Journey to Mars

What can happen to an astronaut on the way to the planet and on its surface

marks, Geektimes
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The new US President Donald Trump, contrary to expectations, did not cut the NASA budget. In general, he left everything as it is, signing a paper on the allocation of funds for the projects planned by the agency's specialists. One of such projects is the flight of people to Mars and the landing of the first marsonauts. This should happen no later than 2033.

While some scientists are developing reliable ways to deliver humans to Mars, others are studying the possible dangers that await astronauts and colonists on their way to the goal. There are many such dangers both on the way to the planet and on its surface. Recent studies conducted by specialists of the Center for Regenerative Medicine at Wake Forest University show that, among other problems, astronauts face the threat of leukemia and reduced immunity.

The results of earlier studies indicate that marsonauts will also be threatened with dementia with memory loss from ionizing radiation. What problems can potential travelers to Mars face?

For example, a flight may end without really starting. To travel to Mars, you need a powerful launch vehicle, which has no analogues. It is being developed almost from scratch. Despite the fact that the rocket and each of its elements are subjected to multiple comprehensive checks, troubles still happen. Of the catastrophes of the recent history of cosmonautics, it is worth mentioning the explosion of the Falcon 9 launch vehicle due to unforeseen damage to the composite material wall separating the fuel from the oxidizer. According to Elon Musk, the head of SpaceX, which developed this rocket, the accident was provoked by a number of coincidences, a series of failures of materials and equipment, which had no analogues yet. It's good that in this case only the equipment was damaged, there were no people on board. Even more serious were the accidents of the USSR lunar rocket "N-1", all four tests of which were unsuccessful and were accompanied by victims.

And what if unforeseen problems had arisen on board a launch vehicle going on the first flight to Mars in the history of mankind? There would have been casualties, an extremely expensive rocket would have been destroyed and, most likely, a fat cross would have been put on the exploration of Mars in the near future.

Flight to Mars

Radiation

Well, the rocket has taken off, there are no problems, people are heading to Mars. The journey to the planet takes about 9 months in one direction, that is, it is a real long-term space flight. And here a person is threatened by radiation. The fact is that most of the ionizing radiation does not reach the Earth's surface due to the magnetic field of our planet and its atmosphere. The higher, the greater the radiation density. Perhaps it was because of radiation that cosmonaut Valentin Lebedev, who spent 221 days in Earth orbit, lost his eyesight.

Experts compare the protection provided by the atmosphere from ionizing radiation with steel 1 meter thick. That is, only particles of the highest energy can break through such protection. As for the ISS or spacecraft, here the protection is due only to the thickness of the hull walls, and this is, at best, a few centimeters. According to NASA experts, cosmic radiation can also lead to the development of Alzheimer's disease.

Some experts believe that it is better for women not to fly to Mars. "Since women generally live longer than men, according to NASA's forecast, they have a higher chance of getting cancer in their lifetime, being exposed to the same amount of radiation as men. Calculations have shown that women should not fly to Mars at all, since cumulative exposure to radiation over the entire duration of the flight will exceed the maximum allowable 3% risk of developing cancer," says Dorit Donoviel, deputy director of the National Institute for Space Biomedical Research (NSBRI).

Microgravity

All the way to Mars, a person will be in conditions of almost complete absence of gravity for at least 9 months. And this is also a health problem. People on Earth have an organism adapted to ordinary gravity, and different systems of our body struggle with it, striving to deliver blood and other physiological fluids to the top. Immediately after landing on the ISS (or rocket), these systems continue to operate, so even the appearance of people changes somewhat. For example, due to intracranial pressure, the shape of the eyeballs changes somewhat.

Taste and sense of smell change, the muscles of the body, including the muscles of the heart, weaken. The work of the vestibular apparatus is greatly complicated. In some people, without the force of attraction, the taste and sense of smell completely disappears or significantly weakens. Without exercise, a person loses about 20% of muscle mass in just a couple of weeks.

Experts also note the manifestation of such an effect as the space adaptation syndrome. Some people lose their appetite during microgravity, migraines and dizziness appear. Actually, we are talking about seasickness, which in this case is better called "cosmic".

The longer a person stays in space, the more bone tissue is lost. Due to the lack of habitual loads, bones become lighter and more fragile. About 1.5% of bone tissue is lost every month. It is not yet clear how serious this problem is and whether it is reversible. Of course, there are simulators on the ISS, so astronauts perform physical exercises, trying not to lose shape. But will such equipment fit in a spaceship that will go to Mars?

The spine also suffers – the distance between the vertebrae increases, and the person feels pain. Astronauts solved this problem by resting their hands and feet against the walls of the station, so the spine was compressed and a few minutes were enough to ease the pain.

Psychological problems

If several people are locked in a confined space for several months, then problems will definitely arise. No, it will not necessarily be expressed in conflicts, but the human psyche suffers at such moments. Some people may feel constantly tired, irritable, sleep poorly. Due to the violation of the usual daily rhythm, the noise of aggregates and other factors, people do not feel very comfortable. Some even have to take sleeping pills.

Another psychological problem is isolation from the outside world. There will be communication with the Earth, but the signal will start to lag with the distance from the planet. In addition, Martian travelers will clearly understand that in case of any problems, no one will come to their aid. People are left to themselves, which undoubtedly puts a lot of pressure on the psyche.

