In 1971 a Soviet capsule landed on target, outwardly perfect — but when recovery crews opened the hatch, all three cosmonauts inside were dead, killed by a single valve.

In 1971 a Soviet capsule landed on target, outwardly perfect — but when recovery crews opened the hatch, all three cosmonauts inside were dead, killed by a single valve.

June 30th marked the anniversary of the Soyuz 11 disaster, when three Soviet cosmonauts successfully completed humanity’s first long-duration stay aboard a space station. Concluding the mission, the capsule landed normally in Kazakhstan. Recovery crews are expected to greet newly minted Soviet heroes. Instead, once the capsule was opened, recovery crews found three dead cosmonauts. There was no fire. No explosion. The capsule was largely intact.…