At some point in our lives, each of us has asked this question: how long does it take to fly to the stars? Is it possible to make such a flight in one human life, can such flights become the norm of everyday life? There are many answers to this complex question, depending on who asks. Some are simple, others are more difficult. To find a comprehensive answer, there are too many things to consider.

Unfortunately, no real estimates exist to help find such an answer, and this is frustrating for futurologists and interstellar travel enthusiasts. Like it or not, space is very big (and complex) and our technology is still limited. But if we ever decide to leave the "native nest", we will have several ways to get to the nearest star system in our galaxy.

The closest star to our Earth is the Sun, quite an “average” star according to the Hertzsprung-Russell “main sequence” scheme. This means that the star is very stable and provides enough sunlight for life to develop on our planet. We know that there are other planets orbiting stars near our solar system, and many of these stars are similar to our own.

In the future, if humanity wishes to leave the solar system, we will have huge selection stars that we could hit, and many of them may well have favorable conditions for life. But where are we going and how long will it take us to get there? Don't forget that this is all just speculation and there are no guidelines for interstellar travel at this time. Well, as Gagarin said, let's go!

Reach for the star
As already noted, the nearest star to our solar system is Proxima Centauri, and therefore has great sense start planning an interstellar mission from there. As part of the Alpha Centauri triple star system, Proxima lies 4.24 light-years (1.3 parsecs) from Earth. Alpha Centauri is, in fact, the brightest star of the three in the system, part of a tight binary system 4.37 light-years from Earth - while Proxima Centauri (the dimmest of the three) is an isolated red dwarf 0.13 light-years away from a dual system.

And while conversations about interstellar travel evoke thoughts of all sorts of "faster-than-light" (FSL) travel, ranging from warp speeds and wormholes to subspace drives, such theories are either highly fictional (like the Alcubierre drive) or exist only in science fiction. . Any mission to deep space will stretch over generations of people.

So, starting with one of the slowest forms of space travel, how long does it take to get to Proxima Centauri?

Modern methods

The question of estimating the duration of travel in space is much simpler if existing technologies and bodies in our solar system are involved in it. For example, using the technology used by the New Horizons mission, 16 hydrazine monopropellant thrusters can reach the Moon in just 8 hours and 35 minutes.

There is also the SMART-1 mission of the European Space Agency, which moved to the Moon using ion propulsion. With this revolutionary technology, a variant of which was also used by the Dawn space probe to reach Vesta, it took the SMART-1 mission a year, a month and two weeks to get to the moon.

From fast rocket spacecraft to economical ion propulsion, we have a couple of options for getting around local space - plus you can use Jupiter or Saturn as a huge gravitational slingshot. However, if we plan to go a little further, we will have to increase the power of technology and explore new opportunities.

When we talk about possible methods, we are talking about those that involve existing technologies, or those that do not yet exist but are technically feasible. Some of them, as you will see, are time-tested and confirmed, while others remain in question. In short, they represent a possible, but very time-consuming and financially expensive scenario for traveling even to the nearest star.

Ionic movement

Now the slowest and most economical form of propulsion is the ion propulsion. A few decades ago, ionic motion was considered the subject of science fiction. But in recent years, ion thruster support technologies have moved from theory to practice, and quite successfully. The SMART-1 mission of the European Space Agency is an example of a successful mission to the Moon in 13 months of spiral motion from the Earth.

SMART-1 used solar-powered ion thrusters in which electricity was collected solar panels and was used to power the Hall effect motors. It took only 82 kilograms of xenon fuel to get SMART-1 to the Moon. 1 kilogram of xenon fuel provides a delta-V of 45 m/s. This is an extremely efficient form of movement, but far from the fastest.

One of the first missions to use ion thruster technology was the Deep Space 1 mission to Comet Borrelli in 1998. The DS1 also used a xenon ion engine and used 81.5 kg of fuel. In 20 months of thrust, the DS1 reached speeds of 56,000 km/h at the time of the comet's flyby.

Ion thrusters are more economical than rocket technologies because their thrust per unit mass of propellant (specific impulse) is much higher. But ion thrusters take a long time to accelerate a spacecraft to substantial speeds, and top speeds depend on fuel support and power generation.

Therefore, if ion propulsion is used in a mission to Proxima Centauri, the engines must have a powerful source of energy (nuclear energy) and large fuel reserves (albeit less than conventional rockets). But if you start from the assumption that 81.5 kg of xenon fuel translates into 56,000 km / h (and there will be no other forms of movement), you can make calculations.

At a maximum speed of 56,000 km/h, Deep Space 1 would take 81,000 years to cover the 4.24 light-years between Earth and Proxima Centauri. In time, this is about 2700 generations of people. It's safe to say that an interplanetary ion drive would be too slow for a manned interstellar mission.

But if the ion thrusters are larger and more powerful (i.e., the ion outflow rate is much higher), if there is enough rocket fuel to last the entire 4.24 light years, the travel time will be significantly reduced. But there will still be much more than a human lifespan.

Gravity maneuver

The fastest way to space travel is by using the gravity assist. This method involves the spacecraft using the relative motion (i.e. orbit) and gravity of the planet to change path and speed. Gravity maneuvers are an extremely useful spaceflight technique, especially when using the Earth or another massive planet (like a gas giant) for acceleration.

The Mariner 10 spacecraft was the first to use this method, using the gravitational pull of Venus to accelerate towards Mercury in February 1974. In the 1980s, the Voyager 1 probe used Saturn and Jupiter for gravitational maneuvers and acceleration to 60,000 km / h, followed by an exit into interstellar space.

The Helios 2 mission, which began in 1976 and was supposed to explore the interplanetary medium between 0.3 AU. e. and 1 a. e. from the Sun, holds the record for the highest speed developed with the help of a gravitational maneuver. At that time, Helios 1 (launched in 1974) and Helios 2 held the record for the closest approach to the Sun. Helios 2 was launched by a conventional rocket and put into a highly elongated orbit.

Due to the large eccentricity (0.54) of the 190-day solar orbit, Helios 2 managed to achieve a maximum speed of over 240,000 km/h at perihelion. This orbital speed was developed due to only the gravitational attraction of the Sun. Technically, Helios 2's perihelion speed was not the result of a gravitational maneuver, but a maximum orbital speed, but the craft still holds the record for the fastest man-made object.

If Voyager 1 were moving towards the red dwarf Proxima Centauri at a constant speed of 60,000 km/h, it would take 76,000 years (or more than 2,500 generations) to cover this distance. But if the probe were to reach Helios 2's record speed - a constant speed of 240,000 km/h - it would take it 19,000 years (or more than 600 generations) to travel 4,243 light years. Substantially better, though not close to practical.

EM Drive Electromagnetic Motor

Another proposed method of interstellar travel is the resonant cavity RF drive, also known as the EM Drive. Proposed back in 2001 by Roger Scheuer, the British scientist who created Satellite Propulsion Research Ltd (SPR) to carry out the project, the engine is based on the idea that electromagnetic microwave cavities can directly convert electrical energy into thrust.

