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PROPERTY (Friday 03/25/2011)

hardly a new concept has been more battered, more irresponsibly tried to make the concept of ownership. Distorted, misrepresented, concealed, covered, stained, matted, with him everything has happened. Understandably, the concept of property is at the core of the operating system, and also the support of liberation.

When it comes to property, and this is very important, we refer to the Media Ownership of production, not ownership of assets. Speaking of ownership, without specifying which, is a hoax.

is not the same property of a motorcycle, a bicycle or a shirt, which are assets that ownership of Polaris, it is a means of production, in capitalism, is a means of exploitation of the workers.

A social system is as relationship property repeat, Media Production. The whole social structure is based on that relationship. But ... Why is it essential that relationship property? How does the characterization of the social system?

The ratio of property needs and determines consciousness, spirituality, a culture that justifies it, perpetuate and reproduce. Value and culture influence each other. Awareness and relationship property form a set that supports the social system. Each system belongs to a set of social relations of property and specific awareness.

The slave system, for example, stood on the enslavement of workers and a culture, spirituality, justifying this slavery.

It follows that for a Revolution Case of Media Ownership of production is not trivial, is not a choice that is made lightly, is on the contrary, a central point progress of the revolutionary process. Entangled

this topic postulating that evil is a monopoly and other forms capitalist property are not, if we say that socialism is enough social ownership of basic industries and the rest can be capitalist property, and if we clarify the difference between means of production and assets, allow the mix the bourgeoisie. Talking property and not specify what is a trap.

If popular forms of economy are not integrated to form a national social fabric, if they remain isolated, then we are creating the economic basis for confusion in spirituality, weakening the revolutionary cause.

Thus we form a complex opposite Socialism, strengthen the dominant set, the selfish relationship in the economy and culture. We can not and hit hard the capitalist system, it would be impossible to establish the social complex.

conclude that capitalist ownership of the means of production is counter , always. And the success of the revolution is closely linked to the sharpness in front of his fighter.

It is therefore important to construct forms of social ownership of the means of production and also need to spread their advertising and statements of the leaders.

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Further developments in the SLS

The SLS (Space Launch System ) is destined to become the new NASA rocket. After removal of the space shuttle this year, the SLS-also called HLV (Heavy- Launch Vehicle) - is the only pitcher operated by the U.S. space agency. That if finally approved. The initial design envisaged a rocket with a capability in low Earth orbit (LEO) of 70-130 tons to be ready by 2016 according to the NASA Authorization Act 2010. All too complex and expensive for the taste of the country's political class.


Initial design SLS (NASA).

So NASA has decided to review the project and recently we learned the final design will emerge from among three candidates. The first, called RAC-1 by the working group that studies (RAC comes Requirements Cycle Analysis) is very similar to what we have seen so far. RAC-1 would be a rocket with a cryogenic core stage, which uses liquid hydrogen and oxygen (LH2/LOX) - RS-68 engine or SSME ( shuttle motors ). Around this central stage would install two solid-fuel rockets (SRB) or liquid (LRB).

But the novelty lies the second candidate, RAC-2. This first stage used kerosene and LOX plus a second cryogenic stage. In short, a design reminiscent of the Saturn V moon rocket . Another design team, RAC-3, is studying strange configurations that use multiple sets of EELV rocket stages as the Atlas or the Falcon 9.


RAC-2 option would be similar to the Saturn V (NASA).


One proposal for SLS should use an engine similar to F-1 of the Saturn V (NASA).

Despite the novelty of RAC-2 and RAC-3, RAC-1 configuration remains the favorite, as it would maximize the infrastructure and technologies shuttle. To save money, NASA now considered first develop a more modest version of this launcher, Block 0 , it would use the same engine SSME and SRB of the shuttle and have a low-orbit capacity of 70 tons. The strange thing is that this version is virtually identical to the proposal Jupiter 130 initiative DIRECT.



Jupiter 130 is very similar to RAC-1 design of the SLS (directlauncher.com)

This version could be ready for 2014. After three test flights, could send the Orion spacecraft and / or commercial vehicles to the ISS in 2016. If money permits, the Block 0 version would move to Block 1, with a capacity of 100 tons. Block 1 would have five-segment SRB (similar to the Ares I rocket disappeared) and five SSME. Over time could be made versions Block 2 and Block 3. Block 2 would have a capacity of 130 tons and would have a second cryogenic stage with three (!) J-2X engine or a modified SSME. Block 3 would have a large center stage and could put in orbit up to 150 tons.

As we see the drama of the SLS, far from abating, every day becomes more strange. In any case, even assuming that the SLS is finally approved, will the NASA money to seek a profit?

