The interstellar arc – the problems of the "human savior"



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"The planet is the cradle of the mind, but one can not live forever in the cradle," wrote Konstantin Ciolkovsky at the beginning of the twentieth century. Now, scientists are increasingly saying that sooner or later people will have to leave Earth and look for new homes.

© Joe Bergeson
© Joe Bergeson

Do not sleep!

In science fiction books and films, interstellar spacecraft crews are generally in an anabolic state during flight. Convenient: a long journey for them is instantaneous. However, looking at the situation more realistically, there are problems. What will happen to a spacecraft during the year of flight? Will it be able to recover and, if necessary, rebuild if security systems can take into account all risk factors and avoid obstacles? And what happens if the passenger's anabolic equipment fails, as in the movie Passengers, whose heroes woke up 90 years earlier than expected? How invaluable scientific data will mankind have if experiments are abandoned in flight and only sleep?

It may be that similar issues have forced people to think about traveling through the curb space without falling asleep. One can use the "method of change": say, some astronauts wake up every year and watch a spaceship. One year later, they are replaced by others. What if mankind does not find a way to cause deep sleep – anabolism – before the start of the expedition? After all, only the earliest experiments are taking place so far.

Such discussions resulted in "generational ship" projects. It is much slower than the speed of light on the interstellar spacecraft. Such a ship must fly for thousands of years. During this time, settlers will age and die, their places will be occupied by descendants – and this scenario would be pursued until fate was achieved.

One of the most famous generations of spacecraft projects was based on Orion. This explosion (a nuclear impulse ship) was created in the mid-20th century in the United States. He had to be accelerated by nuclear explosions near the end of the spacecraft. Some explosive products hit the "tail" of the spacecraft, where the massive plate absorbs the energy of the impact and passes it through the damper. The scope of the Energy Limited Orion Starship project is impressive: the spacecraft has a diameter of 20 kilometers. According to the developers, even the nearest star system, the Alfa Centauri, this ship would be taken in 1330 years. A spaceship would be basically a small space city. However, NASA chose cheaper designs and the Orion ship remained a theory.

But if things were different, could we send the first settlers into space now? Unfortunately not. The Generation Ship Concept solves many theoretical problems of long space flight – and creates new problems. Let's look at the difficulties that generations of generations can face and what to keep in mind when traveling to distant stars.

Orion Starship © NASA
Orion Starship © NASA

Where to fly?

Proponents of space colonization can be divided into two groups: the plans to create Mars and convinced that the new Earth can only be found alongside other stars. Exoplanet researchers confirm that outside the Solar System, it is possible to find life bodies that are suitable for life, although this is not easy.

To make the movement successful, it is important that the planet is as close to the Earth as possible. It is necessary to have a low temperature and liquid water. The star on which the planet is spinning must be as calm as possible – frequent and intense flashes of the star cause severe temperature peaks. The flow of particles emitted by electrons from a star can damage the planet's atmosphere and, in the long run, a gaseous sheath and a full stroke. The solar system probably happened with Mercury.

The area around the star, which is the existence of liquid water, is called the living zone. This is a kind of "middle latitude" of the planetary system. Here, the planets are far from the star, getting enough energy to keep the water from falling. However, they are not too close to the place where water can evaporate. According to a fairy tale about a girl who is a heroine of three bears at home, this space is called "The Golden Wing Zone." While there was no beast in the house, she decided to die a little and tested all three beds at home: one bed was – very hard, the other – very soft, and the third was fair. It seems like you just need to look at all the planets in the system and choose the right one. Unfortunately, not all life-zone planets are suitable for us: they may contain liquid water, but all other conditions on Earth may be totally inappropriate.

In the summer of 2016, astrophysicists at the European Southern Observatory announced the discovery of the closest exoplanet on Earth. It revolves around Centauri Proxima, the star closest to the Solar System, and is now called Centauri Proxima b. According to scientists, it flies in its luminous area and may contain liquid water. No known climate model contradicts this. But the Proxima Centauri b is called our new home early. It is much closer to its star than the Land of the Sun, and the effects of such a neighborhood may be unpredictable.

