Is it difficult for astronauts to fall asleep in weightlessness?
This is a question worth discussing, because there are many reasons that affect sleep. First of all, it is necessary to distinguish whether astronauts work in space in one shift or two shifts. On the International Space Station and most space shuttles, all astronauts sleep at the same time. They hang their sleeping bags on the places they like to sleep, such as walls, corners, ceilings, etc. When astronauts implement shift work, like on some space shuttles including the Space Laboratory, the astronauts sleep in a small bunk. After it is closed, the noise from the studio can be isolated. At first, the astronauts felt a little uneasy, feeling like they were lying in a narrow shoe box, and most astronauts had the illusion that their backs felt comfortable for 10-15 seconds.
However, when you plan to sleep, you need to get used to the fact that you have no feeling in your back and sides, and that you are actually floating in the sleeping bag, just hanging upside down with a rope, so that you The drowsy feeling of gravity is non-existent, and some astronauts are not used to it. They were sleepless and so nervous that they had to take sleeping pills to fall asleep. Others sleep soundly even in these unique circumstances.
What needs to be added is: if your head is in an unventilated place while sleeping, the exhaled carbon dioxide will accumulate near your nose. When the carbon dioxide in your blood reaches a certain level, An alarm system in the back of your head will sound a warning, causing you to wake up and feel short of breath. At this time, you can take a few steps or change places and fall asleep again.
2. Do astronauts feel any special feelings when wearing clothes in space?
Apart from special requirements for comfort and safety, astronauts’ spacesuits are usually no different from what we wear on Earth. For example, clothing must be made of fire-resistant materials. When wearing a space suit in weightless conditions, the astronaut is actually floating in the suit. Only when the suit touches the skin does the astronaut feel that he is wearing clothes.
3. Is it fun to float in space?
Astronauts all think that floating in space is very interesting once they adapt to the microgravity environment. By the way, scientists don't like to call microgravity zero gravity because unless you're standing right in the center of a spacecraft in free fall around the Earth, you're inevitably subject to tiny accelerations and tidal forces. The influence, even if their effect is very small, only one millionth of the earth's gravity, we cannot consider it to be zero gravity or 0 gravity. That's why we call it weightlessness.
Living in a microgravity environment is very interesting, and different people feel different. About 30%-40% of astronauts participating in space flight for the first time develop "space adaptation syndrome" (which is a type of motion sickness) in the first two or three days after entering space. Such symptoms will not occur. Blood flows to the upper body, congesting the sinuses and tongue, affecting people's senses. In about a week, the astronauts' bodies will have a response to adapt to weightlessness.
In the case of weightlessness, the spine becomes longer due to the lack of gravity, making the person taller (1-2 inches taller). In weightlessness, when all the muscles relax, the thighs will be lifted slightly upwards, the arms will be stretched forward, and the body will be slightly arched, as if in water. Since there is no sense of "up" or "down", you need to rely on other signs to determine "up" and "down". When designing the interior of the space shuttle, consider using the difference between the ceiling and the floor for positioning.
In microgravity, astronauts often experience illusions. When an astronaut tells his brain which direction is "up," it immediately thinks it's an illusion. This way, things like positioning, transfer, or movement in space don't feel the same as on the ground. Walking in space is very easy, and astronauts quickly get used to walking around and using fixed feet to anchor themselves to the space station. Walking in space becomes much more difficult when wearing a spacesuit because the suit is bulky, like a balloon, and limits vision and touch.
4. How long can you wear a space suit?
Generally it can be worn for 5-7 hours. Of course, it also depends on the consumable materials in the space suit, such as oxygen, electricity, cooling water, etc.
A space suit is simply a small spacecraft, and working in a space suit is very hard. The wearing time is also related to the wearer's requirements for comfort and wear resistance.
5. What to do if you encounter a fracture or serious illness in space?
Fortunately, NASA's 120 astronauts in space have never encountered this situation. In the early days there were problems with Apollo 13 astronaut Fred's urinary infection and a small outbreak of influenza. There are always enough medicines on board the spacecraft to deal with these emergencies. Once an accident occurs while flying around the Earth, whether on a space shuttle or on the International Space Station, the astronauts must be returned to Earth as quickly as possible. NASA has also developed a large seven-seater return capsule for the International Space Station, which is used as a "space ambulance" in special circumstances.
