EmDrive: China's radical new space drive

[Malogg Profile]

EmDrive: China's radical new space drive




Scientists in China have built and tested a radical new space drive. Although the thrust it produces may not be enough to lift your mobile phone, it looks like it could radically change the satellite industry. Satellites are just the start: with superconducting components, this technology could generate the thrust to drive everything from deep space probes to flying cars. And it all started with a British engineer whose invention was ignored and ridiculed in his home country.

The latest research comes from a team headed by Yang Juan, Professor of Propulsion Theory and Engineering of Aeronautics and Astronautics at the Northwestern Polytechnic University in Xi'an. Titled "Net thrust measurement of propellantless microwave thruster," it was published last year in the academic journal Acta Physica Sinica, now translated into English.

The technology is controversial because of that key word "propellantless". Space drives rely on Newton's laws of motion: all are based on the principle of firing propellant out the back at high speed, pushing the spacecraft forward. Even with endless power from solar cells, thrust is still limited by the supply of propellant, even with high-velocity ion drives. Numerous attempts have been made to overcome this, from the infamous Dean Drive of the 1950's to Nasa's experiments with antigravity from spinning superconductors in the 1990's. All have failed, and the efforts of pseudoscientific cranks and scammers have left the field thoroughly discredited.

British engineer Roger Shaywer stepped into this dangerous field in 2001, after twenty years with European satellite firm EADS Astrium. He set up his own company, Satellite Propulsion Research (SPR) Ltd, with the aid of a modest grant from the UK's Department of Trade and Industry.

Shawyer aimed to develop an EmDrive: a closed, conical container which, when filled with resonating microwaves, experiences a net thrust towards the wide end. It seems to violate of the law of conservation of momentum, implied by Newton, which says that no closed system can have a net thrust. However, Shawyer says net thrust occurs because the microwaves have a group velocity which is greater in one direction than the other and Einstein's relativity comes into play. Group velocity, the speed of a collection of electromagnetic waves, is a tricky business -- a pulse of light can even have a group velocity which is greater than the speed of light -- but can it really cause net thrust?

Shawyer built a demonstration thruster to test the theory in 2003. The thrust was tiny -- 16 mN, equal to the weight of a couple of peanuts -- but enough to validate the concept. However, sceptics were quick to attack. None of them actually inspected the apparatus, but Shawyer was assailed from all sides online and in the science press. Criticism was unsophisticated: Newton said it was impossible, therefore he must be a fraud. Even the most advanced theoretical critique, produced by John Costella, a PhD in relativistic electrodynamics, amounted to arguing about the direction of an arrow on one of Shawyer's diagrams.

Shawyer continued to produce and test more advanced demonstrators, working out elaborate ways of ensuring that the test results are valid and not the result of air currents, friction, ionization, interference or electromagnetic effects.

Such effects can easily ruin experiments where small forces are involved. The Nasa investigation into supposed antigravity eventually found that the apparatus was actually causing electronic interference within the measuring system and producing false readings rather than negating the Earth's pull.

Boeing's Phantom Works, which works on various classified projects and has been involved in space research, went as far as acquiring and testing the EmDrive, but say they are no longer working with Shawyer.

In 2007 the Russian Research Institute of Space Systems launched an experimental micro-satellite called Yubileiny (Jubilee) with a "non-traditional" engine which, according to Director Valery Mesnshikov, functions without ejecting reaction mass. However, it was later stated that "further developments" were needed and nothing further appears to be been published on Russian reactionless drives.

Meanwhile, the EmDrive was picked up by Yang at Xi'an, who has a background in space propulsion systems.

The Chinese team took a cautious approach. They started with a new analysis in terms of quantum theory in 2008 which indicated that the theoretical basis was sound and net thrust is possible. The next paper in 2010 quantified the amount of thrust that could be produced, and stated that the team was getting positive experimental results. The latest paper describes their latest thruster and gives the test results in details, showing that with a couple of kilowatts of power they can produce 720 mN (about 72 grams) of thrust.

It may not sound very much, less than three ounces, but in space a little thrust goes a long way. Boeing's advanced XIPS thruster, which fires out Xenon ions at high speed, generates less than a quarter as much thrust from twice as much power. It's used to maintain satellites in position, or move them to a slightly different orbit. Crucially, Xips weights about twenty kilos, more than an equivalent EmDrive, and the propellant for prolonged operation can weigh much more.

