Cosmic radiation is a big problem for spacecraft designers. They seek to protect astronauts from it, who will be on the surface of the moon or go on long journeys into the depths of the universe. If the necessary protection is not provided, then these particles, flying at great speed, will penetrate the astronaut's body, damage his DNA, which can increase the risk of cancer. Unfortunately, until now, all known methods of protection are either ineffective or impracticable.
Materials traditionally used to build spacecraft, such as aluminum, trap some cosmic particles, but more robust protection is needed for years of spaceflight.
The US Aerospace Agency (NASA) willingly takes on the most extravagant, at first glance, ideas. After all, no one can predict for sure which of them will one day turn into a serious breakthrough in space research. The agency has a special institute for advanced concepts (NASA Institute for Advanced Concepts - NIAC), designed to accumulate precisely such developments - for a very long term. Through this institute, NASA distributes grants to various universities and institutes - for the development of "brilliant follies".
The following options are currently being explored:

Protected by certain materials. Some materials, such as water or polypropylene, have good protective properties. But in order to protect the spaceship with them, a lot of them will be needed, the weight of the ship will become unacceptably large.
Currently, NASA employees have developed a new heavy-duty material, akin to polyethylene, which is going to be used in the assembly of future spacecraft. "Space plastic" will be able to protect astronauts from cosmic radiation better than metal screens, but much lighter than known metals. Experts are convinced that when the material is given sufficient heat resistance, it will even be possible to make spacecraft skins from it.
It used to be thought that only an all-metal shell would allow a manned spacecraft to pass through the Earth's radiation belts - streams of charged particles held by the magnetic field near the planet. During flights to the ISS, this was not encountered, since the station's orbit passes noticeably below the dangerous area. In addition, astronauts are threatened by flares on the Sun - a source of gamma and x-rays, and the details of the ship itself are capable of secondary radiation - due to the decay of radioisotopes formed during the "first meeting" with radiation.
Scientists now believe that the new RXF1 plastic copes better with the listed problems, and low density is not the last argument in its favor: the carrying capacity of rockets is still not large enough. The results of laboratory tests in which it was compared with aluminum are known: RXF1 can withstand three times the load at a three times lower density and captures more high-energy particles. The polymer has not yet been patented, so the method of its manufacture is not reported. It is reported by Lenta.ru with reference to science.nasa.gov.

inflatable structures. The inflatable module, made of highly durable RXF1 plastic, will not only be more compact at launch, but also lighter than a one-piece steel structure. Of course, its developers will also need to provide for sufficiently reliable protection against micrometeorites, coupled with "space debris", but there is nothing fundamentally impossible in this.
Something is already there - this is a private inflatable unmanned ship Genesis II is already in orbit. Launched in 2007 Russian missile"Dnieper". Moreover, its mass is quite impressive for a device created by a private company - over 1300 kg.

CSS (Commercial Space Station) Skywalker is a commercial project of an inflatable orbital station. NASA allocates about 4 billion dollars to support the project for 20110-2013. We are talking about the development of new technologies for inflatable modules for space exploration and celestial bodies solar system.

How much the inflatable structure will cost is not reported. But the total costs for the development of new technologies have already been announced. In 2011, $652 million will be allocated for these purposes, in 2012 (if the budget is not revised again) - $1262 million, in 2013 - $1808 million. estimates "Constellations", without focusing on one large-scale program.
Inflatable modules, automatic docking devices, in-orbit fuel storage systems, autonomous life support modules and complexes that provide landing on other celestial bodies. This is only a small part of the tasks that are now set before NASA to solve the problem of landing a man on the moon.

Magnetic and electrostatic protection. Powerful magnets can be used to deflect flying particles, but magnets are very heavy, and it is not yet known how dangerous a magnetic field strong enough to reflect cosmic radiation will be for astronauts.

Spacecraft or station on the surface of the moon with magnetic protection. A toroidal superconducting magnet with a field strength will not allow most of the cosmic rays to penetrate into the cockpit located inside the magnet, and thereby reduce the total radiation doses from cosmic radiation by tens or more times.

NASA's promising projects are an electrostatic radiation shield for the lunar base and a liquid mirror lunar telescope (illustrations from spaceflightnow.com).

Liquid hydrogen protection. NASA is considering using spacecraft fuel tanks containing liquid hydrogen that can be placed around the crew compartment as a shield against space radiation. This idea is based on the fact that cosmic radiation loses energy when it collides with the protons of other atoms. Since the hydrogen atom has only one proton in the nucleus, the proton of each of its nuclei "slows down" the radiation. In elements with heavier nuclei, some protons block others, so cosmic rays do not reach them. Hydrogen protection can be provided, but not enough to prevent the risks of cancer.

