Author Topic: EM Drive Developments - related to space flight applications - Thread 10  (Read 1635286 times)

Offline Bob Woods

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...

Expensive, but worth it. Can we start a cost-estimation?

I do that for a living, and my group in NG builds some of the best cubesat hardware available.  We can handle up to about 500W of power (continuous) and a projected reliability of >80% at 3 years in single systems or way better than that with redundancy (which we also support).  That core HW, including flight software, launch costs, ground station support, and mission ops over a reasonable lifespan is on the order of $1M.
How cheap CAN you get it?  Probably <$100K but the projected reliability is in the trash can.  Satellites in this cost range have a >50% likelihood to never be heard from once deployed and will never survive deep space radiation.  Outside the Earth's magnetosphere, the radiation is HARSH.
Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

Offline Monomorphic

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Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

The PLA I used would out-gas in a vacuum. However, there is vacuum rated 3D printer filament available.
« Last Edit: 01/05/2018 12:55 pm by Monomorphic »

Online Phil Stooke

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FYI:

Acta Astronautica
Articles in Press


Comments on theoretical foundation of “EM Drive”

In Press, Accepted Manuscript, Available online 4 January 2018
C.-W. Wu
-------
Highlights

The theoretical derivation of the net thrust in “EM drive” is found to be inaccurate.

Self-contradiction in physics is found in the concept of “EM drive”.

The theoretical foundation of the “EM drive” is found to be not solid.

Offline Rodal

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FYI:

Acta Astronautica
Articles in Press


Comments on theoretical foundation of “EM Drive”

In Press, Accepted Manuscript, Available online 4 January 2018
C.-W. Wu
-------
Highlights

The theoretical derivation of the net thrust in “EM drive” is found to be inaccurate.

Self-contradiction in physics is found in the concept of “EM drive”.

The theoretical foundation of the “EM drive” is found to be not solid.

Here is the link:

https://www.sciencedirect.com/science/article/pii/S0094576517317356


"Comments on theoretical foundation of “EM Drive” "
C.-W. Wu

Institute of Mechanics, Chinese Academy of Sciences, No.15 BeisihuanXi Road, Beijing 100190, China
Received 24 November 2017, Revised 29 December 2017, Accepted 4 January 2018, Available online 4 January 2018

Abstract
Quote
The concept of EM Drive has attracted much attention and groups of work have been conducted to prove or verify it, of which the published experimental outcome is criticized in great details while the theoretical foundation has not been discussed. The present essay investigates on the theoretical derivations of the net thrust in the “EM drive” and reveals the self-contradiction arising at the very start, when the law of conservation of momentum was utilized and opposed simultaneously.

pdf Article is behind $35.95 paywall

article contains one figure: 





Recall that Acta Astronautica was the peer-reviewed publication where Roger Shawyer published this article in 2015:

http://www.emdrive.com/IAC14publishedpaper.pdf

Acta Astronautica 116 (2015) 166–174

"Second generation EmDrive propulsion applied to SSTO launcher and interstellar probe"
Roger Shawyer
« Last Edit: 01/05/2018 07:09 pm by Rodal »

Offline Augmentor

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ref: https://www.sciencedirect.com/science/article/pii/S0094576517317356

Highlights are provided as follows:

• The theoretical derivation of the net thrust in “EM drive” is found to be inaccurate.

• Self-contradiction in physics is found in the concept of “EM drive”.

• The theoretical foundation of the “EM drive” is found to be not solid.

- end -

Now, the difficulty with any emDrive theory is that it appears to be a quantum phenomena which requires one to pick a quantum mechanic interpretation or invent a new one.

There are at least 18 major interpretations
https://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics

 and a few dozen minority interpretations.
https://en.wikipedia.org/wiki/Minority_interpretations_of_quantum_mechanics

The leading contenders are:

Copenhagen Interpretation - The standard interpretation which has a number of anomalies but has both historical traction and greatest momentum in universities.

deBroglie Bohm Interpretation - This interpretation explains a few of the anomalies. Couder's work using oil drops to demonstrate macro level effects similar to quantum effects makes this an interesting approach.Gaining momentum but falls short of being comprehensive.

Transactional Interpretation - Cramer's theory explains the most of the anomalies and is the leading interpretation. Kastner extends TI to quantum field theory (QFT). Comprehensive.

