What is the extreme altitude that the human body can withstand? The general consensus is that 9,000 meters, beyond 9,000 meters, humans cannot survive. The extreme altitude of 9000 meters is only speculative and has no empirical evidence.
The absolute limit height supported by the theory is 19,000 meters above sea level, which is also called Armstrong line here. The atmospheric pressure above the dividing line is very low, and it is doomed to survive without a spacesuit. At a height of 19,000 meters, water can boil to 37 ° C. In other words, when your body reaches this height, the fluid in the body will begin to evaporate.
How high can a naked person fly at an altitude of 19,000 meters without wearing protective clothing?
The answer to empirical data is 13,000 meters. William Rankin, who jumped from a height of 13,000 meters and crossed thunder clouds, verified the human limit 60 years ago.
That was a summer in 1959, with US Marine Corps Lieutenant Colonel William Rankin driving the F8U on a routine mission.
Before taking off, the briefer reminded Rankin that when passing through southern Virginia, he would encounter a lightning zone of up to 10,000 meters. No problem, the plane is higher than the lightning zone. Rankin submitted a flight plan at an altitude of 13,000 meters, with a speed of 860 kilometers per hour and a journey of 70 minutes.
As Rankin approached Norfolk, Virginia, he saw dark thunderstorm cirrus clouds approaching the horizon. Rankin added a little oil and pulled the plane up a bit. When the aircraft was flying at Mach 0.82 (923 kilometers per hour) at 14,000 meters, a loud noise came from the engine. F8U–The only engine on a single-engine fighter jet went out.
Rankin pulled up the joystick in an attempt to activate the auxiliary power turbine and maintain the basic electrical and hydraulic control systems on the aircraft. With too much force, the joystick was broken.
Rankin has only one last choice left, to eject and leave the plane. Unprotected ejection at an altitude of more than 13,000 meters is equivalent to high-level suicide operations.
When Rankin chose to eject, he was equipped with a helmet and a simple flight jacket for ordinary flight. At this time, the temperature inside the cabin was 24 ° C, and the temperature outside the cabin was minus 55 ° C. Rankin pulled the handle on the seat to trigger the ejection procedure.
The canvas wind fell from his head, and the explosive impact violently assaulted the seat, and Rankin left the F8U. He was accompanied by a helmet, an oxygen mask and a parachute, and his left-hand gloves were ripped off.
“I had a terrible feeling. My stomach was doubled and my nose seemed to explode.” Rankin recalled his ejection experience. “My wrists and ankles started to burn, and I could no longer feel my left hand.”
Within seconds, Rankin froze, his body suddenly decompressed, and blood flowed from his eyes, ears, nose, and mouth.
“My eyes seemed to be pulled out of my eyes, and my head was cracked, and my ears were cracked.” Pain hit every inch of Rankin’s skin, and he remained awake.
Fortunately, Rankin found his oxygen mask, and 5 minutes of air supply saved most of his life. At this time he came to the boiling storm clouds, and estimated to reach the ground in 10 minutes based on a reasonable descent rate.
Rankin just breathed a sigh of relief and suddenly realized in horror that his parachute had opened. The storm interfered with the air pressure parachute, and the parachute opened at 3000 meters was expected to open early.
The parachute was entangled with the storm in the clouds, lightning flashed in front of Rankin’s eyes, hail hit his head, and rain poured into his nostril.
Taking a breath and taking a sip of water, Rankine rolled in the sea of clouds, dizzy and vomiting, but he remained awake until he passed the storm cloud of lightning and thunder.
Rankin’s body became warmer and warmer, and the surrounding air calmed down. Evergreen appeared in the sight, and after jumping off the plane, Rankine saw the ground for the first time.
The parachute hung from the pine tree, Rankin hit the trunk and finally landed. He looked at his watch. At 6:40, he experienced a 40-minute landing process.
Rankin was taken to the hospital by a passerby and, surprisingly, his injuries were not serious. The doctor treated his internal bleeding, fractures and frostbite, and examined the effects of decompression at high altitude in a decompression room.
A month later, Rankin was discharged from the hospital and wrote a book called “The Man Riding a Thunderbolt.”
Salute 1, the first human space station. In June 1971, Soyuz 11 docked with the space station, and three crew members entered the space station to work.
After 24 days of work, Alliance 11 returned to Earth. On the way back, the return capsule was separated from the orbital capsule at an altitude of 17000 meters. The impact of the separation activated the ventilation valve, and the cabin air began to leak.
At this time, due to the small space in the cabin, none of the three astronauts wore space suits. And the ventilation valve was under the seat, and the astronauts couldn’t reach it.
The pressure in the cabin dropped sharply, and it dropped to the pressure outside the cabin in 112 seconds, close to the vacuum state.
The biosensor showed that in the 4 seconds after the start of the decompression, the crew member Dobrowsky’s breathing frequency increased from 16 times per minute to 48 times per minute. He began to suffocate and died within 40 seconds.
The return module landed as planned, opened the door, and saw three bodies.
The autopsy of the crew found that everyone’s lungs were bleeding, the blood was high in nitrogen, and the brain was bleeding.
After that, an important item was added to the mandatory regulations of the aerospace industry. Astronauts must wear space suits during launch and landing.
Later experience of the Soyuz and other space shuttles returning to the atmosphere also proved that spacesuits are vital to human protection when taking off and returning. In accidents, spacesuits saved lives several times.
Pressure was released at 17000 meters, and three lives confirmed that humans cannot survive naked at this height.
When the human body is at normal atmospheric pressure, the nitrogen dissolved in body tissues and fluids remains saturated, 4% nitrogen is dissolved in blood, and 96% nitrogen is dissolved in fat and other tissues.
When the external environmental pressure drops, the dissolved nitrogen in the body exceeds saturation, and the supersaturated nitrogen will be discharged from the body through the circulatory system and the respiratory system. This is a natural desaturation process.
If the external environmental pressure gradually decreases, the desaturation process of nitrogen in the body is naturally completed.
If the external environmental pressure drops sharply, the desaturation process in the body is too late to complete, and supersaturated nitrogen will form bubbles in the body.
For example, Rankine’s abdomen is caused by a rapid increase in nitrogen in soft tissues and veins.
For example, Alliance 11 crew members had lung and brain hemorrhages due to the clogging of blood vessels by air plugs formed by nitrogen bubbles in the blood.
Although Rankine’s high-altitude jumper confirmed the survivability of 13,000 meters, the consequences are difficult to predict without a 5-minute oxygen mask.
Life under the protection of the atmosphere is very delicate, and the human body can only live in safe areas under the limit.
However, technology has greatly expanded our active area, and a delicate body equipped with powerful equipment can land on the moon, and it will go further and further in the future.