If a fracture occurs, bone-fixing equipment is also prepared on the spacecraft. When humans set off into outer space, such as when exploring Mars, the spacecraft will carry medical equipment. There will be one or more astronauts who are well-trained in medical knowledge and can provide rescue and treatment. Because in this case, returning to Earth in the short term is impossible. Where possible, the spacecraft will be staffed by experienced doctors.
6. How many people can the space station accommodate?
The International Space Station can accommodate up to 7 astronauts. The number of astronauts increased from 3 to 6 at the beginning, and to 7 in 2003 (but now due to resource problems on the space station, there are only 3 astronauts on the space station - Translator). Of course, in an accident it is not possible for all staff to return immediately. That's why NASA is modifying its return capsule to accommodate more people than the Russian Soyuz spacecraft.
7. How do astronauts on the space station spend their spare time in space?
They have different preferences based on their own preferences. During the flight, they can each choose their own entertainment. Some are using their laptops to read or send emails to family, others are listening to music or playing games, and still others are on the phone with friends and family on the ground or chatting with other colleagues. However, when most astronauts first entered the space station, they spent most of their spare time standing by the window, looking at the universe and watching the earth disappear from under the space station.
8. How are the astronauts for the International Space Station selected? What do you think about this?
Any adult male or female who is in good physical condition and meets the basic requirements for astronauts can be selected to participate in astronaut training. To become a mission specialist or astronaut on the International Space Station, the minimum requirements are at least a bachelor's degree in engineering, natural sciences or mathematics from a nationally recognized institution, with more than three years of relevant work experience in this field, a higher degree would be more appropriate . Space shuttle pilots must have at least 1,000 hours of jet flying experience and have better eyesight than experts. Competition is fierce, with an average of 4,000 applicants competing for 20 places every two years. Astronauts are recruited regularly.
9. How do you map space? How do you know which direction to go in?
Let me briefly introduce it. It is not easy to fully understand this complex issue, because you really need to enter university for systematic study.
The most basic thing is that you need to know that the universe is composed of three spaces, so you should determine your exact position in the coordinate system composed of these three axes. In the field of astronomy, astronauts use azimuth, altitude, right ascension, distance and time to map space.
When flying in space, our three coordinates are designated as X, Y, and Z. Then everyone has a consistent reference system, that is, the position and orientation of the coordinate system, from which to measure and position. Generally this system has the center of the earth as its origin. The Z axis is upward, and the X axis and Y axis are on the same plane. Sometimes it can be assumed that it rotates with the Earth, and sometimes it is fixed in space. This "reference system" can also be loaded on your laptop computer.
Spacecraft (and all current large aircraft) are equipped with a navigation system that can know where it is near its three coordinates The movement of the flying object continuously calculates the changes of the spacecraft relative to the reference system. Of course, by looking at the designated target, you can also predict its direction, and you will soon know where you are and where you are going. , if it deviates from the set route, you can also consider making corresponding adjustments.
10. What kind of tableware do astronauts use to eat in space? Are they different?
Ordinary tableware used in aerospace, such as knives, forks, and spoons, are the same as those used on earth. Most of the food and drinks astronauts eat can be placed in containers. The difference is that when it's time to eat these foods, they float out. Some foods, like peas, beans, etc. are prepared with sauce added so that they stick to the utensils. Food is available hot, cold or frozen. The drinks come in squeezable bottles, like sports drink bottles. But there are some things that are difficult for astronauts to adapt to. They often complain that they cannot get fresh vegetables and fresh-tasting coffee during long missions.
By the way, at Russia's Mir space station, fresh fruits and vegetables like tomatoes are available once the transport shuttle arrives. American astronaut Shannon Lucid said that they often socialize with Russian astronauts. Maybe in a few years, fresh vegetables will be available on the International Space Station and on expeditions to Mars. There's no guarantee of fresh-tasting coffee and soda just yet, but at least one soft drink company has begun developing a container for use in weightless conditions. In addition, due to the transfer of body fluids during spaceflight, astronauts' sense of taste and smell change. Astronauts in orbit often choose food with strong taste.
