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Found it! https://spaceflightblunders.wordpress.com/2017/04/07/lunar-orbit-rendezvous-when-your-cmp-dies/ https://spaceflightblunders.wordpress.com/2017/04/07/

Found it! https://spaceflightblunders.wordpress.com/2017/04/07/lunar-orbit-rendezvous-when-your-cmp-dies/ https://spaceflightblunders.wordpress.com/2017/04/07/lunar-o... From the article, I was wrong about not knowing whether the CMP was alive: "Unless there was a very serious issue with the CM’s communications systems, NASA would know of the CMP’s fate immediately. Every astronaut wears biomedical sensors at all times, as part of their constant-wear garment. This telemetry is sent to the flight surgeon." More discussion here: https://space.stackexchange.com/questions/45426/procedure-to-deal-with-the-death-of-apollo-astronaut-during-a-lunar-mission https://space.stackexchange.com/questions/45426/procedure-to... A comment from that page: "Probably the worst scenario would be for the CMP to be alive, but disabled and not in his spacesuit. There would be no way for the other astronauts to get to the CMP without depressurizing the CM, thus killing the CMP. It's an obvious choice between three astronauts stranded in lunar orbit, versus two getting home alive. Nonetheless, I can only imagine the regret that the astronaut who would have to depressurize the CM would have." So it is even worse than the way I remembered it: the LM pilots would likely know that the CMP pilot was alive but incapacitated and they were about to kill him.

hyperpallium2 6y ago
You can survive vaccuum for a brief period of time.
- js2 6y ago
  > Flight recorder data from the single cosmonaut outfitted with biomedical sensors showed cardiac arrest occurred within 40 seconds of pressure loss. […] The autopsies took place at Burdenko Military Hospital and found that the cause of death proper for the cosmonauts was hemorrhaging of the blood vessels in the brain, with lesser amounts of bleeding under their skin, in the inner ear, and in the nasal cavity, all of which occurred as exposure to a vacuum environment caused the oxygen and nitrogen in their bloodstreams to bubble and rupture vessels. Their blood was also found to contain heavy concentrations of lactic acid, a sign of extreme physiologic stress. Although they could have remained conscious for almost 40 seconds after decompression began, less than 20 seconds would have passed before the effects of oxygen starvation made it impossible for them to function. https://en.wikipedia.org/wiki/Soyuz_11 https://en.wikipedia.org/wiki/Soyuz_11
  - Breza 6y ago
    If you want to see how disabling even a little loss of pressure can be, check it this video. https://youtu.be/7wT9-zaK3Zo https://youtu.be/7wT9-zaK3Zo
onwardly 6y ago
Apparently you can survive about 40 seconds in a vacuum. One option would be for one pilot to enter (as quickly as possible!) then put the CMP into a spacesuit, then re-admit the other astronaut. No clue if they could enter and re-pressurize the capsule within 30 seconds- sounds like a long-shot. https://www.newscientist.com/article/mg20627561-700-maxed-out-how-long-could-you-survive-a-vacuum/ https://www.newscientist.com/article/mg20627561-700-maxed-ou...
- JohnBooty 6y ago
  It takes about 45 minutes to don a modern spacesuit -- and that assumes the person donning the spacesuit is assisting with the process, not incapacitated. https://www.nasa.gov/audience/foreducators/spacesuits/facts/index.html https://www.nasa.gov/audience/foreducators/spacesuits/facts/... Edit: This says it can actually be done in five minutes in an emergency if one's willing to skip every safety check, but getting an unresponsive person into one seems like surely it would be more of a challenge -- particularly if the "helper" was wearing a spacesuit himself. Those things are awfully restrictive! And I would wager it's not a scenario they practiced. https://airandspace.si.edu/stories/editorial/how-do-you-put-apollo-spacesuit https://airandspace.si.edu/stories/editorial/how-do-you-put-...
  - iainmerrick 6y ago
    I think they are suggesting: - Enter the command module, in spacesuit - Quickly re-pressurize - Help incapacitated astronaut into suit (temporarily removing own suit if necessary) - Once both suited up, open airlock again to admit remaining astronaut But I’m not sure if that would have been possible. Was there really a way to re-pressurize in a few seconds, 2001 style?
    - ud_0 6y ago
      > - Help incapacitated astronaut into suit (temporarily removing own suit if necessary) > - Once both suited up, open airlock again to admit remaining astronaut These steps don't seem to be necessary. Since the CM can be opened from the inside towards the LM, the third astronaut could just wait in the LM and be let in that way. I think the only question is really how quickly can you repressurize the CM. It was basically a cone-shaped pressure vessel 3.23m tall and 3.91m wide, that's 51.71m^3 of volume. I'd estimate about 50% is taken up by machinery, so how fast can you repressurize 25m^3 to 1/3 sea level (which was apparently standard for the spacecraft)? My guess would be it could be done pretty quickly, maybe 2 minutes?
Syzygies 6y ago
If he was incapacitated slowly, he might have time to don a spacesuit, anticipating this scenario? NASA must know. I've been in a number of situations myself where swift incapacitation would have killed me. This is common.
- Breza 6y ago
  Looking at other times when astronauts became ill, they tended to tough it out until too late to put on a space suit.
Breza 6y ago
Similarly, Collins wrote a memo to the astronaut corps explaining that on the Mercury missions, if someone became incapacitated during EVA, they'd have to cut their life support cable and close the hatch and come home alone.
- Stratoscope 6y ago
  Very interesting and grim! But Mercury capsules only carried a single astronaut. You may be thinking of Gemini or Apollo?

