Cannae's six-unit CubeSat satellite. Render: Cannae Inc.
Experts and enthusiasts have been arguing since 2003 about the possibility of the existence of a hypothetical "magic" electromagnetic EmDrive motor. The principle of its operation is very simple: the magnetron generates microwaves, the energy of their oscillations is accumulated in a high quality resonator, and the fact of the presence of a standing wave electromagnetic oscillations in a closed resonator special form is the source of traction. This creates traction closed loop, that is, in the system completely isolated from external environment , no exhaust.
On the one hand, this engine seems to violate the law of conservation of momentum, as pointed out by many physicists. On the other hand, British inventor Roger Shawyer is a firm believer in the performance of his EmDrive - and (see several hundred pages of discussions on the NASASpaceFlight forum). The tests carried out on Earth (the results of 22 tests) seem to confirm the performance of EmDrive.
It's time to end the controversy.
The final point in the debate intends to put Guido Petta (Guido Fetta) - like-minded Scheuer and the designer of another hypothetical engine Cannae Drive, which works on the same principle: the generation of microwaves and the creation of thrust in a closed circuit without exhaust.
On August 17, 2016, Guido Petta announced that he intended to launch an experimental Cannae Drive into orbit - and test it in action. Guido Petta is the CEO of Cannae Inc. Now Cannae Inc. licensed electromagnetic propulsion technology to Theseus Space Inc., which will launch the CubeSat satellite into low Earth orbit.
Among the founders of Theseus Space are Cannae Inc. itself, as well as little-known firms LAI International, AZ and SpaceQuest.
The launch date has not yet been announced. Perhaps enthusiasts will be able to raise money and build an experimental apparatus in 2017.
The sole purpose of this satellite is to test the Cannae Drive engine for six months. The satellite will try to move using Cannae Drive's electromagnetic propulsion.
Cannae Drive developers say their engine is capable of generating thrust up to several Newtons and "higher levels", which is best suited for use in small satellites. The engine does not require fuel, it has no exhaust.
The volume of the engine on the CubeSat satellite is no more than 1.5 units, that is, 10 × 10 × 15 cm. The power supply is less than 10 watts. The satellite itself will consist of six units.
Cannae satellite. Render: Cannae Inc.
Immediately after the successful demonstration in orbit, Theseus Space intends to offer new engine third party manufacturers for use on other satellites.
Enthusiasts are sure: if EmDrive works, then in the future it will become possible creation not only effective space engines, but also flying cars, as well as ships, aircraft - any transport on electromagnetic traction.
Cannae is not alone in wanting to test the operation of an electromagnetic drive in space. German engineer Paul Kocyla has designed a small pocket EmDrive and is now raising money through a crowdfunding campaign. It costs €24,200 to launch a prototype into space on a PocketQube mini-satellite. In three months, we managed to raise 585 euros.
EmDrive prototype by German engineer Paul Kocyla
Recently scientific work Scheuer were published in the public domain. “All around the world, people have been measuring cravings. Some built engines in their garages, others in large organizations. They all give out cravings, there is no great secret. Someone thinks that there is some kind of black magic here, but this is not so. Any normal physicist should understand how it works. If someone does not understand, it is time for him to change jobs, ”the British engineer categorically.
Did you know,
what is a thought experiment, gedanken experiment?
It is a non-existent practice, an otherworldly experience, the imagination of what is not really there. Thought experiments are like daydreams. They give birth to monsters. Unlike a physical experiment, which is an experimental test of hypotheses, a “thought experiment” magically replaces an experimental test with the desired, untested conclusions, manipulating logical constructions that actually violate logic itself by using unproved premises as proven ones, that is, by substitution. Thus, the main task of the applicants of "thought experiments" is to deceive the listener or reader by replacing a real physical experiment with its "doll" - fictitious reasoning under honestly without physical verification.
Filling physics with imaginary, "thought experiments" has led to an absurd, surreal, confusing picture of the world. A real researcher must distinguish such "wrappers" from real values.
