Now interstellar travel and colonization seem highly unlikely. The basic laws of physics simply prevent this from happening, and many people don't even think about it as impossible.
Others are looking for ways to break the laws of physics (or at least find a workaround) that will allow us to travel to distant stars and explore brave new worlds.
Alcubierre Warp Drive
Anything called a "warp drive" refers to Star Trek rather than NASA. The idea behind the Alcubierre warp drive is that it could be a possible solution (or at least the beginning of a search for it) to overcome the limitations of the universe that it imposes on travel faster than the speed of light.
The basics of this idea are pretty simple, and NASA uses a treadmill example to explain it. Although a person can move at a finite speed on a treadmill, the combined speed of the person and the treadmill means that the end will be closer than it would have been if traveling on a normal treadmill.
The treadmill is just a warp drive moving through space-time in a kind of expansion bubble. In front of the warp drive, spacetime is compressed. It expands behind him. In theory, this allows the engine to move passengers faster than the speed of light.
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One of the key principles associated with the expansion of spacetime is believed to have allowed the universe to expand rapidly just moments after the Big Bang. In theory, the idea should be feasible.
More difficult will be the creation of the warp drive itself, which will require a massive bag of negative energy around the craft. It is unclear whether this is possible in principle. No one knows. In addition, manipulation of space-time leads to even more tricky questions about time travel, feeding the device with negative energy, and how to turn it on and off.
The main idea came from the physicist Miguel Alcubierre, who also explained the possibilities of the warp drive as moving along the waves of space-time instead of taking the longest path. Technically, the idea does not violate the laws of travel faster than the speed of light, and even its mathematical justification speaks in favor of its possible implementation.
Interstellar Internet
It's terrible when there is no Internet on Earth and you cannot load Google Maps on your smartphone. During interstellar travel, it will be even worse without it. Going into space is only the first step, scientists are already starting to think about what to do when our manned and unmanned probes need to send messages back to Earth.
In 2008, NASA conducted the first successful tests of an interstellar version of the Internet. The project was launched back in 1998 as part of a partnership between NASA's Jet Propulsion Laboratory (JPL) and Google. Ten years later, the partners acquired the Disruption-Tolerant Networking (DTN) system, which allows images to be sent to a spacecraft 30 million kilometers away.
The technology must be able to cope with long delays and interruptions in transmissions, so it can continue transmission even if the signal is interrupted for 20 minutes. It can pass through, between, or through everything from solar flares and solar storms to pesky planets that can get in the way of data transmission without losing information.
According to Vint Cerf, one of the founders of our terrestrial Internet and a pioneer of the interstellar one, the DTN system overcomes all the problems that plague the traditional TCIP / IP protocol when it needs to work over long distances on a cosmic scale. With TCIP / IP, a Google search on Mars will take so long that the results will change while the request is being processed, and the output will be partially lost. With DTN, engineers have added something completely new - the ability to assign different domain names to different planets and choose which planet you want to search the Internet on.
What about traveling to planets we are not yet familiar with? Scientific American suggests there may be a way, albeit very expensive and time consuming, to get the Internet to Alpha Centauri. By launching a series of self-replicating von Neumann probes, a long series of relay stations can be created that can send information along the interstellar chain.
The signal born in our system will pass through the probes and reach Alpha Centauri, and vice versa. True, it will take a lot of probes, the construction and launch of which will take billions.
And in general, given that the most distant probe will have to cover its path for thousands of years, it can be assumed that during this time not only technologies will change, but also the total cost of the event. Let's not rush.
Embryonic colonization of space
One of the biggest problems with interstellar travel - and colonization in general - is the amount of time it takes to get anywhere, even with some warp drives up your sleeve.
The very task of delivering a group of settlers to their destination creates a lot of problems, so proposals are born to send not a group of colonists with a fully manned crew, but rather a ship filled with embryos - the seeds of future humanity.
Once the ship reaches the desired distance to its destination, the frozen embryos begin to grow. Then they leave children who grow up on a ship, and when they finally reach their destination, they have all the abilities to conceive a new civilization.
Obviously, all this, in turn, raises a huge heap of questions, such as who and how will carry out the growing of embryos. Robots could raise humans, but what kind of humans will robots raise? Will robots be able to understand what a child needs to grow and flourish? Will they be able to understand punishments and rewards, human emotions?
Anyway, it remains to be seen how to keep frozen embryos intact for hundreds of years and how to grow them in an artificial environment.
One proposed solution that could solve the problems of a robot nanny could be a combination of a ship with embryos and a ship with suspended animation, in which adults sleep, ready to wake up when they have to raise children.
