How to get to Alpha Centauri - technical details. How long will it take to travel to the nearest star? Is it possible to fly to Alpha Centauri?

At some point in our lives, each of us 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 is asking. Some are simple, others are more complex. There is too much to take into account to find a complete answer.

Unfortunately, there are no real estimates that would help find such an answer, and this frustrates futurists and interstellar travel enthusiasts. Whether we like it or not, space is very large (and complex) and our technology is still limited. But if we ever decide to leave our “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.

Part one: modern methods

In the future, if humanity wishes to leave the solar system, we will have a huge choice of stars to go to, and many of them may well have conditions favorable to life. But where will we go and how long will it take us to get there? Keep in mind 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 a star

As noted, the closest star to our solar system is Proxima Centauri, and so it makes a lot of sense to start planning an interstellar mission there. Part of the triple star system Alpha Centauri, Proxima is 4.24 light years (1.3 parsecs) from Earth. Alpha Centauri is essentially the brightest star of the three in the system, part of a close binary system 4.37 light-years from Earth - while Proxima Centauri (the faintest of the three) is an isolated red dwarf at 0.13 light-years from the dual system.

And while talk of interstellar travel brings to mind all sorts of "faster than the speed of light" (FSL) travel, 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 into deep space will last for generations.

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

Modern methods

The question of estimating the duration of travel in space is much simpler if it involves existing technologies and bodies in our Solar System. For example, using the technology used by the New Horizons mission, 16 hydrazine monopropellant engines could get to the Moon in just 8 hours and 35 minutes.

There's also the European Space Agency's SMART-1 mission, which propelled itself toward the Moon using ion propulsion. With this revolutionary technology, a version of which was also used by the Dawn space probe to reach Vesta, the SMART-1 mission took a year, a month and two weeks to reach the Moon.

From fast rocket spacecraft to fuel-efficient 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 possibilities.

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 still remain in question. In short, they present a possible, but very time-consuming and financially expensive scenario for traveling even to the nearest star.

Ionic movement

Currently, the slowest and most economical form of propulsion is the ion propulsion. A few decades ago, ion propulsion was considered the stuff of science fiction. But in recent years, ion engine support technologies have moved from theory to practice, and very successfully. The European Space Agency's SMART-1 mission is an example of a successful mission to the Moon in a 13-month spiral from Earth.

SMART-1 used solar-powered ion engines, in which electrical energy was collected by solar panels and used to power Hall effect engines. To deliver SMART-1 to the Moon, only 82 kilograms of xenon fuel were required. 1 kilogram of xenon fuel provides a delta-V of 45 m/s. This is an extremely efficient form of movement, but it is far from the fastest.

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

Ion engines are more economical than rocket technology because their thrust per unit mass of propellant (specific impulse) is much higher. But ion engines take a long time to accelerate a spacecraft to significant speeds, and the maximum speed depends on the fuel support and the amount of electricity generated.

Therefore, if ion propulsion were to be used in a mission to Proxima Centauri, the engines would need to have a powerful power source (nuclear power) and large fuel reserves (albeit less than conventional rockets). But if we 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), calculations can be made.

At a top speed of 56,000 km/h, it would take Deep Space 1 81,000 years to travel the 4.24 light years between Earth and Proxima Centauri. In time, this is about 2,700 generations of people. It's safe to say that interplanetary ion propulsion will be too slow for a manned interstellar mission.

But if the ion engines are larger and more powerful (that is, the rate of ion outflow will be 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 significantly more human life left.

Gravity maneuver

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

The Mariner 10 spacecraft was the first to use this method, using the gravitational pull of Venus to propel itself toward Mercury in February 1974. In the 1980s, the Voyager 1 probe used Saturn and Jupiter for gravity maneuvers and acceleration to 60,000 km/h before entering interstellar space.

The Helios 2 mission, which began in 1976 and was intended 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 using 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 placed into a highly elongated orbit.

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

If Voyager 1 were moving towards the red dwarf star 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 reached Helios 2's record speed - a sustained speed of 240,000 km/h - it would take 19,000 years (or more than 600 generations) to travel 4,243 light years. Significantly better, although not nearly practical.

Electromagnetic motor EM Drive

Another proposed method for interstellar travel is the RF Resonant Cavity Engine, also known as EM Drive. Proposed back in 2001 by Roger Scheuer, a British scientist who created Satellite Propulsion Research Ltd (SPR) to implement the project, the engine is based on the idea that electromagnetic microwave cavities can directly convert electricity into thrust.

While traditional electromagnetic motors are designed to propel a specific mass (such as ionized particles), this particular propulsion system is independent of mass response and does not emit directed 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 under the influence of force.

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

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

In 2010, Professor Zhuang Yang of Northwestern Polytechnic University in Xi'an, China, began publishing a series of articles on her research into EM Drive technology. In 2012, she reported high input power (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 the system worked.

Based on calculations based on NASA's prototype (which was estimated to have a power rating of 0.4 N/kW), an electromagnetic-powered spacecraft could travel to Pluto in less than 18 months. This is six times less than what was required by the New Horizons probe, which was moving at a speed of 58,000 km/h.

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 i's are dotted in this technology, it is too early to talk about its use.