Relativists and positivists argue that the "thought experiment" is a very useful tool for testing theories (also arising in our minds) for consistency. In this they deceive people, since any verification can only be carried out by a source independent of the object of verification. The applicant of the hypothesis himself cannot be a test of his own statement, since the reason for this statement itself is the absence of contradictions visible to the applicant in the statement.
We see this in the example of SRT and GR, which have turned into a kind of religion that governs science and public opinion. No amount of facts that contradict them can overcome Einstein's formula: "If the fact does not correspond to the theory, change the fact" (In another version, "Does the fact not correspond to the theory? - So much the worse for the fact").
The maximum that a "thought experiment" can claim is only the internal consistency of the hypothesis within the framework of the applicant's own, often by no means true, logic. Compliance with practice does not check this. A real test can only take place in a real physical experiment.
An experiment is an experiment, because it is not a refinement of thought, but a test of thought. Thought that is consistent within itself cannot test itself. This has been proven by Kurt Gödel.
Evgeny Zolotov
The story about the "impossible" EmDrive engine has become one of her most read materials. And, of course, I constantly tracked the topic, hoping one day to write a sequel. But such a case was provided only the other day: a reputable scientific journal published an article by a group of employees from one of the NASA laboratories, who not only tested the engine in order to once again measure the emerging thrust, but also submitted a test report to the judgment of independent experts (what is called a peer review ), which did not reveal serious errors. And this means that the possibility of an “impossible” engine has now become an order of magnitude greater.
If you have forgotten or have never heard, let me restore the picture in general terms EmDrive, as it is commonly called, is by by and large an ordinary microwave oven, only made not in the form of a cube, but in the form of a truncated and, most importantly, cone closed on both sides. A microwave emitter is attached to the narrow end, it turns on, and that's it!
There is no fuel that would be thrown "overboard". So, according to classical physics, namely the Law of Conservation of Momentum, thrust cannot arise. However, the inventors of the EmDrive (British engineer Roger Schaer and other individuals who later took up the same topic independently) insist that according to different reasons- due to "quantum imbalance" or something else in the same vein that modern physics does not take into account - thrust does take place and, supposedly, even managed to be measured.
Note that Schaer and others are not at all claiming that Newton's laws are wrong. They only say that they have stumbled upon an effect that will clarify existing laws. This is a fundamentally important point, which greatly helped the "EM-propulsion" - providing it with interest from serious researchers.
This is where the paradoxical part begins. On the one hand, all sane popular science and scientific resources consider such an engine to be pseudoscientific. On the other hand, quite serious people unexpectedly took up it: first, several scientific groups from China, and then NASA. Nothing has been heard about the Chinese since then, but the Americans are not lost: in the US, this work is financed from the pocket of taxpayers, so the results should be available to everyone.
And now, two years ago, the first, very encouraging NASA report appeared: there really is thrust, albeit for an unknown reason. And the other day the prestigious Journal of Propulsion and power publishes from the staff of the NASA Eagleworks laboratory - in which the fact of the occurrence of thrust is again confirmed, and this time on a sensitive torsion suspension in a vacuum (but still on Earth). It also offers a cautious explanation.
The explanation is far from the main part of the article, because it is more of a guess, but it was it that made the most noise. The fact is that an existing theory is involved, which is literally almost a hundred years old: the theory of the pilot wave (Pilot wave). It was put forward back in the 20s of the last century and then clarified several times.
I'm afraid I will explain it only very roughly (and I will be grateful if experts correct!), but the essence, in general, is the assumption that we are forced to describe quantum processes using inconvenient statistical methods only because we do not notice some lower-level real dynamics quantum particles - which actually move like macroscopic bodies, along very specific trajectories determined by the properties of vacuum. This theory came in handy here, because it allows us to explain the vacuum as a medium that supports density fluctuations: EmDrive transfers an impulse to the vacuum (repels from it, as if from water) and this is how thrust arises in a closed system.
