NASA: New "impossible" engine works, could change space travel forever

On Friday, August 1, 2014 4:15:10 PM UTC-4, David Spain wrote:
On Friday, August 1, 2014 3:47:58 PM UTC-4, David Spain wrote:

What looks interesting is thrust is generated in the direction away from the wide end towards narrow, just the opposite of a rocket nozzle!







In other words this engine doesn't spew, it sucks! ;-)







Dave







PS: Check out Roger Shawyer's paper from he



http://www.emdrive.com/IAC13paper17254.v2.pdf







There is also a claim that this "engine" when run in reverse cycle kills momentum by generating (presumably) electrical power from vacuum. Hence trading off kinetic energy for electricity when operating as a brake. Oh boy....



And he



http://www.emdrive.com/theorypaper9-4.pdf



Dave

And he

http://ntrs.nasa.gov/archive/nasa/ca...0140006052.pdf

On Friday, August 1, 2014 4:45:10 PM UTC-4, David Spain wrote:
On Friday, August 1, 2014 4:15:10 PM UTC-4, David Spain wrote:

On Friday, August 1, 2014 3:47:58 PM UTC-4, David Spain wrote:



What looks interesting is thrust is generated in the direction away from the wide end towards narrow, just the opposite of a rocket nozzle!















In other words this engine doesn't spew, it sucks! ;-)















Dave















PS: Check out Roger Shawyer's paper from he







http://www.emdrive.com/IAC13paper17254.v2.pdf















There is also a claim that this "engine" when run in reverse cycle kills momentum by generating (presumably) electrical power from vacuum. Hence trading off kinetic energy for electricity when operating as a brake. Oh boy....







And he







http://www.emdrive.com/theorypaper9-4.pdf







Dave



And he



http://ntrs.nasa.gov/archive/nasa/ca...0140006052.pdf

And here and he

http://cannae.com/introduction
http://arc.aiaa.org/doi/abs/10.2514/6.2014-3853 (pay-walled, USD $25)

Am a little confused over inventor, Roger Shawyer or Guido Fetta? Seems as if Eagleworks tested the Cannae (Fetta's) device. But the China lab tested Shawyer's device. The devices look dissimilar, but they might work on the same principle (haven't read Fetta's AIAA paper).

On Friday, August 1, 2014 4:04:30 PM UTC-4, Rick Jones wrote:
Alain Fournier wrote:

I wouldn't bet on electrons from the material. The thing would get

highly charged before having much thrust. Photon engine might be

possible. I would think that one side of the contraption gets hot

which heats the air on the outside of that side of the engine. This

heated air provides the thrust.



I would have throught NASA would have been clever enough to have put

the thing in a vacuum chamber no? Or am I ass-u-me-ing too much

there?



rick jones

They did but didn't evacuate the chamber! doh! 1 atm with chamber door closed, according to this excerpt from NTRS abstract (cited elsewhere on this thread):

/quote
Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micro-newton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure.
/end-quote

Dave

This doesn't look very promising either (from same NTRS abstract):

/quote

Several different test configurations were used, including two different test articles as well as a reversal of the test article orientation.
In addition, the test article was replaced by an RF load to verify that the force was not being generated by effects not associated with the test article. The two test articles were designed by Cannae LLC of Doylestown, Pennsylvania. The torsion pendulum was designed, built, and operated by Eagleworks Laboratories at the NASA Johnson Space Center of Houston, Texas.

Approximately six days of test integration were required, followed by two days of test operations, during which, technical issues were discovered and resolved. Integration of the two test articles and their supporting equipment was performed in an iterative fashion between the test bench and the vacuum chamber. In other words, the test article was tested on the bench, then
moved to the chamber, then moved back as needed to resolve issues. Manual frequency control was required throughout the test. Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article).

/end-quote

There, I've almost re-posted the entire NTRS abstract. Which is all that is currently available off NASa's NTRS server.

Dave

On Friday, August 1, 2014 5:43:23 PM UTC-4, David Spain wrote:
On Friday, August 1, 2014 4:04:30 PM UTC-4, Rick Jones wrote:

Alain Fournier wrote:



I wouldn't bet on electrons from the material. The thing would get



highly charged before having much thrust. Photon engine might be



possible. I would think that one side of the contraption gets hot



which heats the air on the outside of that side of the engine. This



heated air provides the thrust.







I would have throught NASA would have been clever enough to have put



the thing in a vacuum chamber no? Or am I ass-u-me-ing too much



there?







rick jones



They did but didn't evacuate the chamber! doh! 1 atm with chamber door closed, according to this excerpt from NTRS abstract (cited elsewhere on this thread):



/quote

Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micro-newton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure.

/end-quote



Dave

Which of course means it's quite possible, given the testing as done, that Alain is right! Esp. considering that the "null" test device also produces thrust (or should I say a force?)...

Dave

On 2/08/2014 5:47 AM, David Spain wrote:
What looks interesting is thrust is generated in the direction away
from the wide end towards narrow, just the opposite of a rocket
nozzle!

In other words this engine doesn't spew, it sucks! ;-)

Dave

PS: Check out Roger Shawyer's paper from he
http://www.emdrive.com/IAC13paper17254.v2.pdf

There is also a claim that this "engine" when run in reverse cycle
kills momentum by generating (presumably) electrical power from
vacuum. Hence trading off kinetic energy for electricity when
operating as a brake. Oh boy....