Nuclear thermal and nuclear electrical motion

Another possibility for interstellar flight is to use a spacecraft equipped with nuclear engines. NASA has been studying such options for decades. A nuclear thermal propulsion rocket could use uranium or deuterium reactors to heat 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 rocket uses the same reactor to convert heat and energy into electricity, which then powers an electric motor. In both cases, the rocket would rely on nuclear fusion or fission to generate thrust, rather than the chemical fuel that all modern space agencies run on.

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

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

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 fission or fusion, NASA scientists could deliver a spacecraft to Mars in just 90 days if the Red Planet is 55,000,000 kilometers from Earth.

But when it comes to traveling to Proxima Centauri, it would take centuries for a nuclear rocket to reach a significant fraction of the speed of light. Then it will take several decades of travel, followed by many more centuries of slowdown on the way to the goal. We are still 1000 years from our destination. What is good for interplanetary missions is not so good for interstellar ones.

Part two: theoretical methods

Using existing technology, it would take a very, very long time to send scientists and astronauts on an interstellar mission. The journey will be painfully long (even by cosmic standards). If we want to accomplish such a journey in at least one lifetime, or even a generation, we need more radical (read: purely theoretical) measures. And while wormholes and subspace engines are absolutely fantastic at the moment, there have been other ideas for many years that we believe in being realized.

Nuclear propulsion

Nuclear propulsion is a theoretically possible "engine" for rapid space travel. The concept was originally proposed by Stanislaw Ulam in 1946, a Polish-American mathematician who took part in the Manhattan Project, and preliminary calculations were made by F. Reines and Ulam in 1947. Project Orion was launched in 1958 and lasted until 1963.

Led by Ted Taylor of General Atomics and physicist Freeman Dyson of the Institute for Advanced Study at Princeton, Orion would harness the power of pulsed nuclear explosions to provide enormous thrust with very high specific impulse.

In a nutshell, Project Orion involves a large spacecraft that gains speed by supporting thermonuclear warheads, ejecting bombs from behind and accelerating from a blast wave that goes into a rear-mounted “pusher,” a propulsion panel. After each push, the force of the explosion is absorbed by this panel and converted into forward movement.

Although this design is hardly elegant by modern standards, the advantage of the concept is that it provides high specific thrust - that is, it extracts the maximum amount of energy from the fuel source (in this case, nuclear bombs) at minimal cost. Additionally, this concept can theoretically achieve very high speeds, some estimate up to 5% of the speed of light (5.4 x 107 km/h).

Of course, this project has inevitable disadvantages. On the one hand, a ship of this size will be extremely expensive to build. Dyson estimated in 1968 that the Orion spacecraft, powered by hydrogen bombs, would have weighed between 400,000 and 4,000,000 metric tons. And at least three-quarters of that weight would come from nuclear bombs, each weighing about one ton.

Dyson's conservative calculations showed that the total cost of building Orion would be $367 billion. Adjusted for inflation, this amount comes out to $2.5 trillion, which is quite a lot. Even with the most conservative estimates, the device will be extremely expensive to produce.

There's also the small issue of the radiation it will emit, not to mention the nuclear waste. It is believed that this is why the project was scrapped as part of the partial test ban treaty of 1963, when world governments sought to limit nuclear testing and stop the excessive release of radioactive fallout into the planet's atmosphere.

Fusion rockets

Another possibility for using nuclear energy is through thermonuclear reactions to produce thrust. In this concept, energy would be created by igniting pellets of a mixture of deuterium and helium-3 in a reaction chamber by inertial confinement using electron beams (similar to what is done at the National Ignition Facility in California). Such a fusion reactor would explode 250 pellets per second, creating a high-energy plasma that would then be redirected into a nozzle, creating thrust.

Like a rocket that relies on a nuclear reactor, this concept has advantages in terms of fuel efficiency and specific impulse. The speed is estimated to reach 10,600 km/h, far exceeding the speed limits of conventional rockets. Moreover, this technology has been extensively studied over the past few decades and many proposals have been made.

For example, between 1973 and 1978, the British Interplanetary Society conducted a study into the feasibility of Project Daedalus. Drawing on modern knowledge and fusion technology, scientists have called for the construction of a two-stage unmanned scientific probe that could reach Barnard's Star (5.9 light-years from Earth) within a human lifetime.

The first stage, the largest of the two, would operate for 2.05 years and accelerate the craft to 7.1% of the speed of light. Then this stage is discarded, the second one is ignited, and the device accelerates to 12% of the speed of light in 1.8 years. Then the second stage engine is turned off, and the ship flies for 46 years.

Project Daedalus estimates that the mission would have taken 50 years to reach Barnard's Star. If to Proxima Centauri, the same ship will get there in 36 years. But, of course, the project includes a lot of unresolved issues, in particular those that cannot be resolved using modern technologies - and most of them have not yet been resolved.

For example, there is practically no helium-3 on Earth, which means it will have to be mined elsewhere (most likely on the Moon). Second, the reaction that drives the apparatus requires that the energy emitted significantly exceeds the energy expended to start the reaction. And although experiments on Earth have already surpassed the “break-even point,” we are still far from the volumes of energy that can power an interstellar spacecraft.