Hygiene

On the ISS, people cannot take baths or wash in the shower. The same can be said about the spacecraft that will fly to Mars. Special napkins and formulations are what awaits space travelers all along the way. It is necessary to change underwear less often, and you will have to forget about washing at all – dirty clothes may be able to be washed already on Mars. But, most likely, it is simply disposed of in one way or another.

Arrival on Mars

Descent

So, the Marsonauts, who had been on the road for 9 months, overcame all the problems and arrived at Mars. There is a need to land on the planet. But here, too, not everything is as simple as it may seem. The problem is mainly the descent. The fact is that the atmosphere of Mars is about 100 times less dense than the atmosphere of Earth. Accordingly, during the descent, more resistance will be needed in order not to crash into the surface at full speed. Heavy objects are gaining very high speed, so there are limitations in the mass that can be delivered to Mars once.

This, according to NASA employee Bret Drake, is a ton (that's how much Curiosity weighs). "How we will descend through the atmosphere remains an important task. With current landing methods, we can only lower a metric ton to Mars. This is not enough to establish a colony, more is needed for a colony," Drake said.

The developers of the Low-Density Supersonic Decelerator inspect the lower part of the system

He also says that if it is necessary to establish a colony on Mars, from 20 to 30 tons of cargo will have to be lowered at a time. Now NASA and various private companies working on landing on Mars are trying to create a reliable way to lower people to the surface of the planet. Perhaps it will be a disk-shaped Low-Density Supersonic Decelerator.

Cold and hunger

If everything worked out with the descent, then it is worth remembering that the average annual temperature on Mars is minus 62 degrees Celsius. The temperature from the equator gradually decreases to the poles. It can be hot on Mars during the day, and terribly cold at night. There is also a problem of significant temperature differences on the ISS. So, the ISS heats up to 90 degrees Celsius, facing the Sun and cools down to -90 on its opposite side. Scientists and engineers have found a way out of this difficult situation by achieving the creation of specialized temperature control systems.

But the problem is that such systems are designed to work in a vacuum. As for Mars, scientists are still thinking about how to ensure a comfortable existence for Marsonauts or colonists.

"We need a solution that provides better insulation in cold conditions and a different way to remove heat in hot conditions. A spacesuit in a vacuum is like a thermos, but a spacesuit on Mars will be more like a cup of coffee on the kitchen table – coffee in a cup cools down much faster compared to coffee in a thermos," Drake said.

Food for people on Mars is also a problem. If we are talking about landing with a return, then you can do with the usual dry-frozen food for astronauts. If we are talking about colonists, then we will also have to grow food here. How? While it is not completely clear, experts are still working on this issue. Some scientists believe that the soil of Mars with the addition of certain substances can be made suitable for growing crops.

In the second case, you will have to monitor the concentration of oxygen released by plants in the atmosphere of the room where the colonists live. Too much oxygen is a possibility of spontaneous explosions or even the departure of the crew.

And again radiation

Specialists from the Department of Radiation Oncology at the University of California conducted research to test how ionized radiation will act on astronauts on Mars. As it turned out, 12-24 weeks after irradiation with low doses of ionizing radiation (5 or 30 doses of 48Ti or 16O), the experimental animals retain signs of cognitive dysfunction. The problem is associated with a change in the dendritic structure, a change in the level of protein in synapses and inflammation of the nervous tissue. The problem has been identified in animals; perhaps a similar problem will manifest itself in humans. There is a risk that due to a decrease in cognitive functions in humans under the influence of ionizing radiation, people simply may not be able to manage the systems entrusted to them without completing scientific and engineering tasks or even forgetting what needs to be done.

Another manifestation of radiation exposure is a fairly high probability of leukemia and decreased immunity in people. The reason is the same radiation. The problem was identified by scientists at the Center for Regenerative Medicine at Wake Forest University. They transplanted human stem cells into mice and exposed the animals to weak ionizing radiation. We are talking about a special type of cells called hemacytoblasts. These cells give rise to all other blood cells. Hematopoietic stem cells are located in the red bone marrow, which, in turn, are located inside the cavities of most bones.

In this study, hemacytoblasts of healthy adults aged 30-55 years were studied. As it turned out, under the influence of radiation, the ability of these cells to produce any kind of blood cells decreased by 60-80%. In addition, radiation led to mutations in genes that are involved in the hematopoietic process, which led to a decrease in the ability of hemacytoblasts to produce mature blood cells.

The next step was to check the work of cells exposed to radiation. As it turned out, when transplanting them to mice, the latter began to get leukemia. Scientists believe that this may serve as proof that cosmic radiation can cause the appearance of leukemia in humans.

Together with the above–mentioned decrease in immunity during a person's long-term stay in microgravity conditions will have a negative impact on the successful outcome of an expedition to Mars of any type - even a temporary landing of astronauts, even the arrival of colonists on the planet.

And after all, we should not forget that in the first case, people will also have to return to Earth, which will lead to the repeated influence of radiation, microgravity and other problems described earlier. Plus, experts need to find a reliable way to take off from the surface of Mars to return to Earth.

Whatever it was, experts do not lose hope for the development of reliable security measures that will be able to protect people from some dangers and reduce the negative impact of others. The fact that scientists and engineers believe in the successful outcome of the journey can be said by NASA's planned manned flight to Mars by 2033 and Elon Musk's plans for a similar flight and the creation of a colony on a neighboring planet.

Portal "Eternal youth" http://vechnayamolodost.ru  28.03.2017