BEIJING, Oct. 12 (Xinhua) — As long as oxygen tanks last enough to keep astronauts breathing, they can survive in space suits, according tomedia reports. Currently, two oxygen tanks and an emergency oxygen supply system in the extravehicular spacesuit (EMU), commonly used by astronauts, provide 6.5-8 hours of oxygen supply.
How long can astronauts survive in space suits? Currently, two oxygen tanks and an emergency oxygen supply system in the extravehicular spacesuit (EMU), commonly used by astronauts, provide 6.5-8 hours of oxygen supply.
The human mind is bewildered by the intricacies and mysteries of space, and is committed to solving the mysteries, from the belief in the flat Earth theory centered on the “earth’s heart” to the shadow of black holes captured today, to fantasizing about space elevators and witnessing commercial companies perform manned orbital flights, along with the development of human science and technology, we have made great progress in the field of astronomy.
These advances have made the dream of human society’s expansion into space a reality, and while the idea of human expansion into space remains controversial, it raises the question of whether man can survive in space forever as he explores space.
We should all know that the answer to this question is obvious – that humans cannot survive in space for long. But what happens when we’re protected by space suits? In the Oscar-winning film Gravity, an astronaut struggles to float in space in a space suit and details how she survived all the difficulties. If so, how long will it last?
What threats will astronauts face in empty space?
Before we answer how long space suits protect astronauts, we should be aware of the threats that exist in space.
Astronauts entering empty space can do fatal damage to their bodies.
The most obvious feature of space is the absence of any respirable oxygen, which is the main reason humans cannot survive in space, and the oxygen stored in the body’s blood keeps people awake for only about 15 seconds, after which oxygen-deprived blood is delivered to the brain, where people gradually lose consciousness. However, this condition does not necessarily mean “death sentence”, if the unconscious astronauts in 1-2 minutes in time to pull back oxygen-filled breathing space, they may survive.
At the same time, astronauts holding back breathing in space can actually lead to faster death, which may sound counterinspiration. The truth is that when air enters the lungs, it exerts constant pressure on the walls of the lungs, which is equivalent to atmospheric pressure on Earth, which fluctuates very little when we need to inhale and exhale. There is no atmosphere in space, so there is no atmospheric pressure, no atmospheric pressure to balance the body’s internal air pressure, our lungs will gradually expand, and eventually rupture. The expanding air rushes into the respiratory circulation system, causing a gas embolism. If you hold your breath in empty space and prevent rapidly expanding air from leaving your body, it can easily lead to lung rupture and acceleration. So, while this may sound ridiculous, the first thing to do when someone is floating in space is to keep exhaling normally.
Ebullism, a form of bubble in body fluids, is another potentially fatal phenomenon caused by a lack of atmospheric pressure in the human body.
Liquid boiling point refers to reaching a certain temperature, the liquid vapor pressure is equal to the pressure around it. Similarly, without external pressure in space, the boiling point of body fluids (saliva, tears, sweat, etc.) is greatly reduced, so they immediately begin to evaporate. Fortunately, blood does not boil because the blood circulation system keeps blood pressure stable and prevents blood from boiling. However, the nitrogen molecules dissolved in the blood can vaporize, causing the blood circulation tissue to swell and the body to swell twice as much, causing serious damage to some organ tissues.
Fortunately, our skin is elastic enough to hold steam inside the body to prevent it from expanding to a certain extent in space. If it returns to normal atmospheric pressure, the expanding body returns to normal.
In addition, astronauts exposed to unshielded cosmic radiation and solar wind, in addition to causing some fatal sunburn, the human body will also lead to damage to human tissue, DNA mutations, increase the probability of cancer and cataracts, and may lead to infertility. In addition, there are very fast micro meteors and space debris in space, can be like bullets through the human body.
Films and books on the subject of space exploration make it widely believe that when the human body is in space, it freezes immediately, but that’s not the case. Although space is indeed cold (depending on where you are located), there is also a lack of any form of matter in space, and the only way for heat to leave the body is through radiation (transmission and conflow require a medium to transfer heat). Given the speed at which heat passes through radiation, the body freezes in space for 12-20 hours.
To sum up, in open space, astronauts without spacesuits can remain conscious for 15 seconds, survive for 1-2 minutes, and then die in the above-mentioned circumstances, eventually freezing their bodies into ice sticks.
When astronauts travel in space wearing two different types of space suits, the first is a pressure suit, which is worn during liftoff and return to earth’s atmosphere, and can protect astronauts in the event of a decompression emergency and any accident that may occur during lift-off and landing; But it still doesn’t change the lack of oxygen, and astronauts will die in a minute or two.
Pressure clothing is actually a human-shaped clothing, is composed of the upper torso, lower torso, cooling clothing and helmet four parts.
The second space suit is the extravehicular space suit (EMU), which, as the name suggests, is worn in any extravehicular activity and is therefore used to protect astronauts from all of the above threats. For ease of understanding, extravehicular spacesuits can be divided into two main parts: pressure suits and life support systems.
