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NASA says puzzling new space drive can generate thrust without propellant

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August 2, 2014

According to a puzzling report, a new thruster design appears to be able to accelerate a c...

According to a puzzling report, a new thruster design appears to be able to accelerate a craft without the use of propellant (Image: Cannae)

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A NASA study has recently concluded that the "Cannae Drive," a disruptive new method of space propulsion, can produce small amounts of thrust without the use of propellant, in apparent discordance with Newton's third law. According to its inventor, the device can harness microwave radiation inside a resonator, turning electricity into a net thrust. If further verified and perfected, the advance could revolutionize the space industry, dramatically cutting costs for both missions in deep space and satellites in Earth orbit.

The basic principle behind space propulsion is very simple: for every action, there is an equal and opposite reaction. Use a rocket engine to throw mass one way, get propelled the other way. And according to the law of conservation of momentum, the more mass you throw behind you and the faster you throw it, the stronger your forward thrust will be.

One consequence for space travel is that, to counter Earth's gravity and reach orbital velocity, rockets need to carry a very large amount of propellant: For instance, in the now-retired Space Shuttle, the mass of the fuel was almost twenty times greater than the payload itself. In satellites the impact is smaller, but still very significant: for geostationary satellites, fuel can make up as much as half the launch weight, and that makes them more expensive to launch and operate.

But now, a NASA study has concluded that a new type of spacecraft propulsion is able to generate thrust without propellant. This appears to violate the law of conservation of momentum: in other words, if no mass (fuel or otherwise) is being ejected from the system, where is the thrust coming from? Where is the equal and opposite reaction?

The thruster appears to work by resonating microwave radiation to produce a net force (Ima...

According to its inventor, US scientist Guido Fetta, the thruster works as a resonating cavity for microwave radiation. The cavity redirects the radiation pressure to create an unbalanced force, and that force produces a net thrust.

In its study NASA didn't attempt to explain the phenomenon, and instead contented itself with verifying that the system did indeed generate a small amount of thrust, between 30 and 50 micro-Newtons. This is a tiny amount, only enough to levitate a mass of three to five milligrams (a few eyelashes) here on Earth; but, astonishingly, it is a net thrust nonetheless.

"Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma," the study concludes.

The system has many striking similarities with the EmDrive, designed by British aerospace engineer Roger Shawyer, although the explanation that Shawyer provides for the working mechanism is quite different from Fetta's or NASA's.

According to one peer-reviewed paper, the EmDrive thruster was able to produce 720 mN of t...
According to one peer-reviewed paper, the EmDrive thruster was able to produce 720 mN of thrust from an electricity input of 2.5 kW (Photo: EmDrive)

"At first sight the idea of propulsion without propellant seems impossible," says Shawyer. "However, the technology is firmly anchored in the basic laws of physics and following an extensive review process, no transgressions of these laws have been identified."

According to Shawyer, the thruster works because of relativistic effects: the microwaves are moving at a significant fraction of the speed of light at both ends of the resonator, and so, he claims, the resonator and the microwaves have two separate frames of reference, with the two forming an open system that ultimately doesn't violate the laws of physics, conservation of momentum included.

The interesting thing about EmDrive is that, back in 2009, a Chinese peer-reviewed journal tested Shawyer's thruster design, registering 720 mN of thrust at an input power of 2.5 kW. That's enough to make a tennis ball hover, and then some; in fact, if the results are confirmed, such levels of thrust would already be practical for satellitar applications.

Salient characteristics of the EmDrive compared to a more conventional ion propulsion syst...
Salient characteristics of the EmDrive compared to a more conventional ion propulsion system (Image: EmDrive)

The system could generate electricity from solar panels, and because it is much lighter than current thrusters, it could more than halve the weight launch of satellites, leading to very significant reductions in launch costs. A practical microwave thruster could also meaningfully extend the lifetime of satellites and pave the way for deep space robotic missions.