While traditional electromagnetic thrusters are designed to propel a certain mass (like ionized particles), this particular propulsion system is independent of mass response and does not emit directional radiation. In general, this engine was met with a fair amount of skepticism, largely because it violates the law of conservation of momentum, according to which the momentum of the system remains constant and cannot be created or destroyed, but only changed by force.

However, recent experiments with this technology have obviously led to positive results. In July 2014, at the 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference in Cleveland, Ohio, NASA advanced jet scientists announced they had successfully tested a new electromagnetic propulsion design.

In April 2015, scientists from NASA Eagleworks (part of the Johnson Space Center) said they had successfully tested this engine in a vacuum, which could indicate a possible application in space. In July of the same year, a group of scientists from the Space Systems Department of Dresden technological university developed her own version of the engine and observed tangible thrust.

In 2010, Professor Zhuang Yang from Northwestern Polytechnic University in Xi'an, China, began publishing a series of articles about her research into EM Drive technology. In 2012, she reported a high power input (2.5 kW) and a recorded thrust of 720 mn. It also conducted extensive testing in 2014, including internal temperature measurements with built-in thermocouples, which showed that the system worked.

NASA's prototype (which was given a power estimate of 0.4 N/kilowatt) calculated that an electromagnetically propelled spacecraft could make a trip to Pluto in less than 18 months. This is six times less than the New Horizons probe, which was moving at a speed of 58,000 km / h, required.

Sounds impressive. But even in this case, the ship on electromagnetic engines will fly to Proxima Centauri for 13,000 years. Close, but still not enough. In addition, until all the e is dotted in this technology, it is too early to talk about its use.

Nuclear thermal and nuclear electrical propulsion

Another possibility to carry out interstellar flight is to use a spacecraft equipped with nuclear engines. NASA has been exploring such options for decades. A nuclear thermal propulsion rocket could use uranium or deuterium reactors to heat the hydrogen in the reactor, turning it into ionized gas (hydrogen plasma), which would then be directed into the rocket nozzle, generating thrust.

A nuclear electric-powered missile includes the same reactor, which converts heat and energy into electricity, which then powers an electric motor. In both cases, the rocket will rely on nuclear fusion or fission for thrust, rather than the chemical propellants that all modern space agencies run on.

Compared to chemical engines, nuclear engines have undeniable advantages. First, it has a virtually unlimited energy density compared to propellant. In addition, a nuclear engine will also produce powerful thrust compared to the amount of fuel used. This will reduce the amount of fuel required, and at the same time the weight and cost of a particular device.

Although thermal nuclear engines have not yet gone into space, their prototypes have been created and tested, and even more have been proposed.

And yet, despite the advantages in fuel economy and specific impulse, the best proposed nuclear thermal engine concept has a maximum specific impulse of 5000 seconds (50 kN s/kg). Using nuclear engines powered by nuclear fission or fusion, NASA scientists could get a spacecraft to Mars in just 90 days if the Red Planet were 55,000,000 kilometers from Earth.

But if we're talking about the journey to Proxima Centauri, it would take centuries for a nuclear rocket to accelerate to a substantial fraction of the speed of light. Then it will take several decades of travel, and after them many more centuries of deceleration on the way to the goal. We are still 1000 years away from our destination. What is good for interplanetary missions is not so good for interstellar missions.

Let's say the earth ends. The sun is about to explode as an asteroid the size of Texas is approaching the planet. The major cities are populated by zombies, and in the countryside, farmers are hard at work planting corn because other crops are dying. We urgently need to leave the planet, but here's the problem - no wormholes have been found in the Saturn region, and FTL engines have not been delivered from a galaxy far, far away. The nearest star is more than four light years away. Will humanity be able to achieve it with modern technology? The answer is not so obvious.

It is unlikely that anyone would argue that a global environmental catastrophe that will endanger the existence of all life on Earth can only happen in the cinema. Mass extinctions have occurred on our planet more than once, during which up to 90% died. existing species. The Earth experienced periods of global glaciation, collided with asteroids, went through bursts of volcanic activity.

Of course, even during the most terrible disasters, life never completely disappeared. But the same cannot be said about the species that dominated at that time, which were dying out, making way for others. Who is the dominant species now? Exactly.

It is likely that the opportunity to leave your home and go to the stars in search of a new one can someday save humanity. However, it is hardly worth hoping that some cosmic benefactors will open the way to the stars for us. It is worth figuring out what our theoretical possibilities are to reach the stars on our own.

space ark

First of all, traditional chemical propulsion engines come to mind. At the moment, four terrestrial vehicles (all of which were launched back in the 1970s) have managed to reach the third space velocity, sufficient to leave the solar system forever.

The fastest of them, Voyager 1, has moved away from Earth at a distance of 130 AU in the 37 years since its launch. (astronomical units, that is, 130 distances from the Earth to the Sun). Each year, the device overcomes approximately 3.5 AU. The distance to Alpha Centauri is 4.36 light years, or 275,725 AU. At this speed, it would take the spacecraft almost 79,000 years to reach the neighboring star. To put it mildly, the wait will be long.

Photo of the Earth (above the arrow) from a distance of 6 billion kilometers, taken by Voyager 1. The spacecraft traveled this distance in 13 years.

You can find a way to fly faster, or you can just accept and fly for several thousand years. Then only the distant descendants of those who set off on the journey will reach the end point. This is precisely the idea of ​​the so-called ship of generations - the space ark, which is a closed ecosystem designed for a long journey.

In fiction, there are many different stories about the ships of generations. They were written about by Harry Harrison ("The Captive Universe"), Clifford Simak ("Generation Achieved"), Brian Aldiss ("Non-Stop"), from more modern writers - Bernard Werber ("Star Butterfly"). Quite often, the distant descendants of the first inhabitants generally forget about where they flew from and what is the purpose of their journey. Or even begin to believe that the entire existing world is reduced to a ship, as, for example, is told in Robert Heinlein's novel Stepchildren of the Universe. Another interesting plot is shown in the eighth episode of the third season of the classic Star Trek, where the crew of the Enterprise is trying to prevent a collision between a generational ship whose inhabitants have forgotten about their mission and a habitable planet to which it was heading.

The advantage of the generation ship is that this option will not require fundamentally new engines. However, it will be necessary to develop a self-sustaining ecosystem that can exist without outside supplies for many thousands of years. And do not forget that people can simply kill each other.

Conducted in the early 1990s under a closed dome, the Biosphere-2 experiment demonstrated a number of dangers that can lie in wait for people during such travel. This is the rapid division of the team into several groups hostile to each other, and the uncontrolled reproduction of pests, which caused a lack of oxygen in the air. Even ordinary wind, as it turned out, plays a crucial role - without regular swinging, trees become brittle and break.

To solve many of the problems of a long flight will help technology, immersing people in prolonged suspended animation. Then neither conflicts are terrible, nor boredom, and the life support system will require a minimum. The main thing is to provide it with energy for a long time. For example, with the help of a nuclear reactor.

