I’m curious what it would feel like if an astronaut’s spacesuit ran out of air while they were on mars, vs taking the suit off?inspired this question
Eva suits use pure oxygen. This allows much lower pressure and hence a more flexible suit than using air would. Atmospheric pressure on mars is about 1% of earths, even with pure oxygen that is too low to survive.
So the big question is what does the suit do when it runs out of oxygen. I see two posibilities.
- The pressure in the suit remains the same, but replacement of CO2 with oxygen stops. The person will feel they are suffocating.
- The pressure in the suit drops as CO2 is removed but not replaced. I suspect in this case with a conventional suit the person will quietly pass out and die, with a "mechanical counterpressure" suit the person will find themselves unable to breathe because the mechanical counterpressure is no longer balanced.