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Myths Soyuz 1 Eureka 88

The April 24, 1967, cosmonaut Vladimir Mikhailovich Komarov killed when his Soyuz 1 capsule hit the ground at high speed. Komarov was the first cosmonaut who died during a space mission and for many years the details of his death were surrounded by a halo of mystery. It was not until perestroika the late 80's to know what happened exactly with the Soyuz 1. Unfortunately, during those years also many rumors leaked out that over time have acquired status of truths. Today it is still customary to read books and articles that reflect these unfounded myths. And the sad thing is that we now have at our disposal all the time files. This is the true story of the Soyuz 1.


Vladimir Mikhailovich Komarov .

The Soyuz and the lunar program

In 1966 the Soviet space program was going through a critical situation. While in the United States, NASA put in place the various elements to put a man on the moon in the USSR, the indecision of the government had succeeded in crippling the Soviet response to Apollo program. The death of the great chief engineer Sergey Korolyov in 1966 had been a blow to the design bureau OKB-1 and its plan of N1-L3 Moon landing. However, Vasili Mishin, Korolev's successor as head of the OKB-1, hoping to be able to launch a cosmonaut around the moon before the Americans with L1/Zond ships. Both the program and the N1-L3 L1 made use of a vehicle common, the Soyuz spacecraft ("union" in Russian). But to ensure the success of the lunar adventure, the Soyuz would first show itself in low Earth orbit. The version of the Soyuz for orbital flight was called 7K-OK ( Orbitalni Korabl / Орбитальный Корабль "orbiter") or 11F615. It consisted of three modules: the orbital module (BO, Bitovoi Otsek / Бытовой Отсек, БО), the capsule SA ( Apparat Spuskaemi / Спускаемый Аппарат, СА) and the service module PAO ( Priborn-Agregatni Otsek / Приборно-Агрегатный Отсек, ПАО).


Sergey Korolyov (left) and Vasily Mishin, the first leaders of the OKB-1/TsKBEM/Energía.


Zond/7K-L1 Nave.


Detailed model of the Soyuz LOK for the N1-L3 Programme by Vadim Lukashevich (www.buran.ru).

ground testing the first prototype of the 7K-OK spacecraft began on May 12, 1966, much later than expected. The ship had many defects that the very Nikolai Kamanin, the head of the Cosmonaut Training Center (TsPK) wrote in his diary strong criticism on the design of the vehicle. Mid, 1966, the State Commission created to oversee the 7K-OK program decided that the first mission of the Soyuz would be the coupling of two unmanned spacecraft in orbit down by Igla system. Until then, the engineers of OKB-1 (then called TsKBEM) expected to launch two missions before automatic solo to refine the various systems. But time was pressing. There was a moon race to win and the State Commission decided to delete these test flights.



Soyuz 7K-OK (Novosti Kosmonavtiki / RKK Energy).

The first two 7K-OK spacecraft arrived at the Baikonur cosmodrome in August. The launch was scheduled for September. First take off the 7K-OK (A) No. 2, a Soyuz with pluggable system (or "male"). Would follow 24 hours after the 7K-OK (P) No 1 with a passive ("female"). If all went well, the two ships would couple and fly in formation for three days. The technicians were confident that the first manned flight could take off in December.


Nave 7K-OK (A), active.


Soyuz 7K-OK (P).

Finally, on November 28, 1966 at 16:00 Moscow time a rocket was launched from Baikonur 11A511-derived Semiorka-R-7 with the first Soyuz . Once placed in an orbit of 181 x 232 km would be named Kosmos 133 . The problems began immediately. A fuel leak in the orbital maneuvering system (DPO) caused the tank pressure to fall from 340 atmospheres to 38 atmospheres in less than two minutes. Fifteen minutes later, the Kosmos 133 had lost all its fuel in this system and was running at two revolutions per minute. The link with the 7K-OK (P) was given up as lost and canceled its release.

But the guidance system also failed, so it was impossible to maneuver the spacecraft for the ignition of the main engine braking (SKDU). After many attempts, the engineers were able to slow the spacecraft system using the other orientation (DO) and the auxiliary motor (DKD) rather than the main motor. On 30 November the ship made reentry, but the capsule disappeared from radar screens when it was at about 70-100 kilometers high and 200 kilometers from the city of Orsk. The self-destruct system, consisting of 23 kg of TNT, had been activated to ensure that the Soyuz could land in China. The wreckage ended up falling on the Marianas Islands in the Pacific Ocean.

loss capsule deprived engineers valuable information to improve systems ship. The State Commission and Mishin was agreed to launch the next 7K-OK (P) on a solo flight. From the ship was heading into space on December 14, 1966 at 14:30, but the launch was aborted seconds before liftoff. A few minutes later, while technicians inspected the Soyuz rocket, the escape tower (SAS) was activated unexpectedly fire the launcher. Technicians immediately fled the area and ran to seek refuge in the bunker. Just in time, because shortly after the Soyuz, carrying fuel to the brim, exploded destroying the ramp area and killing 31 more Korostylov. The capsule of the second 7K-OK landed without a scratch within walking distance of the ramp.