Propellant can account for as much as half the launch weight of a geostationary satellite. This means that, in principle, fitting one with an EmDrive rather than a conventional drive, could halve launch costs. Shawyer notes that EmDrives no more powerful than the Chinese one could keep the International Space Station in position without the need for costly refueling.

Meanwhile, Shawyer is moving on to bigger plans. The amount of thrust produced by an EmDrive is determined by the Q value of the cavity, which measures how well it resonates. A tuning fork has a high Q value in air; put it in treacle and it is damped and does not resonate so well. By using superconducting apparatus, Shawyer says that the Q value, and hence thrust, can be boosted by a factor of several thousand -- producing perhaps a tonne of thrust per kilowatt of power. Suddenly it's not about giving a satellite a slight nudge, it's about launching spacecraft.

Shawyer estimates that the prototype superconducting thruster could be ready in 2016. Even the most hardened sceptic would find it hard to ignore a thruster capable of levitating itself in the air. However, the EmDrive cannot violate the law of conservation of energy. It can exert force, but accelerating a vehicle over a distance still requires a huge amount of power, and ultimately it still needs a big power supply. Personal EmDrive jetpacks are unlikely, but Shawyer has plans for a deep space propulsion unit, an EmDrive-assisted spaceplane capable of taking off from an a runway and travelling to Australia in three hours -- and a personal air vehicle the size of a car.

However, aerospace companies are not in a hurry to do business with Shawyer, and he will not be able to build the superconducting thruster without funding.

Yang's experimental work is continuing; she says she is not able to discuss her work until more results are published this year. There is also the tantalising prospect of a demonstration at an aerospace conference. This might make the EmDrive hard to ignore and force a showdown with skeptics. So far the reaction in the west to Yang's work has been muted -- perhaps polite disbelief would be the best description. 2013 may change all that.

http://www.wired.co.uk/news/archive/201 ... old-fusion

Great stuff. . . .

[Malogg Profile]

In 2008 they said it was impossible >>>Chinese Say They’re Building ‘Impossible’ Space Drive



Chinese researchers claim they’ve confirmed the theory behind an "impossible" space drive, and are proceeding to build a demonstration version. If they’re right, this might transform the economics of satellites, open up new possibilities for space exploration –- and give the Chinese a decisive military advantage in space.

To say that the "Emdrive" (short for "electromagnetic drive") concept is controversial would be an understatement. According to Roger Shawyer, the British scientist who developed the concept, the drive converts electrical energy into thrust via microwaves, without violating any laws of physics. Many researchers believe otherwise. An article about the Emdrive in New Scientist magazine drew a massive volley of criticism. Scientists not only argued that Shawyer’s work was blatantly impossible, and that his reasoning was flawed. They also said the article should never have been published.

"It is well known that Roger Shawyer’s ‘electromagnetic relativity drive’ violates the law of conservation of momentum, making it simply the latest in a long line of ‘perpetuum mobiles’ that have been proposed and disproved for centuries," wrote John Costella, an Australian physicist. "His analysis is rubbish and his ‘drive’ impossible."

Shawyer stands by his theoretical work. His company, Satellite Propulsion Research (SPR), has constructed demonstration engines, which he says produce thrust using a tapering resonant cavity filled with microwaves. He is adamant that this is not a perpetual motion machine, and does not violate the law of conservation of momentum because different reference frames apply to the drive and the waves within it. Shawyer’s big challenge, he says, has been getting people who will actually look into his claims rather than simply dismissing them.


Such extravagant claims are usually associated with self-taught, backyard inventors claiming Einstein got it all wrong. But Shawyer is a scientist who has worked with radar and communication systems and was a program manager at European space company EADS Astrium; his work rests entirely on Einstein being right. The thrust is the result of a relativistic effect and would not occur under simple Newtonian physics. Many have dismissed his work out of hand, and British government funding has ceased. He has had some interest from both the United States and China. Now the Chinese connection with the Northwestern Polytechnical University (NPU) in Xi’an seems to have paid off.

"NPU started their research program in June 2007, under the supervision of Professor Yang Juan. They have independently developed a mathematical simulation which shows unequivocally that a net force can be produced from a simple resonant tapered cavity," Shawyer tells Danger Room. "The thrust levels predicted by this simulation are similar to those resulting from the SPR design software, and the SPR test results."

What’s more, Shawyer says, NPU is "currently manufacturing" a "thruster" based on this theoretical work.

The NPU have confirmed that they have reproduced the theoretical work, and are building a demosntration version of the Emdrive.