In early 2017, seven exoplanets were discovered spinning around the cold red dwarf TRAPPIST-1 in the constellation Aquarius. The sizes of all planets are similar to Earth. Hypothetically, liquid water can exist on all seven planets, but is most likely to be found on the planets TRAPPIST-1e, f and g. Astrophysicists believe that new telescopes, for example in Chile, began building the Great European Telescope in 2014 – will be able to accurately show if there is water on these planets.

More importantly, even the closest exoplanet for us is far away. Until its 4.24 light years – the existing cosmic aircraft would fly for tens of thousands of years, and the planet TRAPPIST-1 – ten more times. Technologies are evolving, but spatial distances appear to be infinite. As a result, projects like generations of spacecraft are reconsidered over and over again.

The engines of the future

But is it possible to overcome these distances more quickly? The possibilities of the existing space apparatus are not clearly good, but there is a constant search for new ways. One of the most impressive projects is the sun (photon) candles. They use light pressure on the surface of the mirror. In the solar system, candles can use sunlight and this technology already exists. In 2010, Japan launched the IKAROS machine. Interplanetary Kite Accelerated by Sun Radiation). It is equipped with a 14-meter square candle, composed of four petals. They are equipped with solar cells. IKAROS had to loosen the candles from the sun and push them to push. With this task, the machine worked perfectly.

However, the wind pressure in the Sun is relatively low, so you'll have to look for other sources to get out of our system. There are designs that cut these laser devices. Solar sails have undeniable advantages: they do not need to be fed and the spacecraft they feed can be very light. However, there are not enough resources for launching an interstellar sailboat for humanity. You will need very powerful and accurate lasers or you will have to look for a different solution to this problem.

Another promising mechanism is the ionic one. Its working body is inert ion gas (argon, xenon) or mercury. An ionized material of electric field can be accelerated to a very high speed. The system "pulls" positive ions from the material and launches it into space, creating a jet boost. Ion motors used in Hayabusa (in 2010 he brought soil samples from Itokawa asteroids) and Dawn (launched in 2007 to Vest and Cerer) for probes.

Such a motor achieves a high relative boost and low fuel consumption. The disadvantage of modern ion engines is a very low thrust, so such a motor would not be able to start from Earth and would have to be built off our planet.

Another interesting concept is the interstellar motor Bussardo. A spacecraft with such a motor captures an interstellar material (mainly hydrogen) with a powerful "funnel" of a powerful magnetic field. The funnel should be thousands or even tens of thousands of kilometers in diameter. The collected hydrogen is used in a thermonuclear rocket engine. This will make the ship independent of the fuel being transported.

Unfortunately, this mechanism also has several technical limitations. Its maximum speed would not be very high, because each captured hydrogen atom reduces the impulse of the vessel and can only be compensated by a low speed (~ 0.1 c). To circumvent this restriction, the greatest possible use must be made of the captures of atoms.

Society of spaceships

How many people could go on an interstellar expedition? Expert assessments vary greatly, despite the fact that most of them have been optimistic about hundreds of flights, not thousands of years. John Moore, an anthropologist at the University of Florida in 2002, assumed that a stable population of 200 years would suffice for a small population of about 160 people. Strict "social engineering", as would not be necessary in anti-utopias, would be our normal family based on a space colony. Everyone would have about 10 suitable partners for the wedding.

Even today, when the choice seems endless, most people do not have long-term partners. However, in such small populations, there is a risk of declining genetic diversity. It may decline gradually and unexpectedly – for example, in the case of a dangerous infection, the shipment would face a "bottleneck" effect when the population suddenly falls and then recovers easily. Genofondo is poor and affects the descendants of the survivors of the catastrophe. In the animal world, this effect has affected the genetic diversity of cheetahs – it is believed that only a few individuals have lived. The species has emerged on the verge of extinction, now around 7,000 individuals in wildlife around the world. Because of their long, cohesive crossing, they are less disease-resistant and, in nature, most juveniles die in the first year.

Another threat to settlers is the "founding effect." It arises when a new territory is occupied by a small number of species. They do not preserve the genetic pool of the entire initial population and may also face the problem of genetic decline.

Anthropologist Cameron Smith of Portland State University estimated in 2013 that tens of thousands would be needed to deal with these problems during a 150-year flight. According to their estimates, a stable population of about 40,000 people, of which at least 23,500 are fertile. In any case, the colony may be smaller if you have a large bank of embryos.