11. How long do astronauts stay on the International Space Station?
Most astronauts stay on the International Space Station for 90 consecutive days - that is the average "rotation" time of the current astronaut program. Some people come back early for various reasons, and others may stay for a long time, especially when it is necessary to provide the basis for human exploration of Mars and to fly for a long time to conduct medical research on the lives and work of astronauts. It is worth mentioning that the longest stay in space was a Russian physician, Dr. Valery Polyakov, who set this record in 1994 and stayed on the space station for 438 days (14 1/2 months). Before that, It was a flight record of 241 days set in 1988. The longest time an American has lived in space is 188 days, which is also the world record for female astronauts. It was created by Dr. Shannon Lucid.
12. Why does the earth have gravity but not in space?
There is gravity in space, but I know you don’t mean this. It can be explained this way: the generation of gravity is related to mass. Mass affects space in a very specific way (Einstein would say, mass curves space.) This effect is transmitted by the force we call gravity, discovered by Isaac Newton. According to our observations the theory of gravity is correct. If this were not the case, the Apollo moon landings would not have been possible. Likewise, the decrease in gravity of an object is proportional to the square root of the distance between the objects.
On the earth, the gravity generated by the mass of an object acts like a "pressure" on the object in contact with the ground, which we call "weight". When there is no such contact, for example in Earth orbit, the craft is not in direct contact with the Earth and there is no gravity. But the spacecraft still has mass, so it will generate its own gravity area (of course there is no gravity for a small space shuttle).
That is to say, all central stars with significant mass in space, such as the sun, the earth and other planets, have gravity. Newton also discovered that objects in a vacuum can move in a straight line forever without acceleration. However, when an object, such as a space station, is pulled by the earth and moves in the earth's orbit, it cannot be considered to be in a state of "weightlessness"; in this way, the "weightlessness" experienced by a space station operating in orbit is not The effect of gravity does not exist, but the effect of gravity on it disappears. Once there is resistance, atmospheric resistance, engine power, centrifugal acceleration caused by rotation, etc., the weightlessness phenomenon disappears.
13. What was it like when the space shuttle launched?
On the launch pad, due to the orientation and position of the cockpit, the astronauts were back-to-back with their feet facing up (the aerospace doctor prescribed the time they should be in this state before launch). After the hatch is closed and all final inspections have been completed, the astronauts are silently looking forward to the launch, recalling in their minds the operating procedures they have trained in the past few years.
For example, are all the cabinets above them locked? Does the reminder card in front of you remind you what steps to take in an emergency? The final countdown reaches 6 seconds, and the three liquid rocket thrusters are ignited. When the space shuttle rocks back and forth 5 feet, you can clearly feel its shaking. At this time, the orbiter swings and vibrates strongly. But the astronauts couldn't hear the thunderous roar of any engines.
Then the count reached zero, and the command came from the wireless device on the helmet: "Ignition, lift off." The two solid-fuel rocket thrusters ignited, and the space shuttle began to rush into space. At this time, you won't feel very obvious acceleration, which is similar to the feeling when an airplane takes off. The fuel in the rocket thruster does not burn evenly, causing severe turbulence during propulsion. The entire cabin bounces like a car racing over cobblestones at top speed.
Once the pushers are lit, they will not stop until the fuel is burned out. Two minutes after takeoff, the space shuttle's emptied containers began to fall off, the noise disappeared, and each astronaut's discomfort was greatly reduced. The fuel in the three liquid thruster engines continued to burn and hum, and when the fuel burned out, the shuttle became lighter and continued to accelerate. (Because according to Newton's theory, acceleration is equal to the square of mass.)
At 7.5 minutes after liftoff, 90% of the fuel in the huge external container had been burned, and the space shuttle weighed 2,000 tons at takeoff. , and now it is less than 200 tons, and the pressure has reached 3g-three times the gravity of the earth. Engine decelerates to 3g’s. At this acceleration, astronauts wearing heavy spacesuits find it very difficult to breathe and will subconsciously breathe and raise their chests.
Finally, the main engine shuts down. Within seconds, the engine's propulsion dropped to zero. The astronaut will suddenly feel the pressure on his chest disappear and feel a sense of weightlessness. At this time, the astronaut is already in space.
14. Why do we want to build a space station? What is it used for?
Our country has many reasons for proposing to build a permanent platform in Earth orbit, and we can benefit a lot through international cooperation with other countries.