Biosuit. This Bio-Suit project is being developed by a group of professors and students at the Massachusetts Institute of Technology (MIT). "Bio" - in this case, does not mean biotechnology, but lightness, unusual convenience for spacesuits, and somewhere even the imperceptibility of the shell, which is, as it were, a continuation of the body.
Instead of sewing and gluing the space suit from separate pieces of various fabrics, it will be sprayed directly onto the skin of a person in the form of a quickly hardening spray. True, the helmet, gloves and boots will still remain traditional.
The technology of such spraying (a special polymer is used as a material) is already being tested by the US military. This process is called Electrospinlacing, it is being worked out by specialists from the US Army Research Center - Soldier systems center, Natick.
Simplistically, we can say that the smallest droplets or short fibers of the polymer acquire electric charge and under the influence electrostatic field rush to their goal - the object that needs to be covered with a film - where they form a fused surface. Scientists from MIT intend to create something similar, but capable of creating a moisture and airtight film on the body of a living person. After hardening, the film acquires high strength, while maintaining elasticity sufficient for the movement of arms and legs.
It should be added that the project provides for an option when several different layers will be sprayed on the body in this way, alternating with a variety of built-in electronics.

The line of development of space suits in the view of MIT scientists (illustration from the site mvl.mit.edu).

But after all, if you do not start moving towards this result now, the "fantastic future" will not come.

16.3. Flashes in the eyes and in the electronic chips

The reader is well aware of the space odyssey of American astronauts to the moon. Earthlings traveled to the Moon on Apollo spacecraft during several expeditions. For several days the astronauts were in outer space, including a long period of time outside the earth's magnetosphere.

Neil Armstrong (the first astronaut to walk on the moon) reported to Earth about his unusual sensations during the flight: sometimes he observed bright flashes in his eyes. Sometimes their frequency reached about a hundred per day (Fig. 16.5). Scientists began to understand this phenomenon and quickly came to the conclusion that ... galactic cosmic rays are responsible for this. It is these high-energy particles that, penetrating into the eyeball, cause the Cherenkov glow when interacting with the substance that makes up the eye. As a result, the astronaut sees a bright flash. The most effective interaction with matter is not protons, which are the largest in the composition of cosmic rays of all other particles, but heavy particles - carbon, oxygen, iron. These particles, having a large mass, lose much more of their energy per unit of distance traveled than their lighter counterparts. It is they who are responsible for the generation of the Cherenkov glow and the excitation of the retina - the sensitive membrane of the eye. Now this phenomenon is widely known. It was probably observed even before N. Armstrong, but not all space pilots reported this to Earth.
Now a special experiment is being carried out on board the International Space Station to study this phenomenon in more depth. It looks like this: a helmet stuffed with detectors for detecting charged particles is put on the astronaut's head. The cosmonaut must fix the moment of the passage of the particle through the flashes he observes, and the detectors make an independent “examination” of their passage through the eye and the detector. Light flashes in the eyes of cosmonauts and astronauts are an example of how the human organ of vision - the eye - can serve as a detector of cosmic particles.
However, the unpleasant consequences of the presence of high-energy cosmic rays in space do not end there...

About twenty years ago, it was noticed that the work of on-board computers of satellites could be disrupted. These violations can be of two types: the computer can “freeze”, and recover after a while, but sometimes fail. Again, studying this phenomenon, scientists came to the conclusion that heavy GCR particles are responsible for it. Just as in the case of the eyeball, they penetrate the chip and cause local, microscopic disturbances in its "heart" - a sensitive area of ​​the semiconductor material from which it is made. The mechanism of this effect is shown in Fig. 16.6. As a result of rather complex processes associated with a violation of the movement of electric current carriers in the chip material, a malfunction occurs in its operation (they are called “single failures”). This is an unpleasant phenomenon for the onboard equipment of modern satellites, stuffed with computer systems that control its operation. As a result, the satellite may lose orientation or fail to execute the necessary command from the operator from the Earth. In the worst case, if the necessary backup computer system is not on board, the satellite can be lost.

Pay attention to fig. 16.7. It depicts the frequency of failures observed on one of the satellites over a number of years. The solar activity curve is also plotted here. There is a high correlation between both phenomena. During the years of minimum solar activity, when the GCR flux is maximum (remember the modulation phenomenon), the frequency of failures increases, and it falls at the maximum when the GCR flux is minimal. It is impossible to fight this unpleasant phenomenon. No protection saves the satellite from these particles. The penetrating power of these particles with their enormous energies is too great.
On the contrary, an increase in the thickness of the skin spaceship leads to the opposite effect. Neutrons are produced as a result nuclear reactions GCR with substance create a strong radiation background inside the ship. These secondary neutrons, interacting with the material located near the chip, generate, in turn, heavy particles, which, penetrating inside the chips, create failures.

