30 June - Soyuz 11 tragedy in 1971

 

On 30 June 1971, the Soviet space mission Soyuz 11 ended in tragedy when all three cosmonauts—Georgy Dobrovolsky, Viktor Patsayev, and Vladislav Volkov—were killed during re-entry. After spending 23 days aboard Salyut 1, the world’s first space station, the crew successfully completed their mission and undocked to return to Earth. However, during the final phase of descent, a pressure equalization valve accidentally opened, causing the cabin to rapidly depressurize. Because the cosmonauts were not wearing pressure suits, they lost consciousness within seconds and died from asphyxiation. When recovery teams reached the landed capsule near Dzhezkazgan, Kazakhstan, they found all three crew members dead in their seats. The Soyuz 11 disaster remains the only incident in history where humans have died in space itself, and it led to significant redesigns of the Soyuz spacecraft to prevent similar catastrophes in the future.