People dreaming of space should think about more pressing problems than asking questions about the existence of extraterrestrial civilizations and their lack of desire to visit us or at least hear. After all, we have not only been sending people into orbit for quite a long time, we are also talking about space tourism that is already almost felt on the horizon, we are happily surprised at the plans of the world space agencies to settle on Mars and the news about private companies investing hundreds of millions of dollars in studying issues. associated with survival on other planets.
“Space is a harsh environment that very rarely forgives human errors and technical failures,” the researchers write in the book Biology in Space and Life on Earth: The Effects of Spaceflight on Biological Systems).
But, unfortunately, human errors and technical failures are not the only issues that we all need to think about before embarking on the era of space colonization.
“The main problem in such missions is biomedical. And it consists in how to maintain human health in the conditions of a long stay in such harsh conditions, - comments retired astronaut Leroy Chiao.
Below we will consider examples of the consequences that people flying into space have to face both during the flights themselves and after they return home.
Microgravity is a silent killer
At first glance, it might seem that weightlessness is one of the most enjoyable things associated with space travel, but do not underestimate microgravity and its effect on human biological systems.
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Lack of gravity in space weakens and makes our cardiovascular system less efficient. Instead of distributing blood throughout our bodies as usual and effortlessly, its ineffective work allows blood to concentrate in the head and chest, which significantly increases the risk of developing arterial hypertension (constantly high blood pressure). In more serious cases, when the efficiency of oxygen supply and distribution in the body is reduced due to weightlessness, the risk of developing cardiac arrhythmias increases.
Since muscle activity in microgravity is significantly reduced (the muscles do not need to fight the earth's gravity), some of the main muscles of the body begin to atrophy when a person is in space for a long time. The loss of muscle mass and its strength is an indispensable bonus of every long-term space mission. That is why the crew members of the International Space Station are required to do physical exercises every day for a couple of hours, aimed at strengthening the calf muscles, quadriceps, as well as the muscles of the neck and back.
Partial blindness
The risk of consequences from a long stay in space is not only subject to the human muscular system. There have been cases when, after a long stay in space, there were alarming signs of visual impairment. And these cases, I must admit, were, unfortunately, not isolated.
Two-thirds of astronauts on the International Space Station reported vision problems. The main suspicion, according to experts from the aerospace agency NASA, falls on changes in the distribution of fluid in the cranial cavity, in the eyes and in the spinal cord in response to conditions created by microgravity. The result is the appearance of visual impairment syndrome due to increased intracranial pressure. In our country, this syndrome is most often called intracranial hypertension (ICH). Fortunately, technology does not stand still, and one day we will get the tools that will allow us not only to understand, but also to effectively prevent the consequences of the connection between intracranial pressure and microgravity.
The inevitability of exposure
Some people on Earth are concerned about the radiation from electrical devices like smartphones. I wonder what they would say if they knew what level of radiation a person has to face in space?
"In space, the dose rate of radiation can be 100-1000 times higher than on Earth," says Keri Zeitlin of the US Southwestern Research Institute.
"The very same radiation is present in the form of cosmic rays - highly charged particles, from which we on Earth are screened by the magnetic field of our planet and its atmosphere."
The impact of this effect on the human body can go far beyond our understanding of a healthy environment. The average dose of radiation to which a person on Earth is exposed to natural sources during the year is 2.4 mSv (millisievert) with a spread from 1 to 10 mSv. Anything above 100 mSv sooner or later can lead to cancer. Meanwhile, astronauts aboard the International Space Station could be exposed to 200 mSv. If we talk about interplanetary flights, then this level will generally be about 600 mSv. Even a flight to the nearest neighboring planet, Mars, can lead to genetic mutations, DNA strand breakdown, and a 30 percent increased risk of cancer.
Fortunately, the ISS crew is protected from most of the radiation thanks to the same magnetic field that keeps us safe on the planet's surface. But if we are talking about a real flight to Mars, then we do not yet have any suitable protection for this. NASA is trying to solve this issue, which is developing methods to optimize shielding means, as well as methods of biological countermeasures against radiation exposure.
Fungal infection
Despite all our efforts to ensure the safety and cleanliness of spacecraft inside, the problem of the appearance and impact on the human body of pathogenic organisms in space remains unresolved. According to a study published by the American Society of Microbiology, the growth rate of Aspergillus fumigatus, the most common cause of fungal infections in humans, is completely unaffected by harsh space conditions.
If such a banal and widespread thing as fumigatus is capable of getting and existing on the ISS, then, most likely, there may be other and more lethal pathogenic microorganisms at the station. Given the far from easy accessibility of the nearest hospital, any infection on board the spacecraft can lead to very serious consequences. Therefore, only further improvement of living conditions and the level of hygiene, as well as the development of technologies capable of providing medical diagnostics and assistance in space, will be able to save astronauts from big problems that once began, it would seem, from the smallest and insignificant.
Mental disorders
It is not only the physical health of long-term astronauts in space that is at risk. Being in a small, hermetically sealed space tin can for many months, during which you have to communicate with the same people every day, realize that you cannot even just lie down comfortably on the bed or get up and walk freely - all this and many other things can heat your mental state to the limit and ultimately cause serious psychological trauma.
NASA-funded research on long-term space travel shows that the main concerns of American astronauts during their missions aboard the International Space Station are related to the question of how to deal with the crew. In his personal diary, an astronaut wrote about the stress he experienced in such interpersonal relationships:
“I really want to get out of here. From these cramped closets in which you have to spend a long time with the same people. Even those things that you in your everyday life, most likely, would not pay attention to, after a certain time begin to bother here so much that they can drive anyone crazy."
A lot of research has already been done on the safety and protection of the psychological health of astronauts during their stay in space, and will be carried out even more, taking into account the increase in the duration of space flights.
Maximum maintenance of human health during long space flights is a very serious problem and a very time consuming task to solve, but even this does not stop people who want to become space pioneers. There are indeed people in the world who are ready for literally anything. Despite all the risks described in the results of numerous studies, despite all the potential dangers that await humans in space, despite all the risks to the health of our biological systems and psyche, the NASA aerospace agency in 2016 received more than 18,000 applications for the right become astronauts. Record number! We can only hope that the research being carried out today in the near future will really allow us to carry out safe space travel, in terms of the level of threats not overtaking ordinary earthly ones.
NIKOLAY KHIZHNYAK