Related to the theme of the ship of generations is a very interesting paradox called Wait Calculation, described by scientist Andrew Kennedy. According to this paradox, new, more quick ways movement, allowing later ships to overtake the original settlers. So it is possible that by the time of arrival, the destination will already be overpopulated by the distant descendants of the colonialists who set off later.

Installations for suspended animation in the movie "Alien".

Riding on a nuclear bomb

Suppose we are not satisfied that the descendants of our descendants will reach the stars, and we ourselves want to expose our face to the rays of an alien sun. In this case, one cannot do without a spacecraft capable of accelerating to speeds that will deliver it to a neighboring star in less than one human lifetime. And here the good old nuclear bomb will help.

The idea of ​​such a ship appeared in the late 1950s. The spacecraft was intended for flights inside the solar system, but it could well be used for interstellar travel. The principle of its operation is as follows: a powerful armored plate is installed behind the stern. From the spacecraft in the direction opposite to the flight, low-power nuclear charges are evenly ejected, which are detonated at a small (up to 100 meters) distance.

The charges are designed in such a way that most of the explosion products are directed to the tail of the spacecraft. The reflecting plate takes over the impulse and transmits it to the ship through the shock absorber system (without it, overloads will be fatal for the crew). The reflective plate is protected from damage by a flash of light, gamma radiation and high-temperature plasma by a coating of graphite lubricant, which is re-sprayed after each explosion.

The NERVA project is an example of a nuclear rocket engine.

At first glance, such a scheme seems insane, but it is quite viable. During one of the nuclear tests on Eniwetok Atoll, graphite-coated steel spheres were placed 9 meters from the center of the explosion. After testing, they were found intact, proving the effectiveness of the graphite protection for the ship. But signed in 1963, the "Treaty on the Prohibition of Tests of Nuclear Weapons in the Atmosphere, Outer Space and Under Water" put an end to this idea.

Arthur C. Clarke wanted to power the Discovery One spacecraft from 2001: A Space Odyssey with some sort of nuclear explosive propulsion. However, Stanley Kubrick asked him to abandon the idea, fearing that the audience would consider it a parody of his film Dr. Strangelove, or How I Stopped Being Afraid and Loved the Atomic Bomb.

What speed can be developed with a series of nuclear explosions? Most of the information exists about the Orion explosive project, which was developed in the late 1950s in the United States with the participation of scientists Theodore Taylor and Freeman Dyson. It was planned to accelerate the 400,000-ton ship to 3.3% of the speed of light - then the flight to the Alpha Centauri system would have lasted 133 years. However, according to current estimates, a ship can be accelerated to 10% of the speed of light in a similar way. In this case, the flight will last approximately 45 years, which will allow the crew to survive before arriving at their destination.

Of course, the construction of such a ship is a very expensive business. Dyson estimates that Orion would have cost about $3 trillion in today's dollars to build. But if we find out that a global catastrophe will threaten our planet, then it is likely that a ship with a nuclear pulse engine will become humanity's last chance for survival.

gas giant

A further development of the Orion ideas was the Daedalus unmanned spacecraft project, which was developed in the 1970s by a group of scientists from the British Interplanetary Society. The researchers set out to design an unmanned spacecraft capable of reaching one of the nearest stars during a human lifetime, Scientific research and transmit the received information to Earth. The main condition for the study was the use in the project of either existing or foreseen technologies in the near future.

The target of the flight was Barnard's Star, located at a distance of 5.91 light years from us - in the 1970s it was believed that several planets revolved around this star. We now know that there are no planets in this system. The developers of the Daedalus aimed to create an engine that could deliver the ship to its destination in a time not exceeding 50 years. As a result, they came up with the idea of ​​a two-stage apparatus.

The necessary acceleration was provided by a series of low-power nuclear explosions occurring inside a special propulsion system. Microscopic granules from a mixture of deuterium and helium-3, irradiated by a high-energy electron beam, were used as fuel. According to the project, up to 250 explosions per second should have occurred in the engine. The nozzle was a powerful magnetic field created by the ship's power plants.

According to the plan, the first stage of the ship worked for two years, accelerating the ship to 7% of the speed of light. The Daedalus then jettisoned its spent propulsion system, shedding most of its mass, and launched its second stage, which allowed it to accelerate to its final speed of 12.2% of light. This would have made it possible to reach Barnard's Star 49 years after launch. It would take another 6 years to transmit a signal to Earth.

The total mass of the Daedalus was 54,000 tons, of which 50,000 were thermonuclear fuel. However, the alleged helium-3 is extremely rare on Earth - but it is abundant in the atmospheres of gas giants. Therefore, the authors of the project intended to produce helium-3 on Jupiter using an automated plant "floating" in its atmosphere; the entire mining process would take approximately 20 years. In the same orbit of Jupiter, it was supposed to carry out the final assembly of the ship, which would then launch to another star system.

The most difficult element in the whole Daedalus concept was precisely the extraction of helium-3 from the atmosphere of Jupiter. To do this, it was necessary to fly to Jupiter (which is also not so easy and fast), establish a base on one of the satellites, build a plant, store fuel somewhere ... And this is not to mention the powerful radiation belts around the gas giant, which additionally would make life difficult for technicians and engineers.

Another problem was that the Daedalus was unable to slow down and orbit Barnard's Star. The ship and the probes it launched would simply pass by the star along a flyby trajectory, overcoming the entire system in a few days.

Now an international group of twenty scientists and engineers, operating under the auspices of the British Interplanetary Society, is working on the project of the Icarus spacecraft. "Icarus" is a kind of "remake" of Daedalus, taking into account the knowledge and technology accumulated over the past 30 years. One of the main areas of work is the search for other types of fuel that could be produced on Earth.

At the speed of light

Is it possible to accelerate a spaceship to the speed of light? This problem can be solved in several ways. The most promising of them is an annihilation engine based on antimatter. The principle of its operation is as follows: antimatter is fed into the working chamber, where it comes into contact with ordinary matter, generating a controlled explosion. The ions generated during the explosion are ejected through the engine nozzle, creating thrust. Of all the possible engines, the annihilation engine theoretically allows you to achieve the highest speeds. The interaction of matter and antimatter releases an enormous amount of energy, and the speed of the outflow of particles formed during this process is close to the speed of light.

But then there is the question of fuel extraction. Antimatter itself has long ceased to be science fiction - scientists first managed to synthesize antihydrogen back in 1995. But it is impossible to get it in sufficient quantities. Currently, antimatter can only be obtained with the help of particle accelerators. At the same time, the amount of the substance they create is measured in tiny fractions of grams, and its cost is astronomical sums. For one billionth of a gram of antimatter, scientists from the European Center for Nuclear Research (the same one where the Large Hadron Collider was created) had to spend several hundred million Swiss francs. On the other hand, the cost of production will gradually decrease and may reach much more acceptable values ​​in the future.

In addition, we will have to come up with a way to store antimatter - after all, when it comes into contact with ordinary matter, it is instantly annihilated. One solution is to cool the antimatter to ultra-low temperatures and use magnetic traps to prevent it from coming into contact with the walls of the tank. At the moment, the record storage time for antimatter is 1000 seconds. Not years, of course, but taking into account the fact that for the first time antimatter was kept for only 172 milliseconds, there is progress.