Here, two important things should be emphasized. Firstly, the pilot wave theory is not a pseudoscientific fiction, but one of the many equally probable explanations of quantum processes, which satisfactorily accurately describes the observed effects and is confirmed, among other things, by experimental data. And, secondly, the very fact of publishing a NASA article in such a publication at least removes the question of the correctness of measuring thrust on a suspension (remember, this was one of the arguments of skeptics: they say, in real space the engine behaves differently). Simply put, the article can be understood as follows: NASA does not know for sure why thrust occurs, but they know how to measure it - and a simple reader can rely on them for this.
From here - new space for guesses. Omitting the figures, which, in general, should not be given much importance now (the task was to demonstrate the existence of the effect, and the search for optimization ways is on the list for the future), the authors of the work state: already in its current form, EmDrive, although an order of magnitude less efficient than classic rocket engines , but two orders of magnitude more efficient than other "exhaust-free" propulsion, such as a solar sail, laser acceleration, photon engine. Considering that the speed limit is imposed only by the speed of light, and no power at all (nothing prevents building such engines with literally many kilometers of batteries - there would be enough electricity to power them!), This makes EmDrive the most promising direction for research and development of the solar system as minimum.
So, everything now rests on a general check in space. The Chinese, let me remind you, have already intended to carry out this. Have you done it and with what results? Unknown. However, in this case silence makes one more wary than disappointed. After all, it is clear that the first to confirm the operation of such an engine in space, and then the first to give a theoretical justification, will become the founders of a new branch of physics and the fathers of unexpected, unpredictable discoveries and technologies!
As someone well said, we cannot imagine where EmDrive will lead us if it turns out to be true, because we are at the very beginning of the journey. Just as the spectral lines eventually led to the semiconductor revolution, so the "impossible engine" "starting from the vacuum" does not necessarily have to become only the basis for the rocket technology of the future. Side effects will definitely be discovered, related discoveries will be made, new questions will be posed: not every day, year and even a century it is possible to clarify or refute one of the fundamental laws of physics!
And how nice it is that we live just in those days when this story is being written!
The scientific journal of the American Institute of Aeronautics and Astronautics published an article on a strange and controversial device - the EmDrive engine. According to a number of physicists, this design cannot work in principle. This would violate the fundamental law of nature, the conservation of momentum. Others are trying to find a reasonable explanation for why EmDrive still works, or at least reliable evidence that it works. They are attracted to a shaky but grandiose goal - an engine that can turn electricity into thrust without fuel or jet stream. Or - the final closure of a long-term dispute.
A scientific publication can be an important step in the history of the "impossible" engine. Despite the existence of dozens of experimental tests, their results have not been published in peer-reviewed journals. This is hampered by the absence theoretical foundations explaining how EmDrive works. In addition, many experiments cannot be called "clean" - there are many factors that can create the appearance of an engine. We will talk about them later, but we will start with other questions.
What it is?
This is a hypothetical engine proposed by the British inventor Roger Scheuer. Feeding on electricity, he (according to Scheuer and his not too numerous supporters) creates a weak thrust without the use of a working fluid. This strange fact is also indicated by some other experiments. However, the blatant violation of the law of conservation of momentum forces one to approach such statements with particular care - and many experts point to errors in the design of experiments that could create the illusion of a weak but existing thrust.
The miracle engine is arranged simply, any enthusiast who has mastered the control of the soldering iron can assemble it. It consists of two main parts: a magnetron and a resonator. The magnetron is vacuum tube used to generate radiation in a conventional microwave. It consists of a hollow cylinder-anode and a central hair-cathode. Under the action of voltage, electrons fly out from the cathode and begin to move along complex trajectories inside the cylinder, emitting microwaves. They are transmitted along the waveguide from the magnetron to the resonator, which looks like a copper bucket with a lid. According to the inventor of the engine, Roger Scheuer, this is where the fun begins.
According to Scheuer, main feature EmDrive is a form of resonator. The inventor assumes that due to the difference in the diameter of the front and rear walls (as at the bottom of the bucket and its lid), they are affected by forces of different magnitudes caused by a standing electromagnetic wave in the resonator. Their resultant pushes the engine forward, creating thrust, which is directed towards the "bottom". Subsequently, after several messages arguing with this idea, Scheuer clarified that the real mechanism is somewhat more complicated and may be associated with the manifestation of the effects of the special theory of relativity (SRT).
