page_title: Vostok (spacecraft)
section_title: Vostok 3KA
hierarchical_section_title: Vostok (spacecraft) / Design / Vostok 3KA
context_page_description: The Vostok was a type of spacecraft built by the Soviet Union. The first human spaceflight was accomplished with Vostok 1 on April 12, 1961, by Soviet cosmonaut Yuri Gagarin.
  The spacecraft was part of the Vostok programme, in which six crewed spaceflights were made, from 1961–1963. Two further human space flights were made in 1964 and 1965 by Voskhod spacecraft, which were modified Vostok spacecraft. By the late 1960s both were superseded by the Soyuz spacecraft, which are still used as of 2020.
context_section_description: The Vostok 3KA was the spacecraft used for the first human spaceflights. They were launched from Baikonur Cosmodrome using Vostok 8K72K launch vehicles. The first flight of a Vostok 3KA occurred on March 9, 1961. The first flight with a crew—Vostok 1 carrying Yuri Gagarin—took place on April 12, 1961. The last flight—Vostok 6 carrying the first woman in space, Valentina Tereshkova—took place on June 16, 1963.
  A total of 8 Vostok 3KA spacecraft were flown, 6 of them with a human crew.
  Specifications for this version are:
  Reentry Module: Vostok SA. SA stands for Spuskaemiy apparat - descent system. It was nicknamed "Sharik" (Russian: шарик, lit. 'little sphere').
  Crew Size: 1
  Diameter: 2.3 m sphere
  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. PA stands for Priborniy otsek - instrument section.
  Length: 2.25 m
  Diameter: 2.43 m
  Mass: 2,270 kg
  Equipment in pressurized compartment
  RCS Thrusters: 16 x 5 N (8 + 8 for automatic + manual)
  RCS Thrusters pressure: 59 PSI (4 bars)
  RCS Propellants: Cold gas (nitrogen) at 2200 PSI (150 bar)
  RCS Propellants: 20 kg stored in 12 pressure bottles (5 + 5 + 2 for first, second and reserve)
  Main Engine(the S5.4) (TDU): 397 kg
  Main Engine Thrust: 15.83 kN
  Main Engine Propellants: RFNA/amine
  Main Engine Propellants: 275 kg
  Main Engine Isp: 266 s (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 inclination
caption: Vostok spacecraft