Arthur Digbee wrote:
Brad Marshall wrote:If history has taught us anything there doesn't seem to be a limit for human endurance. Every year people are pushing the boundaries further and further. If Everest were 35,000 feet someone would eventually get to the top, probably with improved oxygen gear. Then someone would come along and do it without oxygen and us mere mortals would once again be amazed.
I'm inclined to agree with that.
But there's an upper limit somewhere. Olympus Mons, for one.
I was in the Canadian Air Force in the 1960's, working on the CF104 supersonic jet fighter. That jet was designed to reach 100,000 feet. So the pilot's ejection seat was designed so he would survive the fall, if he ejected from that altitude.
First of all, he'd be breathing an oxygen-air mix already.
For the descent, his seat carried a bottle of O2 that would let him breathe at least down to 20,000 feet -- I think 10 minutes. While falling, his body is idle, so his O2 requirement should be low. Note that his parachute is NOT deployed for the fall. He has only enough oxygen to fall to 20,000 directly (do not stop at go).
The ejection seat assumes that the pilot is unconscious. There had to be a desperate reason why he bailed, and also during the fall, if anything went wrong, he'd no longer have a guarantee of oxygen delivery.
At around 20,000 feet the seat automatically cuts loose, although his survival pack is still tethered below him.
Finally at 10,000 feet (I think) the parachute automatically deploys, and he floats gently to the ground.
Limits to altitude?
I've heard of 16,000 feet marks the "death zone" because the body can no longer rebuild wear-and-tear, and slowly but inexorably begins to die.
The climbers who reach to summit of Everest without oxygen are extra-ordinary folks, and from their stories, you know they've reached the limit.