After this tragedy was not until the February 7, 1967 for the second Soyuz (7K-OK (P) No 3) in space, to be christened Kosmos 140. The launch had been canceled the day before by a technical failure. In the fourth orbit, the stellar sensor guidance system failed and lost again maneuvering fuel. On February 9 the ship began reentry, but the control system failed and the capsule was forced to perform a ballistic descent. The rescue team would find the iceberg on the Aral Sea, at 510 kilometers from the area expected. Before they could reach she sank into the sea. And that was supposed that the capsule should float. The depth was not excessive, not ten yards, so he could be rescued with the help of a helicopter Mil Mi-6. Upon inspecting the vehicle engineers discovered with horror inch hole in the heat shield in place that should be installed a temperature sensor. If you had taken the Kosmos 140 crew, cosmonaut would have died from decompression sickness (not wearing a space suit) and then have sunk into the seabed.


coupling system between two Soyuz 7K-OK showing extravehicular activity required to move from one ship to another (Soyuz 4 and 5).


The Soyuz 1

It did not take an expert to realize that the 7K-OK was not ready for manned flight. Unfortunately, the State Commission and Mishin thought this was a good opportunity to advance to NASA, now mired in utter confusion after the tragedy of Apollo 1. On March 25, 1967 it was decided to continue with the original plan. The next manned Soyuz would not only, but also carry out an ambitious mission that included a link to another 7K-OK (Soyuz 2) that would carry three crew. After mating, two astronauts would perform an extravehicular activity (EVA) and the Soyuz 2 would the Soyuz 1. Manned mission would be the most complex to date.


Soyuz 7K-OK for integration on the ground. Protective covers can be seen green (against the vacuum and temperature changes) that cover the entire ship, but some parts (radiator) of the propulsion module (below).


Vladimir Komarov was elegidocomandante of the Soyuz 1, Yuri Gagarin reserve. Valeri Bykovsky, Alexei Yeliseyev and Yevgeni Jrunov would be the crew of the Soyuz 2. Jrunov Yeliseyev and should perform the EVA suits and return Yastreb with Komarov on Soyuz 1. After a short but intense training, the astronauts would travel from Moscow to Baikonur on several flights between 6 and 14 April. That same day, the State Commission tentatively decided to set the release date for April 24. The Soyuz 1 lift off from Area 1 or "Gagarin ramp, while the Soyuz 2 would from Area 31.


Komarov during training for the mission.


Crew of Soyuz 1 and Soyuz 2 with Yuri Gagarin.

April 15, at 23:00 began the refueling of the Soyuz 1. The Soyuz 2 would receive its load of hypergolic propellants on 17 April. Three days after the State Commission met to confirm the composition of the crew and decided that the launch of the Soyuz 1 would take place on 23 April at 3:55 Moscow time. The Soyuz 2 was off on April 24 at 03:10. The day came and Komarov key rose shortly after midnight local time. After to undergo a medical checkup donned his flight suit, a simple gray cotton mono, and he left the launch pad at 03:00. They took leave of the Commissioners, among whom were Mishin and Kamanin. Gagarin himself Komarov accompanied to the entrance hatch of the ship.

At the scheduled time, the Soyuz 1 (7K-OK (A) No. 4) took off with Komarov inside, becoming the first cosmonaut who performed a second space flight. Once in orbit was 196.2 x 225 km, the nightmare began. The left panel of the Soyuz failed to deploy and also missed a telemetry antenna, the wave communications system short and the solar sensor 45K. This sensor was responsible for maintaining the ship facing the Sun continuously. With a solar panel out of service and without proper guidance, the electric current decreased to 14 amps, well below normal.



So should have been Soyuz 1-Soyuz 2.

Komarov tried to guide the ship during the fifth orbit using manual control and sensor system of ions, but without much success. To his despair he found it very difficult to determine the spacecraft orientation with respect to horizon. Between the seventh and the thirteenth orbit, Komarov should take the opportunity to sleep out of reach of Soviet shortwave stations. Upon completion of this period, the cosmonaut announced that the ion orientation system failed again. Bad news because no operational guidance system was unable to return to Earth. At this point it was clear that the link with the Soyuz 2 was impossible, so that the State Commission decided to cancel the mission and ordering the return of Komarov at the 17 th orbit. The three crew of the Soyuz 2 complained bitterly about the "excessive caution" by the Commission.

