| Birth Name: | Viktor Ivanovich Patsayev |
| Type: | Cosmonaut |
| Nationality: | Soviet |
| Birth Date: | 1933 6, df=yes |
| Birth Place: | Aktyubinsk, Kazakh ASSR, Russian SFSR, Soviet Union |
| Death Place: | Soyuz 11, Outer space |
| Occupation: | Engineer |
| Selection: | 1968 USSR Civilian Specialist Group 3 |
| Time: | 23d 18h 21m |
| Mission: | Soyuz 11 |
| Awards: | Hero of the Soviet Union |
| Resting Place: | Kremlin Wall Necropolis |
Viktor Ivanovich Patsayev (Russian: Виктор Иванович Пацаев; 19 June 193330 June 1971)[1] was a Soviet cosmonaut who flew on the Soyuz 11 mission and was part of the third space crew to die during a space flight. On board the space station Salyut 1 he operated the Orion 1 Space Observatory (see Orion 1 and Orion 2 Space Observatories); he became the first man to operate a telescope outside the Earth's atmosphere.
After a normal re-entry, the capsule was opened and the crew was found dead.[2] It was discovered that a valve had opened just prior to leaving orbit that had allowed the capsule's atmosphere to vent away into space, suffocating the crew.[3] One of Patsayev's hands was found to be bruised, and he may have been trying to shut the valve manually at the time he lost consciousness.
Patsayev's ashes were interred in the Kremlin Wall on Red Square in Moscow.[4] He was posthumously awarded the title of Hero of the Soviet Union, the Order of Lenin and the title of Pilot-Cosmonaut of the USSR. The lunar crater Patsaev and the minor planet 1791 Patsayev are named for him.[5]
An account of Patsayev's life and space career appears in the 2003 book Fallen Astronauts: Heroes Who Died Reaching for the Moon by Colin Burgess.