Thirdly, the question of the cost of such a vessel remains. Even by the modest standards of the Project Daedalus unmanned vehicle, a fully equipped vehicle would weigh 60,000 tons. To give you an idea, the gross weight of NASA SLS is just over 30 metric tons, and the launch alone will cost $5 billion (2013 estimates).

In short, not only would a fusion rocket be too expensive to build, but it would also require a level of fusion reactor far beyond our capabilities. Icarus Interstellar, an international organization of citizen scientists (some of whom worked for NASA or ESA), is trying to revive the concept with Project Icarus. Formed in 2009, the group hopes to make the fusion movement (and more) possible for the foreseeable future.

Fusion ramjet

Also known as the Bussard ramjet, the engine was first proposed by physicist Robert Bussard in 1960. At its core, it is an improvement on the standard fusion rocket, which uses magnetic fields to compress hydrogen fuel to the fusion point. But in the case of a ramjet, a huge electromagnetic funnel sucks hydrogen from the interstellar medium and dumps it into the reactor as fuel.

As the vehicle gains speed, the reactive mass enters a confining magnetic field, which compresses it until thermonuclear fusion begins. The magnetic field then directs energy into the rocket nozzle, accelerating the craft. Since no fuel tanks will slow it down, a fusion ramjet can reach speeds on the order of 4% of light speed and travel anywhere in the galaxy.

However, there are many potential downsides to this mission. For example, the problem of friction. The spacecraft relies on a high rate of fuel collection, but will also encounter large amounts of interstellar hydrogen and lose speed - especially in dense regions of the galaxy. Secondly, there is little deuterium and tritium (which are used in reactors on Earth) in space, and the synthesis of ordinary hydrogen, which is abundant in space, is not yet within our control.

However, science fiction fell in love with this concept. The most famous example is perhaps the Star Trek franchise, which uses Bussard collectors. In reality, our understanding of fusion reactors is not nearly as good as we would like.

Laser sail

Solar sails have long been considered an effective way to conquer the solar system. Besides the fact that they are relatively simple and cheap to manufacture, they have the big advantage that they do not require fuel. Instead of using rockets that need fuel, the sail uses radiation pressure from stars to propel ultra-thin mirrors to high speeds.

However, in the case of interstellar travel, such a sail would have to be propelled by focused beams of energy (laser or microwaves) to accelerate it to near light speed. The concept was first proposed by Robert Forward in 1984, a physicist at Hughes Aircraft Laboratory.

His idea retains the advantages of a solar sail in that it does not require fuel on board, and also that laser energy does not dissipate over a distance in the same way as solar radiation. Thus, although the laser sail will take some time to accelerate to near light speed, it will subsequently be limited only by the speed of light itself.

According to a 2000 study by Robert Frisby, director of advanced propulsion concepts research at NASA's Jet Propulsion Laboratory, a laser sail would accelerate to half the speed of light in less than a decade. He also calculated that a sail with a diameter of 320 kilometers could reach Proxima Centauri in 12 years. Meanwhile, the sail, 965 kilometers in diameter, will arrive in just 9 years.

However, such a sail will have to be built from advanced composite materials to avoid melting. Which will be especially difficult given the size of the sail. Costs are even worse. According to Frisby, the lasers would require a steady flow of 17,000 terawatts of energy, which is roughly what the entire world consumes in one day.

Antimatter engine

Science fiction fans are well aware of what antimatter is. But in case you forgot, antimatter is a substance made up of particles that have the same mass as regular particles but the opposite charge. An antimatter engine is a hypothetical engine that relies on interactions between matter and antimatter to generate energy, or thrust.

In short, an antimatter engine uses hydrogen and antihydrogen particles colliding with each other. The energy emitted during the annihilation process is comparable in volume to the energy of the explosion of a thermonuclear bomb accompanied by a flow of subatomic particles - pions and muons. These particles, which travel at one-third the speed of light, are redirected into a magnetic nozzle and generate thrust.

The advantage of this class of rocket is that most of the mass of the matter/antimatter mixture can be converted into energy, resulting in a high energy density and specific impulse superior to any other rocket. Moreover, the annihilation reaction can accelerate the rocket to half the speed of light.

This class of rockets will be the fastest and most energy efficient possible (or impossible, but proposed). While conventional chemical rockets require tons of fuel to propel a spacecraft to its destination, an antimatter engine will do the same job with just a few milligrams of fuel. The mutual destruction of half a kilogram of hydrogen and antihydrogen particles releases more energy than a 10-megaton hydrogen bomb.

It is for this reason that NASA's Advanced Concepts Institute is researching this technology as a possibility for future missions to Mars. Unfortunately, when considering missions to nearby star systems, the amount of fuel required grows exponentially and the costs become astronomical (no pun intended).

According to a report prepared for the 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, a two-stage antimatter rocket would require more than 815,000 metric tons of propellant to reach Proxima Centauri in 40 years. It's relatively fast. But the price...

Although one gram of antimatter produces an incredible amount of energy, producing just one gram would require 25 million billion kilowatt-hours of energy and cost a trillion dollars. Currently, the total amount of antimatter that has been created by humans is less than 20 nanograms.