And even faster

Numerous science fiction films have taught us that you can get to other star systems much faster than in a few years. It is enough to turn on the warp drive or hyperspace drive, lean back comfortably in your chair - and in a few minutes you will be on the other side of the galaxy. The theory of relativity prohibits travel at speeds faster than the speed of light, but at the same time leaves loopholes to get around these restrictions. If we could tear or stretch space-time, we could travel faster than light without breaking any laws.

The gap in space is more commonly known as a wormhole, or wormhole. Physically, it is a tunnel connecting two distant regions of space-time. Why not use such a tunnel to travel into deep space? The fact is that the creation of such a wormhole requires the presence of two singularities at different points in the universe (this is what is beyond the event horizon of black holes - in fact, gravity in its purest form), which can break space-time, creating a tunnel that allows travelers " cut" path through hyperspace.

In addition, to maintain such a tunnel in a stable state, it is necessary that it be filled with exotic matter with negative energy - and the existence of such matter has not yet been proven. In any case, only a super-civilization can create a wormhole, which will be many thousands of years ahead of the current one in development and whose technologies, from our point of view, will look like magic.

The second, more affordable option is to "stretch" the space. In 1994, Mexican theoretical physicist Miguel Alcubierre suggested that it was possible to change its geometry by creating a wave that compresses the space in front of the ship and expands it behind. Thus, the starship will be in a "bubble" of curved space, which itself will move faster than light, thanks to which the ship will not violate fundamental physical principles. According to Alcubierre himself, .

True, the scientist himself considered that it would be impossible to implement such a technology in practice, since this would require a colossal amount of mass-energy. The first calculations gave values ​​in excess of the mass of the entire existing Universe, subsequent refinements reduced it to "only" Jupiter.

But in 2011, Harold White, who heads NASA's Eagleworks research group, made calculations that showed that if some parameters were changed, Alcubierre's bubble could require much less energy to create than previously thought, and it would no longer be necessary to recycle the entire planet. White's group is now working on the possibility of an "Alcubierre bubble" in practice.

If the experiments show results, this will be the first small step towards creating an engine that allows you to travel 10 times faster than the speed of light. Of course, a spacecraft using the Alcubierre bubble will travel many tens or even hundreds of years later. But the very prospect that this is actually possible is already breathtaking.

Flight of the Valkyrie

Almost all proposed starship designs have one significant drawback: they weigh tens of thousands of tons, and their creation requires a huge number of launches and assembly operations in orbit, which increases the cost of construction by an order of magnitude. But if humanity still learns to get a large amount of antimatter, it will have an alternative to these bulky structures.

In the 1990s, writer Charles Pelegrino and physicist Jim Powell proposed a design for a starship known as the Valkyrie. It can be described as something like a space tractor. The ship is a bundle of two annihilation engines connected to each other by a heavy-duty cable 20 kilometers long. In the center of the bundle are several compartments for the crew. The ship uses the first engine to gain speed close to light, and the second - to extinguish it when entering orbit around the star. Thanks to the use of a cable instead of a rigid structure, the mass of the ship is only 2100 tons (for comparison, the mass of the ISS is 400 tons), of which 2000 tons are engines. Theoretically, such a ship can accelerate to a speed of 92% of the speed of light.

A modified version of this ship, called the Venture Star, is shown in the movie Avatar (2011), one of whose scientific consultants was just Charles Pelegrino. Venture Star takes off on a journey, accelerating with lasers and a 16-kilometer solar sail, before braking at Alpha Centauri with an antimatter drive. On the way back, the sequence changes. The ship is capable of accelerating to 70% the speed of light and flying to Alpha Centauri in less than 7 years.

Without fuel

Both existing and future rocket engines have one problem - fuel always makes up the majority of their mass at the start. However, there are designs for starships that will not need to take fuel with them at all.

In 1960, physicist Robert Bassard proposed the concept of an engine that would use hydrogen in interstellar space as fuel for a fusion engine. Unfortunately, despite all the attractiveness of the idea (hydrogen is the most common element in the universe), it has a number of theoretical problems, ranging from the method of collecting hydrogen and ending with the calculated maximum speed, which is unlikely to exceed 12% of the light. This means that it will take at least half a century to fly to the Alpha Centauri system.

Another interesting concept is the application of a solar sail. If you build a huge super-powerful laser in Earth orbit or on the Moon, then its energy could be used to disperse a starship equipped with a giant solar sail to sufficiently high speeds. True, according to the calculations of engineers, in order to give a manned ship weighing 78,500 tons a speed of half the speed of light, a solar sail with a diameter of 1000 kilometers would be required.

Another obvious problem with a starship with a solar sail is that it needs to be slowed down somehow. One of her solutions is to release a second, smaller sail behind the starship when approaching the target. The main one will disconnect from the ship and continue its independent journey.

***

Interstellar travel is a very complex and costly undertaking. To create a ship capable of covering space distance in a relatively short period of time is one of the most ambitious tasks facing humanity in the future. Of course, this will require the efforts of several states, if not the entire planet. Now it seems like a utopia - governments have too many worries and too many ways to spend money. A flight to Mars is millions of times easier than a flight to Alpha Centauri - and yet, it is unlikely that anyone will now dare to name the year when it will still take place.

Either a global danger threatening the entire planet, or the creation of a single planetary civilization that can overcome internal squabbles and want to leave its cradle can revive work in this direction. The time for this has not yet come - but this does not mean that it will never come.

Is it possible to fly to a star? Well, at least the nearest one?

The development of science and technology resembles a wave. Well no. Again yes, and again no. But in the end anyway Yes!

Is it possible to fly to the stars?

At least to the next one?

NO IMPOSSIBLE. Never! Billions and billions of tons of fuel are needed. And just an unimaginable amount of fuel to deliver it all into orbit. Impossible.

YES POSSIBLE. Only 17 grams of antimatter is needed.

NO IMPOSSIBLE. 17 grams of antimatter is worth $170 trillion!

YES POSSIBLE. The price of antimatter is falling all the time. In 2006, according to NASA, 1 gram is already worth 25 billion dollars.

NO IMPOSSIBLE. Even if you produce 100 grams of antimatter and learn how to store it for years and not 1000 seconds as it is now. Does not matter. 17 grams of antimatter is about 22 atomic bombs that were dropped on Hiroshima. No one will allow such a risk at launch. After all, a trap for antimatter, no matter how reliable it is in itself, when it is destroyed, antimatter will interact with matter. And tragedy is unavoidable.

YES IS POSSIBLE. NASA, though in the most “crazy” institute, ordered an antimatter assembler http://www.membrana.ru/particle/2946. After all, there is antimatter in the solar universe. And the calculated engines are capable of reaching speeds of 70% of the speed of light http://ria.ru/science/20120515/649749893.html. So the flight to the stars is slowly passing from the hands of fundamental science into the hands of applied science.

I want to emphasize one unrecorded point. Many say how to fly? What fuel is needed to fly to a star in a certain time? (for example, to α - Centauri, the distance is approximately 4.365 light years).