Here it is necessary to remind the reader that heavy charged particles are found not only in cosmic rays. They are also present in the composition of the radiation belts, especially a lot of them in the inner, closest to the Earth, part. Here, there are both protons and heavier particles. And their energy can exceed hundreds of MeV. Now let's remember the South Atlantic anomaly, which "sags" above the Earth. It is easy to imagine that the electronics of a spacecraft flying at an altitude of 500 kilometers should “feel” these particles. The way it is. Take a look at Figure 16.8 and you can see that the highest failure rate occurs right in the area of ​​the anomaly.

A similar phenomenon occurs during powerful solar flares. Protons and heavy nuclei in SCRs can cause the same single failures in chips. And they are indeed observed. One such example is shown in Fig. 16.9: during a powerful solar storm on July 14, 2000. (due to the fact that it took place on July 14 on Bastille Day, it was given the name “Bastille Day”), intense streams of solar protons “fell down” on the Earth’s magnetosphere, causing malfunctions in the operation of satellites. The only salvation from GKL - chip killers - is the technical means associated with the duplication of especially important electronic elements of on-board equipment.
Not only engineers, creators of onboard electronic equipment, are concerned about the presence of high-energy cosmic rays in space. Biologists are also studying the mechanisms of action of these particles. Briefly, they look like this.
Water, the main substance of biological tissues, is ionized under the influence of radiation, free radicals are formed, which can destroy the molecular bonds of DNA. The scenario of direct damage to the DNA molecule during the deceleration of a heavy charged particle is also not excluded (Fig. 16.10).

Rice. 16.10. The interaction of heavy GCR particles with a DNA molecule within its linear dimensions of ~ 20 angstroms can lead to disturbances in its structure in two ways: either through the formation of free radicals, or directly, by damaging the molecule itself.

Rice. 16.11. Alpha particles (helium nuclei) and other heavy particles of cosmic rays affect cells more effectively than electrons - light particles. Heavy particles lose much more energy per unit path in matter than lighter ones. This is clearly demonstrated in this figure: with the same doses of radiation from electrons and heavy particles, the number of damaged cells in the latter case is greater

Result? Unpleasant genetic consequences, including carcinogenic. Figure 16.11 clearly demonstrates the effect of heavy particles on biological tissue: the number of damaged cells in the case of exposure to particles heavier than protons increases dramatically.
Of course, one cannot assume that heavy elements in cosmic rays are the only agent capable of causing cancer. Biologists, on the contrary, believe that among all other factors external environment that can affect DNA - radiation does not play a leading role. For example, some chemical compounds are capable of causing much more sensitive disturbances than radiation. However, under the conditions of a long space flight, outside the Earth's magnetic field, a person finds himself alone, mainly with radiation. Moreover, this is not quite the usual radiation familiar to humans. These are galactic cosmic rays, which, as we now know, contain heavy charged particles. They do cause DNA damage. It is obvious. The implications of this interaction are not entirely clear. What does the statement about the possible, for example, carcinogenic consequences of such an interaction mean?
It should be noted here that today specialists in space medicine and biology are not able to give an exhaustive answer. There are issues that need to be addressed in future research. For example, DNA damage alone does not necessarily lead to cancer. Moreover, DNA molecules, having received a danger signal about a violation of their structure, try to turn on the “repair program” on their own. And this happens, sometimes, not without success. Any physical injury, the same hammer blow on the body, causes much more damage at the molecular level than radiation. But cells restore DNA, and the body “forgets” about this event.
The stability of DNA is extremely high: the probability of mutation does not exceed 1 in 10 million, regardless of local conditions. This is the fantastic reliability of the biological structure responsible for the reproduction of life. Even superstrong radiation fields cannot break it. There are a number of bacteria that do not mutate in huge radiation fields, reaching many thousands of Gy. Even crystalline silicon and many structural materials cannot withstand such a dose load.
The problem here, as it seems to biologists, is that there may be a failure in the repair program: for example, the chromosome may end up in a completely unnecessary place in the DNA structure. Now this situation is getting dangerous. However, even here a multivariate sequence of events is possible.
First, we must take into account that the process of mutation - the reproduction of "wrong cells" takes a long time. Biologists believe that decades can pass between the primary adverse effect and the negative realization of this effect. This time is necessary to form a neoplasm of cells subjected to mutations, consisting of many billions. Therefore, predicting the development of adverse effects is a very problematic matter.
Another side of the problem of the effect of radiation on biological structures is that the process of exposure to low doses is not well understood. There is no direct relationship between the magnitude of the dose - the amount of radiation - and radiation damage. Biologists believe that different types chromosomes react differently to radiation. One of them “requires” significant doses of radiation for the manifestation of the effect, while others need even ultra-small ones. What is the reason here? There is no answer to this yet. Moreover, the consequences of exposure of biological structures to two or more types of radiation at the same time are not quite clear: say, GCR and SCR, or GCR, SCR and radiation belts. The composition of these types of cosmic radiation is different, and each of them can lead to its own consequences. But the effect of their combined influence is not clear. The final answer to these questions lies only in the results of future experiments.

