The science

In fact, astronauts, of course, also cry. However, as NASA experts explained, in microgravity, tears do not flow down, as on Earth, but remain in place. They gather around the eyeball.

Moreover, such tears deliver a lot of discomfort.

In May 2011, the astronaut Andrew Feustel, perhaps the first to know what happens when your eyes water in space.

During a spacewalk, Feustel experienced a severe burning sensation in his eye. As it turned out later, a little anti-fogging agent got inside the astronaut's helmet, which caused lacrimation. He was able to rub his eye on a sponge device, which is usually used to pinch his nose to equalize pressure, and relieve his condition.

According to the scientific explanation, tears should not cause pain. Though we don't know exactly why we cry ourselves tears have a softening effect. But, as you know, weightlessness has a negative effect on human vision, which is caused by the displacement of fluid towards the head. It is also possible that dry eyes occur in space, and the sudden ingress of liquid can cause a burning sensation.

As fellow astronaut Ron Parise explained, if there are too many tears, they come out of the eyes and float around. In other words, you can enjoy watching your weightless tears float before you.

State of weightlessness

What is the state of weightlessness? We are used to thinking that astronauts float in space, acting contrary to the laws of gravity. Therefore, many believe that there is no gravity in space. In fact, gravity exists everywhere in the universe and is the most important force that affects everything that exists in space.

What happens to an astronaut who is in zero gravity? More precisely, this state could be called free fall.

Why don't astronauts fall to Earth? This is where the law of free fall acceleration comes into play. If an astronaut drops an apple on a space station, then all of them will fall: the apple, the astronaut, and the station. Only they fall not on the Earth, but around it because they are accelerating relative to the earth. Objects in Earth orbit appear to be floating, when in fact they are moving at the same orbital speed as the spacecraft, over 28,000 kilometers per hour.

Liquid in weightlessness

Experiments with water in zero gravity on the International Space Station.

Drinking water in space is also not an easy task. Since water does not flow out in microgravity, all liquid from the containers is drunk through a straw. Without it, the astronauts would have to "bite off" small pieces of the floating water bubble.

How do astronauts go to the toilet? Water, for obvious reasons, cannot be used for draining either. Waste products are sucked into a special funnel with a hose, and then thrown into outer space.

On the eve of Cosmonautics Day, we present the five most interesting news from space from Chris Hadfield.

1. This story started back in May 2011. The ISS crew was working in outer space when astronaut Andrew Feustel complained of a sharp pain in his right eye. How to cope with the “mote” if you are in zero gravity, and you are wearing a clumsy spacesuit? With difficulty, but managed to wipe the eyes. After the story was heard on Earth, Chris Hadfield got a question from a student: is it possible to cry in space? And here is the video response.

As it turned out, crying in space is not only difficult, but also painful. With zero gravity, tears won't run down your face - the salty liquid will accumulate into one large ball of water under your eye. And then it will spread over the face, get into the nose, ears, and the other eye. In general, the best way out of the situation is to blot your tears with a towel. Otherwise, it will hurt, promises Headfield, demonstrating this experience with ordinary water.

2. "Tears Hurt" is a great title for a new Chris Hadfield song. The Canadian became the first astronaut in history to record his own music track in orbit. Jewel in the Night he sang on one of the Christmas evenings on the ISS. The lyrics were written by Headfield's brother, and the song itself talks about what the Earth looks like when you look at it from space. Chris did not even expect such pop popularity and now promises to give the world a whole album of real space songs.

Headfield's career prospects are clear. Pop stars invite him to sing a duet, even though he has not yet returned to Earth.

3. The most familiar and ordinary things in weightlessness can cause a lot of problems. Here, for example, is an instruction on how to brush your teeth in conditions where all the necessary ingredients simply scatter around you. Squeamish please do not watch. It turns out that the astronauts simply swallow toothpaste and dirty water after the whole procedure.

It is equally necessary to act carefully when cutting your nails or shaving.

Obviously, astronauts train a good reaction on Earth, otherwise the ISS would have to be cleaned for several hours every day. By the way, cleaning is also not an easy task. Here Chris Hadfield describes how to deal with stains and dirt on the ISS.