I will try to answer these questions from my point of view. How to fly? I can say that the most suitable starship at the moment is our planet Earth. On Earth, there is everything that a person and the world around him need to survive on a stellar expedition. What fuel is needed to fly to a star in a certain time?

My answer will be like this. The fuel for the starship will be solar energy and heat. The sun is the most powerful and durable source of energy at any given time. While the Sun burns and provides our Earth with warm rays, our starship continues to surf the cosmic expanses led by the Sun.

I have made approximate calculations of our space expedition. How long will we fly in our starship before running out of solar fuel. Approximately 4.57 billion years remain for the Sun to burn. During this time, we will fly approximately 18 orbits on Earth around the center of our Milky Way galaxy. The distance traveled around the center of galaxies, taking into account the lifetime of the Sun and the speed of rotation of the Sun around the center of the galaxy, is approximately equal to 220 km/s. Our path of the stellar expedition will be 3.17 10 ^ 19 km = 3.3514 10 ^ 6 light years. During our space expedition, the star ship (planet Earth) would have reached the M31 galaxy (Andromeda Nebula) close to us. We and our Earth fly 19,008,000 km every day. We have been traveling through outer space all our lives on our ship called Earth ...

Thank you!!!

Will not work. Interstellar distances, as they were, and will be, despite the fact that we, as it were, will already be in the Andromeda galaxy. After all, they will change little in that component of the Galaxy in which we now live. But the most important thing here is that in 4.5 billion years we will hopefully be flying for the weekend to admire the quasars. And we will no longer need it in principle

Nicholas! Your answer essentially coincides with Folko's suggestion. We sit on the Earth and travel through the Galaxy together with it. However, in my opinion, this option is somewhat reckless. Firstly, moving along with the Sun through the Galaxy, we do not have much chance of getting close to other stars. This means that we will not be able to study them up close. If such a chance falls, then we will have to be very tight. It is better to keep your home away from other stars.

In this regard, it just becomes clear that staying at home, so to speak, "fixing yourself better" in your solar system, is not the best strategy. Little can happen to our Earth. So it’s better to think in advance about finding a new place to live, just in case. Of course, I understand astronomers that it is better to sit next to a telescope and build models based on very indirect data. However, this way, to put it mildly, is not very informative. It is better to get information about other objects outside the solar system directly on the spot. I am sure that it will be possible to see enough of "miracles" such that you will never see from the Earth. It is in this regard that the expeditions of the Americans to the moon are primarily suspicious. They didn't discover anything new. This is what makes me doubt it.

Viktor Mikhailovich, in fact, I had in mind a little different. I believe that first you need to get comfortable within the solar system. In parallel with this, I think humanity will reach physical and then technical ideas that will help us realize the intersection of interstellar distances within reasonable time limits. Those. I think everything has its time.

And as for the plan for a spare pallet for life, there are both Mars and Venus and satellites of the planets of the giants, Mercury is also suitable.

Seryozha! At the expense of everything in its time - this is somewhat not about that. Until we have invented a way to travel in space or in some other way with speeds close to or greater than the speed of light, then we will settle down, as best we can, in the solar system. But as soon as there is a way to fly to the stars, at least the nearest ones, then there will immediately be enthusiasts to do it. So, "We are waiting until the first star..." Nikolai, on the other hand, proposes to fly by inertia on the Earth itself. Here we are in agreement. So we won’t fly to anything, and if we fly, it would be better if we didn’t fly.

As for Mars, Venus or Mercury, I did not understand. We won't be able to live there, even on Mars. Mars still needs to be able to turn into a habitable planet. And about Venus and Mercury - it's really bad here. If we learn how to terraform planets, then I think we will be able to fly to other stars as well. These tasks now appear to be of comparable complexity.

It takes 5 years to fly to some star, and in the meantime 50-100 years will pass on the earth. The times when people were ready, like Bykov from the Strugatsky epic, to do such a thing, have passed (probably). But to fly in such a way as to be in time there, but then it is easier to return to the familiar world. Moreover, it is necessary to fly to where there are planets, preferably in the green zone and preferably stone ones, it would be nice with an oxygen atmosphere. And not the fact that there are such within a radius of 30 pc. It just makes sense to fly just for the sake of just flying a little. You will achieve little scientific results from this, everything that the mission there learns about the star after the time during which the mission flies there and the signal comes from there, these data will become obsolete.

As for Mercury, you can live there in the polar regions, there are quite a few zones where there is water and relatively low temperatures. Venus is balloons or something similar. Mars - construction in the polar zones of domed cities, why not? I believe that the technology of building covered large residential facilities in the next 50-100 years will reach a level where it will be possible to afford it.

Seryozha! I understand that you are reasoning within the framework of physics known today. If you rely on SRT, then it will be so, as you say. Fly 5 years in proper time - it will be tens and hundreds of years in the Earth system, depending on the proximity to the speed of light. However, SRT is most likely not a general theory. If there are additional dimensions, then the speed of light will have a status like the speed of sound in hydrodynamics. Therefore, I think it is necessary to look at the problem more broadly, especially since evidence for the presence of additional dimensions, although not directly obtained yet, is becoming an increasingly important aspect of all research in physics. We need to work in this direction.

If we manage to overcome the threshold of the speed of light, then the next speed limit may be far beyond its limit. And this means that it is possible to get to the nearest stars in hours and minutes. And this is a different situation. In the meantime, of course, we are limited in building models of flight to the nearest stars.

As for Mercury, humanity as a whole will not live there. And there is little water, and space is very limited, and besides the temperature, the radiation is also gigantic. You can also live in the sulfur clouds of Venus, if only you get everything you need from somewhere. But if there is no Earth, then there will be nowhere to receive it from. The same with Mars. Three problems everywhere except the Earth (for now!), - oxygen, water, radiation.

It is all the more interesting to build a ship with an engine powered by antimatter. Since the design characteristics do not interfere with creating an engine with a speed of 70% of the speed of light and at this speed, one can study the paradoxes of time and space in practice. But will 70% be enough to manifest the deep laws of physics?

It is all the more interesting to build a ship with an engine powered by antimatter.

There is no such engine even in the project. But even if there was, then how to test it if there is no fuel. And the conjectures of some physicists that antimatter can be obtained in grams are just conjectures. Not a single problem, in fact, has been technically solved regarding its creation, retention and use.

Let me remind you that the much simpler problem of creating nuclear power still requires enormous costs. The nuclear rocket engine was created, but it never flew in the form of a stand. More difficult than atomic installations, but still much easier, the problem of confining ordinary high-temperature plasma than the problem of confining antimatter has not been solved. To this is added a whole bunch of unresolved problems associated with the implementation of movement at a speed close to the speed of light in a space filled with various particles and dust. So the construction of such a ship is a hopeless project. The problem must be solved in a fundamentally different way.

I found information that Skolkovo accepted an application for " perpetual motion machine". Well, it would be okay to call it the "Installation for obtaining vacuum energy." But no - "perpetual motion machine." http://lenta.ru/news/2012/10/22/inf/ So really not everything that individual physicists say there is evidence-based information.