"This result is important for planning long-term flights: it means that you can fly farther and fly longer. Although, in general, radiation doses are large, and the question remains how to reduce them in order to preserve the health of astronauts," says one of the authors of the study, Vyacheslav Shurshakov from the Institute biomedical problems of the Russian Academy of Sciences.

The "Matryoshka-R" experiment aboard the ISS was started back in 2004, when special passengers were delivered to the station. One looked quite respectable. Saxon type of face, a figure to the envy of many - a meter seventy-five and seventy kg. As they say, not a "fat" superfluous. He is of European origin and is known in scientific circles as "Mr. Rando". But another, a Russian, has a more unusual “appearance”: on the scales, he pulls only thirty kg, but you can’t say about height and a meter with a cap - 34 centimeters. In diameter. In other words, it is ... a ball.

Both the "Saxon" and his spherical companion are mannequins. They are also called phantoms: both, despite the differences, almost one to one imitate human body. Or rather, the chemical and biological "material" from which people are woven. Each is stuffed with the most sensitive detectors, sensors of ionizing radiation.

"We need to measure the dose of radiation that affects critical internal organs - the gastrointestinal tract, the hematopoietic system, the central nervous system. It is impossible to put a dosimeter directly into the human body, so tissue-equivalent phantoms are used," experts say.

Such a phantom was first placed on the outer surface of the ISS in a sealed container, which, in terms of absorption parameters, corresponded to space suit, and then was moved inside the station. Russian scientists, together with colleagues from Poland, Sweden, Germany and Austria, recalculated the collected data using the NUNDO computer model and obtained accurate estimates of the radiation dose for each internal organ.

Calculations have shown that the actual effect of radiation on the internal organs is much lower than that shown by "ordinary" dosimeters. During a spacewalk, the dose in the body will be 15% lower, and inside the station - all 100% (that is, two times) less than the dose that is measured by an individual dosimeter located in a pocket on the cosmonaut's chest.

According to experts, an annual exposure limit has been set, which no one has the right to exceed: it is 500 milliSievert. There is also the so-called professional limit, or, as they say, the career limit. It must not exceed 1 Sievert. Is it a lot or a little? According to experts, the maximum allowable dose that an astronaut can accumulate over all the years of work on Earth and in space is capable of taking 2-3 years of his life. Nobody has ever had anything like it. But there is general rule: doses should be as low as reasonably achievable. That is why it is so important for scientists to know how "critical" organs react to radiation. What specific doses are received during strong solar flares by the hematopoietic system, brain, lungs, liver, kidneys ...

Near the Earth, its magnetic field continues to protect - even if weakened and without the help of many kilometers of atmosphere. Flying in the region of the poles, where the field is small, the astronauts sit in a specially protected room. And for radiation protection during a flight to Mars, there is still no satisfactory technical solution.

Decided to add to the original answer for two reasons:

1. in one place it contains an incorrect statement and does not contain a correct one
2. just for the sake of completeness (quotes)

1. In the comments Susanna criticized The answer is largely correct.

The field weakens over the Earth's magnetic poles as I stated. Yes, Susanna is right that it is especially large AT THE POLE (imagine lines of force: they gather exactly at the poles). But on high altitude ABOVE THE POLES it is weaker than in other places - for the same reason (imagine the same lines of force: they went down - to the poles, and at the top they were almost gone). The field seems to be sinking.

But Susanna is right that cosmonauts of the Ministry of Emergency Situations do not take shelter in a special room due to the polar regions A: My memory failed me.

But still there is a place over which special measures are taken(I confused it with the polar regions). It - over the magnetic anomaly in the South Atlantic. There, the magnetic field "sags" so much that the radiation belt and take special measures without any solar flares. I could not quickly find a quote about special measures not related to solar activity, but I read about them somewhere.

And, of course, it is worth mentioning the outbreaks themselves: they also hide from them in the most protected room, and do not walk around at this time throughout the station.

All solar flares are carefully monitored and information about them is sent to the control center. During such periods, the astronauts stop working and take refuge in the most protected compartments of the station. Such protected segments are the compartments of the ISS next to the water tanks. Water delays secondary particles - neutrons, and the dose of radiation is absorbed more efficiently.