What's wrong with him?
Indeed, if you look at the first explanation of the mechanism of the engine, it turns out that it resembles the story of Baron Munchausen, who pulled himself and his horse out of the swamp by the hair. EmDrive is a closed system that does not throw anything into the surrounding space. Such an object cannot increase its momentum without external influences, just as Munchausen could not increase his own, no matter how hard he pulled. Proponents of the engine parry these arguments by saying that it is possible to admit the repulsion of the resonator from the vacuum state or to involve SRT in the explanation. However, physicists have repeatedly noted the roughness of such estimates or the lack of physical meaning in them.
But still, the essence of Scheuer's statements was not so much in theoretical descriptions, but in the fact that he allegedly fixed the real thrust from the engine. On his website, the researcher indicates a thrust value of about 200-230 mN / kW - more than ion engines, which push spacecraft, throwing out charged particles accelerated in an electric field.
Deciding that it was up to theoreticians to explain this thrust, several groups of experimenters tested the EmDrive in their labs. This work was done by researchers from China's Northwestern Polytechnic University and the Technical University of Dresden. Recently they were joined by the authors of an article published in the Journal of Propulsion and Power, researchers from the NASA Eagleworks division, who traditionally work on the agency's most controversial and "futuristic" projects.
Yes, but small?
The first tests gave seemingly encouraging results: a certain force acted on the switched-on device. However, its value turned out to be much less than the value predicted by Scheuer, and the more accurately the experiment was carried out, the less thrust was recorded. But the point is in principle: where can it even come from? If we do not consider the confused explanations of Scheuer, then we can distinguish several side processes, which theoretically can provide traction. These can be air flows associated with engine heating, or thermal expansion of the experimental setup itself. A weak force can be created by repulsion from charges “settling” on the walls of the test chamber, or by the interaction of the EmDrive with the magnetic fields of the wires, or by the pressure of the radiation leaving the resonator.
The easiest way to deal with air flows is to conduct tests in a vacuum. Such tests were carried out by scientists from Dresden, who found thrust at a level of only 0.02-0.03 mN / kW - at the limit of measurement error. In addition, physicists noted that they used a resonator (the same copper "bucket") with a low quality factor. The radiation quickly left it, increasing the chances for the contribution of other side processes. NASA Eagleworks got a slightly higher figure of 1.2±0.1 mN/kW. At the same time, they claim to have traced all possible sources of side processes.
Is it a lot or a little?
Strictly speaking, a millinewton (mN) is less than the weight of one grain of sugar. But if we talk about jet flight in space, then even a thrust of 1 mN, continuously operating for several years, allows you to disperse a 100-kilogram apparatus to decent speeds.
It can be calculated that in ten years such a probe will accelerate by 3 km / s and (taking into account the starting second cosmic velocity) will overcome about 3.5 billion km. But if we evaluate the thrust at the level that Scheuer promises (200 mN/kW), we will get an acceleration of up to 600 km/s and a distance of 660 astronomical units, the distance from the Sun to the Earth.
So - weakly, but for a very long time and economically spending working body- Ion and photon engines operate. The first "shoot" into space with charged ions accelerated to tens of kilometers per second. Their thrust can reach 60 mN/kW, but they require the use of a working fluid - usually a supply of inert gas. For example, the Dawn apparatus, which recently completed its main mission to explore Ceres, was forced to take on board 425 kg of xenon.
Photon engines have an incomparably lower thrust, on the order of several micronewtons per kilowatt of laser radiation power. The source of thrust in them is the impulse of photons flying out into outer space. But photon engines do not require to take either fuel or working fluid with them.
At the very end of 2016, the Chinese Academy space technologies(CAST) said it has been conducting its own research on the potential of EmDrive and its applications for several years. According to one of the leaders of CAST, Chen Yue, the organization conducted its own, "long-term and repeated" experiments, which confirmed the presence of traction in EmDrive. The prototype used in China produced only a few millinewtons, but in soon new designs designed for 100 mN and more will be developed. Perhaps they will be tested already in orbit.