The space station provides a new way to improve human living standards. By now everyone should know that in Earth orbit, space provides many very useful environments that cannot be found on Earth, such as weightlessness, high vacuum, high temperatures, extreme cold, extreme heat, unfiltered sunlight and the ability to See the full panorama of Earth and its environment, as well as use an astronomical telescope to observe the universe unobstructed by an atmosphere filled with air, clouds and pollutants.
These special environments allow us to conduct scientific research on humans, animals, plants, etc. and obtain major scientific and technological innovations. They also bring new medical breakthroughs, technological developments, new industrial products, new pharmaceuticals and many other new opportunities and challenges that help our country stay ahead of the curve. Of course, this also makes our economy, industry, trade and commerce more competitive and creates new jobs, knowledge and wealth.
Because the space station can stay in space for a long time, it allows us to utilize so many space resources for a long time, while the space shuttle can only stay in space for up to 14 days. The space station can also provide more power, a larger area, more tools and other equipment, and is simply like a large research base, product development center and technology demonstration center on the ground. During long-term flights, the space station can also become a space launch site, a springboard and a launch platform moving at a speed of 23,000 feet/second for humans to better explore outer space.
15. What are the physical requirements to become an astronaut?
No special requirements other than good health. Both men and women can apply to be candidates for astronaut training as long as they meet these requirements and the basic qualifications I gave in question 8.
16. What are the unusual features of a space suit?
A spacesuit is simply a small spacecraft. It needs to ensure the health and continuous work of astronauts during extravehicular activities. Since there is no air pressure and no oxygen to sustain life in space, humans must have an environment suitable for their survival. Like the air in the space shuttle's working compartment, the air in the space suit can be controlled and adjusted.
In this way, the main function of the space suit must be to provide oxygen for breathing, maintain stable air pressure around the body, and keep the blood in the body in a liquid state.
In a vacuum or very low pressure, the blood in the body boils like hot water on a mountaintop.
The spacesuits equipped on the space shuttle can withstand 4.3 pounds per foot of pressure, which is only one-third of normal atmospheric pressure (each atmospheric pressure is equal to 14.7 psi). Because the gas in the spacesuit is 100% oxygen, unlike our Earth's atmosphere which only contains 20% oxygen, astronauts wearing spacesuits are much more comfortable than those in the mountains at 10,000 feet above sea level or at sea level. People without spacesuits breathe more oxygen. Astronauts breathe pure oxygen for several hours before leaving their spacecraft to work in space. This is a necessary procedure to remove dissolved nitrogen from the blood and prevent the release of air bubbles when the air pressure drops, a condition commonly known as decompression sickness in diving.
On the other hand, if pure oxygen is breathed for too long under normal atmospheric pressure, it will turn into a gas harmful to the human body. This kind of oxygen intake and nitrogen discharge is excessive, useless and annoying waiting for astronauts. It is really a troublesome thing. We designed the internal air pressure of the space suit to 8.3 psi, which can shorten the oxygen intake and exhaust time. Nitrogen time.
Space suits must protect astronauts from fatal injuries. In addition to preventing the impact of micrometeoroids, space suits must also protect astronauts from the temperature extremes of space. Without the earth's atmosphere to filter the radiation of sunlight, the temperature on the side facing the sun can be as high as 250 degrees, and on the side facing away from the sun, it is minus 250 degrees.
The main features of the space suit are: in addition to the multi-layered structure of boots and gloves, there is a life support system on the back, a display control module on the chest, and it is designed for spacewalkers and emergency situations. equipment, especially a backup oxygen supply system. These are combined into a collective called an EMU (Extravehicular Maneuvering Unit), which enables free conversion between different subsystems and can be easily and safely connected either under normal circumstances or in an emergency.
There are also some special devices: urine storage, which transports urine to the waste disposal system after returning to the shuttle or space station; a liquid cooling and ventilation suit made of mesh-like elastic fiber , there is a zipper at the front entrance of the suit, and it weighs 6.5 pounds; water is constantly flowing in the cooling tube in the underwear, making the astronauts feel very comfortable when wearing it. The reason for installing cooling tubes is because there is a pure oxygen layer inside the clothes, which cannot provide as much cooling as in ordinary air. There are also underwear drinking bags that can hold 21 ounces, a "detection cap" or communication carrier combination device, headphones and microphones for two-way communication, early warning and alarm devices, and biomedical detection subsystems.
