Merky600 t1_j5w3i5s wrote on January 25, 2023 at 11:37 PM

IIRC There was a valve they could have closed to stop the depressurization. Catch was, it needed to be turned a large number of times to close. Perhaps they attempted it. Took long time to shut. More time than they had.

Edit: Crap. I was wrong and it was worse than I thought.

"Based on examination of the hatch and valves, officials determined that air leaked from one of the two ventilation/equalization valves, located behind the control panel.•Although the crew would have been immediately aware of the leak, they had to determine its source, so they switched off radio transmitters to isolate the leak’s noise. Crew commander Dobrovolskiy’s body was found apparently attempting to cover the control panel with a checklist.•The crew could not close the valve because it lacked a manual closure mechanism and was inaccessible.•Within 40 seconds of depressurization during descent, the crew suffocated."

Merky600 t1_j5w420s wrote on January 25, 2023 at 11:41 PM

https://sma.nasa.gov/docs/default-source/safety-messages/safetymessage-2010-09-09-soyuz11depressurization-vits.pdf?sfvrsn=1fae1ef8_6

Dont____Panic t1_j60wuyy wrote on January 26, 2023 at 10:44 PM

Another cosmonaut tried to close the valve on a different capsule later and said it took him 53 seconds.

The crew probably had less than 15 seconds of useful consciousness.

Merky600 t1_j69fn26 wrote on January 28, 2023 at 6:27 PM

53 seconds to close the valve. That’s what I must be remembering. From an other incident.