I know this is off-topic
Yes. Yes it is indeed off topic. It is becoming you signature pattern. Keep it up and members will start reporting you to the mod.
but you might want to change your avatar because every time I read your comments I read them as if Butters were reading them. It's hilarious.
So? Every time I see yours I think "Oh, this crackpot".
As for the definition of stress in the context in which it was used, I mean psychological stress of being in a potentially dangerous environment.
That is what test pilots do for a living. What of it?
I suspect pulse and rate of breathing would be monitored.
Wait...WHAT? They were continuously monitored. IT was the Flight Surgeons frakkin job to monitor that data. How in seven hells do you not know this?
Hyperventilation while in orbit and possibly passing out would probably be very bad in orbit.
Why? Once you have established orbit, you can go for a nap if you like because Newton is in the driving seat. Or loose consciousness if you prefer, Newton is still in the driving seat. You seem to have some fantasy concept that they had to fly seat of the pants, teeth gritted with sweaty brow, grimly clasping a joystick whilst their life depended upon not a moments inattention. Twasn't so, m'laddie buck. On Apollo, they pretty much kept the same schedule with all three astronauts sleeping at the same time.
Best to test and train for it in a vacuum chamber on Earth first.
Apart from critical phases they spent the vast majority of their time in shirt sleeves and zero G. How a vacuum chamber on Earth might be useful is anyones guess.
Ain't no 9-11 in orbit.
Off topic red herring. You really like those.