The real difficulty for emDrive theory is that the effect may be relativistic instead of quantum mechanic. Enter Mach effects especially for any closed or open cavity with dielectrics. Mach effects rely on General Relativity and parametric amplification.

Other efforts include Unruh radiation especially McCulloch and Dynamic Casimir effect. Both of which also are related to parametric amplification.

Loop quantum gravity theory combines both relativity and quantum mechanics. This theory may eventually prove to be required for any propellentless propulsion system.

In any emDrive theory, to ignore either quantum mechanics or general relativity is a rather dangerous game. Even so, one has to look at particle physics and quantum field theory to gain an appreciation and understanding of the complex processes occurring within the RF closed cavity system.

About the best anyone can do is use a Feynman diagram to explain their theory. Such a diagram would permit experiments at the particle level and permit exploring beyond photons and electrons to the quasiparticle realm of  phonons and polarons, and perhaps even Weyl fermions, massless charge quasiparticles.

Offline Bob Woods

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So let's go back a couple of years in this thread and sum up: No one has proposed a complete explanation of the EM drive in a comprehensive manner that has garnered acceptance. Yet, of the results that have been published, there have been null and positive results, but replication has not been consistent. No results that I have seen rises so far above the noise floor to warrant a "Eureka" moment.

Major governments, including China, "may" be conducting in space tests, but they're not going to tell because of the national security implications. On top of that are the folks who ARE doing experiments who are fairly quiet, maybe because of concerns on protecting future economic rights.

Monomorphic, you're the one left that has been quite open and helpful but has not published a comprehensive set of results. So the Rebel Alliance of physicists and wannabe's wait.


"Help us Monomorphic, you're our only hope."  ;)


« Last Edit: 01/06/2018 12:26 am by Bob Woods »

Offline ThinkerX

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So let's go back a couple of years in this thread and sum up: No one has proposed a complete explanation of the EM drive in a comprehensive manner that has garnered acceptance. Yet, of the results that have been published, there have been null and positive results, but replication has not been consistent. No results that I have seen rises so far above the noise floor to warrant a "Eureka" moment.

Major governments, including China, "may" be conducting in space tests, but they're not going to tell because of the national security implications. On top of that are the folks who ARE doing experiments who are fairly quiet, maybe because of concerns on protecting future economic rights.

Monomorphic, you're the one left that has been quite open and helpful but has not published a comprehensive set of results. So the Rebel Alliance of physicists and wannabe's wait.


"Help us Monomorphic, you're our only hope."  ;)

Mostly, I agree, though I continue to hold out hope that Shell will publish her research, and maybe a couple others. (Star Drive, maybe?)

Offline Bob Woods

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Mostly, I agree, though I continue to hold out hope that Shell will publish her research, and maybe a couple others. (Star Drive, maybe?)
I do too. However....

One of the great strengths of this site was the open, near real time sharing of information. I think it portends a model of open discussion that could be close to a new revolution of science.

I think humans progress fastest when we openly share with each other. When the power of collaboration is shared within the offices of a great university, great things happen. When it's shared with humanity at large, I believe the attainments could rise exponentially.

Yes, the risks may be larger than the rewards. We won't know until we try.
« Last Edit: 01/06/2018 04:31 am by Bob Woods »

Offline liang0yun

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Expensive, but worth it. Can we start a cost-estimation?

I do that for a living, and my group in NG builds some of the best cubesat hardware available.  We can handle up to about 500W of power (continuous) and a projected reliability of >80% at 3 years in single systems or way better than that with redundancy (which we also support).  That core HW, including flight software, launch costs, ground station support, and mission ops over a reasonable lifespan is on the order of $1M.
How cheap CAN you get it?  Probably <$100K but the projected reliability is in the trash can.  Satellites in this cost range have a >50% likelihood to never be heard from once deployed and will never survive deep space radiation.  Outside the Earth's magnetosphere, the radiation is HARSH.
Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

EM引擎出现已经快20年了,尚未进入实用阶段,说明这个技术很不靠谱。
尽管如此,好多人都想自己动动手,制造一个emdrive。据说,,,能够制造出来具有推力的引擎,并且得到公认的人并不多。
那么如何制造这样一个引擎呢?有人制造过,却未能测到推力。他说费用在数万元。。。
各位大婶,,各位大神。。。
你们有没有知道怎么自行制造一个emdrive。。有没有资料。求共享。。