And even if we could produce antimatter cheaply, we would need a massive ship that could hold the required amount of fuel. According to a report by Dr. Darrell Smith and Jonathan Webby of Embry-Riddle Aeronautical University in Arizona, an antimatter-powered interstellar spacecraft could reach the speed of 0.5 times the speed of light and reach Proxima Centauri in just over 8 years. However, the ship itself would weigh 400 tons and require 170 tons of antimatter fuel.

A possible way around this would be to create a vessel that would create antimatter and then use it as fuel. This concept, known as the Vacuum to Antimatter Rocket Interstellar Explorer System (VARIES), was proposed by Richard Aubauzi of Icarus Interstellar. Based on the idea of ​​in-situ recycling, the VARIES vehicle would use large lasers (powered by huge solar panels) to create antimatter particles when fired into empty space.

Similar to the fusion ramjet concept, this proposal solves the problem of transporting fuel by extracting it directly from space. But again, the cost of such a ship will be extremely high if we build it using our modern methods. We simply cannot create antimatter on a huge scale. There is also a radiation problem to be solved, since the annihilation of matter and antimatter produces bursts of high-energy gamma rays.

They not only pose a danger to the crew, but also to the engine so that they don't fall apart into subatomic particles under the influence of all that radiation. In short, an antimatter engine is completely impractical given our current technology.

Alcubierre Warp Drive

Science fiction fans are no doubt familiar with the concept of warp drive (or Alcubierre drive). Proposed by Mexican physicist Miguel Alcubierre in 1994, the idea was an attempt to imagine instantaneous movement in space without violating Einstein's theory of special relativity. In short, this concept involves stretching the fabric of spacetime into a wave, which would theoretically cause the space in front of an object to contract and the space behind it to expand.

An object inside this wave (our ship) will be able to ride this wave, being in a “warp bubble,” at a speed much higher than the relativistic one. Since the ship does not move in the bubble itself, but is carried by it, the laws of relativity and space-time will not be violated. Essentially, this method does not involve moving faster than the speed of light in a local sense.

It is "faster than light" only in the sense that the ship can reach its destination faster than a beam of light traveling outside the warp bubble. Assuming the spacecraft is equipped with the Alcubierre system, it will reach Proxima Centauri in less than 4 years. Therefore, when it comes to theoretical interstellar space travel, this is by far the most promising technology in terms of speed.

Of course, this whole concept is extremely controversial. Among the arguments against, for example, is that it does not take quantum mechanics into account and can be refuted by a theory of everything (like loop quantum gravity). Calculations of the required amount of energy also showed that the warp drive would be prohibitively voracious. Other uncertainties include the safety of such a system, spacetime effects at the destination, and violations of causality.

However, in 2012, NASA scientist Harold White announced that he and his colleagues began exploring the possibility of creating an Alcubierre engine. White stated that they had built an interferometer that would capture the spatial distortions produced by the expansion and contraction of spacetime in the Alcubierre metric.

In 2013, the Jet Propulsion Laboratory published the results of warp field tests conducted in vacuum conditions. Unfortunately, the results were considered “inconclusive.” In the long term, we may find that the Alcubierre metric violates one or more fundamental laws of nature. And even if its physics prove correct, there is no guarantee that the Alcubierre system can be used for flight.

In general, everything is as usual: you were born too early to travel to the nearest star. However, if humanity feels the need to build an “interstellar ark” that will accommodate a self-sustaining human society, it will be possible to reach Proxima Centauri in about a hundred years. If, of course, we want to invest in such an event.

In terms of time, all available methods seem to be extremely limited. And while spending hundreds of thousands of years traveling to the nearest star may be of little interest to us when our own survival is at stake, as space technology advances, the methods will remain extremely impractical. By the time our ark reaches the nearest star, its technology will become obsolete, and humanity itself may no longer exist.

So unless we make a major breakthrough in fusion, antimatter, or laser technology, we will be content with exploring our own solar system.

LECTURE:

"IN SEVEN MILLION YEARS"

Lecturer Moiseev I.M.

SSO "Energia" MVTU named after. Bauman

village

Ust-Abakan

Dear comrades! I want to warn you right away that we will talk about controversial and rather abstract issues. Much of what I want to tell you is not the pressing problem of today. However, understanding the problem that I will talk about and the possibility of solving it has a serious worldview character.

We will have to operate with very large, by our standards, numbers. I want you to understand them well, I remind you: a million is a thousand thousand, a billion is a thousand million. Just counting to a thousand will take 3 hours. Up to a million - 125 days. To a billion - 350 years. Introduced? Well then. Then we can begin.

20 billion years ago the Universe began.

Somewhere 5-6 billion years ago our Sun burst into flames.

4 billion years ago, a molten ball cooled down, which is now called planet Earth. About a million years ago Man appeared.

States have existed for only a few thousand years.

About a hundred years ago, radio was invented and finally, 27 years ago, the space age began.

This time. Now let's talk about spatial scales.

We live on planet earth. Our planet is a very small part of the solar system, which includes the first star - the Sun, 9 large planets, dozens of planetary satellites, millions of comets and asteroids and many other smaller material bodies. Our solar system is located on the periphery of the Galaxy, a huge star system that includes 10 billion stars like the Sun. There are thousands of such galaxies in the Universe

billion This is the world we live in. Now that we have introduced all this, it is time to set the first task.