During the spacewalk, the astronaut straps on the ground a 310-pound Monomanual Maneuvering Unit (MMU), a one-man nitrogen thruster backpack, which is attached to the spacesuit's portable life support on the system. Using a hand controller that can control rotation and translation, astronauts can accurately fly into or move around the spacecraft cargo ship docking dock, or freely enter payloads or buildings near the space shuttle or space station, or can reach many other seemingly Outer areas that are out of reach. Astronauts wear MMU’s, known as “space bikes,” and play a large role in launching, servicing, maintaining, and retrieving artificial satellites.
17. What material are space suits made of? How are they made?
Our universal spacesuits/EMUs have 12 interlayers, each with its own special purpose. Starting from the inner layer, the innermost 2 layers are underwear made of frozen liquid. The material is elastic fiber with inner seam tubular plastic. The next layer is a bladder layer coated with nylon, and the outside is covered with a layer of daclon fabric. . The lower 7 layers are a protective layer against heat and small meteorites, made of aluminized Myra and laminated dacron cotton and linen. The outer layer of these seven layers of clothing is a layer of chemical fabric.
18. Who was the first American astronaut to enter space twice?
The first American to enter Earth orbit twice was Gordon Cooper. First flight: May 15-16, 1963, piloting the Mercury 9 spacecraft, which lasted 1 day, 10 hours and 20 minutes. Second flight: June 3-7, 1965, flying Gemini 5 with Pete Conrad, lasting 7 days, 10 hours and 2 minutes.
In fact, Gus Gleason was the first American astronaut to fly into space twice on a rocket.
But on July 21, 1961, the "Liberty Bell" he piloted for his first flight was only a suborbital spacecraft, which took him along a parabola for 15 minutes at an altitude of 190 kilometers and was in a state of weightlessness for five minutes. Then he started his second flight, this time he entered the Earth's orbit. On March 23, 1965, he and John Young flew around the Earth three times on Gemini 3. Incidentally, this flight brought the first computer into space: a small computer capable of running 7,000 calculations per second. Gleason used it to calculate changes in Earth's orbit. From then on, astronauts could actually fly through space instead of just following a fixed orbit around the earth.
19. Could the Hubble Space Telescope replace the International Space Station?
The Hubble Space Telescope is still far away from the International Space Station. First, its orbital inclination is 28.47 degrees (the International Space Station is 51.6 degrees), and secondly, its average altitude is 590 kilometers.
20. How much does a space suit weigh?
The net weight of the spacesuit, including backpack, is nearly 280 pounds (on the ground). Of course in space it has no weight (even though nothing changes).
21. Why do astronauts have to wear such heavy equipment?
Once astronauts enter the pressurized living chamber, they put on the same clothes that people on the ground wear on warm spring days, usually shorts, short-sleeved shirts, and socks (because their feet need some protection) Crash protection and cold protection, but they do not walk, so no shoes are required) They only need to wear special clothing during launch and return and when stepping out of the pressure chamber for spacecraft or extravehicular activities. The launch/landing suit is fireproof and maintains pressure around the body if the shuttle's pressurization system goes out of control.
The spacesuits worn by astronauts during extravehicular activities must provide oxygen and pressure to maintain survival. They have to protect astronauts from fast-moving space debris, so their spacesuits have to be pressurized. The suit must keep them warm when they turn away from the sun and become colder. The suit provides wireless equipment for communication with astronauts on the ground, in shuttles and other extravehicular activities. It provides the light needed for short-distance walking in space and working in the dark, prevents astronauts' eyes from direct sunlight, makes it easy to carry tools for working outside, and provides food that meets the physiological needs of astronauts. The spacesuit must be guaranteed to be trouble-free for six hours and can adapt to the requirements of different astronauts. You can think of it as a small spaceship. On Earth it weighs 280 pounds, but in space it weighs nothing.
22. How long does it take to enter space?
It takes about 8.5 minutes for the space shuttle to launch, pass through the external tank and solid rocket, and reach the earth's orbit at the so-called orbital speed, so it has to keep rotating around the earth. (Specially compiled by China National Space Administration/Tang Chengge and Shen Xianyun)
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