According universetoday, a team of researchers from the medical center of the University of Rochester (URMC) in new York announced the results of their research. Long-term presence of astronavtov in space, for example, during the flight to Mars, can lead to health problems because of galakticheskogo radiation. In particular, to the degeneration of the brain, and perhaps even the onset of Alzheimer's disease.

Earlier, in 2012 about similar findings were reported by Russian scientists. According to Natalia Pupils in the paper "Area of the world", "if you fly in the Martian expedition to modern space vehicle, flight will take not less than 500 days. During this period the space mission of the health of astronauts may be lost forever. This is evidenced by the results of Russian research was established on his initiative and physiologists, which was discussed at the Joint Institute for nuclear research (JINR) at the visiting session of the Bureau of the Department of physiology and fundamental medicine of RAS.

The greatest danger scientists see in the galactic radiation: it can deprive a person of vision and understanding, without which no goal to be reached, no home to return will not work.

Approval of researchers about the danger of heavy ions for astronauts not speculative, they are based on the data of the accelerator experiments with animals, conducted in the Laboratory of radiation biology, joint Institute for nuclear research (LRB JINR) in collaboration with the Institute of biomedical problems of RAS (IMPB RAS), Institute of biochemistry RAS (IBCH) and in cooperation with biologists from the U.S. national space Agency (NASA).

The heavy ions worse protons

In far space outside the Earth's magnetic field - the man lurking dangerous cosmic radiation coming from the depths of the galaxy.

"Galactic cosmic rays are flows of elementary particles of light and heavy ions, - explains the Director of the Scientific research Institute of nuclear physics named Dwishlca (SINP) Mikhail Panasyuk. Atoms cosmic rays are deprived of electron shells, in fact they are "naked" kernel. The reason for this interaction with a substance in the process of their transfer in the Universe. The most common component of cosmic rays - the hydrogen ions his protons. These particles are accelerated by shock waves - residues from supernova explosions. Such stars explode in our Galaxy, not more often than once in 30 - 50 years. The particle flux of galactic cosmic rays permanent, unlike solar cosmic rays, which are generated in the Sun or in the interplanetary medium during the solar flares. Therefore, the total contribution of solar cosmic rays for a long time is insignificant. But during solar flares (within several hours, days) stream of solar cosmic rays may exceed the flux of galactic cosmic rays. Besides energy particles of solar cosmic rays, usually less than that of particles, galactic cosmic rays. There are also extragalactic cosmic rays entering our Galaxy from other galaxies. Their power is greater than that of galactic cosmic rays, but flows are much smaller. Cosmic rays have a huge range of energies: 106 (1 MeV) to 1021 eV (1 Sm)".

Installed on space research satellites energomass spectrometers registered composition of cosmic rays. It was found that slightly less than one percent of all particles galactic radiation are heavy ions with an energy of 300 - 500 MeV/nucleon - nuclei of heavy chemical elements. In the fraction of light and heavy ions galactic radiation is most ions of carbon, oxygen and iron from these stable elements in the evolution of stars formed the stellar core.

The results of measurements of space satellites served as the basis for further model calculations showed that beyond the Earth's magnetosphere on a square inch of space falls in the year approximately 105 heavy ions, and a day - about 160 particles with charge Z greater than 20. So, during the flight to Mars for each day it is, the number will fall on a square centimeter of the surface of the body astronaut.

Space heavy ions have such high energy that "stitch" siding modern spacecraft in outer space, like a cannon-cores, bombarding fine silk. As this may damage the long journey to health messengers of the Earth, scientists have found the Laboratory of radiation biology JINR.

To Mars - touch?

"We have been able to understand why the same dose different radiation (the flow of heavy ions, neutron, gamma-rays can cause different effects on living cells, " says Director of the laboratory of radiation biology JINR the corresponding member of RAS Evgeny Krasavin. - It turned out that the differences in the effectiveness of different emissions associated with the physical characteristics of radiation, and biological properties of the living cells is its ability to repair DNA damage after exposure. In experiments with heavy ion accelerators, we found that the most severe damage to DNA occur under the influence of heavy ions. The difference between exposure to x-rays (beam of photons) and heavy-ion beam can imagine figuratively: fire the gun in the wall of the small shot is harmful x-rays, shoot the same wall by a cannon ball is the destruction of one of the heavy ion. Heavy particles, having a large mass, lose much more of their energy per unit of distance traveled than their lighter counterparts. Because of this, passing through the cell, heavy ion on its way produces great destruction. When the cell nucleus undergoes heavy particle, formed damage "cluster-type" with multiple breaks chemical bonds in the DNA fragment. They cause different types of severe chromosomal damage in the nuclei of cells".

Further logic of scientists was. Hydrogen ions (protons with energy of 200 - 300 MeV/nucleon have time to full braking to run in the water path length 11 see the Human body is 90 % water. Extrapolating this result on the living human body, we obtain the conclusion: even light ions on its way can harm the thousands of cells of our body. In case of heavy ions with a charge of more than 20 should expect even more deplorable health outcome.

What human organs can be damaged galactic heavy ions most strongly and dangerous?