We must not forget about passive engines that do not require either electricity or fuel for their work - about solar sails. The thrust they develop is determined by the area of the sail and the distance to the Sun. Near the Earth, 1 m² of reflective material will develop a thrust of 0.1 mN. The total thrust of the Japanese experimental apparatus IKAROS with a sail of 200 m² reached just 2 mN. To understand the scale, we add that the thrust of the engines of the super-heavy rocket Saturn V, which sent astronauts to the moon, was 34,000,000 N.
Maybe they are wrong?
The publication of a work in a peer-reviewed scientific journal means that the article has been reviewed by several independent experts in the relevant field. This procedure supports enough high level articles, but even it does not avoid errors.
We can recall how in 2014 the international collaboration BICEP published the results of its many years of research in one of the most prestigious scientific journals Physical Review Letters. Scientists claimed to have discovered traces of gravitational waves while studying the CMB. However, this interpretation was incorrect, and the sensational results turned out to be the influence of galactic dust.
The journal in which the Eagleworks team published their work boasts a seven times lower citation index than Physical Review Letters. Therefore, there is even an opinion that the review procedure in it is not so strict and could miss the work, despite the flaws. It is worth noting that the NASA Eagleworks division itself is a very small laboratory with funding of $50,000 per year. This can hardly be enough to perform high-precision research and purchase the necessary equipment.
It works - okay?
If 100% evidence of EmDrive's performance existed, they would require serious work by theorists. But so far, the absence of an explanation is an unshakable rock against which all the arguments of too big enthusiasts of the “impossible engine” are broken. It even became an argument for refusing to publish early articles in serious scientific journals.
Simpler people like to notice that “it works and it’s okay, you don’t have to know how.” However, this approach can lead to unexpected problems in long-term space missions. For example, if the operation of the engine is associated with magnetic field, then it can behave unpredictably among the magnetic fields of outer space. No one wants the spacecraft to lose its only source of thrust somewhere halfway to Mars or distant Kuiper belt objects. So the classic requirement to provide reliable evidence must be accompanied by a requirement to explain everything that happens in the engine - but so far the creators of EmDrive cannot show either one or the other.
It is interesting to see why professional scientists work with such dubious projects. On the one hand, the discovery of real traction in EmDrive may point to fundamentally new effects and the long-awaited "new physics" beyond the boundaries of existing models. On the other hand, by “closing” the thrust of an impossible engine, scientists will finally be able to resolve a dispute that has long bothered everyone. And along the way - to create new ultra-precise methods for studying ultra-small forces.
Successful space exploration constantly requires mankind to study and discover new technologies that would make it possible to have more powerful equipment and create crew life support systems for further space flights. One such revolutionary technology could be a hypothetical electromagnetic motor EmDrive, which until recently was considered impossible. However, in 2016, NASA published the results of a study and experiments carried out by the engine, which prove its performance. The next step of the American space agency in the study of this issue is to conduct experiments on the EmDrive engine in outer space.
But let's start in order
First of all, let's briefly consider the principle of operation of an ordinary rocket engine. There are three most popular types rocket engines:
- Chemical - the most common type of rocket engine. Its principle of operation is as follows: depending on the aggregate state of the fuel (solid fuel or liquid engine) in one way or another, the oxidizer is mixed with the fuel, forming fuel. After a chemical reaction, the fuel burns out, leaving behind combustion products - a rapidly expanding heated gas. A jet of this gas exits the rocket nozzle, forming the so-called "working body", which is the same "fiery" jet that we often see, for example, in television programs or films.
- Nuclear - a type of engine in which a gas (such as hydrogen or ammonia) is heated as a result of obtaining energy from nuclear reactions (nuclear fission or fusion).
- Electric - an engine in which the heating of the gas occurs due to electrical energy. For example, the thermal type of such an engine heats up the gas (working fluid) with the help of heating element, while static type- accelerates the movement of gas particles using an electrostatic field.
Jet engine assembly
The body of such an engine must consist of non-consumable metal.