A series of years of rearing children together with a return to hibernation could, in theory, lead to a stable population. A carefully crafted batch of embryos can provide the genetic diversity that will keep the population more or less stable once a colony is established.
An additional batch can also be included in the ship with embryos, which will further diversify the genetic fund in the future.
Von Neumann probes
Everything that we build and send into space inevitably faces its own problems, and it seems an absolutely impossible task to do something that travels millions of kilometers and does not burn, fall apart or fade away. However, the solution to this problem may have been found decades ago.
In the 1940s, physicist John von Neumann proposed a mechanical technology that would be reproduced, and although his idea had nothing to do with interstellar travel, everything inevitably came to this.
As a result, the von Neumann probes could be used, in theory, to explore vast interstellar territories. According to some researchers, the idea that all this came to our minds first is not only pompous, but also unlikely.
Scientists from the University of Edinburgh published a paper in the International Journal of Astrobiology, in which they investigated not only the possibility of creating such a technology for their own needs, but also the likelihood that someone had already done it. Based on previous calculations that showed how far a vehicle can travel using different modes of movement, scientists have studied how this equation would change when applied to self-replicating vehicles and probes.
Scientists' calculations were built around self-replicating probes that could use debris and other space materials to build junior probes. The parent and child probes would multiply so rapidly that they would cover the entire galaxy in just 10 million years - provided they were moving at 10% the speed of light.
However, this would mean that at some point we should have been visited by some such probes. Since we have not seen them, we can find a convenient explanation: either we are not technologically advanced enough to know where to look, or we are truly alone in the galaxy.
Slingshot with a black hole
The idea of using the gravity of a planet or moon for a shot, like from a slingshot, was taken into service in our solar system more than once or twice, primarily by Voyager 2, which received an additional push first from Saturn, and then from Uranus on its way out of the system …
The idea involves maneuvering the ship, which will allow it to increase (or decrease) its speed as it moves through the planet's gravitational field. Science fiction writers are especially fond of this idea.
Writer Kip Thorne put forward an idea: such a maneuver could help the device solve one of the biggest problems of interstellar travel - fuel consumption. And he suggested a more risky maneuver: acceleration with binary black holes. It will take a minute to burn fuel to pass the critical orbit from one black hole to another.
After making several revolutions around black holes, the device will pick up speed close to light. All that remains is to aim well and activate rocket thrust in order to chart a course for the stars.
Unlikely? Yes. Amazing? Definitely. Thorne emphasizes that there are many problems with such an idea, for example, accurate calculations of trajectories and time, which will not allow sending the device directly to the nearest planet, star or other body. There are also questions about returning home, but if you decide on such a maneuver, you definitely do not plan to return.
A precedent for such an idea has already been formed. In 2000, astronomers discovered 13 supernovae flying through the galaxy at an incredible speed of 9 million kilometers per hour. Scientists at the University of Illinois at Urbana-Champagne have found that these wayward stars were ejected from the galaxy by a pair of black holes, which ended up locked in a pair in the process of destruction and merging of two separate galaxies.
Starseed Launcher
When it comes to launching even self-replicating probes, there is a problem with fuel consumption.
This does not stop people from looking for new ideas on how to launch probes at interstellar distances. This process would require megatons of energy if we were using the technology we have today.
Forrest Bishop of the Institute of Atomic Engineering said he had created a method for launching interstellar probes that would require an amount of energy roughly equivalent to that of a car battery.
The theoretical Starseed Launcher will be roughly 1,000 kilometers in length and will consist primarily of wire and wire. Despite its length, this whole thing could fit in one cargo ship and be charged with a 10-volt battery.
Part of the plan includes launching probes, which are slightly larger than a microgram in mass and contain only the basic information necessary for further construction of probes in space. Billions of such probes can be launched in a series of launches.
The main point of the plan is that self-replicating probes will be able to team up with each other after launch. The launcher itself will be equipped with superconducting magnetic levitation coils that create a reverse force to provide thrust.
Bishop says that some details of the plan need work, such as countering interstellar radiation and debris with probes, but in general, construction can begin.
Special plants for space life
Once we get somewhere, we need ways to grow food and regenerate oxygen. Physicist Freeman Dyson came up with some interesting ideas on how this could be done.
In 1972, Dyson gave his famous lecture at Birkbeck College, London. At the same time, he suggested that with the help of some genetic manipulation, it would be possible to create trees that can not only grow, but also thrive on an inhospitable surface, for example, comets.
Reprogram the tree to reflect ultraviolet light and conserve water more efficiently, and the tree will not only take root and grow, but it will grow to sizes unthinkable by earth standards. In an interview, Dyson suggested that in the future, black trees may appear, both in space and on Earth.
