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-...

- 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?

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?

I mean we're just guessing and spitballing here, and all of this assumes that whatever incapacitated the CMP is fixable by the other astronaut. But it does look like there may be a decent chance the CMP could survive this. Of course, he might have internal injuries or they might not be able to restart his heart. But seems like this procedure would be worth a try.