So. We need to get to the nearest star system - the Alpha Centauri system. This system includes 3 stars: Alpha Centauri A - a star similar to our Sun, Alpha Centauri B and Proxima Centauri - small red stars. It is very likely that this system also includes planets. The distance to it is 4.3 light years. If we could travel at the speed of light, it would take us almost 9 years to travel there and back. But we cannot move at the speed of light. Currently, we only have chemical rockets at our disposal, their maximum achieved speed is 20 km/sec. At this speed, it would take more than 70 thousand years to reach Alpha Centauri. We have electric rocket and nuclear thermal engines at our disposal. However, the former, due to low thrust, cannot accelerate their own weight to decent speeds, and the latter, roughly speaking, are only twice as good as chemical ones. Science fiction writers love to send their heroes to the stars on photon, or more correctly, annihilation rockets. Annihilation engines can theoretically accelerate a rocket to speeds very close to the speed of light in just one year. But in order to make annihilation propulsion systems, a large amount of antimatter is needed, and how to obtain it is completely unknown. In addition, the design of such an engine is completely unclear. But we need a real engine. So that we know how to make it and can start working on creating it right now. Otherwise, if we wait until they find principles that are currently unknown, we may be left with nothing. Fortunately, such an engine exists. True, so far only on paper, but if you and I want, we can create it in metal. This is a pulsed thermonuclear rocket engine. Let's get to know him in more detail. In this engine, small portions of thermonuclear fuel burn at high frequency. In this case, very large energy is released, the reaction products - elementary particles - scatter at high speed and push the rocket forward. Let us dwell on the main problems associated with the creation of such an engine and on ways to solve them.

Problem number one is the problem of arson. It is necessary to set fire, that is, to initiate a thermonuclear reaction in a small, no more than 10 milligrams in weight, thermonuclear fuel tablet.

Such a tablet is usually called a target. In order for the reaction to proceed sufficiently intensely, the temperature of the target must reach hundreds of millions of degrees. Moreover, in order for most of the target to react, this heating must be carried out in a very short time. /If we heat it slowly, the target will have time to evaporate without burning out./ Calculations and experiments show that energy of one million joules must be invested into the target in a time of one billionth of a second. The power of such an impulse is equal to the power of 200 thousand Krasnoyarsk hydroelectric power stations. But the power consumption will not be so great - 100 thousand kilowatts, if we explode 100 targets per second.

The first solution to the problem of arson was found by the famous Soviet physicist Basov. He proposed setting fire to targets with a laser beam, in which the required power could actually be concentrated. Intensive work is being carried out in this area and in the near future the first thermonuclear power plants operating on this principle will be launched. There are other options for solving this problem, but they have not been explored much yet.

A solution was found here too.

It has been proposed to use flows of small solid particles or liquid droplets heated to a high temperature to release heat. Such devices are new, but quite feasible.

When designing our engine, many more problems will arise, but all of them are solvable, and, what is important, solvable at the current level of development of science and technology.

Let's imagine the engine as a whole. It is based on a combustion chamber - a truncated cone, several tens of meters in size. On the axis of this cone, thermonuclear explosions occur 100 times per second, each with a force of several tons of TNT. The jet stream flows from the wide base of the cone. This cone is formed by two rings of solenoids. There are no walls. There is a strong magnetic field inside the cone. The upper solenoid contains a laser ignition system, a system for supplying targets to the combustion chamber, and a system for selecting electricity necessary to power the laser installation. /For this purpose, part of the energy of explosions is taken away./ Liquid streams flow along the side generatrices of the cone - this is a radiator. To provide the necessary thrust, we will need to install about 200 such engines on our rocket.

We made the propulsion system. Now let's talk about the payload. Our device will be manned. Therefore, the main part will be the habitable compartment. It can be made in the shape of a dumbbell. The “dumbbell” will measure two to three hundred meters. It will rotate around its transverse axis to create artificial gravity. It will be surrounded on all sides by thermonuclear fuel, which will protect the crew from cosmic radiation. In addition to the habitable compartment, the payload will include a power supply system, a communications system, and auxiliary systems.

As you can see, there is nothing impossible in building an interstellar spaceship, just a lot of complexity. All problems are surmountable. Now I will introduce you to the characteristics of the ship obtained as a result of the preliminary design.		Weight at start
million tons		Engine weight
thousand tons		Engine weight
Payload weight		Maximum speed
speed of light		Flight time
years	1000	Crew

Human

Please pay attention - just fly. He won't be able to return. It is easy to calculate that, maintaining the same design, in order to be able to return, our ship at the start must weigh 8 billion tons. This clearly exceeds our capabilities. And why come back? We can transmit all new - and very huge, it should be noted - information by radio. And we will need to stay in the Alpha Centauri system, land on the planets and begin to explore them.

How are we going to do this?