4. Chris Hadfield is very fond of taking pictures in zero gravity. And here it is not the process that brings more pleasure, but the result. A series of his photographs from space on Earth every time cause admiration and delight.

A recent photo of snow-covered Minsk, sent from orbit, has gained particular popularity. "Success! For many months we have been trying to get a high-quality image of Minsk, Belarus, the hometown of the happy ISS crew member Oleg Navitsky,” Headfield posted this post along with the photo.

5. Shares Chris Headfield and some of the medical details of living on the ISS. In one of the communication sessions with the Earth, he said that astronauts go through a lot of examinations every day to assess how weightlessness affects human health. It turns out that some people in space lose their eyesight. And in order to understand this phenomenon, the eyes of the ISS crew members undergo a dozen procedures on advanced optical equipment.

Such stories cause, among other things, a deep sense of envy for Canadians who can communicate live with their space heroes. Our Roskosmos does not provide such opportunities. Secrecy, damn it!

There are not many sunrises

In just a day, the ISS crew meets 16 sunrises - the Sun rises and sets every hour and a half. Because of this, sleeping astronauts becomes uncomfortable. Therefore, especially for the team, their own time zone was developed, averaged over the time between Moscow and Houston - the two main earthly mission control centers. Special protective curtains on the windows plunge the ISS into darkness at certain hours, creating the illusion of night.

"Sleep my joy, sleep...»

The process of sleeping in space is not as comfortable as it might seem at first glance. Even the artificially created illusion of night cannot compensate for the lack of gravity: astronauts have to sleep strapped in so as not to float while sleeping in zero gravity. In addition, the ISS is very noisy due to the large amount of equipment, all kinds of pumps, fans and filters. But despite all the nuances, sleep in weightlessness is more peaceful than on Earth. And in some cases, while sleeping in zero gravity, astronauts even get rid of snoring.

Everyday life in orbit is fraught with many secrets. The public is increasingly interested in the arrangement of the life of astronauts on the International Space Station. What does a daily routine look like in zero gravity?

Astronaut Chris Hadfield had a great career: he went into space three times and was the first Canadian to go into outer space. He also wrote a remarkable book, The Astronaut's Guide to Life on Earth, where he spoke in detail about his career and view of the profession. However, Hadfield is known to millions of people thanks to popular YouTube videos that he himself recorded on the International Space Station (ISS). The reason for the success of his videos is simple: he decided to tell the general public about the everyday life of astronauts, about the peculiarities of life in zero gravity.

His new status as an Internet celebrity was finally sealed by a video recording of Hadfield playing a cover version of David Bowie's "Space Oddity" with guitar while enjoying the weightlessness of the ISS. The video aroused great interest in the network, at the moment it has been viewed by more than 30 million people.

To talk about everyday life in orbit, one must first describe the International Space Station, which is home to every astronaut. The ISS is a gigantic spacecraft weighing over 400 tons, the embodiment of joint work and material expenditure of 14 countries. The ISS moves in orbit at a speed of 27,700 km / h, the station goes around our planet 16 times a day. Consequently, astronauts can observe 16 sunrises and sunsets in one day, which is amazing for newcomers to the ISS, who can hardly look away from windows with breathtaking views.

Getting on board the ISS, you immediately understand that in weightlessness there are no concepts of "top" and "bottom". Astronauts feel equally comfortable in any position of the body; in the same module, someone on the “wall” can exercise on a sports simulator, while another astronaut can hang upside down, doing scientific research. In orbit, each person determines for himself where is the top for him, and where is the bottom. Newcomers to the ISS are startled by the constant noise levels. Pumps, fans and other life support systems are continuously working. The background buzz is regularly interrupted by very loud pops, reminiscent of the sound of exploding firecrackers. These are small meteorites crashing into the station's armored plating. To protect the windows from meteorite impacts, they are covered with special metal shutters when astronauts get ready for bed.

