VOSTOK

The Vostok programme was a Soviet human spaceflight project that succeeded in putting a person into Earth's orbit for the first time. The programme developed the Vostok spacecraft from the Zenit spy satellite project and adapted the Vostok rocket from an existing ICBM design. "Vostok" was a classified word before the first release of the program's name to the press.

There were six manned spaceflights in the Vostok programme, all of which took place between 1961 and 1963. The programme preceded the Voskhod programme, which used modified Vostok capsules. By the late 1960s, those programmes were superseded by the Soyuz programme, which continues as of 2011.

The 4,730-kilogram (10,428-pound) Vostok spacecraft consisted of a capsule and an instrument module. The capsule, which carried the cosmonaut, was a 2.3-meter (7.5-foot) silver sphere with a round entry hatch. A second hatch covered the parachute compartment. Four metal straps and power and control cables joined the capsule to the 2.25-meter-long (7.4 feet) instrument module, which included batteries, oxygen tanks, guidance equipment, and a retro-rocket.

Vostok reached Earth orbit on a modified R-7 missile. At the end of the mission Vostok fired its retro-rocket to slow down and fall from orbit. The instrument module detached and burned up in the atmosphere. The heat-shield-protected capsule dropped until it reached the lower atmosphere, and a parachute opened to slow its fall. The cosmonaut ejected 4,000 meters (13,120 feet) above the ground and floated to Earth on a parachute.

Soviet engineers helped ensure that Soviet cosmonauts would beat American astronauts into space by basing Vostok on an existing unmanned satellite design. Code-named Kosmos, the satellite was designed to photograph military activities and bases around the world and then reenter the atmosphere to deliver its film. Hundreds of Kosmos spy satellites flew between the 1960s and the 1990s.

Before launching a cosmonaut, Soviet engineers tested five Vostoks in the Korabl-Sputnik program (May 1960 to March 1961). Korabl-Sputnik 1 became stranded in orbit, and Korabl-Sputnik 3 reentered off course. Flight controllers commanded it to self-destruct. Korabl-Sputniks 2 through 5 carried dogs. Except for the two lost on Korabl-Sputnik 3, all the canine cosmonauts were recovered safely.

The successful Korabl-Sputnik 4 and 5 missions gave the green light for Vostok 1 (April 12, 1961). With a cry of "Poyekhali (Let's go)!" twenty-seven-year-old Yuri Gagarin lifted off for a 108-minute single-orbit flight. The first spaceflight went well until atmosphere re-entry, when cables linking the capsule and the instrument module failed to separate completely. The capsule gyrated wildly through re-entry as it dragged the instrument module behind it. The cables broke after about ten minutes, and Gagarin landed unhurt.

Vostok 2 (August 6 and 7, 1961) was a twenty-four-hour, eighteen-minute flight by Gherman Titov, who became the first person to sleep, eat, and get spacesick in orbit. Because of Titov's illness, doctors postponed Andrian Nikolayev's Vostok 3 flight until August 1962. Vostok 4 (August 12 to 15, 1962) carried Pavel Popovich to within 6.5 kilometers (4 miles) of Vostok 3.

Valeri Bykovskii's four-day, twenty-three-hour Vostok 5 flight (June 14 to 19, 1963) remains the longest solo space mission. Vostok 6 (June 16 to 19, 1963) carried Valentina Tereshkova, the first woman in space, to within 5 kilometers (3.1 miles) of Vostok 5. Soviet engineers canceled a planned one-week Vostok 7 flight so that they could concentrate on building Vostok's successor, the Voskhod spacecraft.