Is there such a possibility? Yes, I have. We launch, say, a hundred ships from the solar system. One hundred thousand volunteers. In 60 years, they, their children and grandchildren will arrive in the Alpha Centauri system and enter orbit around the most convenient planet for exploration. After reconnaissance, people will begin to remake the entire planet, because it is unlikely to turn out to be a copy of our Earth. If it is too hot, you can close it from the star with a dust screen. If it’s too cold, we can direct additional energy at it using large and very light mirrors, we can make these. We can change the atmosphere too.

The only thing that can stop Humanity on its stellar path is nuclear war. The same means that allow Humanity to reach the stars can destroy it at the very beginning of its journey. Of course, I don’t need to agitate you for peace. But I will allow myself to remind you that now an active struggle for the peaceful future of Humanity is the only thing that can save not only our lives, but also the vast future of our Humanity.

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

The development of science and technology resembles a wave. Not really. Again yes, and again no. But in the end still Yes!

Is it possible to fly to the stars?

At least to the nearest one?

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

YES POSSIBLE. Only 17 grams of antimatter is needed.

NO IMPOSSIBLE. 17 grams of antimatter are worth 170 trillion dollars!

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 to store it for years and not 1000 seconds as now. Doesn't matter. 17 grams of antimatter is approximately the 22 atomic bombs that were dropped on Hiroshima. No one will allow you to take such risks when launching. After all, a trap for antimatter, no matter how reliable it may be in itself, when it is destroyed, the antimatter will interact with matter. And tragedy cannot be avoided.

YES IT IS POSSIBLE. NASA, albeit in the “craziest” institute, ordered an antimatter collector http://www.membrana.ru/particle/2946. After all, antimatter exists 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 to the hands of applied science.

I want to highlight one overlooked point. Many people say how to get there? What kind of 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 get there? 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 surrounding world need to survive on a stellar expedition. What kind of fuel is needed to fly to a star in a certain time?

My answer would 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 a given time. While the Sun is burning and providing warm rays to our Earth, our starship continues to plow through space, led by the Sun.

I made approximate calculations of our space expedition. How long will we fly on our starship before the solar fuel runs out? The Sun has approximately 4.57 billion years left to burn. During this time, we will fly on Earth approximately 18 orbits 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 220 km/s. Our stellar expedition path will be 3.17·10^19 km = 3.3514·10^6 light years. During our space expedition, the starship (planet Earth) would have reached the M31 galaxy close to us (the Andromeda nebula). We and our Earth fly 19,008,000 km every day. All our lives we have been traveling through outer space on our ship called Earth...

Thank you!!!

Will not work. Interstellar distances, as they were, will be, despite the fact that we 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 on weekends to admire quasars. And in principle we won’t need this anymore

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

In this regard, it becomes clear that staying at home, so to speak, “to gain a better foothold” in our solar system, is not the best strategy. Little can happen to our Earth. So it’s better to worry about finding a new place to live in advance, 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 path, to put it mildly, is not very informative. It’s better to receive information about other objects outside the solar system directly on the spot. I am sure that you will be able to see enough “miracles” that you will never see from Earth. It is in this regard that American expeditions to the Moon are primarily suspicious. They discovered practically nothing new. This makes me doubt it.

Viktor Mikhailovich, in fact, I meant something slightly 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 a reasonable time frame. Those. I believe everything has its time.

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

Seryozha! As for everything in its time - that’s not what it’s about. Until we have invented a way to travel in space or in some other way at speeds close to or greater than the speed of light, we are inhabiting the Solar System as best we can. But as soon as a way appears to fly to the stars, at least the nearest ones, there will immediately be enthusiasts to do it. So, “We’re waiting until the first star...” Nikolai proposes to fly by inertia on the Earth itself. Here we are in agreement. So we won’t fly to anything, and if we do fly, it would be better if we didn’t fly.

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

It takes 5 years to fly to some star, while on earth it will take 50-100 years. The times when people, like Bykov from the Strugatsky epic, were ready to do such a thing are gone (probably). But flying in such a way as to get there in time, but then returning to the familiar world is easier. Moreover, you need 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 it’s not a fact that there are such people within a radius of 30 pcs. There is simply little point in flying just for the sake of just getting there. 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, this data will become outdated.

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

Seryozha! I understand that you are arguing within the framework of physics known today. If you rely on SRT, then it will be as you say. Flying for 5 years in your own time will be tens and hundreds of years in the Earth system, depending on your 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 the status of a type of speed of sound in hydrodynamics. Therefore, I think we need to look at the problem more broadly, especially since evidence of 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 you manage to overcome the speed of light threshold, then the next speed limit may be far beyond it. 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 in addition to the temperature, there is also gigantic radiation. 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 get it from. It's the same with Mars. Three problems everywhere except the Earth (for now!) - oxygen, water, radiation.

It is even more interesting to build a ship with an antimatter engine. Since the calculated characteristics do not interfere with creating an engine with a speed of 70% of the speed of light, and at this speed it is possible to study the paradoxes of time and space in practice. But is 70% enough to manifest the deep laws of physics?

It is even more interesting to build a ship with an antimatter engine.

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

Let me remind you that the much simpler problem of creating nuclear energy still requires enormous costs. A nuclear rocket engine has been created, but in the form of a stand and has never flown. More difficult than nuclear installations, but still much easier, the problem of confining conventional high-temperature plasma than the problem of confining antimatter has not been solved. Added to this is a whole bunch of unsolved problems associated with moving 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 radically different way.

