Solar sails are the first ever realistic option for future interstellar flights. Its potential has been confirmed by the successful mission of the Japanese IKAROS probe. Last year, NASA began work on a spaceship with a sail 1,000 square kilometers big, which could go three times further than Pluto, thereby leaving the Solar System.
New hopes broadened the debate about travel to the stars. Anthropologists and historians are pondering the only realistic vision of the human crew in flight to the stars: multi-generational crews. Do psychology, history, genetics, sociology and other areas of knowledge about human communities can be of some help here? In the last few years, it has been found that in order to ensure adequate genetic diversity it will be necessary to send not 150-200 colonists but at least 10,000 people. Optimally: up to 40,000!
So in my opinion, there is a new problem. While groups of 200 people can still create communities on the "everyone knows everyone" principle, it is impossible for communities of thousands of people. For co-operation to be possible and effective, it will be necessary to have a common belief in the rules applicable to all, and arising from some higher, inviolable order.
A successful interstellar expedition will, in other words, require design in the field of religion. Otherwise, we will never reach the stars.
What kinds of beliefs, rituals and religious institutions will be most needed?
In the second or third generation, when the last contact with Earth is eventually broken, crew members will experience an unimaginable psychological crisis. Some may even try to revolt and turn back the ship. This will be prevented by apocalyptic prophets who will begin to talk about the near discovery of the "super engine" and reaching the stars "in this generation," as in the Gospel of Mark. There, the higher civilization will create a kingdom of God's wisdom and happiness. (Similarly, at the beginning of Christianity, the hermits like John the Baptist gave us the hope that was strong enough for ... 2000 years!)
Certainly, many readers realize that the monstrous 40,000-passenger spaceship is a closed ecosystem with people, animals, plants and other living things down to the smallest bacteria. Perhaps some elements of animism - the belief that we come from plants and animals - will increase the concern of passengers for non-human life? Any gap or extinction of any element in the food chain can in a few years turn a starship into a ghost ship.
For Christians, especially Catholics, the good news comes from having to keep the same number of deaths and births due to drastically reduced resources. There is no place for a laxity or uncontrolled birthdays. Probably every erotic adventure will be under strict control. What is more, purity may be so appreciated that the elite engineers and pilots of the interstellar vessel will vow celibacy just as today's Catholic bishops and priests. Women's rights will be limited. Legends of brave space explorers such as Valentina Tereshkova will be regarded as dangerous heresies.
Unfortunately, not everyone is respecting the law. What to do with those who will have children against the law, or even commit worse offenses such as murder (light sin because it limits the demand for food) or theft (worst offense)? There is no way to keep and feed criminals in prisons. The "Final Cleansing" chambers will be opened once a month, and the void of the Cosmos will cleanse sinners from their sins. (Their bodies will be later retrieved and put back into the food chain).
The general picture of society and religion in the interstellar travel will necessarily diverge from the dreams of today's liberals and supporters of human rights. We will return to the dogma, the Inquisition, the forbidden books and the "eye for eye" principle. In order to survive.
Is it worth it?
The expedition can nevertheless make sense if in the middle of the cruel and archaic beliefs a prophecy of the mysterious Book of Earth is preserved, the collection of perfect laws and the full description of the world, where everyone loves and respects one another, and human thought can unfold freely. Moreover, the mysterious Book would contain a description of powerful technologies that enable mass production, communication, and civic freedom as in the 21st century on Earth. According to the prophecy, the Book will be found by the will of the gods in the penultimate generation, just as in Judaism priests "found" Deuteronomy Book in the 7th century BC.
In fact, for two generations before the end of the expedition, the dormant Artificial Intelligence of the ship will take over. Robots will bring the Book and teach travelers about the Big Bang, evolution, science, human rights, Darwin, Newton and others. Their children, the first Settlers will again remind us: or rather the people we would like and inadvertently try to be.
Photo from here
More info:
Ryan Whitwam, NASA is designing a massive solar sail to reach interstellar space, here
Sarah Feht, How Many People Does It Take to Colonize Another Star System? here
Nick Kanas, The Psychology and Sociology of Interstellar Travel, here