# Scientists have figured out how many people will need to fly to the nearest star system

Dreams of settling other planets, mankind began to dream long before we had the first spacecraft for manned flights. And with the opening of the last few decades, several thousand new extrasolar planets, some of which may well be inhabited or at least suitable for colonization (currently great interest in the planet Proxima b system, Proxima Centauri), the dream of interstellar flight and colonization begin to gradually take on the status of future prospects.

, of course, before you even start to think about the implementation of such missions, we will have to solve a lot of very complex technical issues. For example, to fly on what ship? How to bring your people to live on the same planet Proxima b, if it is suitable for life? The second question turned out to be the subject of a new study by French scientists, who decided to calculate the minimum number of people to a healthy team, consisting of several demographic generations of earthlings, was able to successfully reach our nearest star system. Their work will soon be published in Journal of the British Interplanetary Society.

The authors of the study are Frederic Marin, doctor of astrophysics from the Astronomical Observatory of Strasbourg, as well as Dr. Camille Beluffi, an expert on the physics of elementary particles and subelementary working in scientific startup Casc4de.

Their study is the second in a series of scientific papers directed the question of the reality of manned interstellar flight to Proxima b. Their first job is called "Legacy: the use of Monte Carlo method to calculate the prospects of interstellar travel with the team of people belonging to different generations," was published in August 2017 in the same journal, Journal of the British Interplanetary Society. The second, which we are discussing today, is called "Computer calculation of the minimum number of people required for the flight to Proxima Centauri b". His latest research Dr. Marin and Dr. Beluffi started with analysis of many concepts that describe the options for interstellar travel. Among these proposals, there are both "more conservative" approach, using the same spacecraft, working on the basis of nuclear pulse (for example, the same "Project Orion", not to be confused with the cosmic NASA machine "Orion") and Fusion engines ( "Project Daedalus ") and the more modern concepts like the same Breakthrough Starshot.

All of these programs are still far from practical implementation and / or do not involve manned missions (as in the case with the same Starshot project). The subject of interest to Marine and Beluffi in their study began and mission, which will most likely be launched in the next few years. For example, one of these missions is to launch a space agency NASA solar probe Parker, scheduled for July-August this year. That the probe be able to achieve the highest possible speed for the space unit created by man is expected to be up to 724 205 km / h or 200 km / s (or 0, 067% of the speed of light).

"These numbers will fully reflect the capabilities of our technology for the duration of this mission. If we started the construction of the spacecraft to fly to Proxima b right now, it could achieve a maximum speed of 200 km / s. Thus, to reach the destination point we could only for 6300 years. Of course, technology does not stand still. Over time, they become more and more advanced. But calculations show that at the beginning of the project of the interstellar trip we will be able to reduce the flight time to 630 years. However, all this only on paper. Technologies to so quickly get to another star system we have now is simply no ", - commented Dr. Marin portal Universe Today.

Taking as its starting point the current opportunities (ie, the flight speed of 200 km / s and 6300 s, needed to get to Proxima as fast b) Dr. Marin and Dr. Beluffi tried to determine what in this case, the minimum number of people required for to the point of destination has been able to get completely healthy team. To carry out these calculations, the researchers used a Monte Carlo method, developed by Martin new program calculations. The Monte Carlo method is a mathematical method of statistical modeling, which allows to obtain an average value, or the possible outcome of the phenomena through random search of all possible scenarios and events, standing in the way of solutions. it is usually used in cases where the application of analytical models of the phenomenon is difficult or completely impossible.

"To solve the problem we have used I developed software. It is called HERITAGE ( "Heritage"), more detail can be consulted in the first work of our scientific research series. It uses a stochastic (random) Monte-Carlo method, which takes into account all the possible simulation results by checking each random scenario of further development of an event, including life and death. The simulation of a few thousand times, we can get a statistically average values that reflect the likelihood of a real space travel, taking into account the team, which will consist of representatives of different generations. This program will allow for the greatest possible number of different biological factors and currently improved to accommodate more and more number of physical factors, "- said Marina.

Among the biological factors: the ratio of men and women on board the spacecraft, their age, the average life expectancy, fertility (birth), as well as the time in which the team will have to maintain the level of reproduction. There is also random factors are taken into account: a number of incidents, accidents, disease, and the number of people who are likely to be exposed to them.

Inserting a formula for calculating the various factors and values, researchers conducted more than a hundred simulations of interstellar travel for determining the minimum required size of the team. It turned out that the conservative conditions for the flight to the nearest star system with a potentially habitable exoplanet and support for generational change in the average will take at least 98 people.

Using fewer crew proportionally reduce the chances of success. For example, the simulations showed that the original crew of 32 people the chance of success of the mission will fall to 0% - largely because in such a small society significantly improve the chances of incest. As a result, despite the fact that the team may have and get to Proxima b, genetically, all these people will be ill - not the best conditions for the creation of the first interstellar colony.

"Our models allow to predict with great accuracy the required minimum of people in the team for many centuries of space travel. In this study, we show how to use the principles of social engineering (eg, annual census spacecraft population, population control and other restrictions) can help create a healthy space of society and its support for a virtually unlimited amount of time ", - says Dr. Marin.

In spite of the fact that the technology and resources needed for the implementation of interstellar travel, we are not available yet (and will not be available for at least a few generations), studies such as this can play a great value for such missions in the future. If we are, of course, generally reach this level. Understanding the likelihood of success of such missions and the increase in this probability to the extent that the chance of success is virtually guaranteed to increase the chances that such projects once really get their practical implementation.

This and previous studies it is important also because in them for the first time takes into account the key biological factors (eg, reproduction), as well as the impact that these factors can be on a team that will be replaced by new generations of people who grew up on board the ship.