2. Just quotes and additional information

Some quotes below mention the dose in Sieverts (Sv). For orientation, some figures and probable effects from the table in

0-0.25 Sound No effect except for moderate blood changes

0.25-1 Sound Radiation diseases from 5-10% of exposed people

7 Sv ~100% deaths

The daily dose on the ISS is about 1 mSv (see below). Means, you can fly without much risk for about 200 days. It is also important for how long the same dose is taken: the one taken in a short time is much more dangerous than the one taken over a long period. The body is not a passive object simply "accumulating" radiation defects: it also has "repair" mechanisms, and they usually cope with gradually increasing small doses.

In the absence of the massive atmospheric layer that surrounds humans on Earth, astronauts on the ISS are exposed to more intense radiation from constant streams of cosmic rays. On the day, crew members receive a dose of radiation in the amount of about 1 millisievert, which is approximately equivalent to the exposure of a person on Earth for a year. This leads to an increased risk of developing malignant tumors in astronauts, as well as a weakening of the immune system.

According to data collected by NASA and experts from Russia and Austria, astronauts on the ISS receive a daily dose of 1 millisievert. On Earth, such a dose of radiation can not be obtained everywhere even for a whole year.

This level, however, is still relatively tolerable. However, it must be borne in mind that near-Earth space stations are protected by the Earth's magnetic field.

Beyond its limits, the radiation will increase many times over, therefore, expeditions into deep space will be impossible.

Radiation in residential buildings and laboratories of the ISS and Mir was due to the bombing of the aluminum skin of the station with cosmic rays. Fast and heavy ions knocked out a fair amount of neutrons from the skin.

At present, it is impossible to provide one hundred percent protection against radiation on spacecraft. More precisely, it is possible, but due to a more than significant increase in mass, but this is just unacceptable

In addition to our atmosphere, the Earth's magnetic field is a protection against radiation. The first radiation belt of the Earth is located at an altitude of about 600-700 km. The station now flies at an altitude of about 400 km, which is significantly lower ... Protection from radiation in space is (also - ed.) The hull of a ship or station. The thicker the walls of the case, the greater the protection. Of course, the walls cannot be infinitely thick, because there are weight restrictions.

The ionizing level, the background level of radiation at the International Space Station is higher than on Earth (about 200 times - ed.), which makes the astronaut more susceptible to ionizing radiation than representatives of traditionally radiation hazardous industries, such as nuclear energy and X-ray diagnostics.

In addition to individual dosimeters for astronauts, the station also has a radiation monitoring system. ... One sensor each is located in the crew cabins and one sensor each in the working compartment of small and large diameter. The system works autonomously 24 hours a day. ... Thus, the Earth has information about the current radiation situation at the station. The radiation monitoring system is able to issue a warning signal "Check the radiation!". If this happened, then we would see the fire of a banner with an accompanying sound signal on the alarm panel of the systems. There have been no such cases during the entire existence of the international space station.

In... the area of ​​the South Atlantic... the radiation belts "sag" above the Earth due to the existence of a magnetic anomaly deep under the Earth. Spaceships flying over the Earth, as it were, “stripe” radiation belts for a very short time ... on turns passing through the region of the anomaly. On other turns, there are no radiation flows and do not create trouble for the participants in space expeditions.

The magnetic anomaly in the South Atlantic is not the only radiation "misfortune" for astronauts. Solar flares, sometimes generating very energetic particles... can create great difficulties for astronauts' flights. What dose of radiation can be received by an astronaut in the event of the arrival of solar particles to the Earth is largely a matter of chance. This value is determined mainly by two factors: the degree of distortion of the Earth's dipole magnetic field during magnetic storms and the parameters of the orbit spacecraft during a solar event. ... The crew may be lucky if the orbits at the time of the SCR invasion do not pass dangerous high-latitude areas.

One of the most powerful proton eruptions, a radiation storm of solar eruptions that caused a radiation storm near the Earth, occurred quite recently - January 20, 2005. A solar eruption of a similar power occurred 16 years ago, in October 1989. Many protons with energies exceeding hundreds of MeV reached the Earth's magnetosphere. By the way, such protons are able to overcome the protection of a thickness equivalent to about 11 centimeters of water. The astronaut's suit is thinner. Biologists believe that if at that time the astronauts were outside the International Space Station, then, of course, the effects of radiation would have affected the health of the astronauts. But they were inside her. The protection of the ISS is large enough to protect the crew from the adverse effects of radiation in many cases. So it was during this event. As measurements with the help of radiation dosimeters showed, the dose of radiation "captured" by the astronauts did not exceed the dose that a person receives during a conventional X-ray examination. The ISS cosmonauts received 0.01 Gy or ~ 0.01 Sievert... True, such low doses are also due to the fact that, as it was written earlier, the station was on “magnetically protected” orbits, which may not always happen.