Offline PotomacNeuron

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EM引擎出现已经快20年了,尚未进入实用阶段,说明这个技术很不靠谱。
尽管如此,好多人都想自己动动手,制造一个emdrive。据说,,,能够制造出来具有推力的引擎,并且得到公认的人并不多。
那么如何制造这样一个引擎呢?有人制造过,却未能测到推力。他说费用在数万元。。。
各位大婶,,各位大神。。。
你们有没有知道怎么自行制造一个emdrive。。有没有资料。求共享。。

Talk to oyzw. Either oyzw here or oyzw at https://lt.cjdby.net/forum-11-1.html.
Or browse monomorphic's posts here, if you can read English.
I am working on the ultimate mission human beings are made for.

Offline Rodal

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ref: https://www.sciencedirect.com/science/article/pii/S0094576517317356

Highlights are provided as follows:

• The theoretical derivation of the net thrust in “EM drive” is found to be inaccurate.

• Self-contradiction in physics is found in the concept of “EM drive”.

• The theoretical foundation of the “EM drive” is found to be not solid.

- end -

Now, the difficulty with any emDrive theory is that it appears to be a quantum phenomena which requires one to pick a quantum mechanic interpretation or invent a new one.

There are at least 18 major interpretations
https://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics

 and a few dozen minority interpretations.
https://en.wikipedia.org/wiki/Minority_interpretations_of_quantum_mechanics

The leading contenders are:

Copenhagen Interpretation - The standard interpretation which has a number of anomalies but has both historical traction and greatest momentum in universities.

deBroglie Bohm Interpretation - This interpretation explains a few of the anomalies. Couder's work using oil drops to demonstrate macro level effects similar to quantum effects makes this an interesting approach.Gaining momentum but falls short of being comprehensive.

Transactional Interpretation - Cramer's theory explains the most of the anomalies and is the leading interpretation. Kastner extends TI to quantum field theory (QFT). Comprehensive.

The real difficulty for emDrive theory is that the effect may be relativistic instead of quantum mechanic. Enter Mach effects especially for any closed or open cavity with dielectrics. Mach effects rely on General Relativity and parametric amplification.

Other efforts include Unruh radiation especially McCulloch and Dynamic Casimir effect. Both of which also are related to parametric amplification.

Loop quantum gravity theory combines both relativity and quantum mechanics. This theory may eventually prove to be required for any propellentless propulsion system.

In any emDrive theory, to ignore either quantum mechanics or general relativity is a rather dangerous game. Even so, one has to look at particle physics and quantum field theory to gain an appreciation and understanding of the complex processes occurring within the RF closed cavity system.

About the best anyone can do is use a Feynman diagram to explain their theory. Such a diagram would permit experiments at the particle level and permit exploring beyond photons and electrons to the quasiparticle realm of  phonons and polarons, and perhaps even Weyl fermions, massless charge quasiparticles.
I think most people (certainly myself) were taught the instrumentalist view of Quantum Mechanics as expressed by the quote from David Mermin,

Quote from: David Mermin
Shut up and calculate


https://en.wikiquote.org/wiki/David_Mermin

What's Wrong with this Pillow? by N. David Mermin, Cornell University, Physics Today, April 1989, page 9, doi:10.1063/1.2810963

http://physicstoday.scitation.org/doi/10.1063/1.1768652?journalCode=pto





(which is often misattributed to Richard Feynman, for good reason, as Feynman himself had some funny things to say about worrying about any of these interpretations  :)  ).   The contending interpretations, differing over whether quantum mechanics can be understood to be deterministic, which elements of quantum mechanics can be considered "real", and other matters, are more important to problems with single photons, rather than a problem like the EM Drive where one has a huge amount of photons, and therefore there are no apparent issues that arise from using the instrumentalist approach, because for a problem involving a huge amount of photons, all the mentioned interpretations should lead to the same calculated answer.

