What are antimatter missiles

Destination Alpha Centauri: Realizable drive systems

Missile Engineering Visions in Time Lapse - Part 3

Drive systems that can be implemented in the future could travel at a speed of around 1/10 or 3/10 of the speed of light. Such speeds are within the flight speed limits for "fuelless" ramjets, light sails, and space planes. With the interstellar ramjet engine, interstellar hydrogen is collected during flight with the help of a strong magnetic field. The higher the speed, the more hydrogen can be used in the R.W. Bussard 1960 presented interstellar ramjet engine ("Interstellar Ramjet") to be collected.

The original aircraft uses a large magnetic funnel to collect charged particles from the interstellar medium and feed them to an H-He fusion reactor, in which the particles are converted into fuel. According to Bussard's calculations, a 1000 t spaceship with 100% reactor efficiency would accelerate almost indefinitely at 1 g and thus reach the speed of light within a year. The disadvantage of Bussard's ramjet engine is that it doesn't work from a standstill, but has to be accelerated to around 4-6% the speed of light in order to get the correct flow of charged particles.

The possibilities of increasing the performance of the interstellar ramjet engine concept include acceleration to the ramjet speed with a light sail, charging the inflowing neutral particles with the help of a laser, increasing the thrust of the spacecraft through antimatter / matter reactions or the use of an accelerator as an alternative for reaction mass propulsion (e.g. by fusion or antimatter catalysis). The problem with interstellar ramjet engines would be size. For example, on a 45-year mission to Alpha Centauri, NASA reckons with a 3000 t spacecraft that would have an inlet with a diameter of 650 km.

Sun or light sails

The so-called solar sail concept makes it possible to dispense with the fuel required to propel a spaceship. The light sail is based on the discovery made by James C. Maxwell in 1873 that light reflected from a mirror exerts pressure on it. Since photons have mass, according to Einstein, a spacecraft can fly from A to B using the rather low coefficient of friction of the universe without having to carry extensive propulsion devices and, above all, fuel. The inexhaustible energy of sun or starlight opens up the possibility of a significant reduction in the mass of spaceships.

Since light exerts pressure on surfaces, a stream of photons can be used for propulsion in an almost frictionless environment. The disadvantage of this solution is that you depend on a strong flow of photons to accelerate the spaceship to the necessary speed. The awning has been described in science fiction literature since the 1920s. Russian aerospace engineers managed to deploy a solar sail in orbit as early as the early 1990s ("Znamya" project). However, it was nowhere near the size of about 300 kilometers, as would be necessary for an interstellar trip to the Alpha Centauri, according to Gregory L. Matloff, an astronomy professor from New York University.

In the case of great distances, the laser beam could be re-bundled using so-called Fresnel zones. Problems would, however, be caused by the long travel time of 1,200 years, which would require the astronauts to be cryogenized and thawed successfully. Alternatives to light sails are e.g. microwave drives or magnetic sails. The electromagnetic is based on Lenz's rule, i.e. that the induced voltage is always directed in such a way that the magnetic field of the current caused by it counteracts the cause of induction.

Microwave drives

Sciene Fictor author Robert Forward proposed a microwave sail that does not have its own drive. His space plane, called Starwisp ("star whispering"), is powered by microwaves that are sent from a solar-powered satellite in orbit or from a moon base.

The spacecraft would mainly consist of a microcircuit covered net sail with a diameter of 1 km, which should weigh only 12 grams. The net acts as a sail that catches the radio waves from the measles. The transmitter is on the earth or on the moon and emits its radio waves bundled in the direction in which the probe is to fly. However, the beam power would have to be at least 10 GW so that the spacecraft weighing 4 g could reach about 20% of the speed of light at an acceleration of 115 G. After that, the spaceplane would travel through space at this speed for decades until it reached its destination as part of a flyby mission without being able to brake at its destination.

Although this drive can be implemented theoretically, it makes new demands on the lightness and strength of materials. Furthermore, the radio transmitter would have to emit radiation that would have to be stronger than all the energy put together that is produced by power plants on earth today.

Fusion engines

The fusion drive (also known as impulse drive) is based on the classic Newtonian reaction principle and is used for subphotonic flight, i.e. for speeds below the speed of light. Electrically charged particles serve as the propulsion medium, which are compressed and accelerated to the speed of light before they leave the rocket's propulsion system.

The accelerated particles are a by-product of the fusion reactors that generate the energy to power the spaceship. By limiting the fuel delivery rate of the fusion reactor, additional "fuel" (mostly in the form of bismuth atoms) can be injected into the propulsion system if more thrust is required. This is often referred to as the "afterburner" of the spaceship.

Fusion drives are a popular drive in science fiction literature and were used, among other things, in the "Star Wars" films. A fusion engine would have to withstand multiple fusion reactions, but it would not need to be as efficient as a fusion reactor, since the main goal of the fusion reaction is to heat the plasma particles to extremely high temperatures. As the temperature of the plasma particles increases, the exit velocity from a magnetic nozzle increases, making the fusion engine a very fast propulsion system.

Nuclear detonation drive

The nuclear detonation drive, which is derived from nuclear weapons research, could prove to be extremely useful for achieving high accelerations of spaceships for interstellar travel. The application is based on the fact that a nuclear fission bomb is dropped from the spaceship every few seconds and detonated a short distance behind it.

The spaceship has a huge baffle and protective plate that catches the vaporized residue from the explosion. Such an "atomic drive" was mentioned in the science fiction literature of the 1930s, but it was only Stanislaw Lem in the 1940s that it was reserved to think seriously about. His considerations culminated in the "Orion" project, in which a prototype aircraft was shot up to a height of 100 m by means of six detonations during a test carried out in the USA in 1959.