Neil Armstrong (the first astronaut to walk on the moon) reported to Earth about his unusual sensations during the flight: sometimes he observed bright flashes in his eyes. Sometimes their frequency reached about a hundred per day ... Scientists ... came to the conclusion that ... galactic cosmic rays are responsible for this. It is these high-energy particles that, penetrating into the eyeball, cause the Cherenkov glow when interacting with the substance that makes up the eye. As a result, the astronaut sees a bright flash. The most effective interaction with matter is not protons, which are the largest in the composition of cosmic rays of all other particles, but heavy particles - carbon, oxygen, iron. These particles, having a large mass, lose much more of their energy per unit of distance traveled than their lighter counterparts. It is they who are responsible for the generation of the Cherenkov glow and the excitation of the retina - the sensitive membrane of the eye.

During long-range space flights, the role of galactic and solar cosmic rays as radiation-hazardous factors increases. It is estimated that when flying to Mars, it is GCRs that become the main radiation hazard. The flight to Mars lasts about 6 months, and the integral - total - radiation dose from GCR and SCR during this period is several times higher than the radiation dose to the ISS for the same time. Therefore, the risk of radiation consequences associated with the implementation of deep space missions increases significantly. So, for a year of flight to Mars, the absorbed dose associated with the GCR will be 0.2-0.3 Sv (without shielding). It can be compared with the dose from one of the most powerful flares of the last century - August 1972. During this event, it was several times less: ~0.05 Sv.

The radiation hazard created by the GCR can be assessed and predicted. A wealth of material has now been accumulated on GCR temporal variations associated with the solar cycle. This made it possible to create a model on the basis of which it is possible to predict the GCR flux for any given period of time.

Things are much more complicated with the SCL. Solar flares occur randomly, and it is not even obvious that powerful solar events occur in years that are necessarily close to maximum activity. At least experience recent years shows that they also occur during the time of the fading luminary.

Solar flare protons pose a real threat to space crews on long-range missions. Taking again the August 1972 flare as an example, it can be shown, by recalculating the fluxes of solar protons into a radiation dose, that 10 hours after the start of the event, it exceeded the lethal value for the crew of the spacecraft if it were outside the ship on Mars or, say , on the moon.

Here it is appropriate to recall the flights of the American "Apollo" to the Moon in the late 60s - early 70s. In 1972, in August, there was a solar flare of the same power as in October 1989. Apollo 16 landed after its lunar journey in April 1972, and the next one, Apollo 17, launched in December. Was the Apollo 16 crew lucky? Certainly yes. Calculations show that if the Apollo astronauts were on the Moon in August 1972, they would have been exposed to a radiation dose of ~4 Sv. That's a lot to be saved. Unless… unless quickly returned to Earth for emergency treatment. Another option is to go to the cockpit of the Apollo Lunar Module. Here the radiation dose would decrease by 10 times. For comparison, let's say that the protection of the ISS is 3 times thicker than that of the Apollo lunar module.

At altitudes of orbital stations (~400 km), radiation doses exceed the values ​​observed on the Earth's surface by ~200 times! Mainly due to the particles of the radiation belts.

It is known that some routes of intercontinental aircraft pass near the northern polar region. This area is the least protected from the intrusion of energetic particles, and therefore, during solar flares, the risk of radiation exposure to the crew and passengers increases. Solar flares increase radiation doses at aircraft flight altitudes by 20-30 times.

Recently, the crews of some airlines have been informed about the beginning of the onset of the invasion of solar particles. One recent powerful solar eruption, in November 2003, caused the Delta crew on a Chicago-Hong Kong flight to deviate from their path: take a lower latitude route to their destination.

Earth is protected from cosmic radiation by the atmosphere and magnetic field. In orbit, the radiation background is hundreds of times greater than on the surface of the Earth. Every day, the astronaut receives a radiation dose of 0.3-0.8 millisieverts - about five times more than with X-rays. chest. When working in open space the effect of radiation is even higher. And in moments of powerful solar flares, you can grab a 50-day norm in one day at the station. God forbid to work overboard at such a time - for one exit, you can choose the allowable dose for your entire career, which is 1000 millisieverts. Under normal conditions, it would have been enough for four years - no one has flown so much yet. Moreover, the damage to health from such a single exposure will be much higher than from extended for years.

Yet low Earth orbits are still relatively safe. The Earth's magnetic field captures charged particles from the solar wind, forming radiation belts. They have the shape of a wide donut that surrounds the Earth at the equator at an altitude of 1,000 to 50,000 kilometers. The maximum particle density is reached at altitudes of about 4,000 and 16,000 kilometers. Any prolonged delay of the ship in the radiation belts poses a serious threat to the life of the crew. Crossing them on their way to the Moon, American astronauts risked receiving a dose of 10-20 millisieverts in a few hours - as in a month of work in orbit.

