Science fiction writers and filmmakers have long been treating us with representations of humanity scattered throughout the universe, so if you or your relatives thought that we have long been a star species, you can be forgiven. Unfortunately, we still have to overcome many technical limitations to make this fairy tale come true. For example, the laws of physics.
Yet several privately funded initiatives - like the Tau Zero Foundation, Project Icarus, and Breakthrough Starshot - have emerged more recently, all of which hope to bring space closer to us. The August discovery of a planet the size of Earth also gave us new hope of visiting another world. And if we have to conquer Mars by the end of this century, what about the rest of the world?
Is travel to other galaxies possible? What kind of spacecraft could take us to them?
Where to fly?
Where can we go? There are more stars in the universe than grains of sand on Earth - about 70,000,000,000,000,000,000,000 - and billions of them, according to various estimates, have from one to three planets in a potentially habitable zone, the Goldilocks zone, in which it is not too hot or too cold.
At the moment, since we're just getting started, the best contender for the excursion is our closest stellar neighbor - the triple star system Alpha Centauri, 4.37 light years from Earth. This year, astronomers at the European Southern Observatory discovered an Earth-sized planet orbiting the red dwarf star Proxima Centauri. The planet, which was named Proxima b, has a mass of 1.3 Earths, but is also very closely located to Proxima Centauri: it makes a complete revolution around its sun in 11 Earth days. What particularly interested exoplanet hunters is that the planet is in the right temperature range to ensure the existence of liquid water, and it certainly is a marker of potential habitability.
The downside is that we don't know if this planet has an atmosphere. And given its proximity to Proxima Centauri - closer than Mercury's orbit to the Sun - it is likely to be exposed to dangerous solar flares and radiation. It is also tidally blocked, that is, it faces only one side of its star. In general, not everything is so smooth with this planet.
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How do we get there?
This is the $ 64 trillion question. Even at the fastest speed our current technology can afford, the path to Proxima b will take 18,000 years. And there is every chance that our earthly descendants will arrive there long before us and grab all the glory. But many bright minds - and deep pockets - are looking for ways to quickly navigate space.
Breakthrough Starshot - a $ 100 million plan sponsored by Russian billionaire Yuri Milner - plans to send a tiny unmanned probe driven by a light sail, which in turn will "inflate" a ground laser. The idea is that if the spacecraft is small enough - less than a gram - and the sail is light enough, the laser will be enough to gradually accelerate it to one-fifth the speed of light. The journey to Alpha Centauri at this speed would take 20 years.
Milner is hoping for a miniaturization of technology that will equip the tiny device with a camera, thrusters, power supply, communications and navigation equipment so that he can report on arrival at its destination, and send a couple of photos at the same time. If this plan succeeds, it could lay the foundation for the next phase of space exploration: with direct human participation.
How about a warp drive?
On TV shows like Star Trek everything seemed so simple. But today the laws of physics tell us that travel faster than light - or even at the speed of light - is impossible. NASA's Evolutionary Xenon Thruster is an ion thruster that is believed to be able to accelerate a spacecraft to a speed of 145,000 km / h using only a fraction of the fuel required for a modern rocket.
But even at this speed, we will not be able to go far from the solar system without touching our grandchildren and great-grandchildren along the way. Until we learn to warp space and time, interstellar travel will be very, very slow. Such a journey can be thought of as a final destination rather than a means to reach that point.
How to survive interstellar travel?
Warp drives and ionic propulsion sound great, but they will be of little use if our interstellar wanderers die of hunger, dehydration, or suffocate long before they leave our solar system. It's time for us to think about the ecosystem that interstellar humanity can equip between these very stars. It is necessary to move from an industrial view of reality to an ecological one.
Rachel Armstrong, professor of experimental architecture at Newcastle University in the UK, explains these words: “It's about populating spaces, not just creating iconic objects,” she says. The interior of a spacecraft or space station is today a sterile and industrial environment. Armstrong thinks we need to think about these boats from an ecological point of view - the vegetation that can be grown in them, the types of soil that we need to take with us. In the future, this will evolve into giant biomes full of organic life, instead of the cold, metal boxes we see today.
Can't you just sleep all the way?
Cryosleep, hibernation, hibernation, or stasis in one form or another is often offered as a convenient solution to the inconvenient problem of keeping people alive over a long journey that can take more than one life. The facility full of frozen bodies and heads at the Alcor Life Extension Foundation is a testament to human optimism that one day we will learn how to unfreeze people. But so far such technologies do not exist.
They also propose to send frozen embryos, which could survive all the difficulties, since they do not need food, water or breathing. But who will nurture these people when they arrive?
There is reason for optimism. From the very beginning of human existence, we have looked at the stars and projected our hopes and fears, worries and dreams onto them, says Armstrong. But since projects like Breakthrough Starshot are developing, this is no longer a dream - this is an experiment.
ILYA KHEL
