The Vostok (Восток, translated as "East") was a type of spacecraft built by the Soviet Union's space program for human spaceflight.

The craft consisted of a spherical descent module (mass 2.46 tonnes, diameter 2.3 meters), which housed the cosmonaut, instruments and escape system, and a conical instrument module (mass 2.27 tonnes, 2.25 m long, 2.43 m wide), which contained propellant and the engine system. On reentry, the cosmonaut would eject from the craft at about 7,000 m (23,000 ft) and descend via parachute, while the capsule would land separately.

The Vostok spacecraft was originally designed for use both as a camera platform (for the Soviet Union's first spy satellite program, Zenit) and as a manned spacecraft. This dual-use design was crucial in gaining Communist Party support for the program. The basic Vostok design has remained in use for some forty years, gradually adapted for a range of other unmanned satellites. The descent module design was reused, in heavily-modified form, by the Voskhod programme.

There were several models of the Vostok leading up to the manned version:

• Vostok 1K - prototype spacecraft. Used to test basic systems and prove the concept.
• Vostok 2K - photo-reconnaissance and signals intelligence spacecraft . Later named Zenit-2.
• Vostok 3K - Manned spacecraft.

Vostok 3KA spacecraft specifications

Reentry Module: Vostok SA. Also known as: Spuskaemiy apparat - 'Sharik' (sphere).

• Crew Size: 1
• Length: 2.3 m
• Diameter: 2.3 m
• Mass: 2,460 kg
• Heat Shield Mass: 837 kg
• Recovery equipment: 151 kg
• Parachute deploys at 2.5 km altitude
• Crew seat and provisions: 336 kg
• Crew ejects at 7 km altitude
• Ballistic reentry acceleration: 8 g (78 m/s²)

Equipment Module: Vostok PA. Also known as: Priborniy otsek.

• Length: 2.25 m
• Diameter: 2.43 m
• Mass: 2,270 kg
• Equipment in pressurized compartment
• RCS Propellants: Cold gas (nitrogen)
• RCS Propellants: 20 kg
• Main Engine (TDU): 397 kg
• Main Engine Thrust: 15.83 kN
• Main Engine Propellants: Nitrous oxide/amine
• Main Engine Propellants: 275 kg
• Main Engine Isp: 266 kgf·s/kg (2.61 kN·s/kg)
• Main Engine Burn Time: 1 minute (typical retro burn = 42 seconds)
• Spacecraft delta v: 155 m/s
• Electrical System: Batteries
• Electric System: 0.20 average kW
• Electric System: 24.0 kW·h

• Total Mass:4,730 kg
• Endurance: Supplies for 10 days in orbit
• Launch Vehicle: Vostok 8K72K
• Typical orbit: 177 km x 471 km, 64.9 inclinaton

See also

• Vostok 1
• Vostok rocket

External Links

• Vostok Specifications