But in the 15 th orbit Komarov reported ion system finally worked again. The engineers proceeded to calculate the information necessary for reentry. Before losing radio contact, Gagarin diligently passed them. Mishin and Kamanin wished him luck. The ship's computer should start braking sequence on the 2:56, but when it came time nothing happened. The engine was not running. Apparently, the guidance system had failed again to pass through the ship area sparsely ions while flying over the night side of the planet.

was decided to bring back the 18 th Komarov and Gagarin orbit proceeded to send a new set of data. The ignition and 150 seconds long, would take place at 05:57. Before entering the Earth's shadow, Komarov should ensure that the spacecraft was oriented with the front engine. Then have to wait until the gyroscopes KI-38 held the position during the night journey. This time the guidance system worked and the engine was turned on at the scheduled time, although the length is slightly lower than expected (146 seconds). To the alarm of the drivers, the signal "Fault-2" was activated on the instrument panel of the Soyuz. Luckily it was not any major failure. The computer decided to cancel the nominal decrease in noting that the center of gravity of the ship was not where was because of the folded solar panel. The spacecraft would carry out a ballistic descent Komarov should support a higher than normal deceleration (about 8 g), but nothing serious. After lighting, Komarov moved into a center seat in the capsule.


Inside a 7K-OK Soyuz capsule.


Soyuz capsule. The parachute container to the right.



Soyuz TMA capsule where you can see the main parachute container (NASA).

Vista
parachute a Soyuz TMA (NASA).


sequence of the Soyuz descent to the main canopy (left) and standby (right) (RKK Energia).

initiated the reentry capsule fifteen minutes after the end of the ignition. Communications were interrupted because of the plasma layer formed around the ship while the heat shield reached more than 2000 ° C. A few minutes later he could hear the quiet voice reciting Komarov parameters down thanks to the VHF antenna located on the main hatch. The Soyuz 1 was about to return home.

The tragedy occurred when it was his turn to parachute. The procedure required to first deploy a small parachute, the pilot parachute, which should stabilize the capsule and pull the main parachute. As expected, the parachute container cover was ejected and then the pilot parachute out. But against all odds, the main parachute stayed inside the container. Was unheard of. In the hundreds of simulations and tests never happened something similar. The ship's computer detected that the rate of fall did not diminish, a sign that there is something wrong with the main parachute. The reserve parachute was activated automatically, but unfortunately became entangled with the parachute pilot was already unfolded and its leadership failed to open properly. The ship rushed with no possibility of stopping its descent. Komarov knew it was going to die. Vladimir

later died when his capsule crashed about 150 km / h (the reserve parachute partially deployed had helped reduce terminal velocity). The impact was fatal necessity, but even worse was the explosion and subsequent fire. Due to the high rate of descent, the heat shield had failed to spread to three kilometers high as expected. A few meters from the ground, solid fuel rockets of the capsule is activated to stop the fall, a worthless work this time. But being the heat shield still in place, the fireworks caused an explosion inside the car to be fueled by the 30 kg hydrogen peroxide system to maneuver the ship.


Rear Soyuz capsule without the heat shield. Be seen the four solid-fuel engines on the sides DMP.

Contrary to popular belief, Komarov remained silent during his last seconds of life . Do not shout or praise turned to their homeland. Nor cursed the engineers who designed the vehicle. If you said something, he kept to himself. The capsule was equipped with a "black box" in which they could record the conversations of the cosmonaut.

Members of the rescue team aboard an Ilyushin Il-14 were the first who flew over the crash site and reported that Soyuz 1 was on fire. A helicopter landed a hundred yards from the capsule shortly after. Rescuers thought they might have survived Komarov and perhaps was out of the ship, so I inspected the area. A few minutes later, Nikolai Kamanin landed in the city of Orsk waiting to be received by Komarov. They told of the tragedy and immediately went to the scene. When he arrived, the capsule was still in flames. At this point it was clear that Komarov was dead and his body was inside the ship. Kamanin gave orders to put out the fire with dirt and proceeded to remove the charred body of the cosmonaut. Komarov's remains were found at 09:30 and taken to Moscow for autopsy. Komarov on April 26 would be buried with full honors in the Kremlin wall as a Soviet hero. A few days later, a group of Pioneers who came to honor the fallen hero Komarov found more remains in the area and decided to bury them. Several cosmonauts also came to the scene to pay tribute to his former comrade.


Remains of the Soyuz capsule 1 after impact. Komarov's body was still inside the vehicle when these pictures were taken.



Remains of the Soyuz 1.


Cosmonauts and engineers from OKB-1 Komarov pay homage to the scene of the tragedy (RKK Energia).

was clear that Komarov died because of an incorrect deployment of the parachute, but was to determine the cause of this strange event. According to the official investigation, the parachute had been incorrectly folded before being inserted into the container. To avoid a similar tragedy, we decided to change the shape of the containers, which would be tapered rather than cylindrical. Also incorporated a pilot parachute to pull over to pull the main parachute and a control system to facilitate the deployment manual.

