway. Pad technicians then sealed the hatch into place with 36 explosive bolts. These could be fired at a moment’s notice to jettison the hatch, so that a rocket-propelled ejection seat inside the cabin could blast the cosmonaut out of the Vostok if anything went wrong during launch.
On ignition, the R-7 accelerated Vostok from standstill to 17,500 miles per hour in less than nine minutes, boosting the capsule to an orbit more than 100 miles high.
The orbital phase of a Vostok mission was uneventful. A periscope with a circular vision port allowed the cosmonaut to check the orientation of his craft against the Earth’s horizon, but apart from checking the clarity of voice communications with mission control, there was little else to do.
At the end of a mission, small rocket motors on the equipment module fired automatically to slow the craft so that it would drift down towards the Earth’s atmosphere. Four metal straps were snapped apart by small explosive charges, releasing the crew module for re-entry.