How long can an astronaut live in space in a spacesuit? About 6.5-8 hours!

How long can an astronaut survive in a spacesuit? At present, the two oxygen tanks and emergency oxygen supply system in EVA spacesuits commonly used by astronauts can provide 6.5-8 hours of oxygen supply. According to foreign media reports, as long as the oxygen tank can keep astronauts breathing for a long time, they can survive in the spacesuit. At present, the two oxygen tanks and emergency oxygen supply system in EVA spacesuits commonly used by astronauts can provide 6.5-8 hours of oxygen supply. < / P > < p > the human mind is bewildered by the complexity and mystery of space, and is committed to unveiling the mystery. From believing in the flat earth theory centered on “geocentrism” to the black hole shadow photographed today, as well as fantasizing about space elevator and witnessing the manned orbital flight of commercial companies, with the development of human science and technology, we have made great achievements in the field of astronomy Great progress. These advances have made the dream of human society expanding into space come true. Although the viewpoint of human colonization and expansion in space is still controversial, a question is raised in the process of human exploration of space: can human beings survive in space forever? < / P > < p > we should all know that the answer to this question is obvious – it is impossible for human beings to survive in space for a long time. But what will happen to us under the protection of spacesuits? In the Oscar winning film, an astronaut in a spacesuit floats and struggles in space, and describes in detail how she overcame various difficulties to survive. Is it really possible to survive in the open space by wearing a space suit? If so, how long will it last? < / P > < p > the most obvious feature of space is that there is no respirable oxygen, which is the main reason why human beings cannot survive in space. The oxygen stored in human blood can only keep people awake for about 15 seconds. After that, the hypoxic blood is transported to the brain, and people will gradually lose consciousness. However, this situation is not necessarily “sentenced to death”. If the comatose astronauts are pulled back into the breathing space filled with oxygen within 1-2 minutes, they may survive. < / P > < p > at the same time, holding one’s breath in space actually leads to faster death, which sounds counter intuitive. The fact is that when air enters the human lungs, it exerts a constant pressure on the walls of the lungs, which is equivalent to the atmospheric pressure on earth. When we need to breathe in and out, the fluctuations are very small. There is no atmosphere in space, so there is no atmospheric pressure. Without atmospheric pressure to balance the air pressure inside the human body, our lungs will gradually expand and eventually rupture. Expanded air will rush into the respiratory circulation system, causing gas embolism. If you hold your breath in the open space and prevent the rapidly expanding air from leaving your body, it is easy to cause lung rupture to accelerate. So, while this sounds ridiculous, when someone is floating in space, the first thing to do is to keep breathing normally. Body fluid boiling is a form of bubble in body fluid, which is another fatal phenomenon caused by the lack of atmospheric pressure. < p > < p > the boiling point of a liquid means that the vapor pressure of a liquid is equal to the pressure around it when it reaches a certain temperature. Similarly, in the absence of external pressure in space, the boiling point of body fluids is greatly reduced, so they immediately begin to evaporate. Fortunately, the blood doesn’t boil, because the blood circulation system can maintain blood pressure stability and prevent blood boiling. However, nitrogen molecules dissolved in the blood can vaporize, causing the blood circulation tissue to expand, and the body will expand to twice the original, causing serious damage to some organs and tissues. < / P > < p > fortunately, our skin is elastic enough to hold steam inside the human body, thus preventing the body from expanding to a certain extent in the space environment. If you return to normal atmospheric pressure, your swollen body will return to normal. In addition, astronauts exposed to space will also suffer from unshielded cosmic radiation and solar wind. In addition to some fatal sunburn, human body will also cause tissue damage, DNA mutation, increase the probability of cancer and cataract, and may lead to infertility. In addition, there are very fast meteors and space debris that can shoot through the human body like a bullet. < / P > < p > space exploration movies and books have led us to believe that when the human body is in space, it will freeze immediately, but this is not the case. Although space is really cold, it lacks any form of matter. The only way for heat to leave the body is through radiation. Given the speed at which heat is transferred through radiation, the body freezes in space within 12-20 hours. < / P > < p > to sum up, in the open space, astronauts without spacesuits can stay conscious for 15 seconds, survive for 1-2 minutes, and then die under the above conditions, and finally freeze into popsicles. < / P > < p > when astronauts travel in space, they wear two different types of spacesuits. The first is pressure suit, which is worn when the spaceship takes off and returns to the earth’s atmosphere. In case of decompression emergency and any accident that may occur during takeoff and landing, the spacesuit can protect the astronauts. In addition, astronauts also need to carry oxygen tanks or other equipment It cushions against space radiation, but it means that these devices cannot make astronauts survive in space. At most, they can only prevent lung explosions and body expansion, but they still can’t change the lack of oxygen. Astronauts will die in a minute or two. < / P > < p > the second kind of spacesuit is