Even beyond that, Shawyer claims that the second generation of his fuel-less thrusters, based on superconductor technology, will be capable of producing an impressive specific thrust of 30 kN per kW of input energy. "Thus for 1 kilowatt (typical of the power in a microwave oven) a static thrust of 3 tonnes (3.3 tons) can be obtained, which is enough to support a large car. This is clearly adequate for terrestrial transport applications."

But before we start talking Sun-powered flying cars and weekend trips to Pluto, the scientific community will undoubtedly need to dissect the experiment with great care and independently verify whether the tiny net thrust reported by NASA could after all be attributed to some external cause that the researchers didn't account for.

Sources: Cannae, EmDrive via Wired

About the Author
Dario Borghino Dario studied software engineering at the Polytechnic University of Turin. When he isn't writing for Gizmag he is usually traveling the world on a whim, working on an AI-guided automated trading system, or chasing his dream to become the next European thumbwrestling champion.   All articles by Dario Borghino
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44 Comments

I'm afraid the author doesn't understand the difference between mass and force.

The Master
2nd August, 2014 @ 11:24 pm PDT

"But Captain, I 'can nae' changes the laws of Physics!"

RIP, Scotty!

Robert Walther
3rd August, 2014 @ 03:35 am PDT

This article belongs in your "April Fool" issue.

DavidFMayerPhD
3rd August, 2014 @ 06:32 am PDT

"According to Shawyer, ...the microwaves are moving at a significant fraction of the speed of light..."

On the contrary, microwaves move at exactly the speed of light. Microwaves ARE light.

Most of the explanatory (?) part of the article seems to come from Shawyer, who is NOT the inventor of the device reported by NASA. I'm missing something?

piperTom
3rd August, 2014 @ 08:00 am PDT

That's awesome but "At first sight the idea of propulsion without propellant seems impossible," isn't true, IKAROS has already deployed a working solar sail and the idea of light sails has been around for decades.

Elie Morisse
3rd August, 2014 @ 08:09 am PDT

Some related information here:

http://en.wikipedia.org/wiki/EmDrive#NASA_replication

PolishBear
3rd August, 2014 @ 08:44 am PDT

Fascinating! An electronic Dean Drive.

http://en.wikipedia.org/wiki/Dean_drive

The Dean drive was a device created and promoted by inventor Norman Lomer Dean (1902–1972) that he claimed to be a reactionless drive.

DemonDuck
3rd August, 2014 @ 10:23 am PDT

A photon drive in microwave.

Slowburn
3rd August, 2014 @ 10:36 am PDT

microwave powered cars means we'll need fireproof asphalt

SuperFool
3rd August, 2014 @ 12:20 pm PDT

Even beyond that, Shawyer claims that the second generation of his fuel-less thrusters, based on superconductor technology, will be capable of producing an impressive specific thrust of 30 kN per kW of input energy. "Thus for 1 kilowatt (typical of the power in a microwave oven) a static thrust of 3 tonnes (3.3 tons) can be obtained, which is enough to support a large car. This is clearly adequate for terrestrial transport applications."

hahah. going from micro newtons, to kilonewtown. 9 orders of magnitutdes---a factor of 1 billion .

this is where science becomes science fiction. outrageous claims .

zevulon
3rd August, 2014 @ 12:46 pm PDT

Oh but yesssss let's start talking flying cars, I can totally spare 1kW in my 300kW Tesla S to make it hover. Will be called the Model H.

BeWalt
3rd August, 2014 @ 12:51 pm PDT

A starship capable of traversing interstellar distance can be possible still in our lifetime with phased standing waves. www.youtube.com/watch?v=6zh9abFF3ZE&feature=youtu.be

Bob Johns
3rd August, 2014 @ 05:18 pm PDT

Well there is a mass energy equivalence.

If the energy is added from one direction will that impart momentum as well?

Craig Jennings
3rd August, 2014 @ 06:50 pm PDT

zevulon: "hahah. going from micro newtons, to kilonewtown. 9 orders of magnitutdes---a factor of 1 billion .

this is where science becomes science fiction. outrageous claims . "

The specific numbers aren't something to be hung up on, really. A violation of conservation of momentum is a violation, no matter what the scale. Micronewtons or meganewtons, it doesn't matter, as soon as you throw out momentum things get spooky fast. Talking relativistic weapons here, with incredibly low launch costs. It's almost fortunate that this is probably some unforeseen experimental error, as with the FTL neutrinos.

