Man has always sought to overcome the unknown. For thousands of years, geographical discoveries have been made at the limit of possibilities, but transport and equipment have always suffered a little more than the pioneer – the ships crashed into a storm, the convoy with provisions fell into the abyss, the sleigh froze into ice, and the man moved and moved to his goal
When there were no white spots on the planet, we began to think about the cosmos. The programs for the development of the Moon and Mars are not a fantasy, but an inevitable future. Behind them – distant flights to the nearest stars. The further a person leaves the Earth, the more difficulties will be encountered along the way.
What threats are waiting for us in space, and what technologies will allow us to survive – we'll tell about this later.
Life without Gravity
On September 6th, 1522, the battered ship "Victoria" returned to Spain – the only one of the five ships of Magellan's round-the-world expedition, on which 18 of 260 crew members sailed. The illustrious navigator was killed by aborigines from Mactan Island in the Philippine province of Cebu.
The story with Magellan well demonstrates the risks that the researcher, dared to go to unknown lands, carries. But the travelers on their way did not come across something completely unknown. We also need to create a new science – space biomedicine – when traveling to the stars (and flying to the nearest planets).
Cosmonauts going to Mars can break their bones and suffer from urolithiasis, they are awaited by insomnia and depression, and in the future – death from cancer. That is why various research groups are currently testing various hypotheses on the ISS. We must know in advance how long a stay in space affects the human body and psyche.
Because of the reaction of the vestibular apparatus, nausea appears, a sense of disorientation appears. Even for pilots with a strong nervous system, for which the stimulation of the vestibular apparatus during the performance of aerobatics is professionally common, severe orientation disturbances may occur, accompanied by emotional and neurotic disruptions. It is known that astronauts feel fine the first few hours after entering orbit, after which most of them have effects associated with the lack of gravity. After a few days, adaptation takes place and unpleasant phenomena disappear.
We evolved as bipedal organisms. Our body was built for millions of years under the influence of gravity. Our bones and muscles developed, resisting the influence of the gravitational field, and ideally learned how to interact with the surrounding world.
In microgravity, the body begins to fail. The cardiovascular system is designed for pumping blood against gravity. For example, in the veins of the legs there are check valves that prevent the accumulation of blood in the legs, but such valves are not present in the vessels of the upper body. Without the influence of gravity, the blood rises to the chest and head, because of which the asthma swells the face, increases the pressure. Stay in conditions of weightlessness for more than 6 months leads to disruption of the circulatory system. For example, there was a violation of gas exchange in the capillaries, resulting in much less oxygen flowing to the tissues and organs.
Before the program of physical support was introduced into orbit, the cosmonauts had to be particularly difficult. After 18 days of flight on the Soyuz-9 spacecraft, cosmonaut Andriyan Nikolaev recorded a 12% decrease in heart volume. Bone tissue lost potassium and calcium, became loose. The composition of the blood has changed: hemoglobin decreased by 25%, the number of red blood cells – by 20%, and platelets – by 50%.
Astronauts literally begin to lose their own bones. First, the body derives calcium and phosphorus, which leads to a gradual weakening of bones and an increased risk of osteoporosis. Loss of bone mass can reach 1.5% per month, and recovery after returning to Earth takes at least three to four years.
Calcium does not just leave the bones – it is washed into the blood and urine, which can lead to the occurrence of urolithiasis. All this happens in the first days of the flight . But the flight to Mars will take almost a year, and after landing the crew will have to act without assistance.
Due to the lack of gravitational compression, the spine lengthens, which leads to back pains. The back muscles significantly deteriorate during their stay in space, decreasing by 19%. More than half of the ISS crew complained of back pain. Cosmonauts are four times more likely than ordinary people to get a herniated intervertebral disc.
Using ultrasound, scientists test non-invasive methods for assessing and measuring intracranial pressure of astronauts. Image: NASA
Another serious problem is sight problems. The reason, according to studies, is an increase in the volume of cerebrospinal fluid. Because of this, the pressure increases, and the fluid first squeezes into the optic nerve case, and then along the spaces between the optic nerve fibers into the eyeball. As a result, hyperopia develops.
Now there are several ways to solve the problem of microgravity. Astronauts on the ISS are engaged in simulators for about two hours a day, counteracting the degradation of bones, muscles and blood vessels. The best solution is artificial gravity. Theoretically, it is quite possible to create it on a ship. Practically, too many resources are needed so far.
Curiosity has on board a RAD device for determining the intensity of radioactive irradiation. This is the first device designed to collect data on harmful forms of radiation on the surface of Mars.
Long-term exposure to cosmic radiation can negatively affect human health. On Earth, we are protected from cosmic rays, because the atmosphere and the magnetic field of the planet act as a shield that inhibits the elementary particles and atomic nuclei. With such particles it is better not to meet – they lead to DNA damage, cell mutation and cancer. And when we get to Mars, we'll have to live with the idea that the planet does not have an ozone layer – nothing protects from ultraviolet radiation.