Rather than having a philosophical debate, if you (or others) disagree, please let us know what difference in the calculation of the EM Drive any of these interpretations can possible make.  Tell us about the calculation (not philosophical differences) pertaining to the EM Drive experiments  ;)  [not other experiments: not single photon, not double slit, not quantum entanglement, etc., but just the EM Drive experiment please]

Again, I expect that a number of people in the audience are very interested in philosophy and history of physics, and I am not criticizing such endeavors, which I agree are indeed quite worthwhile.  I am just asking people that write about the importance of these interpretations to teach me (us ?) what difference it can possibly make for calculations of the EM Drive Developments -related to space flight applications (not for other fundamental physical problems for which one may differentiate between the calculated responses from different interpretations  !!! )
« Last Edit: 01/06/2018 07:57 pm by Rodal »

Offline Augmentor

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...

Expensive, but worth it. Can we start a cost-estimation?

I do that for a living, and my group in NG builds some of the best cubesat hardware available.  We can handle up to about 500W of power (continuous) and a projected reliability of >80% at 3 years in single systems or way better than that with redundancy (which we also support).  That core HW, including flight software, launch costs, ground station support, and mission ops over a reasonable lifespan is on the order of $1M.
How cheap CAN you get it?  Probably <$100K but the projected reliability is in the trash can.  Satellites in this cost range have a >50% likelihood to never be heard from once deployed and will never survive deep space radiation.  Outside the Earth's magnetosphere, the radiation is HARSH.
Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

EM引擎出现已经快20年了,尚未进入实用阶段,说明这个技术很不靠谱。
尽管如此,好多人都想自己动动手,制造一个emdrive。据说,,,能够制造出来具有推力的引擎,并且得到公认的人并不多。
那么如何制造这样一个引擎呢?有人制造过,却未能测到推力。他说费用在数万元。。。
各位大婶,,各位大神。。。
你们有没有知道怎么自行制造一个emdrive。。有没有资料。求共享。。

Translation (editor note)
EM engine has been (around) almost 20 years, yet has not entered the practical stage, indicating that this technology is not reliable.
However, many people want to (do it themselves and (use) their own hands (and resources) and make an emdrive. It is said that there are not many people who can produce engines with thrust and are recognized.
So how to make such an engine? Someone made, but failed to measure the thrust. He said the cost of tens of thousands of dollars. . .
Ladies and gentlemen, ladies and gentlemen. . .
Do you know how to make an emdrive yourself? There is no information. Seeking to share.
-end translation-

FWIW

D

Offline Bob Woods

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...

Expensive, but worth it. Can we start a cost-estimation?

I do that for a living, and my group in NG builds some of the best cubesat hardware available.  We can handle up to about 500W of power (continuous) and a projected reliability of >80% at 3 years in single systems or way better than that with redundancy (which we also support).  That core HW, including flight software, launch costs, ground station support, and mission ops over a reasonable lifespan is on the order of $1M.
How cheap CAN you get it?  Probably <$100K but the projected reliability is in the trash can.  Satellites in this cost range have a >50% likelihood to never be heard from once deployed and will never survive deep space radiation.  Outside the Earth's magnetosphere, the radiation is HARSH.
Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

EM引擎出现已经快20年了,尚未进入实用阶段,说明这个技术很不靠谱。
尽管如此,好多人都想自己动动手,制造一个emdrive。据说,,,能够制造出来具有推力的引擎,并且得到公认的人并不多。
那么如何制造这样一个引擎呢?有人制造过,却未能测到推力。他说费用在数万元。。。
各位大婶,,各位大神。。。
你们有没有知道怎么自行制造一个emdrive。。有没有资料。求共享。。



在这个网站上搜索monomorphic和RFMWGUY的帖子。 Monomorphic简化了EM驱动器的制造和测试。 它不需要几万美元,但有一些成本。 没有什么证明。 尝试在这里开始:
http://emdrive.wiki/Building
RFMWGUY是一个非常早期的建筑商,并发布了许多图片和视频。 Monomorphic大大推进了施工过程。 祝你好运。


[On this site search for posts by monomorphic and RFMWGUY. Monomorphic has simplified EM drive fabrication and testing. It does not take tens of thousand dollars, but is with some costs. Nothing is proven. Try here to start:
http://emdrive.wiki/Building

RFMWGUY was a very early builder and posted many pictures and video. Monomorphic has advanced construction process greatly. good luck to you.]
« Last Edit: 01/07/2018 01:49 am by Bob Woods »

Offline spupeng7

So let's go back a couple of years in this thread and sum up: No one has proposed a complete explanation of the EM drive in a comprehensive manner that has garnered acceptance. Yet, of the results that have been published, there have been null and positive results, but replication has not been consistent. No results that I have seen rises so far above the noise floor to warrant a "Eureka" moment.