an extravehicular spacesuit, which, as the name suggests, is worn in any extravehicular activity, so it is used to protect astronauts from all the above threats. For easy understanding, EVA spacesuit can be divided into two main parts: pressure suit and life support system. < / P > < p > the pressure suit is actually a humanoid garment, which is composed of the upper trunk, lower torso, cooling suit and helmet. From the inside to the outside, astronauts should first wear a cooling suit before going on a random space walk. This clothing is made of mesh spandex and covered with 100 meters long microtubules. In the microtubules, about 4.4-10 degrees Celsius water continuously flows through these microtubules Help heat dissipation. < / P > < p > the next step from the inside to the outside is the hard upper trunk, which is composed of multiple layers of light weight glass fiber. A urethane coated inflatable nylon substrate is in the innermost layer, which plays a role in regulating body pressure. The inflatable nylon substrate outward is polyester suppression layer and anti tearing nylon layer. The next five layers are polyester film layer, which can keep body temperature, and then several layers of waterproof and fireproof layer. The outer layer is white coating, which helps to reflect sunlight. It is made of three different materials. In addition, astronauts also need to wear diapers and gloves with heating function, which helps to keep fingers warm, which is convenient for astronauts to operate flexibly. < / P > < p > life support system, arms, helmets, display and control modules are all installed on the upper torso of the spacesuit, while the safety tether is connected to the D-ring at the lower end of the lower torso. The waist bearing can make the astronaut’s body move and rotate freely. < / P > < p > the space helmet is made of solid plastic, similar to a spacesuit, it helps to provide a pressurized space, gold-plated goggles and sun visors 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 in extravehicular activities. A group of headphones and microphones is used to record and assist in extravehicular activities The special device can realize communication with fellow astronauts. < / P > < p > for the life support system, this backpack device is an essential material for space flight. Without it, the spacesuit is just a suit for a costume party. The life support system includes: oxygen tank, carbon dioxide filter, battery, pressure regulator, no wire and other communication equipment, water tank, pump, cooling system, circulating oxygen fan, etc. All electronic and mechanical components in the life support system are controlled by a display control module mounted on the upper trunk. < / P > < p > the combination of pressure suit and life support system can act as a “single spaceship”, allowing astronauts to conduct extraterrestrial surveys or necessary extravehicular maintenance work on the international space station. < / P > < p > the multi-layer upper and lower trunk spacesuit parts can protect astronauts from cosmic radiation and micro meteors, and help to maintain body temperature and provide a pressurized atmosphere. Just like on earth, we need three basic needs for human survival: food, water and oxygen, which are also the limiting factors for space survival. < / P > < p > since extravehicular activities can last several hours, astronauts need to eat and drink water before carrying out extravehicular activities. To be cautious, they also need to fill the beverage bag and attach a fruit stick to the spacesuit. Astronauts can choose 0.6-liter or 0.9-liter beverage bags according to their own needs, and put a straw with valve device from the beverage bag and place it next to the mouth in the helmet. When the astronauts drink water, the straw valve opens automatically, and the fruit stick is wrapped in edible rice paper and placed in the sleeve near the neck, with the upper end extending near the mouth. Every time an astronaut bites a fruit stick, he pulls the fruit stick close to his mouth. The beverage bag and fruit stick are fixed to the space suit on the upper torso with Velcro. < / P > < p > for the life support system, this backpack device is an essential material for space flight. Without it, the spacesuit is just a suit for a costume party. The life support system includes: oxygen tank, carbon dioxide filter, battery, pressure regulator, no wire and other communication equipment, water tank, pump, cooling system, circulating oxygen fan, etc. < / P > < p > the two oxygen tanks in the life support system backpack can maintain astronauts’ extravehicular activities for about 6.5-8 hours, depending on the individual’s body metabolic rate, because each person’s oxygen consumption and carbon dioxide production are different. At the same time, the pressure of the EVA spacesuit is one third of the earth’s atmospheric pressure, under which the air cannot hold enough oxygen. Therefore, the oxygen tank is filled with 100% pure oxygen, and the carbon dioxide filtration system is also essential because it filters out the breath from the human body and helps the unabsorbed oxygen circulate again. An emergency oxygen pack is attached to the base of the life support system to provide an additional oxygen supply of about 30 minutes. < / P > < p > therefore, although space threatens human life in many ways, the survival time of astronauts in space suits depends on the amount of oxygen contained in them. At present, the space suit can only provide 6.5-8 hours of space exploration time. If astronauts want to continue flying, they need to return to the spacecraft to replace the oxygen tank. The longest space walk record is achieved by Jim Voss and Susan Holmes, who spent 8 hours and 56 minutes repairing the international space station. < / P > < p > so far, humans have no plans to build futuristic space houses in the open space, so unless you are an astronaut, you don’t have to worry too much about the details and limitations of spacesuits