hyperpallium2 6y ago

You can survive vaccuum for a brief period of time.

js2 6y ago
> Flight recorder data from the single cosmonaut outfitted with biomedical sensors showed cardiac arrest occurred within 40 seconds of pressure loss. […] The autopsies took place at Burdenko Military Hospital and found that the cause of death proper for the cosmonauts was hemorrhaging of the blood vessels in the brain, with lesser amounts of bleeding under their skin, in the inner ear, and in the nasal cavity, all of which occurred as exposure to a vacuum environment caused the oxygen and nitrogen in their bloodstreams to bubble and rupture vessels. Their blood was also found to contain heavy concentrations of lactic acid, a sign of extreme physiologic stress. Although they could have remained conscious for almost 40 seconds after decompression began, less than 20 seconds would have passed before the effects of oxygen starvation made it impossible for them to function. https://en.wikipedia.org/wiki/Soyuz_11 https://en.wikipedia.org/wiki/Soyuz_11
- Breza 6y ago
  If you want to see how disabling even a little loss of pressure can be, check it this video. https://youtu.be/7wT9-zaK3Zo https://youtu.be/7wT9-zaK3Zo

onwardly 6y ago

Apparently you can survive about 40 seconds in a vacuum. One option would be for one pilot to enter (as quickly as possible!) then put the CMP into a spacesuit, then re-admit the other astronaut. No clue if they could enter and re-pressurize the capsule within 30 seconds- sounds like a long-shot. https://www.newscientist.com/article/mg20627561-700-maxed-out-how-long-could-you-survive-a-vacuum/ https://www.newscientist.com/article/mg20627561-700-maxed-ou...

JohnBooty 6y ago
It takes about 45 minutes to don a modern spacesuit -- and that assumes the person donning the spacesuit is assisting with the process, not incapacitated. https://www.nasa.gov/audience/foreducators/spacesuits/facts/index.html https://www.nasa.gov/audience/foreducators/spacesuits/facts/... Edit: This says it can actually be done in five minutes in an emergency if one's willing to skip every safety check, but getting an unresponsive person into one seems like surely it would be more of a challenge -- particularly if the "helper" was wearing a spacesuit himself. Those things are awfully restrictive! And I would wager it's not a scenario they practiced. https://airandspace.si.edu/stories/editorial/how-do-you-put-apollo-spacesuit https://airandspace.si.edu/stories/editorial/how-do-you-put-...
- iainmerrick 6y ago
  I think they are suggesting: - Enter the command module, in spacesuit - Quickly re-pressurize - Help incapacitated astronaut into suit (temporarily removing own suit if necessary) - Once both suited up, open airlock again to admit remaining astronaut But I’m not sure if that would have been possible. Was there really a way to re-pressurize in a few seconds, 2001 style?
  - ud_0 6y ago
    > - Help incapacitated astronaut into suit (temporarily removing own suit if necessary) > - Once both suited up, open airlock again to admit remaining astronaut These steps don't seem to be necessary. Since the CM can be opened from the inside towards the LM, the third astronaut could just wait in the LM and be let in that way. I think the only question is really how quickly can you repressurize the CM. It was basically a cone-shaped pressure vessel 3.23m tall and 3.91m wide, that's 51.71m^3 of volume. I'd estimate about 50% is taken up by machinery, so how fast can you repressurize 25m^3 to 1/3 sea level (which was apparently standard for the spacecraft)? My guess would be it could be done pretty quickly, maybe 2 minutes?

Syzygies 6y ago

If he was incapacitated slowly, he might have time to don a spacesuit, anticipating this scenario? NASA must know. I've been in a number of situations myself where swift incapacitation would have killed me. This is common.

Breza 6y ago
Looking at other times when astronauts became ill, they tended to tough it out until too late to put on a space suit.

Breza 6y ago

Similarly, Collins wrote a memo to the astronaut corps explaining that on the Mercury missions, if someone became incapacitated during EVA, they'd have to cut their life support cable and close the hatch and come home alone.

Stratoscope 6y ago
Very interesting and grim! But Mercury capsules only carried a single astronaut. You may be thinking of Gemini or Apollo?