Electromagnetic Drive Produces Thrust in Vacuum: NASA:

http://www.spacedaily.com/reports/N...NOT_Working_on_Warp_Drive_Technology_999.html
"NASA is not working on 'warp drive' technology."
extract:
One of the reasons scientists are urging caution in evaluating the consequences of this research is the very small scale of the actual thrust reportedly produced. Ethan Siegel, a professor of physics and astronomy at Lewis and Clark College in Portland, Oregon said the amount of thrust reported is the first major sign that we should be skeptical.

The original post reported the creation of between 50 and 70 micronewtons, or "less than the weight of a snowflake," Siegel told Space.com. The margin of error for measurement is between 15 and 30 micronewtons.

"You want a signal that's way, way bigger than errors you can measure," he said, also pointing out that the thrust was created in just a few instances among a number of tests which means the results are "not inconsistent with random chance."

NASA officials, in their statement, clarified that they do work towards big, history-making scientific breakthroughs as part of their research mission, even if this particular breakthrough was overblown by some.

"The agency does fund very fundamental research as part of our advanced concepts and innovative investments that push the frontiers of science and engineering," they wrote. "This is part of what NASA does in exploring the unknown, and the agency is committed to and focused on the priorities and investments identified by the NASA Strategic Space Technology Investment Plan.Through these investments, NASA will develop the capabilities necessary to send humans farther into space than ever before."

 

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That leaves at least, the EM Drive and the Mach Efft Thruster, for further testing and possible development.

 

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Another opinion-less posting of an obvious PR-driven press release aimed at placating the many obvious critics who have chimed in. Ho hum. Let's see what the actual teams come up with - whenever down the track that may be.

 

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Yep, that's what most are saying, without your "ho hum"though.

 

http://www.sciencedirect.com/science/article/pii/S0094576515002726
doi:10.1016/j.actaastro.2015.07.002
Abstract
In an IAC13 paper the dynamic operation of a second generation superconducting EmDrive thruster was described. A mathematical model was developed and, in this paper, that model is used to extend the performance envelope of the technology. Three engine designs are evaluated. One is used as a lift engine for a launch vehicle, another as an orbital engine for the launcher and a third as the main engine for an interstellar probe.

The engines are based on YBCO superconducting cavities, and performance is predicted on the basis of the test data obtained in earlier experimental programmes. TheQ values range from 8×107 to 2×108 and provide high values of specific force over a range of accelerations from 0.4 m/s/s to 6 m/s/s.

The launch vehicle is an “all-electric” single stage to orbit (SSTO) spaceplane, using a 900 MHz, eight cavities, fully gimballed lift engine. A 1.5 GHz fixed orbital engine provides the horizontal velocity component. Both engines use total loss liquid hydrogen cooling. Electrical power is provided by fuel cells, fed with gaseous hydrogen from the cooling system and liquid oxygen. A 2 ton payload, externally mounted, can be flown to Low Earth Orbit in a time of 27 min. The total launch mass is 10 ton, with an airframe styled on the X37B, which allows aerobraking and a glide approach and landing.

The full potential of EmDrive propulsion for deep space missions is illustrated by the performance of the interstellar probe. A multi-cavity, fixed 500 MHz engine is cooled by a closed cycle liquid nitrogen system. The refrigeration is carried out in a two stage reverse Brayton Cycle. Electrical power is provided by a 200 kWe nuclear generator. The 9 ton spacecraft, which includes a 1 ton science payload, will achieve a terminal velocity of 0.67c, (where c is the speed of light), and cover a distance of 4 light years, over the 10 year propulsion period.

The work reported in this paper has resulted in design studies for two Demonstrator spacecrafts. The launcher will demonstrate the long-sought-for, low cost access to space, and also meet the mission requirements of the proposed DARPA XS-1 Spaceplane. The probe will enable the dream of an interstellar mission to be achieved within the next 20 years.