Going backwards, presumably.

But that makes no sense at all given that in a vacuum there's no
preferred frame of reference by which "backwards" could be measured.

Sylvia.

Don't buy stock in impossible space drives just yet:

"Yesterday, Wired UK had geeks everywhere salivating at the prospect of a purely
electrical space thruster system--one that should be impossible based on what we
know about classical physics. The article notes that NASA engineers have now
tested one of these devices and found that it appears to produce thrust without
using any fuel. Although there are ways that non-classical physics can make
things work, there are enough red flags raised by material in the initial report
that the news should be greeted very skeptically."

See:

http://arstechnica.com/science/2014/...ives-just-yet/

In article ,
says...

"Until yesterday, everyone in the international community was
laughing at this engine and its inventor, Roger Sawyer. It's
called the EmDrive and everyone said it was impossible
because it went against the laws of physics. But the fact is
that the quantum vacuum plasma thruster works in the lab and
scientists can't explain why.

Sawyer's engine is extremely light and simple. It provides a
thrust by "bouncing microwaves around in a closed container."
The microwaves are generated using electricity that can be
provided by solar energy. No propellant is necessary, which
means that this thrusters can work forever unless a hardware
failure occurs. If real, this would be a major breakthrough
in space propulsion technology."

See:

http://sploid.gizmodo.com/nasa-revea...49987/+barrett

While this thing is a curiosity, the thrust generated is so small, I
wonder how they even measured it in the lab. This is the sort of
technology which needs to be tested in space to prove it really works as
advertised. There is always the possibility that there is some effect
here which makes it "work" in the lab but not in space.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Monday, August 4, 2014 9:32:21 AM UTC-4, Jeff Findley wrote:

While this thing is a curiosity, the thrust generated is so small, I
wonder how they even measured it in the lab. This is the sort of
technology which needs to be tested in space to prove it really works as
advertised. There is always the possibility that there is some effect
here which makes it "work" in the lab but not in space.


Jeff,

The most glaring oversight on the Cannae test devices was not operating them in vacuum. I cannot fathom why that was not done, esp. since Eagleworks had the torsion balance set up in a vacuum chamber to begin with.

I give Cannae a lot a credit for supplying Eagleworks with both a test and "null test" device for testing. I give Eagleworks a demerit for not testing under vacuum conditions, unless Cannae had asked them not to. But if the latter is true, that should have raised a red flag to Eagleworks.

Since all that is currently available on the NTRS service is the abstract of the Eagleworks' paper, I guess we will have to wait until the full report is published before we can draw any conclusions. But the "null test" device giving a positive result is NOT promising.

I believe it possible to design a torsion balance capable of measuring deflection in mirco-newtons. But as you say that is a very small force. Plenty of ways that could happen outside of microwave "propulsion".

I have no comment on the Chinese test of the EmDrive from Shawyer, since I haven't read of the results there.

My problem with resonant chamber based propulsion is based on the EM theory of standing waves. We know that these can interact and cancel out power transmission along a transmission line. In a similar sense you need to induce some form of wave transmission out of the resonant cavity if you hope to obtain in kind of "momentum". Anyone who has tried to balance a transmission line to minimize standing waves to get maximum power transmission to an antenna knows the issue. If you are maximizing the Q of the chamber, how do you know you are getting a net wave propagation out of the chamber and not just inducing standing waves within the resonant cavity?

If you *are* trying to optimize for waves within the chamber an no "emissivity"
I don't understand why wave interactions within the cavity will not cancel out each other's momentum. Also I don't understand how you can ignore wall interactions either. I not convinced it as simple as Fr1 from large wall vs Fr2 from small wall. EM waves don't behave nor interact like billiard balls, sorry. If that were the case we wouldn't need Feynman mechanics.

Shawyer's EmDrive device looks a little easier to understand. The spherical geometry of the the Cannae device I have no clue of. I haven't paid to retrieve Fetta's paper from the AIAA server, but I may at some point.

Dave

On 4/08/2014 11:32 PM, Jeff Findley wrote:
In article ,
says...

"Until yesterday, everyone in the international community was
laughing at this engine and its inventor, Roger Sawyer. It's
called the EmDrive and everyone said it was impossible
because it went against the laws of physics. But the fact is
that the quantum vacuum plasma thruster works in the lab and
scientists can't explain why.

Sawyer's engine is extremely light and simple. It provides a
thrust by "bouncing microwaves around in a closed container."
The microwaves are generated using electricity that can be
provided by solar energy. No propellant is necessary, which
means that this thrusters can work forever unless a hardware
failure occurs. If real, this would be a major breakthrough
in space propulsion technology."

See:

http://sploid.gizmodo.com/nasa-revea...49987/+barrett

While this thing is a curiosity, the thrust generated is so small, I
wonder how they even measured it in the lab. This is the sort of
technology which needs to be tested in space to prove it really works as
advertised. There is always the possibility that there is some effect
here which makes it "work" in the lab but not in space.


Particularly when they didn't even try it in a vacuum.

Sylvia.