Needless to say, independent confirmation is a big deal — though many will want to see it published in a peer-reviewed journal. Even when it is, I doubt the controversy will subside. Prof. Yang has plenty of experience in this type of area, having previously done work on microwave plasma thrusters, which use a resonant cavity to accelerate a plasma jet for propulsion. While the theory behind the Emdrive is very different, the engineering principles of building the hardware are similar. The Chinese should be capable of determining whether the thruster really works or whether the apparent forces are caused by experimental errors.

The thrust produced is small, but significant. Shawyer compares a C-Band Emdrive with the existing NSTAR ion thruster used by NASA. The Emdrive produces 85 mN of thrust compared to 92 for the NSTAR (that’s about one-third of an ounce), but the Emdrive only consumes a quarter of the amount of power and weighs less than 7 kilos, compared to over 30 kilos. The biggest difference is in propellant: NSTAR uses 10 grams per hour; the Emdrive uses none. As long as it has an electricity supply, the Emdrive will keep going.

The possibilities are phenomenal: Instead of going out of service when they run out of fuel, satellites would have greatly extended endurance and be able to move around at will. (We wouldn’t have to shoot them down because of the risk from toxic fuel either.) Deep space probes could go further, faster –- and stop when they arrive. Shawyer calculates that a solar-powered Emdrive could take a manned mission to Mars in 41 days. Provided it works, of course.

What will China do with the technology? It may be relevant that professor Yang is not unknown in military circles, having published a paper called "Plasma Attack Against Low-Orbit Spy Satellites."

Meanwhile, what about the American interest? Shawyer told me that "the flight thruster program is on hold for the present. [O]nce the U.K. government had provided an export license for a U.S. military application, the major U.S. aerospace company we had been dealing with stopped talking to us. "

The company may have decided that the Emdrive could not work. If they’re wrong, China has at least a year’s head start in a technology that will dominate space and make previous satellites as obsolete as sailing ships in the age of steam.



http://www.wired.com/dangerroom/2008/09 ... e-buildin/

Now 2013 the impossible has become the probable

[I2haveseen Profile]

Yeah I first heard about the Relativity Drive (now called Em Drive) in greenglow (Link below: there was a vid 2, but I can't find it, sozz). It's was the breaking of N's 'conservation of momentum' that got the brains upset (big claims, big proof & all that.... Fair nuff).

But that sort of rang untrue to me (sort of???), IDK?? Closed system, fair nuff, but is it??? Or is it just our current perspective???? IDK???? Something is 'off' somewhere (I just can't see it).

On the other hand: WTF is he on about????

amounted to arguing about the direction of an arrow on one of Shawyer's diagrams

Did I say 'WTF???????'
tjhose arrows he's referring to are vectors: AKA ~ they have inertia that gives direction, and that direction (flow if you like) is crucial for calculations. WTF????


http://tech.groups.yahoo.com/group/greenglow/ (◄ Great debates/insights here peeps )
http://www.emdrive.com/

Gr8 post Malogg

[Cia212 Profile]

On the other hand: WTF is he on about????

amounted to arguing about the direction of an arrow on one of Shawyer's diagrams

tjhose arrows he's referring to are vectors: AKA ~ they have inertia that gives direction, and that direction (flow if you like) is crucial for calculations. WTF????

You're right, that arrow could make all the difference in the world, but it's passed off as a trivial critique.

It made enough of a point that "Shawyer has since published a new theory paper (version 9.4) where the paragraph criticized by Costella is simply omitted."

We'll see what happens, but I think the Chinese are wasting their money.

[Clearized1 Profile]

Mass of objects is always the enemy to energy efficient travel, whether it be on Earth, or in space.

I remember watching a 1985 movie called "Explorers". In it a young kid dreams of a circuit, that ultimately when they build it and hook it up to their computer creates a bubble (photon bubble??) that they can control the size/movement of with the computer.

Now, the movie itself was pretty cheesy, but to this day it has stuck in my head, and always had me wondering if it is possible to do something like this, and have it encompass any object of mass, thereby negating the mass of the object, and therefore making travel extremely energy efficient.

Before everyone rips me a new one....I know this is taking a hypothetical idea from a movie of all things... but then again in "Jurassic Park" they talked of recreating prehistoric animals using discovered DNA, and these days scientists are considering this very same idea.....so who knows.

[Cia212 Profile]

Mass of objects is always the enemy to energy efficient travel, whether it be on Earth, or in space.