Major governments, including China, "may" be conducting in space tests, but they're not going to tell because of the national security implications. On top of that are the folks who ARE doing experiments who are fairly quiet, maybe because of concerns on protecting future economic rights.

Monomorphic, you're the one left that has been quite open and helpful but has not published a comprehensive set of results. So the Rebel Alliance of physicists and wannabe's wait.


"Help us Monomorphic, you're our only hope."  ;)
Bob,
wonderful as the Monomorph might be, he is far from being our only hope. Who knows how many builders or theorists there are out there, who will not publish till they are confident they can satisfy the critics  :)
Optimism equals opportunity.

Offline spupeng7

FYI:

Acta Astronautica
Articles in Press


Comments on theoretical foundation of “EM Drive”

In Press, Accepted Manuscript, Available online 4 January 2018
C.-W. Wu
-------
Highlights

The theoretical derivation of the net thrust in “EM drive” is found to be inaccurate.

Self-contradiction in physics is found in the concept of “EM drive”.

The theoretical foundation of the “EM drive” is found to be not solid.

Phil,
there is as yet no theoretical foundation for the emdrive, which does not diverge wildly from established concepts.

Shawyers explanation is an attempt (in my opinion) to avoid controversy and the non-Machian explanations, at least appear to rely on things which don't exist.

Proof will be, if it will be, in the pudding, irrespective of theory. Show me any physical theory which has no paradox.
Optimism equals opportunity.

Offline Bob Woods

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"Help us Monomorphic, you're our only hope."  ;)
Bob,
wonderful as the Monomorph might be, he is far from being our only hope. Who knows how many builders or theorists there are out there, who will not publish till they are confident they can satisfy the critics  :)
I was making a semi-joke out of the Star Wars line "Help me Obi-Wan-Kenobi, you're our only hope." - by Leia Organa

Offline graybeardsyseng

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At this point I am thinking it would be wise for all interested in a cubesat style experiment ( as I certainly am) to review TRL status of the concept and how that works during preparation for available launch vehicles.

Another thread, in May, Robotbeat had a good comment, keep in mind the number of stakeholders required to actually achieve orbit...
"...I do think there's some unnecessary ritual in the whole concept of the Technology Readiness Level formalism. It seems primarily a tool for getting multiple stakeholders to agree on whether a certain technology is mature enough for some application..."

https://www.nasa.gov/pdf/458490main_TRL_Definitions.pdf

What this means to me is quite simply, unless and until somebody has demonstrated suitable TRL no experiment will fly.

 Personally funding a launch is simply beyond my reach. YMMV

I concur.   I think self-funding (rich patron, crowd funding, university cooperation) are the only approach to flying at this point, at least based on openly reported data to date. 

We had a fairly vigorous discussion on this forum of TRL for the EMdrive back about 4 or 6 threads and it was and likely still is clear that a) no-one is going to agree what various TRL levels  means WRT EMdrive and likewise  no-one is going to agree what TRL the EMdrive is at (now or even if more data are available b) I think the cost and time required to get launch providers/funders and other stakeholders  to accept an EMdrive  TRL and schedule and pay for a EMdrive mission would be prohibitive.   

 I personally am more familiar with the DOD definition of TRL but they are similar enough to either  support discussions; likewise they are different enough to support arguments and disagreements should that be anyone's goal . . .

graybeardsyseng
EMdrive - finally - microwaves are good for something other than heating ramen noodles and leftover pizza ;-)

Offline graybeardsyseng

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Monomorphic built his shell on a 3-D printer, with a copper film interior. Would those kinds of thermoplastics (?) be able to be space rated?

The PLA I used would out-gas in a vacuum. However, there is vacuum rated 3D printer filament available.

Anyone know if there is any data available on how various filaments tolerate radiation environments expected on LEO?

graybeardsyseng
EMdrive - finally - microwaves are good for something other than heating ramen noodles and leftover pizza ;-)

Offline sabake

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Just out of curiosity - why haven't anyone tested with array of thrusters/fustrums?