In interplanetary flights, the issue of crew radiation protection is even more acute. The Earth shields half of the hard cosmic rays, and its magnetosphere almost completely blocks the flow of the solar wind. In open space, without additional protective measures, exposure will increase by an order of magnitude. The idea is sometimes discussed of deflecting cosmic particles by strong magnetic fields, however, in practice, nothing but shielding has yet been worked out. Particles of cosmic radiation are well absorbed by rocket fuel, which suggests the use of full tanks as protection against dangerous radiation.

The magnetic field at the poles is not small, but rather large. It is simply directed there almost radially to the Earth, which leads to the fact that particles of the solar wind captured by magnetic fields in the radiation belts, under certain conditions, move (fall out) in the direction of the Earth at the poles, causing auroras. This does not pose a danger to astronauts, since the ISS trajectory passes closer to the equatorial zone. The danger is represented by strong solar flares of class M and X with coronal ejections of matter (mainly protons) directed towards the Earth. It is in this case that the astronauts apply additional radiation protection measures.

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QUOTE: "... It is not protons that interact most effectively with matter, which are the largest number of all other particles in cosmic rays, but heavy particles - carbon, oxygen, iron ...."

Please explain to the ignoramus - where did the particles of carbon, oxygen, iron come from in the solar wind (cosmic rays, as you wrote) and how can they get into the substance that makes up the eye - through the spacesuit?

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I explain... Sunlight is photons(including gamma quanta and x-rays, which are penetrating radiation).

Is there some more sunny wind. Particles. For example, electrons, ions, atomic nuclei flying from the Sun and from the Sun. There are few heavy nuclei (heavier than helium) there, because there are few of them in the Sun itself. But there are many alpha particles (helium nuclei). And, in principle, any nucleus lighter than an iron one can fly (the only question is the number of arriving). Further iron synthesis on the Sun (especially outside it) does not go. Therefore, only iron and something lighter (the same carbon, for example) can fly from the Sun.

Cosmic rays in the narrow sense- this is extra high speed charged particles(and not charged, however, too), arrived from outside the solar system (mostly). And also - penetrating radiation from there(sometimes it is considered separately, not counted among the "rays").

Among other particles, cosmic rays contain the nuclei of any atoms(in varying amounts, of course). Somehow heavy nuclei, hitting the substance, ionize everything in their path(and also - aside: there is secondary ionization - already by what is knocked out along the road). And if they have a high speed (and kinetic energy), then the nuclei will be engaged in this business (flying through matter and its ionization) for a long time and will not stop soon. Respectively, will fly through anything and will not turn off the path- until they spend almost all kinetic energy. Even stumbling directly into another core (and this is rare) they can simply throw it aside, almost without changing the direction of their movement. Or not to the side, but fly further more or less in one direction.

Imagine a car that crashed into another at full speed. Will he stop? And also imagine that his speed is many thousands of kilometers per hour (even better - per second!), And the strength allows him to withstand any blow. This is the core from outer space.

Cosmic rays in the broadest sense- these are cosmic rays in the narrow, plus the solar wind and penetrating radiation from the Sun. (Well, or without penetrating radiation, if it is considered separately).

The solar wind is a stream of ionized particles (mainly helium-hydrogen plasma) flowing from the solar corona at a speed of 300-1200 km/s into the surrounding space. It is one of the main components of the interplanetary medium.

Lots of natural phenomena associated with the solar wind, including space weather phenomena such as magnetic storms and polar lights.

The concepts of "solar wind" (a stream of ionized particles flying from the Sun to the Earth in 2-3 days) and "sunshine" (a stream of photons flying from the Sun to the Earth in an average of 8 minutes 17 seconds) should not be confused.

Due to the solar wind, the Sun loses about one million tons of matter every second. The solar wind consists mainly of electrons, protons, and helium nuclei (alpha particles); the nuclei of other elements and non-ionized particles (electrically neutral) are contained in a very small amount.

Although the solar wind comes from the outer layer of the Sun, it does not reflect the composition of the elements in this layer, since as a result of differentiation processes, the abundance of some elements increases and some decreases (FIP effect).

Cosmic rays - elementary particles and the nuclei of atoms moving with high energies in outer space[

Classification according to the origin of cosmic rays:

• outside our galaxy
• in the galaxy
• in the sun
• in interplanetary space

Extragalactic and galactic rays are usually called primary. It is customary to call secondary flows of particles passing and transforming in the Earth's atmosphere.

Cosmic rays are a component of natural radiation (background radiation) on the Earth's surface and in the atmosphere.

The energy spectrum of cosmic rays consists of 43% of the energy of protons, another 23% of the energy of helium (alpha particles) and 34% of the energy carried by the remaining particles.

