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| A Soyuz 12 launch cover, postmarked in Moscow with a hand cancel on September 27, 1973, signed by Vasily Lazarev and Oleg Grigoryevich Makarov. |
Soyuz 12, launched from Baikonur Cosmodrome on September 27, 1973, was a pivotal Soviet crewed mission. It was the first crewed flight of the redesigned Soyuz spacecraft after the Soyuz 11 tragedy in 1971, and its primary purpose was to test the new spacecraft and the safety measures introduced as a result of that accident. The crew consisted of Vasily Lazarev (Commander) and Oleg Grigoryevich Makarov (Flight Engineer). The mission lasted 1 day, 23 hours, 15 minutes, ending with a safe landing in Kazakhstan on September 29.
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| A Soyuz 12 First Day Cover from "KNIGA", postmarked in Moscow with a hand cancel on March 27, 1974, signed by Vasily Lazarev and Oleg Grigoryevich Makarov. |
The background to Soyuz 12 goes back to Soyuz 11, which returned from Salyut 1 in June 1971. Its three cosmonauts—Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsayev — died during the return to Earth when the spacecraft's descent module lost cabin pressure. The accident resulted in a major redesign of the Soyuz spacecraft. The most obvious operational change was that the crew was reduced from three to two. This provided enough room for the cosmonauts to wear pressure suits during launch and landing.
One of the most significant changes tested on Soyuz 12 was the introduction of the Sokol pressure suit. The cosmonauts wore the suits during launch and descent, although they did not wear them during normal orbital operations. The suit was designed to protect the crew in the event of cabin depressurization. Soyuz 12 was therefore much more than another routine Soviet spaceflight — it was effectively a crewed checkout of the post-Soyuz-11 safety redesign.