7. Conclusions
The two spacecraft design studies and the three different EmDrive engine designs have illustrated the complexity introduced by the Doppler model of EmDrive acceleration. The compensation techniques described are a first attempt at reducing the loss of thrust due to accelerating a high Q cavity. New techniques are currently under investigation to optimise the engine performance whilst simplifying the design. A number of research groups worldwide are now working towards the manufacture and test of Demonstrator Thrusters.

Nevertheless, the performances offered by the SSTO Spaceplane and the Interstellar Probe are a major improvement over vehicle designs based on conventional propulsion systems. Second generation EmDrive offers the best solution for low cost access to space, and for a near term interstellar mission.

 

http://www.emdrive.com/IAC-08-C4-4-7.pdf
ABSTRACT
This paper provides an update on the programme of research and development into a new form of electric propulsion. EmDrive technology provides direct conversion of electrical energy to thrust, using radiation pressure at microwave frequencies in a tapered, high Q, resonant cavity. The work has been carried out with both UK government funding and private investment. A summary of the theory behind EmDrive is given, followed by answers to the most frequently asked questions concerning the production of net force, conservation of momentum and conservation of energy. The theory clearly derives equations for both static and dynamic thrust from the basic laws of physics. The experimental work completed to date is described. The paper also gives a progress report on current programmes. These include an experimental superconducting thruster and development of a flight thruster. A Demonstrator microsatellite proposal is also described, propelled by the flight thruster.


10. CONCLUSIONS:
A theory of EmDrive operation has been developed with the static and dynamic thrust equations derived from basic electromagnetic theory. Following extensive review, no contravention of the laws of the conservation of momentum and conservation of energy has been identified. Design software, based on the thrust equations, was developed to enable an experimental thruster to be manufactured. This thruster was subjected to a comprehensive test programme, which proved the concept and verified the design software. A Demonstrator Engine, with improved design and higher Q, was then tested in both static and dynamic test rigs. The results showed a significant increase in thrust, consistent with the design predictions. Correct dynamic operation was demonstrated, consistent with Newton’s laws. With the basic research on first generation EmDrive completed successfully, work has moved into the flight development phase. Further research into second generation, superconducting technology has started, with initial test data giving the predicted large increase in Q. A microsatellite proposal illustrates that a very modest flight project could demonstrate the major advantages to be gained in commercial, scientific and military missions, by employing EmDrive technology.

 

I'll try and keep up with the latest progress [or otherwise] on this. Not sure of the date of the second paper but it is the first time I have seen it.

 

Hmm....more feasibility studies - based on preexisting tests. Yawn. Try typing 'Roger Shawyer' into YouTube search bar. Lots of 'stuff'.
Skimming through Shawyer's updated theory article as per link in #106, it's clear the poor old fella has learned nothing in all these years. To repeat from earlier postings - if, as per 'propellantless' claims, there is any net thrust whatsoever, energy-momentum conservation fails. Period. Why the hell has not someone tapped Roger on the shoulder and insisted he take a short course in SR? For that matter the whole team and financial backers. Still, according to short video, 8 or so different models have now been tested (in at least 4 different countries), all with reportedly positive results not reasonably explicable by experimental error.
Wonder if there is anyone mucking around in this area that has a real clue as to what is actually going on? No - not 'varying group velocity', or 'vacuum plasma'. It's all there in standard classical EM, imo hidden in plain sight.

 

http://phys.org/news/2015-07-scientists-havent-impossible-space.html

The article stub suggests thermal effects, since the 'control' produced more thrust than the experiment. I suspect thermal leakage from Andrea Rossi's upcoming legal meltdown.

 

Andrea Rossi's claimed 'breakthrough' is in a totally different field, but it's understandable all such 'way-out' claims get to be lumped together in the one (waste-paper) basket. A somewhat more 'balanced' article, linked to in that one given:
http://www.ibtimes.co.uk/emdrive-dr...roversial-space-propulsion-technology-1513151
It's actually not hard to show momentum conservation can explicitly fail in EM. By at least two routes. I've come to feel safe stating that much - professional physicists flatly won't believe it and amateur enthusiast believers won't know how to check.