Eagleon
3rd August, 2014 @ 09:31 pm PDT

Something this article doesn't mention is that the NASA researchers tested two Cannae Drives - the second one was to be used as a control, so it was configured slightly differently to ensure that it wouldn't produce any thrust.

It produced just as much thrust as the first one.

M C
3rd August, 2014 @ 10:23 pm PDT

If NASA has put it in writing that they cannot explain it, that is good enough for me to accept that there is something to be explored here. Whatever mistakes, if any, that may have been made in transferring their press release (I assume) into this article is neither here nor there.

I suppose the first step is to determine what similarities exist in this Cannae drive and Shawyer's EmDrive and then see if that exercise provides any clues as to what is going on. Now is almost, but not quite, the time to wet our knickers in excitement.

Mel Tisdale
4th August, 2014 @ 03:01 am PDT

As reputable scientists repeatedly say, "Science doesn't know everything. New principles and new methods are still being discovered and always will be." That's why science is wiling, even eager to revise itself as new evidence is discovered.

James Smith
4th August, 2014 @ 03:48 am PDT

It is quite possible, that the thrust is produced 'against the universe', or 'against the dark matter', so no Newton harmed.

What is unbeliveable, that how much power level is needed to produce thrust at higher speeds.

Let's belive, that EmDrive can produce 0,72N at 6944m/s from 2,5kW at standstill.

But if EmDrive would produce the same 0,72N from the same 2,5kW at 6944m/s speed, then it would be 200% energy efficiency.

Enter the perpetuum mobile.

So, imho, the massless thrust principle would be only reasonable, if the 100% efficiency point could be reached only at the speed of light.

However, that could give only 8,3 microNewton theoretical thrust from 2,5kW power.

Rumata
4th August, 2014 @ 04:58 am PDT

I vaguely remember a cover story by either Popular Science, or Popular Mechanics? that had to do with "microwave levitation" back in the 1970s, maybe.

mitcorb
4th August, 2014 @ 05:54 am PDT

"Even beyond that, Shawyer claims that the second generation of his fuel-less thrusters, based on superconductor technology, will be capable of producing an impressive specific thrust of 30 kN per kW of input energy."

Fuel-less? I seem to recall the input of energy in the form of Watts.

For a story that is bigger than the invention of the wheel, I'm a little surprised at the casual treatment of basics. Even if this device is powered by a solar cell, it requires fuel. Just not reaction mass.

jimbo92107
4th August, 2014 @ 06:56 am PDT

If this is true, maybe the early studies just don't understand the source well enough. There probably is an action that is not understood and the reaction therefore seems to run against Newton's law.

flylowguy
4th August, 2014 @ 08:14 am PDT

They should redo their experiment in vacuum to rule out air currents caused by the ionic wind effect. If it passes that test we will know if its a genuine breakthrough.

Neil Farbstein
4th August, 2014 @ 08:25 am PDT

I'm sorry but this isn't an informative article - the attempt to provide details on what might be happening is useful, but ultimately, doesn't get to the crux of explaining what NASA have done and why the results are baffling.

The best comments here on this are from M C and Neil Farbstein.

Point #1 from M C:

Something this article doesn't mention is that the NASA researchers tested two Cannae Drives - the second one was to be used as a control, so it was configured slightly differently to ensure that it wouldn't produce any thrust.

It produced just as much thrust as the first one.

-- Indeed! The second was considered 'null'. It still produced thrust. That means the measurements were recording something that they should not have been recording, or the thrust is being generated in a way that isn't understood. My bet is on the first.

Point #2 from Neil Farbstein:

They should redo their experiment in vacuum to rule out air currents caused by the ionic wind effect. If it passes that test we will know if its a genuine breakthrough.

-- Again, indeed! The researchers used a vacuum chamber... but didn't create a vacuum. They left it at atmospheric pressure. There's no obvious explanation for why here.

