Baikonur Cosmodrome Site 31

Baikonur Site 31, also called Site 31/6, is an important place where rockets take off at the Baikonur Cosmodrome in Kazakhstan. It helps launch Soyuz-2 rockets for trips with and without people. The site was first used on January 14, 1961, for testing a special missile that helped create the Soyuz rocket family.

Since 2020, Site 31/6 has become the main place in Russia for launching crewed Soyuz rockets to the International Space Station (ISS). This happened because another launch site, Site 1/5 or Gagarin's Start, could not get money to update for bigger rockets. Before this change, Site 31/6 was only used a few times when Site 1/5 was not available.

History

R-7 launch site

Work started on Site 31/6 at Baikonur in late 1958. It was built as a second place to launch the R-7 intercontinental ballistic missile. Unlike Site 1/5, which was mostly for testing, Site 31/6 was made to launch real missiles. It had special buildings for putting together rockets, preparing nuclear parts, and storing energy. By the end of 1960, the site was finished, and the first R-7 missile launched from there on February 27, 1961.

Spacecraft launch site

Later, Site 31/6 began launching spacecraft, including those carrying people. It could reach different paths in space. By 1966, it had a special area for fueling these spacecraft. The site helped prepare early Soyuz spacecraft for missions.

In December 1966, an accident happened during a mission, but the site started working again in January 1969. It launched many missions in the 1970s and became very important after another accident in 1983. By 2006, it had launched 12 of Russia’s 100 missions with people onboard.

Soyuz-2 upgrades

In 2005, Site 31/6 was chosen to get upgrades for launching bigger Soyuz-2 rockets. These upgrades finished in 2008. The site started launching missions again in 2009. In 2012, it began launching missions with people again after more upgrades. Plans to upgrade another site were cancelled, so Site 31/6 became Russia’s main place for launching people.

Service platform collapse

On November 27, 2025, during a launch, part of the launch pad at Site 31/6 broke down. This made the only working place for launching people in Russia unusable for a time. Workers fixed the platform, and launches were planned to start again on March 22, 2026.

A panorama of the Baikonur Cosmodrome Site 31 taken from atop the Soyuz support structure. Zenit launch pad can be seen in the distance.