Silicon-based trees would be more efficient, and efficiency is the key to long-term survival. Dyson emphasizes that this process will not be minute - perhaps in two hundred years we will finally figure out how to make trees grow in space.
Dyson's idea isn't all that preposterous. NASA's Institute for Advanced Concepts is an entire department dedicated to solving the problems of the future, including the task of growing stable plants on the surface of Mars. Even greenhouse plants on Mars will grow under extreme conditions, and scientists are looking at options to match plants with extremophiles, tiny microscopic organisms that survive in some of the most brutal conditions on Earth.
From alpine tomatoes, which have built-in resistance to ultraviolet light, to bacteria that survive in the coldest, hottest, and deepest corners of the globe, we may one day piece together a Martian garden. All that remains is to figure out how to put all these bricks together.
Local resource utilization
Living off the ground may be a newfangled trend on Earth, but when it comes to monthly missions in space, it becomes necessary. NASA is currently investigating, among other things, local resource utilization (ISRU).
There is not much space on the spacecraft, and building systems to use materials found in space and on other planets will be necessary for any long-term colonization or travel, especially when the destination becomes a place where it will be very difficult to get supplies, fuel, food. etc.
The first attempts to demonstrate the possibilities of using local resources were made on the slopes of Hawaiian volcanoes and during polar missions. The list of tasks includes items such as the extraction of fuel components from ash and other naturally accessible terrain.
In August 2014, NASA made a powerful announcement by revealing new toys that will travel to Mars with the next rover, which will launch in 2020. Among the tools in the arsenal of the new rover is MOXIE, an experiment on local utilization of resources in the form of Martian oxygen.
MOXIE will pick up Mars' unbreathable atmosphere (96% carbon dioxide) and split it into oxygen and carbon monoxide. The device will be able to produce 22 grams of oxygen for every hour of operation.
NASA also hopes MOXIE will be able to demonstrate something else - consistent performance without compromising productivity or efficiency. MOXIE could not only be an important step towards long-term extraterrestrial missions, but also pave the way for many potential converters of harmful gases into useful ones.
2suit
Reproduction in space can become problematic at many different levels, especially in microgravity environments. In 2009, Japanese experiments on mouse embryos showed that even when fertilization occurs under non-zero gravity, embryos that develop outside of Earth's usual gravity (or its equivalent) do not develop normally.
Problems arise when cells have to divide and perform special actions. This does not mean that fertilization does not occur: mouse embryos, conceived in space and embedded in terrestrial female mice, have successfully grown and were born without problems.
It also raises another question: how exactly does child production work in microgravity? The laws of physics, especially the fact that every action has an equal and opposite reaction, makes its mechanics a bit ridiculous. Vanna Bonta, a writer, actress and inventor, decided to take this issue seriously.
And she created 2suit: a suit in which two people can take refuge and start producing kids. They even checked him. In 2008, 2suit was tested on the so-called Vomit Comet (an airplane that makes sharp turns and creates minute conditions of zero gravity).
While Bonta suggests that honeymoons in space could be made real by her invention, the suit also has more practical uses, such as keeping body heat in an emergency.
Longshot Project
The Longshot project was developed jointly by a team of the US Naval Academy and NASA in the late 1980s. The ultimate goal of the plan was to launch something at the turn of the 21st century, namely an unmanned probe that would travel to Alpha Centauri.
It would take him 100 years to reach his goal. But before it goes live, it will need some key components that will also need to be developed.
In addition to communication lasers, durable nuclear fission reactors and an inertial laser fusion rocket engine, there were other elements.
The probe had to gain independent thinking and function, as it would be nearly impossible to communicate at interstellar distances fast enough for the information to remain relevant once it reached the destination. It also had to be incredibly durable as the probe would reach its destination in 100 years.
Longshot was going to be sent to Alpha Centauri with different tasks. Basically, he had to collect astronomical data that would allow accurate calculations of distances to billions, if not trillions, other stars. But if the nuclear reactor that powers the apparatus runs out, the mission will also stop. Longshot was an ambitious plan that never got off the ground.
But this does not mean that the idea died in the bud. In 2013, the Longshot II project literally took off the ground in the form of the student project Icarus Interstellar. Decades of technological advancements have passed since the original Longshot program was introduced, they can be applied to the new version, and the program as a whole has received an overhaul. Fuel costs were revised, the mission was cut in half, and the entire Longshot design was revised from head to toe.
The final draft will be an interesting indicator of how an unsolvable problem is changing with the addition of new technologies and information. The laws of physics remain the same, but 25 years later, Longshot has the opportunity to find a second wind and show us what the future interstellar travel should be like.