I've expanded on all of these points in my write-up here:

http://www.techly.com.au/2014/08/04/impossible-space-thruster-proven-work-nasa-one-understands/

Tristan_
4th August, 2014 @ 08:43 am PDT

My thoughts would be anti-gravity effect or magnetic repulsion.

Both have legs.

I'd want it tested in space far enough away to negate the above!

esar
4th August, 2014 @ 08:50 am PDT

Photons have momentum, as a great variety of experiments have shown: it belongs to Einstein's energy-momentum tensor, rather than a Newtonian mv (as photons do have energy, just no rest mass).

For this system to push spaceships around the solar system it would have to emit a _lot_ of high energy photons, which would (a) require plenty of fuel and (b) work like a bunch of death rays crossing space.

Geometeer
4th August, 2014 @ 09:55 am PDT

Someone mentioned relativistic weapons, but there's a more immediate concern.

I read an article about the emDrive a few years ago and if attached to a nuclear weapon, it has no launch trail and can't be tracked by conventional methods like missiles are. You could launch a silent nuclear attack and the target country would have no idea where it came from.

That this technology fell into the hands of the Chinese government because the west thought it was junk science may one day prove to be a historic tragedy.

Steven Bell
4th August, 2014 @ 10:23 am PDT

"According to its inventor, the device can harness microwave radiation inside a resonator, turning electricity into a net thrust."

Maybe I'm missing something here, but it looks to me that there is indeed a propellant mass, thereby keeping Newton from spinning in his grave:

I'm not sure how the "resonator" works to convert microwave radiation into electricity, but electricity is "electrons on motion," usually in the form of a chain of "electron swap" reactions moving down a conducting wire. There's enough mass in the electron to knock another electron out of its orbit around the nucleus of an atom, such as copper, and replace it. The new loose electron than knocks loose an orbiting electron from another atom and the cycle repeats.

That's what they taught me in Navy electronics school back in the 60's, at least. Of course, we were still using vacuum tubes back then, but I haven't heard of a repeal of this basic electricity principal.

Electrons have mass, though admittedly not very much. When you mash them up with neutrons and electrons, you get atoms, which assuredly have mass.

So, if you can figure out how to convert microwave radiation into electricity and then blow out all the resulting electrons in one direction, as seems to be the case, you do indeed have a propulsion mass. But, not very much.

Am missing something here?

ClassicPlastic
4th August, 2014 @ 11:24 am PDT

Ha! I delight when people just can't believe a "law" of physics can't be broken. They can, they have, and they continue to be. Perpetual motion is impossible? How long has the earth and other planets been rotating AND orbiting? Seems pretty perpetual to me. We will duplicate that someday. Now, look at any pre-60's race car. Notice the skinny tires? That's because engineers "KNEW" that wider tires would not result in better traction; there would be less lbs/sq.in. downward pressure. It wasn't until an "uneducated" experimenter, I believe it was Mickey Thompson, but I'm not sure, tried it. Voila! Traction! Apparently, tire rubber didn't know about that law. Admit it, we don't "know" as much as we'd like to think we know…there was a time, in the 1800's, when they were convinced that anything traveling at a mile a minute would disintegrate…that was soon updated to anything traveling at the speed of sound…then in the 50's, uh oh, time for another update. How about we keep an open mind, because an open mouth might find crow in it!

Old J Hawthorne
4th August, 2014 @ 01:00 pm PDT

Give the spacecraft a can of beans a day. Problem solved.

Cliff Ross
4th August, 2014 @ 01:34 pm PDT

It has been many decades since I studied any physics and I admit at that time it was more in support of studying chemistry. I do seem to remember at near relativistic velocities that there started to be a blurring between matter and energy.

Could not the source of the thrust be some form of energy cluster or possibly some quantum particle being ejected? Energy is being injected into the system, it only makes sense that energy is being ejected also. If not the energy state of the system as a whole must be increasing.

Assuming the results have actually been verified (even if actual output reported differs) by NASA, I think we can probably eliminated most sources of experimental error and subsequent analytical error. This is not to say there are undetected errors being introduced, just that the source of error is one that the researchers being unable to deduce brings no evidence of deliberate fraud if the error is detected in the future.