I found information that Skolkovo accepted an application for a “perpetual motion machine”. Well, okay, they would call it the “Vacuum Energy Receiving Installation.” But no - “perpetual motion machine”. http://lenta.ru/news/2012/10/22/inf/ So, indeed, not everything that individual physicists say is scientifically based information.

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

If we build a chain of antimatter collector - its storage - nanospace ships, then the exploration of Near Space would proceed 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 feasibility of space flights at such speeds. As Folko already said, an important issue will be transfer of received research information to Earth. For a nanoship with its nanoantenna and nanoenergies, radio transmission is unlikely to be effective. Another way is to send a capsule with information to Earth at a speed of 0.7 times the speed of light, but this will take even longer.

Sol writes:

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

Another point of view seems reasonable and optimistic:

zhvictorm writes:

Bye We not invented way of traveling in space or somehow else at 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 earthly civilization, or even more so 70% of the speed of light, then one can really only talk about feasibility of space flights.

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

In general, the idea space nanoships- interesting!

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

It won't hurt to 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 don’t know how to carry out active navigation in the solar system at speeds of 10-20 km/s.

This is exactly what concerns 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 antihelium atoms and that’s all. Moreover, they exist for very small fractions of a second. So everything is still fantasy. I think that we will have to get to the stars in completely different ways, which we don’t know anything about yet.

Of course, projects so far they are more like the level of not even K.E. Tsiolkovsky, and N.I. Kibalchich. However, I do not see any fundamental, fundamental obstacles to further work in this area. Moreover, I am saying that from FUNDAMENTAL science antimatter smoothly transitions to APPLIED. And, taking into account the cost of modern experimental physics, the more PRACTICAL applications will have antimatter all 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 for combining nanotechnologies and antimatter technologies look especially interesting and promising. Creation of nanoships with antimatter engines. Then, the current amount of antimatter will fly to Uranus quite quickly. Considering that he is a member of the Nanosociety, he probably knows what he is talking about.

Folko writes:

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

This is a question for a person who is wise in life, sensible and rational. Do you think that the founder of Moscow State University is hopelessly outdated?

“The abyss full of stars has opened! The stars have no number, the bottom of the abyss!” M.V. Lomonosov.

Of course, Moscow offers serious prospects, but there is such a provincial village Veshkaima 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 prohibit nighttime astronomical observations; classmates did not understand, but everyone felt the extraordinary determination of this boy and... were proud, saying that such an “eccentric” lived next to them.

An aspiring musician came to the famous composer with the words: “I want to learn 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 such a mundane goal for yourself?”

> > 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 its efforts on exploring its native solar system. But can we go on reconnaissance to a neighboring star? And how many How long will it take to travel to the nearest star?? This can be answered very simply, or you can go deeper into the realm of science fiction.

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

The closest star to planet Earth is . This is the middle representative of the main sequence. But there are many neighbors concentrated around us, so now it’s possible to create a whole map of routes. But how long does it take to get there?

Which star is the closest

The closest star to Earth is Proxima Centauri, so for now you should base your calculations on its characteristics. It is part of the triple system Alpha Centauri 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 comes up, everyone immediately thinks about warp speed and jumping into wormholes. But all of them are either still unattainable or absolutely impossible. Unfortunately, any long-distance mission will take more than one generation. Let's start the analysis with the slowest methods.

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

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

This means we have several vehicle options. In addition, it can be used as a giant gravitational slingshot. But if we plan to travel that 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 are only in the form of drawings.

Ionic strength

This is the slowest method, but it is economical. Just a few decades ago, the ion engine was considered fantastic. But now it is used in many devices. For example, the SMART-1 mission reached 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 efficiency, but definitely not in speed.

For the first time, the ion engine was used for Deep Space 1, flying to (1998). The device used the same type of engine as SMART-1, using only 81.5 kg of propellant. Over the course of 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 explosive is much higher. But it takes a lot of time to speed up. If they were planned to be used to travel from Earth to Proxima Centauri, a lot of rocket fuel would be needed. Although you can take 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 because it allows you to use orbit and planetary gravity to change the route and speed. It is often used to travel to 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 1980s, Voyager 1 used the moons of Saturn and Jupiter to accelerate to 60,000 km/h and enter interstellar space.

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

Due to the high eccentricity of the 190-day orbit, the device was able to accelerate to 240,000 km/h. For this purpose, exclusively 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, this would have taken 19,000 years. It's faster, but not fast 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 convert electrical energy into thrust.

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

But recent experiments are slowly winning over supporters. In April 2015, researchers announced that they had successfully tested the disk in a vacuum (which means it can function in space). In July they had already built their version of the engine and discovered noticeable thrust.

In 2010, Huang Yang began a series of articles. She completed the final work in 2012, where she reported higher input power (2.5 kW) and tested thrust conditions (720 mN). In 2014, she also added some details about the use of internal temperature changes that confirmed the system's functionality.

According to 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, traveling to Proxima Centauri would take 13,000 years. 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 nozzle to generate thrust.

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

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 fuel consumption, which would reduce launch mass and mission costs.