However, years after it was learned that the main cause of the tragedy had nothing to do with the folding of the parachute. Prior to launch, and as usual, the capsule of the Soyuz 1 was coated with an organic resin that should be part of the heat shield ablation. Then the ship was introduced in an oven to cure the resin. For reasons still unknown, the parachute containers even empty-then-no and stopped this process. Resin vaporized entered into containers, resulting in increased roughness of the walls. As a result, the Soyuz 1 parachute failed to deploy due to excessive friction presented by the container. This botched attempt was uncovered by the upper echelons of the OKB-1, although the system manager manned parachute design office was fired. The really terrible part is that the capsule 2 was also subjected to the same polymerization process. Has been released, it is possible that the four cosmonauts have died after returning from space.

Soyuz 1 was a predictable failure and resulted in the loss of innocence for the young space program Soviet. It was obvious that the ship was not ready for manned flight. The most important consequence of the tragedy was the cessation of the N1-L3 lunar programs and L1. If not a miracle happened, the USSR could make up for lost the moon race, as indeed it was.


Komarov's name on the surface of the moon on a list of fallen astronauts.

References:

• History of the Soyuz.
• Sputnik and the Soviet Space Challenge , Asif A. Siddiqi (University Press of Florida, 2003).
• Raketi i Liudi , Boris Chertok (Mashinostroenie Moscow 1999).
• imeni SP Korolev RKK Energia (Ed. Menonsovpoligraf, 1996).
• S oyuz, a universal spacecraft , Rex D. And David J. Hall Shayler (Springer Praxis, 2003).

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THE MIDDLE CLASS: HANDLING OR TO BE ADDRESSED? (Wednesday 24/03/2011)

Several issues were discussed with emphasis within the Bolivarian Revolution: the role of government, property, social classes, all very interesting.

Here we refer to one that we believe crucial, it is the role of the middle class or petty bourgeoisie in the revolution. "Direct or is it for? The answer depends on the direction of the Revolution. Let's see.

The first thing to point out is that ideologies migrate. This means that the ideology of a class can be taken by another class. Thus, the hegemonic class colonizes souls of the dominated classes, this is the basis of domination. Thus a minority class can lead the whole society.

Thus, what is important in the analysis is the ideology that drives the process, rather than the number of the class going. important thing is not the origin of class leaders, but the ideology that permeates. Ortega remember that the coup was a worker, and Gustavo Machado, the great revolutionary leader, was a bourgeois, Engels was a factory owner and Bolivar ... Mantua.

confuse this class with class ideology leads to serious errors.

So we can not conclude that this revolution is led by middle class, the petty bourgeoisie, because many government cadres come from that class.

right thing beneficial to the breakthrough is to determine what goes and what ideology is likely to lead to Socialism. Or more accurately, which competing ideological hegemony of the Revolution. Elucidate.

are two ideologies that are vying for dominance of a revolution: the capitalist ideology and socialist ideology, and all ideological manifestation enroll in one of them.

The ideology of the petty bourgeoisie is a variant of capitalist ideology, characterized as shameful and always defend capitalism: sometimes clearly, when right, and other obliquely, when acts of revolutionary.

is a cowardly ideology ranging from the desire to rise to the middle class that mimics the fear of failure to achieve, and in the attempt, descend to the underworld of poverty. This ideology fearful, acting for the Revolution, between revolutionary rhetoric, denouncing the evils of capitalism and capitalist practice.

His proposals in all social fields are fragmenting. Thus, the People, a political organization, economy, all, makes a mockery of Revolution.

This petty-bourgeois ideology of the middle class can not lead to a revolution! It can only organize his funeral.

The only ideology capable of revolution is the proletarian ideology. This can incarnate in other social sectors and direct the process, but at some point must be with their class, workers, make them aware and place at the forefront of the revolution.

The middle class, the petty bourgeoisie, it must integrate these revolutionary processes, adopt the revolutionary ideology. The rest is pyrotechnics ideological.

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Eureka retake the competition with a view of Google Earth:



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ELECTIONS, POLLS AND IMPERIAL ASSAULT (Wednesday 03/23/2011)

As we approach the 2012 survey the rain intensifies, they are bourgeois protagonists in every election, most seek to false feelings of the electoral table. Some are serious, scientific, these are so rare as useful.

The surveys are not pristine, are strongly influenced by the type of elections investigated and the interests of participants. Let's see.