 

I'm not confusing different fields, just saying that a con is a con is a con...

I tried to read there, but with the pop-ups, the videos that autoplay, and the overlay that wanted me to "Win an Apple Watch", no thanks, and screw that site.

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Please, show us how conservation of momentum can fail, and produce thrust in this way

 

No argument per se there.

Too bad. In Firefox with Flashblock and maybe e.g. Addblock Plus installed, autoplay is tamed and anyway one can always find the pause/stop button, right? As for that overlay, not hard to find an X button in top right hand corner. After that, excuses sort of disappear.

Speaking of excuses, mine is - real technical know-how in such a field just might have considerable monetary value. Various things on my to-do plate and I reserve that matter as one of them to pursue in earnest as breadwinner. I sort of enjoy putting a few clues out there - but not too many. Sorry if you feel unfairly teased or whatever but that's how it is. Call me a fraud if it helps - I won't cry.

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I have FF with adblock plus, but not flashblock. I'll do that. No overlay 'x' showed for me, though..

Why did you think I was gigging you? That was an honest question, but maybe your dodge says more about you than me.

 

I dodged? Maybe that says more about....but never mind. Peace.

 

http://phys.org/news/2015-07-scientists-havent-impossible-space.html


Here's why scientists haven't invented an impossible space engine – despite what you may have read


Experimental problems

Straightaway, there are problems with this experiment. The abstract states: "Our test campaign cannot confirm or refute the claims of the EMDrive." Then, a careful reading of the paper reveals this observation: "The control experiment actually gave the biggest thrust … We were really puzzled by this large thrust from our control experiment where we expected to measure zero."Yes, the control experiment designed not to generate any thrust still measures a thrust. Then there's the peculiar gradual way the thrust seems to turn on and off that looks suspiciously like a thermal effect, and then there are acknowledged heating problems. All this leads to the conclusion stated in the paper that "such a set-up does not seem to be able to adequately measure precise thrusts." Similar problems were seen by the Eagleworks group, with thrust also mysteriously appearing in their control test.Taken together, these results strongly suggest that the measured signatures of thrust are subtle experimental errors. Possible sources include thermal effects, problems with magnetic shielding or even a non-uniform gravitational field in the laboratory leading to erroneous force measurements. As a comparison, the force measured in this latest experiment is roughly comparable to the gravitational attraction between two average-sized people (100kg) standing about 15cm apart. It is an extremely small force.That the experiments detect a measureable thrust is undeniable. Where the thrust comes from, whether it is real or erroneous, is inconclusive. That the experiments in any way confirm the EMDrive works is a falsehood. This was noted by Tajmar himself, who told the International Business Times "I believe there is no real news here yet."The experimental scientists involved have done their jobs to the best of their ability, having tested a hypothesis – albeit a spectacularly unlikely one – and reported their results. These scientists aren't actually claiming to have invented a warp drive or to have broken the laws of physics. All they're saying at the moment is that they've found something odd and unexplained that might be something new but is likely an experimental artefact that needs further study. The panoply of clickbait headlines and poorly researched articles on the topic are doing something of a disservice to their scientific integrity by claiming otherwise.



Read more at: http://phys.org/news/2015-07-scientists-havent-impossible-space.html#jCp

 

I haven't read that but I will. In the conclusion section they note no conservation laws have been violated. The numbers for the 9 ton probe are really interesting.

 

Sorry Dr Toad....I just posted the same link you did.

 

Be terribly ashamed.

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Still yawn, but I'll let you know when I see something of value. Don't hold your breath unless you are a fish in disguise.

 

Because Shawyer has such a great track record of detecting the conservation of momentum violations in his own reviews of his papers?