The idea of ​​nanoships is interesting in itself. But there is an insurmountable problem with the engines. For example, a rocket launched from Earth orbit to Mars on chemical fuel, even without payload, cannot be small. And other motors are also not suitable. By dimensions. All meaning is lost. Antimatter is the only contender in this case.

If you build a chain of antimatter collector - its storage - nanospace ships, then the exploration of the Near Space would go at a different pace. But apparently this is just an interesting idea.

These paradoxes can be studied on ground-based accelerators, including the LHC, at speeds of 0.999999 the speed of light. This topic is about the feasibility of space travel at such speeds. As Folko already said, important issue will transmission of received research information to Earth. For a nanoship with its nanoantenna and nanoenergy, radio transmission is unlikely to be effective. Another way is to send a capsule with information to Earth at a speed of 0.7 of the speed of light, but this will take even longer.

Sol writes:

study... at speeds of 0.999999 the speed of light.

Another point of view seems reasonable and optimistic:

zhvictorm writes:

Till we didn't invent a way to travel through space or somehow else with speeds... greater than the speed of light. But as soon as there is a way fly to the stars...

Ivan writes:

If only such speeds are available to the terrestrial civilization, or, moreover, 70% of the speed of light, then one can really only talk about the feasibility of space travel.

Yes. More precisely, in such a situation they generally inappropriate(long distances). Need to find new physical ideas, explaining the structure of space-time at a deeper level, and hence the possibility of circumventing the limitation associated with the speed of light.

In general, the idea space nanoships- interesting!

For the study and possible settlement of the space around the nearest star, both the speed of 70% of the speed of light and the use of a natural resource in the form of fuel will not hurt.

They won’t interfere, but where can I get them? Not only do we not yet know how to achieve 70% of the speed of light, but we also do not know how to carry out active navigation in the solar system at speeds of 10-20 km/s.

It's just about fuel. Antimatter is still pure fantasy, especially the cost of this substance, expressed in dollars. What they can do now is maybe a few hundred atoms of antihelium and that's it. However, they exist for very small fractions of a second. So it's all fantasy. I think that we will have to get to the stars in completely different ways, about which we still do not know anything.

Of course projects while they look more like a level not even K.E. Tsiolkovsky, and N.I. Kibalchich. However, I do not see any fundamental, fundamental obstacles to further work in this area. Also, I'm talking about from FUNDAMENTAL science antimatter smoothly transitions to APPLIED. And, given the cost of modern experimental physics, the more PRACTICAL applications will have antimatter the better for space exploration. The figure of 70% of the speed of light is of course calculated. But the calculations themselves are based on the current level of knowledge.

As for the thoughts of Prokofiev E.P. then his proposals on the combination of nanotechnologies and antimatter technologies look especially interesting and promising. Creation of nanoships with engines powered by antimatter. Then, already the current amount of antimatter will quickly fly to Uranus. Given that he is a member of the Nano Society, he probably knows what he is talking about.

Folk writes:

Why do we need to fly to the stars? It seems to me much more important to gain a foothold here in the "captivity" of the Sun.

This is a question of a wise man, a sane and rational person. Do you think that the founder of Moscow State University is hopelessly outdated?

“The abyss of Stars is full! There is no number of stars, the abyss of the bottom! M.V. Lomonosov.

Of course, Moscow provides serious prospects, but there is such a provincial village Veshkayma v Ulyanovsk region. In this wonderful place lived a dreamy boy who made a homemade telescope and watched the distant stars with spiritual awe. Teachers and parents tried to ban night astronomical observations, classmates did not understand, but everyone felt the unusual purposefulness of this boy and ... were proud, telling that such an "eccentric" lives next to them.

An aspiring musician came to the famous composer with the words: "I want to learn how to play like you." The maestro is surprised: "Just like me? At your age, I dreamed of creating divine music and playing like God ... and achieved so little. What will become of you if you set yourself such a mundane goal?"

Despite significant advances in space, the cosmos is still largely a mystery to earthlings. Having literally left his mark on the Moon, man still remains at an unattainable distance from the closest stars, such as Alpha Centauri. However, the situation may change soon.

Dimensions of Alpha Centauri and the Sun. Kaptsov Ruslan | Wikimedia Commons

Famous English theoretical physicist Stephen Hawking and Russian billionaire Yuri Milner on April 12 to study the potential habitable zone of the Alpha Centauri system.

The path to the nearest star to Earth is more than 4.3 light years to overcome it for nanodevices that will be launched as part of the project breakthrough starshot, it will take about 20 years. However, the practical implementation of the project is unlikely to begin in the coming years, so for now it remains only to study the theoretical part of the issue. Yes, scientific paper live science presents five of the most curious facts about Alpha Centauri.

1. Alpha Centauri is not a star.

According to NASA classification, Alpha Centauri is not a star, but a star system. It consists of three stars. Proxima Centauri is closest to Earth, but it is also the dimmest of the stellar trinity. The other two stars - Alpha Centauri A and B - are a double star, visually much brighter. However, they are not located directly next to each other.

For comparison, the Earth is located at a distance of about 150 million kilometers from the Sun. The distance between Alpha Centauri A and B is about 23 times greater than this value and is roughly comparable to the distance from the Sun to Uranus.

2. The distance from Earth to Alpha Centauri is huge

Proxima Centauri is located at a distance of 39,900,000,000,000 kilometers from Earth, which is approximately equal to 4.22 light years. That is, if humanity had spacecraft capable of moving at the speed of light, the journey to the nearest star took 4.22 years, and to Alpha Centauri A and B - about 4.35 years.

3. There is a planet in the Alpha Centauri system

In 2012, scientists announced the discovery in the Alpha Centauri system of a planet comparable in size and mass to Earth. It orbits Alpha Centauri B.

It is assumed that the surface of this planet, which is called Alpha Centauri Bb, is covered with molten lava, since it is located very close to the star itself - at a distance of about 6 million kilometers. The presence of this planet gives scientists hope that another planet may exist in the Alpha Centauri system in the so-called "habitable zone", with liquid water on the surface and clouds in the atmosphere.

4. Alpha Centauri - a bright "old lady"

Alpha Centauri A is the fourth brightest star in the night sky. It belongs to the category of yellow stars, like the Sun, while exceeding it in size by about 25%. Alpha Centauri B is an orange star, slightly smaller than the Sun. Proxima Centauri, on the contrary, is seven times smaller than the Sun and belongs to the category of a red dwarf.

Moreover, all three stars are older than the Sun. If the age of our star is about 4.6 billion years, then the stars of the Alpha Centauri system are about 4.85 billion years old.

5. The southern hemisphere knows better

Alpha Centauri is not visible in most of the northern hemisphere, namely, those who live above 29 degrees north latitude.

But observers in the Southern Hemisphere can see it with the naked eye in the night sky. You just need to find the constellation of the Southern Cross in the sky, and then look to the left along the horizontal part of the cross until a bright twinkling point appears. In the summer, residents of the US states of Florida and Texas, as well as parts of Mexico, can observe Alpha Centauri directly above the horizon.