The oligarburgueses, who consider the election marketing exercises and their candidates goods, use surveys as an exploration of the market. Thus, their questions are designed to know the position of "product."

main research is the acceptance of the candidate and his relationship with the other products. The subordinate questions are: denial, why, major problems facing the "buyers" voters "perception of the candidate's image. These results model the campaign, colors, slogans, photos in their family.

campaign revolutionary, although there is in the grounds of bourgeois elections, you must have an objective beyond winning the election. For the Revolution is not enough to win, it is important how you win. Fundamental are the numerical results as well as the organizational awareness training.

The Revolution can not be sustained only in a positive outcome in bourgeois elections, mass awareness needs to undertake and sustain the revolutionary changes . For the bourgeoisie any outcome is good, provided it is given the logic of marketing. The

revolutionary surveys should explore the reality looking to meet other aspects, other edges. For example, what are the motives of the people, their goals, their world view, the relationships they establish, their problems and the solutions they provide, the origin attributed to them. In summary, should try to establish the spirituality of the mass, it depends on the triumph of revolutionary candidate and will depend on the fate of the Revolution.

Revolution is a process that pits two worldviews. These days a copei leader shouting that the government's measures to benefit society and not the individual. This lady, in their ignorance and hatred, was telling a great truth. The Revolution is the rescue of a sense of society and the overcoming of egoism and individualism.

If selfishness advances, so does the bourgeoisie and its candidates. However, if the sense of society rises, dough will better understand what is decided in the elections and take sides, no doubt vote for the candidate of the Revolution. The Revolution will be fortified against attacks of the bourgeoisie, whether in the field it is.

So much for the revolution. We know that the bourgeois legality is respected only when it suits them best when they are unfavorable election lash out against revolutionary governments that they arise. Examples abound, there are Allende, April, Honduras and Libya to tell us that the path of revolution transcends bourgeois legality.

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radiation in space with the Orion Progress

be astronaut is not easy. Although today is a much less dangerous profession in the past, men and women dedicated to the conquest of space know that there are many things that could go wrong during a mission. But of all the dangers there is one that is often overlooked and yet is present in every mission. We refer to radiation.


A violent coronal mass ejection on the Sun generates a stream of energetic particles that can kill an astronaut (ESA / NASA).

All astronauts are exposed to significant doses of radiation during the course of a spaceflight. Although not a major obstacle to short-term missions, the radiation is converted into a huge problem if we want to live in space indefinitely, or travel the Solar System. In fact, for many is the space exploration problem par excellence. One would think that after several decades studying the effects of radiation on humans are able to accurately predict the impact of space radiation on humans. Not really. Not even close. The truth is we do not know many of their long-term effects.

The Origins of the space age, the radiation was a major concern of scientists. Many thought that any human being to venture beyond Earth's atmosphere would be subjected to dose deadly radiation that would kill him instantly or, perhaps, become a kind of mutant monster. The first space missions have demonstrated the existence of a steady stream of energetic particles in space, but at the same time it was found that doses were not lethal. By the way, several animals traveled into space before any man was put into orbit. As none of them was damaged by radiation and became a mutant freak, it was felt that manned space travel was safe.

Nearly five hundred men and women have traveled into space in the last fifty years, proving that space radiation not lethal. And yet there it is.


When performing an extravehicular activity (EVA) takes into account the level of radiation (NASA).


radiation in space

Unlike many people think, the near-Earth space is not a "vacuum" and immaculate, but is packed with all kinds of particles . Some of these particles have sufficient energy to cause damage to our body and break the DNA in our cells. And we all know what that means: cancer. Radiation ionizing radiation to which an astronaut is subjected has three possible sources: the Sun, cosmic rays and Earth's radiation belts. Let us briefly review the characteristics of each source of radiation in space.


The radiation damages the genetic material of our cells.

Sun

The Sun is a star static, but continually ejects material from its surface. This flow of particles called the solar wind , although it is a name that can be confusing. The solar wind is actually a plasma, ie, a flow of charged particles associated with a magnetic field, which is of great importance when analyzing their effects on health. It consists primarily of hydrogen nuclei (protons) and helium (alpha particles), the most abundant of our star and universe. There is a small proportion of heavy nuclei, but nothing spectacular. If it were only by the solar wind, the sun would not cause a hazard to astronauts.


solar wind as a function of solar latitude (NASA / ESA).

The problem is that the sun spits occasionally large amounts of highly energetic particles. These "solar storms" are called solar particle events or SPE (Solar Particle Events ) and its origin is quite complex. To oversimplify, we can say that the SPE is created from the interactions of the solar magnetic field and are associated with two very violent solar phenomena: the flares (flares ) and coronal mass ejections ( Coronal Mass Ejections , CME) . PES are composed mainly of protons with energies of a few megaelectronvoltios hundred (MeV) maximum, plus a few alpha particles and some other heavy nucleus.


SPE Events in recent years (NASA).

