Vostok

This article is about a type of Soviet spacecraft. For Russian base on Antarctica see Vostok, Antarctica.

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

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 7km and descend via parachute, while the capsule would land separately.

The R-7-derived launch vehicle was also called Vostock. It was used to launch unmanned spacecraft for many years after the Vostok program itself had ended.

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 program.

A series of prototype Vostoks, including at least five with animals and some with a test dummy aboard were used to qualfy the spacecraft for manned flight.

• Sputnik 4 (Korabl-Sputnik 1)
• Sputnik 5 (Korabl-Sputnik 2)
• Sputnik 6 (Korabl-Sputnik 3)
• Sputnik 9 (Korabl-Sputnik 4)
• Sputnik 10 (Korabl-Sputnik 5)

Vostok 1 was the first manned spaceflight, and was followed by

• Vostok 2
• Vostok 3
• Vostok 4
• Vostok 5
• Vostok 6

Another seven Vostok flights were originally planned, going through to the April of 1966, but these were cancelled as the race to the moon intensified.

On March 18, 1980 a Vostok-2M rocket exploded on its launch pad at Plesetsk during a fueling operation, killing 48. An investigation into a similar -- but avoided -- accident revealed that the substitution of lead-based for tin-based solder in hydrogen peroxide filters had resulted in the breakdown of the H2O2 and the resulting explosion.

The Vostok was succeeded by the Voskhod spacecraft.