> > How long will it take to travel to the nearest star?

Find out, how long to fly to the nearest star: the closest star to Earth after the Sun, distance to Proxima Centauri, description of launches, new technologies.

Modern humanity spends efforts on the development of the native solar system. But will we be able to go on exploration to a neighboring star? And how much time to travel to the nearest star? This can be answered very simply or delved into the realm of science fiction.

Speaking from the position of today's technologies, the real numbers will scare off enthusiasts and dreamers. Let's not forget that space is incredibly vast and our resources are still limited.

The closest star to the planet Earth is. This is the middle representative of the main sequence. But there are a lot of neighbors around us, so we can already create a whole route map. But how long does it take to get there?

Which star is the closest

The closest star to the Earth is Proxima Centauri, so for now, you should base your calculations on the basis of its characteristics. It is part of the Alpha Centauri triple system and is distant from us at a distance of 4.24 light years. It is an isolated red dwarf located 0.13 light-years from the binary star.

As soon as the topic of interstellar travel pops up, everyone immediately thinks about the speed of deformation and jumping into wormholes. But all of them are either unattainable or absolutely impossible. Unfortunately, any long-range mission will take more than one generation. Let's start with the slowest methods.

How long will it take to travel to the nearest star today

It is easy to make calculations based on the existing technique and the limits of our system. For example, the New Horizons mission used 16 hydrazine monopropellant engines. It took 8 hours and 35 minutes to get to . But the SMART-1 mission was based on ion engines and traveled to the earth's satellite for 13 months and two weeks.

So we have several vehicle options. In addition, it can be used or as a giant gravitational slingshot. But if we plan to go this far, we need to check all possible options.

Now we are talking not only about existing technologies, but also about those that, in theory, can be created. Some of them have already been tested on missions, while others have only been drawn up in the form of drawings.

Ionic strength

This is the slowest way, but economical. A few decades ago, the ion engine was considered fantastic. But now it is used in many devices. For example, the SMART-1 mission got to the Moon with its help. In this case, the option with solar panels was used. Thus, he spent only 82 kg of xenon fuel. Here we win in terms of efficiency, but definitely not in terms of speed.

For the first time, an ion engine was used for Deep Space 1, flying to (1998). The device used the same type of engine as the SMART-1, using only 81.5 kg of propellant. For 20 months of travel, he managed to accelerate to 56,000 km / h.

The ion type is considered much more economical than rocket technology because the thrust per unit mass of the explosive is much higher. But it takes a long time to accelerate. If they were planned to be used to travel from Earth to Proxima Centauri, then a lot of rocket fuel would be needed. Although you can take the previous indicators as a basis. So, if the device moves at a speed of 56,000 km / h, then it will cover a distance of 4.24 light years in 2,700 human generations. So it is unlikely to be used for a manned flight mission.

Of course, if you fill it with a huge amount of fuel, you can increase the speed. But the arrival time will still take a standard human life.

Help from gravity

This is a popular method as it allows you to use orbit and planetary gravity to change route and speed. It is often used to travel to the gas giants to increase speed. Mariner 10 tried this for the first time. He relied on the gravity of Venus to reach (February 1974). In the 80s, Voyager 1 used the moons of Saturn and Jupiter to reach 60,000 km/h and go into interstellar space.

But the record holder for the speed obtained using gravity was the Helios-2 mission, which went to study the interplanetary medium in 1976.

Due to the large eccentricity of the 190-day orbit, the device was able to accelerate to 240,000 km / h. For this, only solar gravity was used.

Well, if we send Voyager 1 at 60,000 km/h, we'll have to wait 76,000 years. For Helios 2, it would have taken 19,000 years. It's faster, but not enough.

Electromagnetic drive

There is another way - radio frequency resonant motor (EmDrive), proposed by Roger Shavir in 2001. It is based on the fact that electromagnetic microwave resonators can transform electrical energy into traction.

While conventional electromagnetic motors are designed to move a specific type of mass, this one does not use a reaction mass and does not produce directional radiation. This view has been met with a great deal of skepticism because it violates the law of conservation of momentum: a system of momentum within a system remains constant and only changes under the action of a force.

But recent experiments are slowly poaching supporters. In April 2015, researchers announced that they had successfully tested the disk in a vacuum (meaning it could function in space). In July, they had already built their own version of the engine and showed noticeable thrust.

In 2010, Huang Yang took over a series of articles. She finished her final work in 2012, where she reported higher input power (2.5kW) and tested thrust conditions (720mN). In 2014, she also added some details about the use of internal temperature changes, which confirmed the operability of the system.

If you believe the calculations, a device with such an engine can fly to Pluto in 18 months. These are important results, because they represent 1/6 of the time that New Horizons spent. Sounds good, but even so, it would take 13,000 years to travel to Proxima Centauri. Moreover, we still do not have 100% confidence in its effectiveness, so there is no point in starting development.

Nuclear thermal and electrical equipment

NASA has been researching nuclear propulsion for decades now. Reactors use uranium or deuterium to heat liquid hydrogen, transforming it into ionized hydrogen gas (plasma). It is then sent through the rocket's nozzle to form thrust.

A nuclear-rocket power plant contains the same original reactor that transforms heat and energy into electrical energy. In both cases, the rocket relies on nuclear fission or fusion to generate propulsion systems.

When compared with chemical engines, we get a number of advantages. Let's start with unlimited energy density. In addition, higher traction is guaranteed. This would reduce the level of fuel consumption, and therefore, would reduce the mass of the launch and the cost of the missions.

So far, there has not been a single launched nuclear-thermal engine. But there are many concepts. They range from traditional solid structures to those based on liquid or gaseous cores. Despite all these advantages, the most sophisticated concept achieves a maximum specific impulse of 5000 seconds. If you use a similar engine to travel to when the planet is 55,000,000 km away (the "opposition" position), then it will take 90 days.

But, if we send it to Proxima Centauri, then it will take centuries for acceleration to move to the speed of light. After that, it would take several decades to travel and another century to slow down. In general, the period is reduced to a thousand years. Great for interplanetary travel, but still not good for interstellar travel.

In theory

You probably already realized that modern technology is rather slow to overcome such long distances. If we want to do this in one generation, then we need to come up with something breakthrough. And if wormholes are still gathering dust in the pages of science fiction books, then we have a few real ideas.

Nuclear impulse movement

This idea was developed by Stanislav Ulam back in 1946. The project started in 1958 and continued until 1963 under the name Orion.

Orion planned to use the power of impulsive nuclear explosions to create a strong push with a high specific impulse. That is, we have a large spacecraft with a huge stock of thermonuclear warheads. During the drop, we use a detonation wave on the rear platform ("pusher"). After each explosion, the pusher pad absorbs the force and converts thrust into momentum.

Naturally, in the modern world, the method lacks elegance, but it guarantees the necessary impulse. According to preliminary estimates, in this case it is possible to reach 5% of the speed of light (5.4 x 10 7 km/h). But the design suffers from flaws. Let's start with the fact that such a ship would be very expensive, and it would weigh 400,000-4,000,000 tons. Moreover, ¾ of the weight is represented by nuclear bombs (each of them reaches 1 metric ton).