The effects of SPE in the human body are much worse than those caused by the solar wind. A lot. Let's say you would not like to be in outer space without protection during such an event, unless you want to be irradiated with potentially lethal doses (1-4 Sv). Fortunately, the SPE are very rare. Our star emits one or two major SPE every eleven years and only 20% come to affect the Earth-Moon system. Although unpredictable, the sun is more likely to generate a SPE when it is near the peak of its activity cycle of eleven years. Once unleashed, it takes twelve hours to two days to reach Earth orbit, which is usually more than enough time to alert the astronauts if they have an adequate detection network.


Cosmic Rays

Having a mysterious name, cosmic rays or GCR (Galactic Cosmic Rays ) are particles that originate in exotic corners of our galaxy. Most were created over millions of years by a supernova explosion or in the accretion disk of a black hole and have traveled thousands of light years before reaching our Solar System.

Unlike the solar wind, their energies are very variable, but what interests us is that they can reach up to 10 GeV per nucleon, between ten and twenty times more than a proton emitted by the Sun This means that some particles move nearly the speed of light. Most cosmic rays are also protons (90%) and alpha particles (8%), but about 2% are heavy nuclei. As we shall see, that 2% is particularly problematic in the face of human spaceflight. Of course, the number of cosmic rays per unit time, ie the flow-is much lower than the solar wind protons in the SPE, which greatly minimizes dangerous. Fortunately, a large number of cosmic rays are deflected by magnetic fields of the Sun and Earth.


Modulation cosmic ray flux as the solar activity cycle. LEO was observed in the flow is very low because of the magnetosphere (NASA).

radiation belts

Strictly speaking, the belts are not a "source" of radiation itself, as they are formed by energetic particles trapped in Earth's magnetic field. The origin of these particles are cosmic rays and solar wind, which explains that the majority are protons with maximum energy a few hundred MeV. Other radiation belts consist of electrons, but these are less dangerous. The shape and intensity of the radiation belts vary with solar activity cycle, but most of protons in a ring that has a maximum density of 6000 kilometers.


Earth's radiation belts. In

early enough to stay in orbit below 500 kilometers high if we are to avoid the effects of the radiation belts. Unfortunately, our planet's magnetic field has a distortion that allows the penetration of radiation belt protons at lower altitudes over a region located off the coast of Brazil (35 º S and 35 º W). This region receives the appropriately named "South Atlantic Anomaly" (SAA South Atlantic Anomaly ) and affects all manned space missions whose orbital inclination exceeds 30 degrees, as is the case Space Station (ISS). Most of the radiation received by the crew of the ISS is due to this anomaly.


levels of radiation in low Earth orbit. You can see the South Atlantic Anomaly (NASA / JAXA).


Earth's magnetosphere protects us from cosmic rays and the PES (NASA).

In a way, it seems as if the universe conspired to prevent astronauts from radiation can defend. If we limit ourselves to the missions in low Earth orbit (LEO), the Earth's magnetic field protect us from the SPE and cosmic rays, but we suffer the effects of the radiation belts. By contrast, the missions beyond Earth will resist the invitation, the SPE and cosmic rays. During solar activity minimum the chance of an SPE are minimal, but instead decreases the intensity of solar magnetic field and doubles the number of cosmic rays into the inner solar system.


flow distribution belt protons (NASA).


The flow of different types of particles of space radiation according to their energy. Fortunately, the most energetic particles are also those with lower flow (NASA).


dose and effects

How to measure radiation doses? In the International System of units is used gray (Gy) to measure radiation absorbed dose , a unit that replaces the traditional rad (1 Gy = 100 rad). Radiation from a gray deposit July 1 (1 J) of energy per kilogram of matter. Not all types of radiation have the same penetrating power and the absorbed dose depends strongly on the nature of the incident particles.

If our interest is to measure the effects of radiation on humans, the absorbed dose is a quantity not particularly useful, since the effects of radiation vary with the type of organ irradiated. Therefore, we use the concept of equivalent dose , which is similar to the absorbed dose but adjusted to take account of damage to living tissue. Its unit is the sievert (Sv, 1 Sv = 100 rem). As is known, the effects of radiation are stochastic. A nice way of saying that there is no minimum dose that can cause damage. A priori, any radiation dose can to cause cancer, although obviously the probability depends on the dose. Hence the panic caused by the mere mention of the word "radiation", but we must not forget that we are all subject to natural sources of radiation. A person normally receives over one year a dose of about 3.6 millisievert (mSv)-ie, 0.0036 Sv-natural causes. Including cosmic rays. Moreover, as important as the dose is the exposure time. To say that a person has suffered a dose of 1 mSv means nothing if we do not specify the duration of irradiation.