I remember watching a 1985 movie called "Explorers". In it a young kid dreams of a circuit, that ultimately when they build it and hook it up to their computer creates a bubble (photon bubble??) that they can control the size/movement of with the computer.

Now, the movie itself was pretty cheesy, but to this day it has stuck in my head, and always had me wondering if it is possible to do something like this, and have it encompass any object of mass, thereby negating the mass of the object, and therefore making travel extremely energy efficient.

Before everyone rips me a new one....I know this is taking a hypothetical idea from a movie of all things... but then again in "Jurassic Park" they talked of recreating prehistoric animals using discovered DNA, and these days scientists are considering this very same idea.....so who knows.

If you negate mass, you also negate thrust. So it really doesn't help. Antigravity would help get you to space cheaper, but it doesn't seem to work.

Gravity control would solve the problem, but that hasn't been successfully demonstrated - unless you believe Edgar Fouche's version of TR-3B research.

[Iwanci Profile]

Do we think that the US may already have such a drive ? I believe that by the time we hear of things they are probably already 15 - 20 years old...

[I2haveseen Profile]

Mass of objects is always the enemy to energy efficient travel, whether it be on Earth, or in space.

I remember watching a 1985 movie called "Explorers". In it a young kid dreams of a circuit, that ultimately when they build it and hook it up to their computer creates a bubble (photon bubble??) that they can control the size/movement of with the computer.

Now, the movie itself was pretty cheesy, but to this day it has stuck in my head, and always had me wondering if it is possible to do something like this, and have it encompass any object of mass, thereby negating the mass of the object, and therefore making travel extremely energy efficient.

Before everyone rips me a new one....I know this is taking a hypothetical idea from a movie of all things... but then again in "Jurassic Park" they talked of recreating prehistoric animals using discovered DNA, and these days scientists are considering this very same idea.....so who knows.

If you negate mass, you also negate thrust. So it really doesn't help. Antigravity would help get you to space cheaper, but it doesn't seem to work.

Gravity control would solve the problem, but that hasn't been successfully demonstrated - unless you believe Edgar Fouche's version of TR-3B research.

Dude. Thats the whole idea of EMDrives. The problen as I see it, is whether or not a closed sytem (the EMDrive) can give thrust. More to the point: how could/dose it work? What the underling mechanism?

Clearized1, can't help but feel 'Before everyone rips me a new one' has connotations on me? Maybe I should 'rip' that out of my sig (hasn't really helped me avoid shit stirreres anyway i guess)????? I'll give it some though on rephaseing


Iwanci, at least

[Cia212 Profile]

Mass of objects is always the enemy to energy efficient travel, whether it be on Earth, or in space.

I remember watching a 1985 movie called "Explorers". In it a young kid dreams of a circuit, that ultimately when they build it and hook it up to their computer creates a bubble (photon bubble??) that they can control the size/movement of with the computer.

Now, the movie itself was pretty cheesy, but to this day it has stuck in my head, and always had me wondering if it is possible to do something like this, and have it encompass any object of mass, thereby negating the mass of the object, and therefore making travel extremely energy efficient.

Before everyone rips me a new one....I know this is taking a hypothetical idea from a movie of all things... but then again in "Jurassic Park" they talked of recreating prehistoric animals using discovered DNA, and these days scientists are considering this very same idea.....so who knows.

If you negate mass, you also negate thrust. So it really doesn't help. Antigravity would help get you to space cheaper, but it doesn't seem to work.

Gravity control would solve the problem, but that hasn't been successfully demonstrated - unless you believe Edgar Fouche's version of TR-3B research.

Dude. Thats the whole idea of EMDrives.

Not really.

Basically, he's saying that a container filled with microwaves can produce thrust by having unequal forces acting on the sides of the vessel. This seems to violate Maxwell's equations and momentum conservation.

He explains this by saying that the vessel's shape (a tapered end) causes the group velocity of the wave to change and results in the experienced pressure difference. I've read 2 articles trying to find out exactly how that's supposed to create the thrust, but it wasn't answered - that leads me to believe this doesn't actually work. Nevertheless, he claims his prototype can produce 90 millinewtons on 700 watts of power.

If it does work, and the vessel could be made of (or lined with) a superconducting material, they expect to extract 30 newtons per watt of input. That's a CRAZY high number but, if it's true, you could create Iron Man-style boots to allow flight with only 25-35 watts of power...or about what a gaming laptop uses.

[I2haveseen Profile]

Ya shitin me, right? Have you read this thread?