If no error exists, as several people have postulated, there may be previously unknown or unproven forces coming into play.

NatalieEGH
4th August, 2014 @ 03:14 pm PDT

This is the worst article I've read on GizMag. Of course, microwave/light based propulsion is possible, without propellant. Microwaves are photons and photons have momentum. This is why stars can bend light with their gravity. This is why blackholes are called blackholes!!! Another example is when sunlight strikes the black-painted pin-wheel under glass, and spins it (WITHOUT PROPELLANT!!!). Photons having momentum is standard physics, no conflict.

ACE
4th August, 2014 @ 03:15 pm PDT

There may be no difference between mass and force.

It is time for some Billionaire to throw down the gauntlet to Shawyer ....... Offer him a big prize to build a bigger one and test it very publicly.

Let's get cracking.

99gusPuppet
4th August, 2014 @ 04:51 pm PDT

NASA tested a rather crude Biefeld-Brown device in a vacuum and concluded it wouldn't work.

Nevermind that their design was unlike what anyone else has made or that some have been tested anchored to a balance scale with blocking so that any air moved by ionic wind would strike the block and thus cancel any such thrust, and they still make the scale rise. Some have even been tested inside a plastic bag so no matter how the air inside the bag moves is can produce no net thrust and the thing still lifts.

Some people have built them powerful enough to lift small loads, and measured the speed and volume of the ion wind moved air - and that airflow is less than would be required to lift the device and payload.

I'd like to see one of these made with a large number of small cells and an electrode grid above to match, then encase it in lightweight expanding foam to ensure there can be no ion wind air moving effect.

There's something else going on other than just blowing air, but when NASA and others that are seeking to "debunk" instead of actually research and investigate a thing deliberately build test apparatus completely unlike any that have been demonstrated to work, then declare "It doesn't work. Nothing to see here."...

What's held back significant research on the Biefeld-Brown effect is that most people fiddling with them also go on and on about perpetual motion and over-unity electrical devices. (One would be that J. Naudin guy in France...)

Now if some big money company would get into R&D on it, there'd be acceptance of the results, even if they were no better (or even worse) than the best that hobbyists have built.

Gregg Eshelman
4th August, 2014 @ 05:01 pm PDT

I've read the abstract of the NASA paper, but not the full article.

http://ntrs.nasa.gov/search.jsp?R=20140006052

The abstract presents little indication controls were implemented to eliminate any of the other effects that could appear as thrust in the test. The electrical (microwave) power levels are very high and the forces are very small making it difficult to know if the measure "thrust" is from a source other then already know effects that are of no value in propulsion of any vehicle. In the short time I've thought about this test I've thought of two well known effects, radiometer and magnet, that could be sources of the forces.

At this level of forces it could be a Crookes radiometer. By applying 2.5 kWatts of power continuously (Over 2 1/2 times the power of a microwave oven) the device would have gotten very hot. They said they had the device in a vacuum chamber with the door closed but kept it a room pressure. They could have easily tested if this is a Crookes radiometer by applying a vacuum in the chamber. Reducing the air pressure will first cause the effect to increase then decrease and become zero at hard vacuum. All that is necessary to cause the radiometer torque is a difference in temperature from one side to the other. Power was being applied so differential temperatures must have developed. While it is not obvious that the tested device is a different color at one end then the other as would be the case for the Crookes radiometer effect, it has been shown simply bending the veins of a radiometer will produce torque without a color difference. This device is shaped very differently on one end then the other.

http://en.wikipedia.org/wiki/Crookes_radiometer

If they had ruled out magnetics they should have said something more then they did. The only thing said is they turned the device around. This is a normal practice in magnetic testing but at these vanishingly small levels of forces it is woefully inadequate because you cannot precisely reverse everything in the test. In collage we used a torsion balance (the same device used in the test) to measure the gravitational attraction between spheres about 2 inches in diameter. That worked very well but did not include an electric current with it's induced magnetics that would significantly complicate the measurements. To show there is no magnetic interaction you need to use field coils to alternately strengthen, cancel and reverse the Earths magnetic field. If they didn't say something, they didn't do it!