So far there has not been a single launched nuclear thermal engine. But there are many concepts. They range from traditional solid designs to those based on a liquid or gas core. Despite all these advantages, the most complex concept achieves a maximum specific impulse of 5000 seconds. If you use such an engine to travel to when the planet is 55,000,000 km away (the “opposition” position), it will take 90 days.

But if we send it to Proxima Centauri, it will take centuries to accelerate to reach the speed of light. After that, it would take several decades to travel and centuries more 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've probably already realized that modern technology is quite slow to cover such long distances. If we want to accomplish this in one generation, then we need to come up with something breakthrough. And if wormholes are still collecting dust on the pages of science fiction books, then we have several real ideas.

Nuclear impulse movement

Stanislav Ulam was involved in this idea 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 shock with a high specific impulse. That is, we have a large spaceship with a huge supply of thermonuclear warheads. During drop, we use a detonation wave on the rear platform ("pusher"). After each explosion, the pusher pad absorbs the force and converts the thrust into impulse.

Naturally, in the modern world the method lacks grace, but it guarantees the necessary impulse. According to preliminary estimates, in this case it is possible to achieve 5% of the speed of light (5.4 x 10 7 km/h). But the design suffers from shortcomings. Let's start with the fact that such a ship would be very expensive, and it would weigh 400,000-4000,000 tons. Moreover, ¾ of the weight is represented by nuclear bombs (each of them reaches 1 metric ton).

The total cost of the launch would have risen at that time to 367 billion dollars (today - 2.5 trillion dollars). There is also the problem of the radiation and nuclear waste generated. 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 compartment through inertial confinement using electron beams. Such a reactor would detonate 250 pellets per second, creating a high-energy plasma.

This development saves fuel and creates a special boost. The achievable speed is 10,600 km (much faster than standard rockets). Recently, more and more people are interested in this technology.

In 1973-1978. The British Interplanetary Society created a feasibility study, Project Daedalus. It was based 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 operate for 2.05 years and will accelerate the ship to 7.1% of the speed of light. Then it will be reset and the engine will start, increasing the speed to 12% in 1.8 years. After this, the second stage engine 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, the time will be reduced to 36 years. But this technology also faced obstacles. Let's start with the fact that helium-3 will have to be mined on the Moon. And the reaction that powers the spacecraft requires that the energy released exceeds the energy used to launch it. And although the testing went well, we still do not have the necessary type of energy that could power an interstellar spacecraft.

Well, let's not forget about 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 thermonuclear reactor will be needed, which also does not fit into the budget.

Ramjet engine

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

The ship will gain speed, and will force the compressed magnetic field to achieve the process of thermonuclear fusion. It will then redirect the energy in the form of exhaust gases through the engine injector and accelerate the movement. Without using any other fuel, you can reach 4% of the speed of light and go anywhere in the galaxy.

But this scheme has a huge number of shortcomings. The problem of resistance immediately arises. The ship needs to increase speed to accumulate fuel. But it encounters huge amounts of hydrogen, so it can slow down, especially when it hits 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, and do not require fuel. The sail uses radiation pressure from the stars.

But to use such a design for interstellar travel, it must be controlled by focused energy beams (lasers and microwaves). This is the only way to accelerate it to a point 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 remain. 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 accelerate to 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 its production requires the use of advanced composites to avoid melting. Don't forget that it must reach huge sizes, 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 constant current of 17,000 terawatts. So you understand, this is the amount of energy that the entire planet consumes in one day.

Antimatter

This is a material represented by antiparticles that 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, such an engine uses hydrogen and antihydrogen particles. 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 the speed of light.

The advantage of this technology is that most of the mass is converted into energy, which will create 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 engine with antimatter spends only a few milligrams for the same actions. This technology would be great for a trip to Mars, but it can't be applied to another star because the amount of fuel increases exponentially (along with the costs).

A two-stage antimatter rocket would require 900,000 tons of fuel for a 40-year flight. The difficulty is that to extract 1 gram of antimatter will require 25 million billion kilowatt-hours of energy and more than a trillion dollars. Right now we only have 20 nanograms. But such a ship 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 consumes 170 tons of antimatter.

As a solution to the problem, they proposed the development of a “Vacuum Antimaterial Rocket Interstellar Research System.” This could use large lasers that create antimatter particles when fired into empty space.

The idea is also based on using fuel from space. But again the moment of high cost arises. In addition, humanity simply cannot create such an amount of antimatter. There is also a radiation risk, as matter-antimatter annihilation can create bursts 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 product is inferior in practicality.

Alcubierre Bubble

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. It suggests stretching the fabric of spacetime in a wave. Theoretically, this will cause the distance in front of the object to decrease and the distance behind it to expand.

A ship caught inside a wave will be able to move beyond relativistic speeds. The ship itself will not move in the “warp bubble”, 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 leaving the bubble. Calculations show that he will arrive at his destination in 4 years. If we think about it in theory, this is the fastest method.

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

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

What follows from this? If you were hoping to make a round trip to the star, the odds are incredibly low. But if humanity decided to build a space ark and send people on a century-long journey, then anything 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.

For now, we can only surf and explore the expanses of our native system, hoping that in the future a new method will appear that will make it possible to implement interstellar transits.