In space, all the usual earthly activities take on a bizarre character, and what seems natural to us on Earth becomes unobvious under conditions of weightlessness. For example, an overnight stay. Astronauts on the ISS sleep in special bags that look like cocoons. They are attached to the wall and provide high comfort despite the absence of pillows or a mattress. The fact is that the astronauts do not toss and turn, trying to find the most comfortable position of the body. Hadfield describes the feeling in a sleeping bag on the ISS as follows: "Sleep like on a cloud that holds up great." A sleeping astronaut on the ISS looks pretty creepy, with his hair flying and his hands floating in the air in front of him. Nevertheless, the quality of sleep on the ISS is at a very high level.

It is customary for us that if we put a spoon next to a plate, then it will remain there, but in zero gravity, any object tries to fly away from you. Therefore, on the ISS, all small items are Velcro. After writing something with a pencil, the astronaut attaches it to the wall of the module. If there were no Velcro, then pencils, combs, markers and spoons would fly in different directions throughout the station, creating real chaos.

Once on board the ISS, astronauts automatically acquire superpowers. They can literally fly, easily move heavy objects, do acrobatic somersaults in the air without much effort. The magical state of weightlessness even affects everyday hygiene procedures. For example, astronauts have to swallow toothpaste. If someone on the ISS spit it out, as we do every day, then it would immediately scatter in all directions, becoming a problem for the crew and all the equipment of the space station. For the same reason, astronauts are deprived of a shower; washing on the ISS is available only in the form of wiping with a special damp cloth. The head is washed with a special shampoo that does not need to be washed off, just dry the hair.

Also, laundry is not possible on the ISS, and all astronauts wear only new clothes. According to the recollections of many cosmonauts, the inability to take a shower or bath is hard to bear on long expeditions. The lack of gravity even affected the arrangement of the toilet on the ISS. The toilet is located in a special booth and is just a hose attached to the wall. After switching on, the hose begins to draw in air with great force. This principle of operation of the toilet made it possible not to turn the ordinary use of the toilet into a disaster for the entire station.

The ISS is equipped with a special water treatment system that can process 7,000 liters of water per year. Accordingly, astronauts' urine and sweat, as well as waste water, are converted into clean drinking water. The creation of a filtration system increased the autonomy of the station, now there is no need to constantly deliver drinking water to the ISS. Perhaps someone will be disgusted by such a fact, but the cosmos does not tolerate excessive sentimentality. Achieving a big goal requires the ability to step over yourself and separate the wheat from the chaff.

The human body was formed under the influence of gravity, respectively, falling into unusual conditions for itself, a number of changes are observed at the physiological level. Nausea is common in zero gravity, and the immune system is generally weakened because the sinuses are not cleared sufficiently. For many newcomers, the first days at the station are filled with headaches and stuffy noses. Once on the ISS, all astronauts add a couple of centimeters in height due to the fact that gravity no longer presses on the spine. When an astronaut on the ISS closes his eyes, he sees periodically appearing bright flashes. This is a visual confirmation of the constant radiation exposure to which all people in orbit are exposed.

A long stay in zero gravity leads to such a strong atrophy of all muscles that after landing the astronaut can hardly control his body and stand on his feet. After the flight, the astronaut needs several months of special training to return to his previous physical form. In order to maintain muscles and bones in a more or less normal state, each astronaut must devote 2 hours of his time daily to physical exercises on special simulators. For example, you need to tie your legs to an exercise bike, otherwise you can easily fly away from it.

The astronauts adhere to a strict diet, within which fried and fatty foods are completely excluded. A feature of the diet on the ISS is the complete absence of bread, as crumbs flying everywhere could lead to clogged air filters and other problems. Astronauts have a varied menu, but almost all food on the ISS is dehydrated. Water is added to a special bag with food, then it is torn open and the meal is started. In space, the taste of any food becomes insipid, and fresh fruits and vegetables on the ISS are only on major holidays.

Every morning the astronaut receives a detailed plan of action for the day, which is divided into 5-minute segments. On a daily basis, an astronaut must conduct scientific research, ensure the station's operability, observe hygiene procedures, take tests, maintain physical fitness, communicate with Mission Control Center specialists, and much more. In their rare leisure hours, astronauts prefer to communicate with their families via video calls, play musical instruments or enjoy incredible views of the Earth from space.