The daily dose of cosmic radiation on the ISS is 1 mSv, that is, a thousandth of a sievert. For comparison, 1 sievert radiation is associated with a 5.5% increase in the risk of cancer. In general, not so scary. Everything becomes much worse when we leave the magnetosphere of the Earth. During the trip, the cosmonauts will be exposed to different types of study. High-energy subatomic particles flying from the Sun, and ionizing radiation caused by a supernova explosion, most rapidly destroy biological tissues. In addition to cancer, they can also cause cataract and Alzheimer's disease.
When these particles enter the shell of the ship's hull, some metal atoms break apart, radiating even faster particles; This is called secondary radiation.
Another study shows that the absence of a protective magnetic field reduces human cognitive functions (speed of thinking, ability to learn, etc.), exacerbating allergic reactions.
The solution of the problem? Scientists are developing ways to reduce exposure, for example, using various protective materials in the ship's hull. But so far the only solution we have is the speed of flight. The faster we get to the Red Planet, the less astronauts will suffer.
Within the framework of the scientific experiment on the preparation of flights to Mars, six people a year lived in a dome house in Hawaii.
Mental illnesses – another great risk for astronauts. Mental illness is difficult to detect and even more difficult to cure.
It's very boring to live aboard the ship. All your activity consists of routine repetitions, built in the working schedule. Monotonous, repetitive tasks lead to apathy, loss of interest, negligence and mistakes.
Another risk is associated with psychological compatibility. You need to live in a limited area in the company of people you may have met several months before the start.
Cosmonauts, as well-trained and highly motivated people, are not inclined to complain or express their emotions sharply. Therefore, it is difficult to recognize the signs of psychological stress in a group of superprofessionals. On Earth, one can not guess about real problems until an emotional explosion occurs, or, more likely, our class specialist quietly withdraws and becomes depressed.
That's why the Experiments in which people are locked up with each other in the same room. NASA had a project called "Hawaii Space Exploration Analog and Simulation", in Russia they organized "Mars-500" – an experiment to simulate a manned flight to Mars, which lasted a record 519 days.
Both experiments showed good communication between crew members, ease of interaction and readiness for teamwork at any length of time. The biggest psychological problem encountered by the participants of the experiments is boredom, but it did not put the whole mission under attack.
However, it is impossible to name objective data obtained. The experimental conditions are too far from the real interplanetary flight. Any participant at any time can refuse further participation and leave the complex, unlike a real flight to Mars. Each participant knew that he was on Earth (and would not perish in an airless space), and the simulation would continue only as long as he himself wanted it. In addition, none of the participants suffered from real diseases, which can wait for astronauts on the way to Mars.
There is no single-valued solution to the problem. It will take many months of tests and careful psychological selection to prepare the team. And still need to solve an important question: to send into space a group of same-sex people or representatives of different sexes?
Cosmic living creatures
Bacteria feel fine on the ISS and, obviously, will fly with us to Mars, and then even further. At the same time, weightlessness can suppress certain immune functions, making people more vulnerable to disease.
Microflora at space stations is actively trying to eat everything that can. It is enough to have high humidity and nutrients, so that bacteria and fungi begin to eat plastic insulation, grow on glass and damage it with acids released by growth.
Life will always find its way – organisms live even on the outer skin of the ISS.
A team of scientists led by Brian Krushian from NASA studied how a long stay in space affects the functioning of the human immune system. It turned out that the immune system of people who had been in a state of weightlessness for about six months worked poorly: the ability to produce T-lymphocytes decreased, the level of leukocytes dropped, and the ability to recognize foreign microorganisms and cells was in a depressed state. This will be a serious problem if dangerous bacteria are on board.
Obviously, we will not be able to destroy all bacteria (this would require the destruction of people), but it is worth working more in the field of maintaining immunity.
Big problems in the big cosmos
The biggest test in space is mutations in the body, in which the immune system refuses, and the drugs do not help, because the metabolism has changed under the influence of microgravity.
How can we cope with mutations and other problems? To date, there is no ready solution to eliminate all the dangers of space travel, but there are several concepts supported by Ilon Mask. In particular, the problem of cosmic radiation can be solved with the help of an optimal layer of body protection, "amplified" by the magnetic field around the ship, which deflects the flow of charged particles. In addition, the search for effective anti-cancer drugs continues.
Mars can simply fly faster – engines with a specific impulse increase by orders of magnitude began to be developed more than half a century ago, and with proper financing and organization of work can be fully realized. But very great efforts are required – that is why no one flies to the Moon at the beginning of the 21st century, although the science fiction writers wrote about this many years ago.