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#2960 by SeeShells on 23 Jan, 2018 19:39
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http://s1039.photobucket.com/user/shells2bells2002/library/CE%20Electromagnetic%20Reaction%20Thruster?sort=2&page=1
You can do a balance beam like I did a couple years ago on my first build. After setting a counter balance weight at one end I used a micrometer to raise and lower the beam to set the scales.
My Very Best,
ShellI have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight. -
#2961 by WarpTech on 23 Jan, 2018 20:11
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I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
Here is anther thought. Two opposing MET drives mounted on a pendulum. One driven in propulsion mode the other in a neutral mode.
The pendulum uses a bounced laser and you operate the drives at the resonant frequency of the pendulum.
https://forum.nasaspaceflight.com/index.php?topic=42978.msg1691070#msg1691070
The pendulum frequency will be much too low. The MEGA is operating at 21.5kHz. I don't think you can make a pendulum that will swing that fast. -
#2962 by Bob Woods on 24 Jan, 2018 01:16
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Off topic but...
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#2963 by madengr on 24 Jan, 2018 01:20
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Has the possibility of circulating DC current within the resonant cavity been considered, creating the torque via the Earth's magnetic field? I'm specifically thinking about impurities at the copper surface (i.e. copper oxide) causing rectification of the resonant mode. Passive InterModulation (PIM) is troublesome in high-power RF connectors, but in that case it's not the DC component, but 3rd order IM and harmonics that are the issue. Though any nonlinearity will generate a DC component.
PIM is usually between two joints/surfaces, but has been observed as a distributed effect in copper foils:
https://www.4taconic.com/uploads/ADD%20Technical%20Articles/1453316395_Distributed%20sources%20of%20passive%20intermodulation%20on%20printed%20lines.pdf
Given the high Q of the resonator and high drive power, I'd think there would be some small nonlinear effects. The NASA paper, they took care to twist the power cables to minimize any static magnetic field. Though I didn't see a mention of cavity currents. I emailed one of the NASA authors several months ago but did not get a reply. Just stumbled on this thread today, so thought I'd bring up the topic.
I regularly use CST (I'm an RF/ Microwave EE) but have never read about modeling a non-linear surface impedance. Given the resonant mode is 2 along the circumference, that may yield two current paths along the circumference.
Anyway, just a thought. -
#2964 by dustinthewind on 24 Jan, 2018 01:23
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I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
Here is anther thought. Two opposing MET drives mounted on a pendulum. One driven in propulsion mode the other in a neutral mode.
The pendulum uses a bounced laser and you operate the drives at the resonant frequency of the pendulum.
https://forum.nasaspaceflight.com/index.php?topic=42978.msg1691070#msg1691070
The pendulum frequency will be much too low. The MEGA is operating at 21.5kHz. I don't think you can make a pendulum that will swing that fast.
Just make the voltage to the M.E.T.'s vary sinusoidal at the lower frequency of maybe 1 hz. Run them at 21.5 khz but turn them on and off (or vary their voltage sinusoidal between min max) at maybe 1 hz or what ever the resonant frequency of the pendulum is. Might help them run more cool.
Never seen one built before.
I am not sure if it might require specialized mirrors unfortunately.
OK never mind it looks like these people built one
Angle amplification for nanoradian measurements
Marco Pisani and Milena Astrua
https://scholar.google.com/scholar?cluster=17562303010736805268&hl=en&as_sdt=0,26QuoteA method to amplify the rotation angle of a mirror, based on multiple reflections between two quasi-parallel
mirrors, is presented. The method allows rotations of fractions of nanoradians to be measured with a simple
setup. The working principle, the experimental setup, and the results are presented.
On second thought I might not recommend using mirrors because the MET's might cause the mirrors to vibrate causing problems with measurements! -
#2965 by Augmentor on 24 Jan, 2018 15:32
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A structure of material supporting a superpolsihed surface may be useful.
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#2966 by Peter Lauwer on 24 Jan, 2018 16:01
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Hi everybody, a small sign of life from my side, after being almost absend for a few months.
I don't have the cold weather as an excuse, like some Americans on this forum (on the contrary, here in the Netherlands the hottest January 24nd since measurements started in 1901 has been recorded). But my EmDrive project almost got to a standstill because I had to empty my parents house after my mother went to a residential home. Quite a daunting task.
Nevertheless, I recently did some tests with the torsion balance, see the attached pictures. The initial tests I usually do with a paper chart recorder since you have better overview, especially when rotating the wire for zero output and to observe drift. When everything seems to work fine, I shift to using an ADC and LabView software.