Astronauts are constantly preparing for any eventuality even before the launch of the rocket, trying to anticipate all possible problems. However, one must always remember that space is a hostile environment in which a person can exist only for a limited time and only thanks to the achievements of science and technology. For an astronaut, there is always a great risk when working in an airless space with zero gravity. Chris Hadfield talks about his first spacewalk in The Astronaut's Guide to Life on Earth.

Hadfield was given the goal of installing the Canadarm2 robotic arm on the ISS. Putting on a spacesuit and once again mentally repeating the algorithm for performing the upcoming work, the astronaut set to work. Hadfield felt calm and confident, the work was carried out successfully, and a special cable, like an umbilical cord, connected him with the ISS, guaranteeing a return to the ship. However, then something happened that once again made me remember the fact that there are no trifles in space.

After several hours of successful work, a sharp pain pierced his left eye. Something hit Hadfield in the eye. He instinctively tried to rub his eye with his hand, but, of course, he could not do this, since he was in a spacesuit. He actively blinked and tried to turn his head, receiving commands from specialists on Earth. But nothing helped, his eyes became wet with tears, and he was practically blind. The fact is that, unlike the realities of earthly life, when a tear, obeying gravity, flows down the cheek, in space it does not go anywhere. The tear remains in the eye, turns into a ball of salty liquid and increases in size. In just a few minutes, Hadfield was practically blind while in outer space. The situation became critical because of, it would seem, such a trifle. It was necessary to finish the work and return to the ISS, but the almost blind astronaut could not help crying. Hadfield saw only blurry spots, his eyes hurt badly as his oxygen supply dwindled. However, everything ended well.

Following commands from the Mission Control Center, the astronaut managed to partially restore his vision after some time. Overcoming himself, Hadfield managed to complete the installation of the manipulator, spending more time on it than planned, and safely return to the ISS. The case described by Hadfield once again indicates that space can always present an unpleasant surprise. And we, ordinary inhabitants of the Earth, should remember that behind the romantic halo of the work of astronauts lies gigantic work, risk and lack of familiar comfort in everyday life.

Many actions that people perform every day automatically and without thinking become impossible in zero gravity. In space, you can not lie, walk and sit, eat the usual food and drink water from a glass. To find out why you can’t cry or sneeze in space, you need to remember the lessons of physics.

In microgravity, tears do not flow down, but remain in place

The law of universal gravitation does not apply in vacuum. The lack of gravity means that tears cannot run down the cheeks, as they do on Earth. The fluid exits the lacrimal canal and remains in the eye - the more the astronaut cries, the larger the bubble will form. He will not be able to fall - he will be held on the skin of the eyelids by the force of surface tension.

The tear fluid contains salt, so it burns and corrodes the eyes. If you cry often, being in zero gravity, then tears can adversely affect the astronaut's vision.

To remove accumulated bubbles from the eyes of astronauts, special miniature trays have been developed attached to plastic containers. If there are few tears, then you can use a handkerchief.

What else can not be done in space

In space, it is impossible to carry out ordinary earthly actions due to the lack of gravity

A few more "prohibitions" and warnings that apply in zero gravity:

• Astronauts cannot cut their hair and shave in the usual way. Both electric shavers and clippers are attached to a tube into which the removed hairs fall.
• Boil a simple kettle. Due to the lack of pressure, the water will boil almost immediately, but only in the place where the heating occurs. Mixing (convection) of air and liquids is impossible due to the lack of gravity. In addition, boiled water instantly cools.
• Use perfume. Astronauts are not allowed to take their favorite perfume into space. Since the human blood system works differently in weightlessness, the olfactory receptors function more intensively. The perception of smells is so aggravated that a microscopic dose of perfume can cause a headache.
• Sneeze. Of course, no one can stop this. However, with a strong sneeze, a reactive reaction can occur, in which the astronaut will begin to rotate or hit the surrounding objects sharply.

Video: astronaut haircut on the ISS

Space dictates its own laws, so astronauts have to train for a long time in orbit in order to stay in zero gravity and learn how to perform ordinary manipulations.