Regardless of the choice of engine type, its operation will require an impressive amount of fuel, which makes the spacecraft much heavier and requires more power from the same engine.
EmDrive engine - what is it and how does it work?
In 2001, the British engineer Roger Scheuer proposed new type electric motor, the principle of which is fundamentally different from the principle of operation of the engines listed above.
The design is a closed metal chamber (resonator) in the form of a truncated cone (something like a bucket with a lid), which has a certain reflectance of microwave radiation. The magnetron connected to the cone generates electromagnetic radiation in the microwave range, which enters the resonator and creates a so-called standing wave there. Due to the resonance, the vibrational energy of the microwaves increases.
As you know, light, or electromagnetic radiation, exerts pressure on the surface. Due to the narrowing of the chamber in one direction, the pressure of microwaves on the smaller base of the truncated cone is less than the pressure on the larger base. If we consider the chamber as a closed system, then the result of the effect described above will only be a load on the material of the chamber, and more on one of its sides. However, the creator of the EmDrive engine concept claims that this system is open due to top speed movement of electromagnetic radiation ("speed of light").
The physical principle of operation of such an engine is not fully understood. Roger Scheuer is convinced that the explanation of this technology is possible within the framework of the well-known Newtonian mechanics. Probably, due to the presence of the reflection coefficient of microwave radiation in the chamber, some small part of the radiation goes outside, beyond the resonator, which makes the system open. At the same time, the output of radiation from the side of the larger base of the truncated cone occurs to a greater extent due to the larger area of the base. Then the outgoing microwave radiation will be an analogue of the working fluid, which creates thrust that moves the spacecraft in the opposite direction from the emitted microwaves.
At the same time, NASA researchers suggest that the truth of the engine's operation lies much deeper, in quantum mechanics, in general relativity, according to which the system is open. Simplifying the theory as much as possible, we can say that particles can disappear and be born in a closed space-time loop.
The possibility of implementing the engine in a similar way was evaluated by several research organizations, including NASA.
Experimental results
Over the course of 15 years, many experiments have been carried out. And although the results of most of them confirmed the efficiency of the engine concept, the opinion of independent experts differed from the opinion of experimenters. main reason refutation of the results of experiments is the fact of incorrect formulation and implementation of the experiment.
Finally, the US space agency, which has sufficient resources to create an experiment capable of making a final verdict, took up research on the EmDrive engine. Namely, the NASA experimental laboratory - Eagleworks, where the prototype of the EmDrive engine was designed. The engine was placed in a vacuum, where any thermal convection was excluded, and it turned out that the prototype was indeed capable of delivering thrust. According to a recent NASA report, the lab has been able to obtain thrust having a power factor of 1.2±0.1 mN/kW. This figure is still significantly lower than the power of rocket engines used today, but about a hundred times higher than the power photon engines and solar sails.
With the release of the report on the experiment, the experiment on the engine in terrestrial conditions is probably over. NASA plans to conduct further experiments on the EmDrive in space.
Application
Availability similar engine in the hands of mankind significantly expands the possibilities of space exploration. Starting relatively small - EmDrive, installed on the ISS, would significantly reduce the fuel reserves at the station. This would extend the life of the station, as well as significantly reduce cargo missions for the delivery of fuel. Consequently, funding for missions and maintenance of the station will be reduced.
If we consider an ordinary geostationary satellite on which it will be installed this engine, then the mass of the apparatus will decrease by more than two times. Similarly, the presence of EmDrive will affect the manned spacecraft, which will move noticeably faster.
If we still work on the engine power, then according to the calculations, the potential of EmDrive allows us to deliver six astronauts and some equipment, and then return to Earth in about 4 hours. Similarly, a flight to Mars, with similar technology, will take a couple of months. The flight to Pluto will take about two years. By the way, the New Horizons station took 9 years to do this.
Summing up, it should be noted that the EmDrive technology can significantly increase the speed of spacecraft, save on the operation of vehicles, as well as fuel. In addition, this engine allows mankind to carry out those space missions that have hitherto been at the limit of the possible.