Pressure clothing is actually a human-shaped clothing, is composed of the upper torso, lower torso, cooling suit and helmet four parts, from the inside out, astronauts in a random spacewalk before wearing a cooling suit, this cooling suit is made of mesh spandex material, covered with 100 meters long micro-tubes, micro-tubes about 4.4-10 degrees Celsius of water continue to flow through these micro-tubes, to help heat.
Next from the inside out is the hard upper body cadres, is composed of multi-layer light-mass fiberglass, a urine coating inflatable nylon substrate in the innermost layer, play a role in regulating body pressure, inflatable nylon substrate outward is polyester inhibitory layer and anti-tearing nylon layer. The next five layers are polyester film layers, which act as a temperature hold, and outwards, several layers of waterproof fireproof layers, the outer outer layer is a white coating that helps reflect sunlight, which is made of three different materials. In addition, astronauts need to wear diapers and heating gloves to help keep their fingers warm, making it easy for astronauts to operate flexibly.
Life support systems, arms, helmets, display and control modules are mounted on the space suit, while safety tethers are connected to the D-ring at the lower end of the lower torso, and waist bearings allow the astronaut’s body to move and rotate freely.
The space helmet is made of sturdy plastic, similar to a spacesuit, and helps provide a pressurized space, gold-plated goggles and sun visors to protect astronauts from direct sunlight, while the helmet’s ventilation system delivers oxygen from the life support system, cameras and lights are installed on the side of the helmet to record and assist extravehiculated activities, and a special device consisting of headphones and microphones allows communication with fellow astronauts.
For life support systems, this backpack device is essential for space flight, without which spacesuits are just a package for a costume dance, life support systems include: oxygen tanks, carbon dioxide filters, batteries, pressure regulators, wireless and other communications equipment, water tanks, pumps, cooling systems, circulating oxygen fans, etc. All electronic and mechanical components in the life support system are controlled by a display control module mounted on the upper body.
The combination of pressure suits and life support systems can act as “single-person spacecraft”, allowing astronauts to conduct extraterrascing surveys or the necessary extravehicopod repairs to the International Space Station.
So how long can astronauts survive in space suits?
The multi-layered upper and lower torso spacesuits protect astronauts from cosmic radiation and micro-meteors, and help maintain body temperature and provide a pressurized atmosphere. Just like on Earth, we humans need three basic needs for survival: food, water and oxygen, which are limiting space survival.
Because extravehy space activities can last several hours, astronauts need to eat food and drink water before performing extravehy space activities. To be cautious, they also need to fill the bag with drinks and attach a fruit stick to the space suit. Astronauts can choose a 0.6-liter or 0.9-liter beverage bag according to their needs, protrude a straw with a valve device from the beverage bag, and place it next to the mouth in the helmet. When astronauts drink water, the straw valve opens automatically, and the fruit stick is wrapped in edible rice paper, placed in sleeves near the neck, with the upper end extending near the mouth. Every time an astronaut bites a fruit stick, he pulls it close to his mouth, and the beverage bag and fruit stick are fastened to the upper torso with a nylon buckle.
For life support systems, this backpack device is essential for space flight, without which spacesuits are just a package for a costume dance, life support systems include: oxygen tanks, carbon dioxide filters, batteries, pressure regulators, wireless and other communications equipment, water tanks, pumps, cooling systems, circulating oxygen fans, etc.
The two oxygen tanks in the life support system backpack maintain extravehicopod activity for about 6.5-8 hours, depending on the person’s body metabolic rate, as each person’s oxygen consumption and carbon dioxide production vary. At the same time, the pressure of the extravehicular space suit is equivalent to one-third of the Earth’s atmospheric pressure, at which the air cannot hold enough oxygen. As a result, the oxygen tank is filled with 100% pure oxygen, and a carbon dioxide filtration system is essential because it filters out the body’s exhaled gas and helps the unsorted oxygen circulate again. An emergency oxygen package attached to the base of the life support system provides an additional oxygen supply of approximately 30 minutes.
Therefore, although space threatens human life in many ways, the survival time of astronauts in space suits depends on the amount of oxygen they contain. Currently, the space suit provides only 6.5-8 hours of space exploration time, and if astronauts want to continue flying, they will need to return to the spacecraft to replace their oxygen tanks, and the longest spacewalk record so far has been achieved by Jim Voss and Susan Helms, who spent 8 hours and 56 minutes repairing the International Space Station.
So far, humans have no plans to build futurist space houses in empty space, so unless you’re an astronaut, you don’t have to worry too much about the details and limitations of spacesuits. In recent years, scientists have been keeping a close eye on other planets in the solar system, and if someone decides to live on an extraterr planet one day, they should first know how long you can live on the mysterious planet. See if these planets are suitable for human existence! (Ye Tingcheng)