In terms of the number of particles, cosmic rays are 92% protons, 6% helium nuclei, about 1% heavier elements, and about 1% electrons.

Traditionally, the particles observed in CR are divided into the following groups... respectively, protons, alpha particles, light, medium, heavy and superheavy... chemical composition primary cosmic radiation is an anomalously high (several thousand times) content of nuclei of the L group (lithium, beryllium, boron) in comparison with the composition of stars and interstellar gas. This phenomenon is explained by the fact that the mechanism of generation of cosmic particles primarily accelerates heavy nuclei, which, when interacting with protons of the interstellar medium, decay into lighter nuclei.

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Curiosity has a RAD device on board to determine the intensity of radioactive exposure. During its flight to Mars, Curiosity measured the radiation background, and today scientists who work with NASA spoke about these results. Since the rover flew in a capsule, and the radiation sensor was located inside, these measurements practically correspond to radiation background, which will be present in the manned spacecraft.

The result is not inspiring - the equivalent dose of absorbed radiation exposure is 2 times the dose of the ISS. And at four - the one that is considered the maximum allowable for nuclear power plants.

That is, a six-month flight to Mars is approximately equivalent to 1 year spent in near-Earth orbit or two years in a nuclear power plant. Given that the total duration of the expedition should be about 500 days, the outlook is not optimistic.
For a person, the accumulated radiation of 1 Sievert increases the risk of cancer by 5%. NASA allows its astronauts to accumulate no more than 3% risk, or 0.6 Sievert, over their careers. Taking into account the fact that the daily dose on the ISS is up to 1 mSv, the maximum period of astronauts' stay in orbit is limited to approximately 600 days for the entire career.
On Mars itself, the radiation should be about two times lower than in space, due to the atmosphere and dust suspension in it, i.e. correspond to the level of the ISS, but exact indicators have not yet been published. The RAD indicators during the days of dust storms will be interesting - let's find out how good the Martian dust is a good radiation screen.

Now the record for being in near-Earth orbit belongs to 55-year-old Sergey Krikalev - he has 803 days on his account. But he scored them intermittently - in total he made 6 flights from 1988 to 2005.

The RAD instrument consists of three solid silicon wafers that act as a detector. Additionally, it has a cesium iodide crystal which is used as a scintillator. The RAD is set to look at the zenith during landing and capture the field at 65 degrees.

In fact, this is a radiation telescope that captures ionizing radiation and charged particles in a wide range.

Radiation in space arises mainly from two sources: from the Sun during flares and coronal ejections, and from cosmic rays that occur during supernova explosions or other high-energy events in our and other galaxies.


In the illustration: the interaction of the solar "wind" and the Earth's magnetosphere.

Cosmic rays make up the bulk of the radiation in interplanetary travel. They account for a radiation share of 1.8 mSv per day. Only three percent of the exposure is accumulated by Curiosity from the Sun. This is also due to the fact that the flight took place in a relatively quiet time. Flashes increase the total dose, and it approaches 2 mSv per day.

The peaks are due to solar flares.

Current technical means are more effective against solar radiation, which has low energy. For example, it is possible to equip a protective capsule where astronauts can hide during solar flares. However, even 30 cm aluminum walls will not protect against interstellar cosmic rays. Lead would probably help better, but this will significantly increase the mass of the ship, which means the cost of launching and accelerating it.

The most effective means of minimizing exposure should be new types of engines that will significantly reduce the time of flight to Mars and back. NASA is currently working on solar electric propulsion and nuclear thermal propulsion. The first one can in theory accelerate up to 20 times faster than modern chemical engines, but acceleration will be very long due to low thrust. An apparatus with such an engine is supposed to be sent to tow an asteroid, which NASA wants to capture and transfer to lunar orbit for subsequent visits by astronauts.

The most promising and encouraging developments in electric jet engines are being carried out under the VASIMR project. But to travel to Mars, solar panels will not be enough - you need a reactor.

A nuclear heat engine develops a specific impulse about three times higher than modern types of rockets. Its essence is simple: the reactor heats the working gas (hydrogen is assumed) to high temperatures without the use of an oxidizer, which is required by chemical rockets. In this case, the heating temperature limit is determined only by the material from which the engine itself is made.

But such simplicity also causes difficulties - traction is very difficult to control. NASA is trying to solve this problem, but does not consider the development of NRE a priority.

Application nuclear reactor still promising in that part of the energy could be used for generation electromagnetic field, which would additionally protect pilots from both cosmic radiation and radiation from their own reactor. The same technology would make profitable the extraction of water on the Moon or asteroids, that is, it would additionally stimulate the commercial use of space.
Although now this is nothing more than theoretical reasoning, it is possible that such a scheme will become the key to a new level of exploration of the solar system.