The vast majority of astronauts traveling to low Earth orbit (LEO), dominated effects due to the radiation belts. The doses in LEO depend both solar activity. Within the ISS are normally kept in the range of 0.4 to 1.1 mSv per day , including the effects of shielding. The long-term expeditions remain six months in orbit, so the equivalent dose reaches values \u200b\u200bof 70-500 mSv per year.


daily dose of radiation received in several missions. The green dots are the Apollo missions. You can see how the missions in LEO to higher altitudes and inclinations are subject to radiation doses similar to those of Apollo (NASA).

And this much or too little? Well, let's say that is enough. Legislation in the U.S. and other countries like Spain limits 50 mSv annual dose maximum a worker can receive in an environment subjected to radiation, although usually not normally exceed 2 mSv / year in these jobs. There are other professions more "conventional" who are also exposed to radiation. For example, airline pilots flying on intercontinental routes can receive 1-5 mSv / year because of cosmic rays. NASA decided in 2000 to revise downwards the maximum he could receive an astronaut in the course of his career, so that the likelihood of cancer mortal throughout his life because of the radiation does not exceed 3%.


maximum radiation dose for NASA.

As we see, the maximum permitted increase with age. Women have a higher risk of cancer because the mammary glands, hence the maximum will be less than in the case of men. Is this dose safe? For now, do not know. The number of astronauts is not high enough for meaningful data from the statistical point of view. Moreover, the problem is that these doses have been set apart from the data obtained by exposure to gamma rays or X rays, but we know very little about the effects of heavy nuclei in the human body. These cores are an essential part of cosmic rays and is very difficult to reduce their effects, unlike what happens with the SPE. Unfortunately, available data suggest that the tumors generated by the action of heavy nuclei are more aggressive and tend to occur earlier.


Some daily doses in several space missions.


astronaut maximum dose along the space race (NASA).


Comparison of doses received by astronauts performing EVAs in low orbit and those without. No great differences (NASA).




radiation detectors on the ISS (NASA).


How to defend ourselves from radiation?

it sounds a platitude, the best defense is to make short-term spaceflight. This simple technique helped to limit the dose received by astronauts on the Apollo missions even though they traveled outside the protection of the radiation belts. The odds of an SPE takes place on a mission a few days is minimal. This is what is called "statistical protection."

However, in the case of a Mars mission we have no choice but to deal with these problems. Unless we use revolutionary methods of propulsion, the duration of a trip to the red planet is large enough to easily get one or two SPE during the course of the mission. To make matters worse, cosmic rays, practically negligible orbital flights, takes on enormous importance in these interplanetary missions long duration.


The Apollo missions were not large doses of radiation because of its short duration (NASA).

Mars missions are divided into two types: conjunction and opposition. Conjunction missions include a long stay on the surface (300-600 days) and a round trip of 150-250 days (the duration depends on the relative position of the planets). Opposition missions covered short stay of only 20-60 days, and travel tempos of 100-400 days. The effects of radiation would be lower in the case of the missions of conjunction, because during the stay in Mars doses significantly reduced thanks to the mass of the planet and its thin atmosphere.


Radiation Dose on the Martian surface due to cosmic rays. The highest regions are the least protected, being outside the atmosphere (NASA).

Therefore, it is obvious that a Martian spacecraft should be equipped with a "safe haven" especially to protect astronauts from the SPE. The best braking materials formed by proton radiation are those with low atomic number elements such as hydrogen. But we have the heavy nuclei of cosmic rays. And here is the problem. Heavy nuclei from cosmic rays moving at relativistic speeds, so when they hit the metal frame of a spacecraft generate a cascade of secondary particles, including neutrons, alpha particles and mesons. These secondary particles are a source of additional radiation very worrying. As a result, sometimes the structure of steel or aluminum spacecraft does not diminish the radiation dose, but increases.

Therefore, the use of several layers of polyethylene (hydrocarbon rich in hydrogen) and water is believed to be the best way to protect the crew of a ship, at least in the case of SPE. Another option would be to include an active shielding using magnetic or electrostatic fields. However, this system is energy intensive, requiring the use of nuclear reactors or huge solar panels. Furthermore it offers complete protection against the most energetic heavy nuclei.


as radiation shielding materials of different density (NASA).


shielding effectiveness of various test on two shuttle missions (NASA).


Effect on radiation dose to use several shields (NASA).


electrostatic shield proposal for a lunar base (NASA).

Without active shielding, the radiation dose on a trip to Mars would be one or two sievert least well above the current limits of NASA. With these figures in mind, it is not surprising that the first human to set foot on the red planet is a man over sixty years.

Ultimately, the radiation in space has not proved an obstacle to reach Earth orbit. But if in the future we want to live on other planets, we have no choice but to learn to protect yourself against this invisible enemy.