At a time when the United States was preparing to put a person on the moon, it was mainly reserved for SF authors to come up with propulsion technologies for interplanetary and even interstellar flights. Although the project was later abandoned for political reasons, the technology could be further improved by using other propellants, such as nuclear particles accelerated by magnetic fields or mass propulsion. Furthermore, by providing propellants along the flight path of the spacecraft, a significant reduction in the take-off mass could be achieved.

Antimatter drives

"Antimatter," the futuristic engine from the Star Trek series, could be the key to reaching Alpha Centauri. When antimatter meets ordinary matter, both of them annihilate each other. According to Albert Einstein's famous formula E = mc2 the matter would be completely transformed into energy.

The European Laboratory for Particle Physics CERN in Geneva has already succeeded in producing antimatter. For an antimatter drive, however, very large amounts of antimatter would have to be produced in the future. A major difficulty is that the production of antiparticles with the current particle accelerators is very low in efficiency. Furthermore, it is necessary to store the antimatter in the spacecraft for a sufficiently long period of time and to convert the annihilation energy (process in which an elementary particle and its antiparticle are converted into two to three photons and are destroyed in the process) into a propulsion beam.

However, there is no doubt about the efficiency of the fuel. Assuming that 50 kg of matter are shot at 50 kg of antimatter at the speed of light, the energy released would correspond to that of 100 atomic bombs.

StarTrek Warp Drives

Warp drives would be based on two fundamental technological breakthroughs that had yet to be achieved: control over gravity and reaching speeds greater than the speed of light.

In the world of "Star Trek" the main propulsion system of the interstellar spacecraft flying at faster than light speed is the space-time curvature drive or warp drive. The propulsion system used in the spaceships of the Federation uses the destruction of matter and antimatter controlled by dilithium crystals to generate the tremendous energy necessary to bend space and travel faster than the speed of light. When traveling very quickly, however, there is a serious problem: You cannot see anything, because all visible light is shifted into the X-ray area. As a subsequent problem, travelers are then exposed to life-threatening X-rays.

In 1994, Miguel Alcubierre worked out a space-time geometry that makes such a space-time curvature drive possible without locally exceeding the speed of light. However, to produce such a metric one would need matter with a negative energy density, so-called exotic matter. So far, however, there is no evidence for the existence of such matter. The Star Trek producer Gene Rodenberry made full use of this drive concept in his "Star Trek" odyssey to take the viewer to the edge of our universe.

Another possibility not to exceed the speed of light locally and still move faster than light is the idea of ​​hyperspace. If one imagines that our space-time is embedded in a higher-dimensional hyperspace (like the earth's surface in space), the previously infinite widths could be bridged in a short time. However, so far there is no evidence of an embedding of space-time in a higher-dimensional space.

Time travel through wormholes

H. G. Wells' novel "The Time Machine" describes the human dream to completely overcome space and time and to travel through time. In 1992 Harry Turtledove published the novel "The Guns of the South", in which the southerners equipped with state-of-the-art weapons through time travel still win the American civil war against the "Yankees".

One theory that ties in with these visions deals with the journey through so-called "wormholes". A hypothetical spaceship could enter one "mouth" of the wormhole and exit through the other very distant "mouth". While travel may be the most interesting aspect of this, "wormholes", if they exist, could prove to be amazing tools for seeing other, older parts of a distant universe.

The Russian writer Ivan Yefremov developed the idea of ​​the "Great Ring" of communicating, galactic civilizations in a novel in the 1950s. To get closer to this goal, however, real-time communication between the distant galaxies would have to become a reality. Whether it is also possible to transport people depends on fully deciphering the physical laws of gravity within the universe.

Use of gravity monsters

In his novel "Path of the Fury" from 1992, David Weber described a powerful drive in which a spaceship can create a small black hole in front of it, push it in front of it and, by falling into it, can generate ever higher speeds.

However, the question arises as to how the energy for creating a black hole should be generated. Sebastian von Hoerner calculated an energy requirement that corresponds to the output of 40 million nuclear power plants in order to bring 10 tons of payload to 98% speed of light in 2-3 years space ship time. Relativistic space travel should therefore only be possible where immense energy is already in abundance.

The interesting thing about Weber's vision, however, is to use black holes to achieve faster than light speed, since black holes are nothing more than gravity monsters, i.e. gigantic accumulations of matter in extremely small spaces, which due to their monstrous mass do not even let light rays escape. This fact prompts me to do another thought experiment: What effects are to be expected when two black holes are superimposed in the universe?

Final scenario: where am I when I am Endo?

If there are places in the universe where the gravitation is completely canceled out by an overlay of black holes, it is quite conceivable that, because of the energy density, completely new effects can be observed within the gravitation-free space in addition to the superposition area. Is it possible at such places to accelerate masses to faster than light?

It is necessary to steer the thought experiments from special and general relativity theory as well as quantum physics in the direction of superposition if one wants to overcome gravity. According to Einstein's interpretation of the special theory of relativity, which is widespread today, a faster than light speed would enable time travel or at least the sending of messages into the past. Could it be that the calculations made by the US physicist Gerald Feinberg in 1967 about so-called "tachyons", i.e. hypothetical particles that can move faster than c, can become reality through the superposition of two black holes?

Perhaps we will need intergalactic maps of gravitation-free overlaying spaces of black holes, i.e. a so-called hypergravitography, in order to overcome time. At certain imaginary places it could then be permanently possible to overcome all forces of attraction and finally to break out of the prison of space and time. Such singularities, in which the previous laws of physics would be overridden, raise two crucial questions for future space travelers: Where am I when I am endo in relation to gravity and in what exo time do I get out again when I? Leave hyper-superposition space? Inside or outside the event horizon? Or even in another parallel universe as suggested by the quantum theory of Everett's Many Worlds? (Artur P. Schmidt)

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