Since none of the articles, including the abstract of the paper, talk about what was done to rule out magnetic effects I'll assume magnetis is the source of the "thrust." The measurements were made with a torsion balance. It actually measures torque not thrust. The electric current sent into the device will produce a magnetic field regardless of what you do to limit the effect. The induced magnetic field will interact with the earths magnetic field and produce a torque, exactly what was measured!

Dominic From NASA
4th August, 2014 @ 06:31 pm PDT

Scenario 1: Its a mistake in the experiment.

Scenario 2. It really works and it will be developed.

Scenario 3. It will be announced that it is a mistake, but it actually works and will be developed underwraps for 'national security reasons'.

asdf
4th August, 2014 @ 06:35 pm PDT

I find it very funny that there are so many people saying "Nay, this can't work because of (X, Y, or Z) isn't happening. The ONLY thing that is constant in this world is change. When a so called law of nature is proven to be incorrect, the scientists have to make changes in that "Law" to accommodate the new information.

Give the process a chance. It may be incorrect, but then again it may really work. That is the fun of trying new things to find out if they work.

BTW, Before the Wright brothers proved powered flight was possible, there were a lot of people saying that it couldn't be done either.

JMOdom
4th August, 2014 @ 06:55 pm PDT

Wow! NASA's roc-heads admit that Newton may be fallible after all... and there are no comments?

Interesting.

Griffin
4th August, 2014 @ 09:23 pm PDT

The linear motor provides propulsion, without mass ejection, unless you regard the rail as mass ejected, which as its 'sucked in' at one end and ejected from the other, is not really the same as ejecting mass carried on the craft.

Nik
5th August, 2014 @ 04:14 am PDT

The British “inventor” is a scam artist, preying upon people who can’t do math. So his most recent claim of being able to build a superconducting Em-drive, capable of accelerating a 3-tonne mass at 1G with 1kw of input, pans out like this:

P = E / t

E = P x t = 1/2mv^2

So in the first second of time (t=1), this of 3000 kg would be accelerated to 9.8 meters per second, through the expenditure of 1000 joules (1 watt = 1 joule per second, 1 joule = 1 kg-m^2/sec^2)

At t=1:

Energy “in” is 1000 joules

Energy of the object = 1/2 mv^2 = 1/2 x 3000 x 9.8^2 = 144060 joules

Basic physics would be severely “violated”, it would seem, so at least one inventor is either nuts, or sucking an energy multiplier of 144 out of an alternate universe … not by a little, but in gobs. And I wonder why science reporters still don’t know basic physics and can’t do simple math? What do you think?

Richard Vesel
5th August, 2014 @ 08:37 am PDT

is this akin to rubbing a notched stick to spin a propellor at its' end?

redjeff53
5th August, 2014 @ 09:53 am PDT

I fail to understand all the scientific wonder at this phenomena . all the energy in the universe was once matter or mass. to harness this energy first discard the conventional laws. then think about the basics. most scientists coach their thinking in the known and conventional. thus the two most commonly heard phrases " THATS IMPOSSIBLE' and " IT,S AN ANOMALY " BOTH ARE FALSE!!!!

Bob Reidel
6th August, 2014 @ 08:18 am PDT

@ Tristan_

Or the guy sabotaging the second device didn't know what he was doing and changed something unimportant.

Slowburn
10th August, 2014 @ 11:33 pm PDT

God forbid we ever have any meaningful breakthrough in propulsion technology! We are still using rockets and fans to move around. Everything is always "impossible" to you people! Where is your hope!

Clint Sharp
4th September, 2014 @ 01:58 pm PDT

And one more thing. If humanity had any freaking common sense and cared about progress AT ALL they'd just build one of the stupid things, throw it up there on a rocket and see if the dang thing works! But because of our invisible made up currency and "power" structure we can't get anything done for DECADES because a project gets crested and then someone else just cancels it five years later. You suck!!! Eat me.

Clint Sharp
4th September, 2014 @ 02:06 pm PDT
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