- If you think about actively proliferating is quickly updated - body tissues, such as blood or skin damage due to natural properties will recover quickly, " explains the Director of the laboratory of radiation biology JINR Evgeny Krasavin. - But on static fabric - Central nervous system, eyes, with no natural ability quick repair damage, a constant flow of heavy ions will have a cumulative negative impacts, causing regular cell death. But the Central nervous system and eye - managers "chips" of our body.

In experiments on animals in Dubna group was established on his initiative under the leadership of RAS academician Mikhail Ostrovsky studied the mechanisms of action of heavy ions in the structure of the eye lens, retina, cornea. At accelerators of JINR proton beam with the energy of 100 - 200 MeV were irradiated mice and solutions cristallino (proteins) of the lens.

"The lens of the eye of man and vertebrates consists of 90% alpha-, beta - and gamma-cristallino, - said in his report at the session of the Bureau OFFM RAS academician Nikolai Ostrovsky. - The content of these proteins in the lens is approximately the same, but they differ significantly in structure and molecular weight. Exposure to ultraviolet radiation or radiation can cause aggregation cristallino - emergence of non-transparent fiber lens. By aggregation are large light-diffusing conglomerates that lead to the lens opacity, that is, to the development of cataracts. Passing through the lens of the eye, even a single heavy ions after some time they can cause turbidity.

To return to Earth person reasonable

The least-was established on his initiative studied the damaging effects of heavy ions on the Central nervous system. According to specialists NASA, during a Mars mission from 2 to 13 percent of the nerve cells will be crossed by at least one ion iron. And through the nucleus of each cell of the body every three days will fly one proton. Therefore there is a danger of very serious irreversible violations of behavioral reactions of the ship's crew. This jeopardized the mission as a whole. The brain is a very delicate instrument, and the violation of small parts of it can lead to loss of health of the whole organism, as it happens in people with a history of stroke, or those who suffer from Alzheimer's disease.

In the Laboratory, NASA space radiation in Brookhaven by using a beam of accelerated to an energy of 1 GeV/nucleon iron ions modeled galactic radiation on predskazala heavy ion Collider RHIC Brookhaven national laboratory. Experiment with rats were called "cognitive test". In a round pool under a thin layer of opaque water placed a small solid ground. In this pool ran the lab rats - first healthy, and then obliczen's beams of ions of iron - and watched how quickly the animals can find this site and to cross it. Healthy rats quickly find the site and went to her along the shortest path. The heavy-ion irradiation dramatically changed cognitive function (ability to learn) animals. A month after the irradiation behavior of rats sharply changed. She wandered for a long time were driving around the pool until she almost accidentally failed to feel firm ground under your feet. The thinking ability of the animal turned out to be badly broken. When irradiated rats x-ray and gamma radiation that effect was not observed.

In order to imagine the possible consequences of irradiation of the body of heavy ions, you "play" the model space danger in primates, the researchers said. Nevertheless identified in rodents damage from exposure to galactic radiation heavy ions is strong enough not to think about it, planning to send people in the long flight to Mars.

How to avoid trouble

From what is known today physicists and biologists, be reduced to zero the risk of radiation exposure of astronauts for more than a year traveling to Mars. Ways to reduce this risk are still in ideas.

The first idea: to plan a trip to Mars during the maximum of the solar activity cycle. In this period the flux of galactic cosmic rays will be less due to the fact that the interplanetary magnetic field in the solar system will distort the trajectory of galactic cosmic rays, seeking to reduce the intensity of their particles and "sweeping away the" from the solar system of particles with energies less 400 MeV/nucleon.

The second idea: to significantly reduce the dose of radiation from galactic radiation with the help of reliable protection of the ship and to provide in the design of the ship special compartment cover with a more powerful protection from the powerful flow unpredictable solar wind. We have already developed new types of protective materials, which would be more effective now used aluminum, for example, hydrogen-containing plastics type of polyethylene. With their help, you can create protection, the 7 cm to reduce the radiation dose to 30 - 35%. However, this is not enough, according to scientists, the thickness of the protective layer should be increased. And if you do not go, you significantly reduce the flight duration - say, at least up to 100 days. One hundred days - figure is only intuitively reasonable. But in any case need to fly faster.

The idea third: to provide pilots Martian vehicle effective anti-radiation drugs, which would greatly strengthen links between proteins, DNA, reducing their vulnerability to the bombing of heavy ions.

The idea fourth: to create around spacecraft artificial magnetic field like the earth's magnetic field. There is a project superconducting toroidal magnet inside and outside the field which is close to zero, so as not to damage the health of astronauts. Powerful field such a magnet, should withdraw from the ship large share of cosmic protons and nuclei, reduced to 3 to 4 times the dose of radiation during the expedition to Mars. The prototype of such a magnet, you have already created and will be used in the experiment for investigation of cosmic rays on Board the international space station.

Yet, while the ideas of protection of the Martian crew weren't implemented, one way out, the claim was established on his initiative: to carry out a detailed radiobiological research in terrestrial conditions on the heavy ion accelerators, which are on the ground will allow to model the damaging effects of heavy nuclei at high energies, coming from the depths of the galaxy. Among such unique accelerator - the Nuclotron physics Laboratory of high energies, JINR, sosaddis on its basis the Collider NICA. On the possibilities of these facilities scientists have high hopes.

And if we hurry to fly to Mars, then either it's time to build faster spacecraft, or leave until the dream of manned missions in far space. Let robots until poputeshestvovat.