It seems from the thread that the biggest issue for current and past tests is detecting reliable thrust signal from the background noise. Yet all developments have tried either to eliminate the noise sources.. or to elevate the power levels (also bringing up the background noise), but not adding to the thrust by adding thrusters.

Yet - if I understand correctly - thrust is expected to come from the fustrum and it should not be extremely hard to place 2 or 4 fustrums on the torsion balance. Yes, it would elevate the weight - but would also multiply the thrust signal while leaving feeding system and overall design pretty much the same. One would also be able to switch on fustrums independently, getting additional thrust with each additional fustrum powered up, that should be visible from analysis. In theory it would also be possible to add thrusters on both sides of torsion balance, adding to the stability of the system..

Offline Augmentor

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Just out of curiosity - why haven't anyone tested with array of thrusters/fustrums?

It seems from the thread that the biggest issue for current and past tests is detecting reliable thrust signal from the background noise. Yet all developments have tried either to eliminate the noise sources.. or to elevate the power levels (also bringing up the background noise), but not adding to the thrust by adding thrusters.

Yet - if I understand correctly - thrust is expected to come from the fustrum and it should not be extremely hard to place 2 or 4 fustrums on the torsion balance. Yes, it would elevate the weight - but would also multiply the thrust signal while leaving feeding system and overall design pretty much the same. One would also be able to switch on fustrums independently, getting additional thrust with each additional fustrum powered up, that should be visible from analysis. In theory it would also be possible to add thrusters on both sides of torsion balance, adding to the stability of the system..

Think of an emDrive array as an array of radios or cellphones. One is affordable to work with; duplicating two more requires getting the first one right.

Arrays add another layer of complexity and assume the thrust elements can reliably produce thrust. In order to develop an array of units aka elements,  at the array level one has to duplicate all the testing for a single thruster, most importantly, electromagnetic compatibility, acceleration and thermal (aka EM, shake and bake).

Generally, the goal is a single unit would provide enough mission-level impulse (thrust x time). MilliNewtons per unit is helpful. Newtons would desirable.

The thrust is developed from amplified effects and powered by one or more energy storage devices, typically a battery or large capacitor. From solar to nuclear, other power sources are possible

Arrays are used for both multiplying thrust to mission level requirements especially when amplification methods have reached a maximum. Other uses of arrays include to provide throttling, positioning and steering.

Testing emDrives in arrays assumes one has the time and resources to build identical units to populate an array and continuously put out thrust in space.

Thrust levels per unit have to be in the millinewton range at a minimum.

Size and weight have to be minimized, and electric power efficiency - from generated vs delivered - has to be quite significant. For any thruster system, measures include Thrust per volume in cubic meters (ft^3), thrust per mass in kg (lb), and thrust per power, N/kWe (lb-force).

Cooling the power& propulsion system needs to be considered and adds to weight and volume of the basic emDrive since a basic emDrive is roughly 1 cubic foot ~12" on a side  ~30 cm, the power supply has to be portable, the electromagnetic compatibility -both emission and susceptibility - has to be determined for a single unit before producing multiples.

The unit drive is an element in an array, typically a linear or planar array. Linear arrays are 1D arrays with two orientations - inline (stack) and lateral (wing). A planar array can duplicated to become one of many boards stacked in a box typically secured on three or four sides; a box-of-boards array is a 2.5 D array.

In any array configuration, an additional requirement to emDrive testing is to determine if there are any E&M emissions from another emDrive that would impair operation of any drive. At the present time, there is no data to support emDrive to emDrive coupling.

The question of 3D arrays involves a framework structure. The first step would be to test at the 2.5 D level with Boards in a Box (BIB) array. In any BIB array or 3D framework structure, any absorption or emission by the structure needs to be considered including acoustic, thermal, RF, particle and fields.

A minor point...a good theory would be extremely helpful to explain the behavior of the emDrive.  While some folks "shut up and calculate", the presumptions are that one has data to calculate, and that the design/build was based on at least some theoretical conjecture instead of flights of fancy.

An array may require a team effort on many levels as well as in production of units. A collaborative effort could  build an array if a specification can be agreed to and funding can be obtained.

Other than that, it's easy.

David








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