Space in the basement, space in the desert

Of course, all these questions will remain at the level of theoretical considerations for a long time. With today's technology, sending people to neighboring star systems will fail and continue for a long time. However, promising research that can approach the cosmic future has been going on for decades.

One of the most famous experiments of this type is the creation of closed ecosystems. Generations of spacecraft passengers will spend thousands of years in it, so the colony must be fully equipped: no help can be expected. Such an experience will be useful in creating a new planet. Closed systems development projects began in the 1970s shortly after the man landed on the moon.

The USSR built the BIOS-3 in 1965-1972. In the basement of the Institute of Biophysics of Krasnoyarsk, scientists installed a sealed space of 14 × 9 × 2.5m and ~ 315m³ divided into four sections. The cabin and crew's equipment occupied only one of them, with the rest of the chamber and phytotron plants and algae capacity. Special species such as a specially developed dwarf wheat variety with a short trunk. The BIOS-3 performed 10 experiments, the longest lasting 180 days. Participants were able to create a fully enclosed gas and water consumption system. They provided 80% of the food.

In the early 1990s, perhaps the most famous closed loop design experiment was Biosphere-2. In Arizona, a complex of several buildings and a conservatory was built on 1.5 ha. Several natural areas have been modeled within: tropical forests, savannah, mangroves and even the ocean. About 3,000 species of plants and animals lived in Biosphere-2. The project team consisted of eight people, equally male and female. They supervised the technique of circulation of water and air, cultivated and performed several tests.

The first phase of the experiment lasted two years. During the year, the settlers managed to reconcile the cultivation of products: in the first months people were constantly feeling hungry. They then adapted to the new diet and many of the participants had better health outcomes after the experiment, such as lowering blood pressure. The biggest problem has been the drop in oxygen levels. The project participant, Jane Pointer, recalls:

It is believed that the oxygen level began to fall as the microorganisms of Biosphere-2 multiplied more than expected. The same thing happened with insects. It was not possible to eradicate them by poison: it could have damaged the balance of the artificial biosphere. Finally, the project organizers had to do the falsifying of the data: the absent oxygen was injected into the system. When the deception was over, the participants in the experiment were criticized. However, the oxygen level continued to decrease, despite the supply of off-gas, so only two years after the start, the first phase of the project was discontinued. The experiment was recognized as flawed. However, the value of such experiments should not be underestimated. First of all, they reveal a myriad of calculations of "underwater stones, helping to create more realistic models.

Second, these projects resemble the fact that spatial-only colonization is not enough for powerful mechanisms. For those who want to reach out to other planets, humanity will need a wide range of knowledge and skills.

Rebellion on board?

The millennial expedition presents many challenges. Some of the problems are related to the environment, such as the harmful effects of cosmic radiation. It can promote the development of cancer, damage the bone marrow, the immune system. That is why, when it comes to space travel, you need to protect yourself. You will need several parameters to predict the prediction system of the radiation environment. The main task is to determine the level of damage to health and to monitor the balance. Settlers will inevitably have to take risks and, for spacecraft builders, figure out how to accommodate safety features in a spacecraft without sacrificing payload.

What is strange, however, is that moral and ethical difficulties pose no less danger. Dedicated devoted people go into space, convinced that it is necessary to settle on other planets. But will your descendants be able to keep such faith and they will? What if "middle" times are represented by being trapped in a high-tech space prison? Ethics will have to find answers, otherwise you will not be able to avoid problems.

The consequences are unpredictable: from pessimism and apathy to open conflicts. In a confined space, the misunderstanding between parents and children, or ideological disputes, would be catastrophic. This is confirmed by the history of the same Biosphere-2. When it was discovered that the oxygen level inevitably declined, the researchers were divided into two groups. Some wanted to leave the Biosphere immediately, while others wanted to complete the project at any cost. It is said that the conflict is so hard that many former participants in the experience are still not talking. And they spent a couple of years in a closed system!

So far, mankind is only at the beginning of the path to the stars. There will still be much research to be done to create a viable self-sufficient space colony and reliable interstellar spacecraft designs.

Technologijos.lt

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