The total launch cost would have risen to $367 billion at the time ($2.5 trillion today). There is also a problem with the generated radiation and nuclear waste. It is believed that it was because of this that the project was stopped in 1963.

nuclear fusion

Here, thermonuclear reactions are used, due to which thrust is created. Energy is produced when deuterium/helium-3 pellets are ignited in the reaction chamber via inertial confinement using electron beams. Such a reactor would detonate 250 pellets per second, creating a high-energy plasma.

In such a development, fuel is saved and a special momentum is created. Achievable speed - 10600 km (significantly faster than standard missiles). Recently, more and more people are interested in this technology.

In 1973-1978. The British Interplanetary Society has created a feasibility study - Project Daedalus. It relied on current knowledge of fusion technology and the availability of a two-stage unmanned probe that could reach Barnard's Star (5.9 light years) in a single lifetime.

The first stage will work for 2.05 years and will accelerate the ship to 7.1% of the speed of light. Then it will be dropped and the engine will start, increasing the speed to 12% in 1.8 years. After that, the engine of the second stage will stop and the ship will travel for 46 years.

In general, the ship will reach the star in 50 years. If you send it to Proxima Centauri, then the time will be reduced to 36 years. But this technology, too, has encountered obstacles. Let's start with the fact that helium-3 will have to be mined on the moon. And the reaction that activates the movement of the spacecraft requires that the energy released exceed the energy used to launch. And while the testing went well, we still don't have the kind of power we need to power an interstellar spacecraft.

Well, let's not forget the money. A single launch of a 30 megaton rocket costs NASA $5 billion. So the Daedalus project would weigh 60,000 megatons. In addition, a new type of fusion reactor will be needed, which also does not fit into the budget.

ramjet engine

This idea was proposed by Robert Bussard in 1960. You can think of it as an improved form of nuclear fusion. It uses magnetic fields to compress hydrogen fuel until the fusion is activated. But here a huge electromagnetic funnel is created, which “pulls out” hydrogen from the interstellar medium and dumps it into the reactor as fuel.

The ship will pick up speed, and cause the compressed magnetic field to reach the fusion process. After that, it will redirect the energy in the form of exhaust gases through the engine nozzle and accelerate the movement. Without the use of other fuel, you can reach 4% of the speed of light and go anywhere in the galaxy.

But this scheme has a huge bunch of shortcomings. The problem of resistance immediately arises. The ship needs to increase its speed in order to accumulate fuel. But it encounters a huge amount of hydrogen, so it can slow down, especially when it gets into dense regions. In addition, it is very difficult to find deuterium and tritium in space. But this concept is often used in science fiction. The most popular example is Star Trek.

laser sail

In order to save money, solar sails have been used for a very long time to move vehicles around the solar system. They are light and cheap, besides they do not require fuel. The sail uses the radiation pressure from the stars.

But in order to use such a structure for interstellar travel, it is necessary to control it with focused energy beams (lasers and microwaves). Only in this way can it be accelerated to a mark close to the speed of light. This concept was developed by Robert Ford in 1984.

The bottom line is that all the benefits of a solar sail are retained. And although the laser will take time to accelerate, the limit is only the speed of light. A 2000 study showed that a laser sail could reach half the speed of light in less than 10 years. If the size of the sail is 320 km, then it will reach its destination in 12 years. And if you increase it to 954 km, then in 9 years.

But for its production it is necessary to use advanced composites to avoid melting. Do not forget that it must reach a huge size, so the price will be high. In addition, you will have to spend money on creating a powerful laser that could provide control at such high speeds. The laser consumes a direct current of 17,000 terawatts. For you to understand, this is the amount of energy that the entire planet consumes in one day.

antimatter

This is a material represented by antiparticles, which reach the same mass as ordinary ones, but have the opposite charge. Such a mechanism would use the interaction between matter and antimatter to generate energy and create thrust.

In general, particles of hydrogen and antihydrogen are involved in such an engine. Moreover, in such a reaction, the same amount of energy is released as in a thermonuclear bomb, as well as a wave of subatomic particles moving at 1/3 of the speed of light.

The advantage of this technology is that most of the mass is converted into energy, which will create a higher energy density and specific impulse. As a result, we will get the fastest and most economical spacecraft. If a conventional rocket uses tons of chemical fuel, then an antimatter engine spends only a few milligrams on the same actions. Such technology would be a great option for a trip to Mars, but it cannot be applied to another star because the amount of fuel is growing exponentially (along with costs).

A two-stage antimatter rocket would require 900,000 tons of propellant for a 40-year flight. The difficulty is that to extract 1 gram of antimatter, 25 million billion kilowatt-hours of energy and more than a trillion dollars will be needed. Right now we only have 20 nanograms. But such a vessel is capable of accelerating to half the speed of light and flying to the star Proxima Centauri in the constellation Centaurus in 8 years. But it weighs 400 Mt and spends 170 tons of antimatter.

As a solution to the problem, they proposed the development of the “Vacuum of an anti-material rocket interstellar research system”. Here one could use large lasers that create antimatter particles when fired in empty space.

The idea is also based on the use of fuel from space. But again there is a moment of high cost. In addition, humanity simply cannot create such an amount of antimatter. There is also the risk of radiation, as matter-antimatter annihilation can create explosions of high-energy gamma rays. It will be necessary not only to protect the crew with special screens, but also to equip the engines. Therefore, the tool is inferior in practicality.

Bubble Alcubierre

In 1994, it was proposed by the Mexican physicist Miguel Alcubierre. He wanted to create a tool that would not violate the special theory of relativity. He proposes stretching the fabric of space-time in a wave. Theoretically, this will lead to the fact that the distance in front of the object will be reduced, and behind it will expand.

A ship caught inside the wave will be able to move beyond relativistic speeds. The ship itself in the "warp bubble" will not move, so the rules of space-time do not apply.

If we talk about speed, then this is "faster than light", but in the sense that the ship will reach its destination faster than a beam of light that has gone beyond the bubble. Calculations show that it will arrive at its destination in 4 years. If you think in theory, then this is the fastest method.

But this scheme does not take into account quantum mechanics and is technically nullified by the Theory of Everything. Calculations of the amount of energy required also showed that an extremely huge power would be required. And we haven't touched on security issues yet.

However, in 2012 there was talk that this method was being tested. The scientists claimed to have built an interferometer that could detect distortions in space. In 2013, an experiment was conducted at the Jet Propulsion Laboratory in a vacuum. In conclusion, the results were inconclusive. If you go deeper, you can understand that this scheme violates one or more of the fundamental laws of nature.

What follows from this? If you were hoping to make a round trip to a star, then the chances are incredibly low. But, if humanity decided to build a space ark and send people on an age-old journey, then everything is possible. Of course, this is just talk for now. But scientists would be more active in such technologies if our planet or system were in real danger. Then a trip to another star would be a matter of survival.

So far, we can only surf and explore the expanses of our native system, hoping that in the future there will be new way, which made it possible to realize interstellar transits.