The unrest is higher than I had in the past with these electronics and sensors. The frame and portal is a little different, more compact then before. It is placed on the floor for better stability (and also because of too small lab-space, I have to admit
), the cover is a temporary one but should be OK.
The portal should be covered, of course. And maybe the temperature difference between the floor and the top of the cover is too large (of the order of 1 degree Celsius) and I have to add some thermal insulation. The damping is about right, slightly overdamped I estimate from the measurement in the last picture (the step-function force is made with a small bar magnet/solenoid system, force = about 15-20 micronewton. It is not calibrated yet).
So far the torsion balance system, first I am going to do some microwave measurements on the frustum and coupling.
The torsion balance arm which can be seen in the picture, is a symmetrical one for testing purposes of the system only. Another balance arm for holding the microwave cavity (e.g., the frustum shaped one) is under construction.
Cheers,
Peter
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#2967 by graybeardsyseng on 25 Jan, 2018 13:12
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Hi everybody, a small sign of life from my side, after being almost absend for a few months.
I don't have the cold weather as an excuse, like some Americans on this forum (on the contrary, here in the Netherlands the hottest January 24nd since measurements started in 1901 has been recorded). But my EmDrive project almost got to a standstill because I had to empty my parents house after my mother went to a residential home. Quite a daunting task.
Nevertheless, I recently did some tests with the torsion balance, see the attached pictures. The initial tests I usually do with a paper chart recorder since you have better overview, especially when rotating the wire for zero output and to observe drift. When everything seems to work fine, I shift to using an ADC and LabView software.
The unrest is higher than I had in the past with these electronics and sensors. The frame and portal is a little different, more compact then before. It is placed on the floor for better stability (and also because of too small lab-space, I have to admit ), the cover is a temporary one but should be OK.
The portal should be covered, of course. And maybe the temperature difference between the floor and the top of the cover is too large (of the order of 1 degree Celsius) and I have to add some thermal insulation. The damping is about right, slightly overdamped I estimate from the measurement in the last picture (the step-function force is made with a small bar magnet/solenoid system, force = about 15-20 micronewton. It is not calibrated yet).
So far the torsion balance system, first I am going to do some microwave measurements on the frustum and coupling.
The torsion balance arm which can be seen in the picture, is a symmetrical one for testing purposes of the system only. Another balance arm for holding the microwave cavity (e.g., the frustum shaped one) is under construction.
Cheers,
Peter
Peter -
Very nice build progress! When you have time could you provide more detail on the design of the torsion balance and support system (and my apologies of I missed this earlier). Drawing or sketch perhaps.
And I love the strip chart recorder - excellent especially for initial system tuning. Digital recording is great and useful but something about pen on paper just feels right too. Maybe my age is showing LOL. Big plus for Labview too - it is worth the effort and cost.
We here in Texas would be happy to trade some of that warm weather. We have had several days down to nearly -10C where I live. That has stopped all work here.
BTW -best wishes for your mother and you in the new living arrangements - having gone through that recently myself that can be a very traumatic and stressful process. Family comes first but it can be very challenging.
Best Wishes,
Herman
graybeardsyseng
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#2968 by dustinthewind on 25 Jan, 2018 14:10
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I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
This appears to be a friction-less slip ring for conveying power to a rotary system. I couldn't figure out where to buy one of how much but if its affordable it might be handy for conveying power to some rotating system such as a pendulum or something.
https://powerbyproxi.com/products/proxi-point-150w/
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#2969 by Monomorphic on 25 Jan, 2018 21:38
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This appears to be a friction-less slip ring for conveying power to a rotary system. I couldn't figure out where to buy one of how much but if its affordable it might be handy for conveying power to some rotating system such as a pendulum or something.
I found it very easy to use LiPo batteries for power and 5G wifi for communication. 5G because I am testing the emdrive on the 2.4Ghz band - so anyone testing the MET could get away with 2.4G wireless since there are no problems with RF interference. The RF amplifier draws ~10A at 12V (120W), which is only a little less than the ~1A at ~200V (~200W) for the MET. My current electrical system could easily handle the added demand. The only drawback is having to change out the battery, though with a little work I could make it so the battery stays attached and I charge it by cable only. -
#2970 by dustinthewind on 26 Jan, 2018 18:33
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I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
I might have an alternative to bouncing a laser between two mirrors. If you still want to do the pendulum approach to amplify thrust displacement you could use two large capacitor plates. They are large and very flat because you want a large area and small distance of separation ~A/d*k=C. A small change in distance leads to a rapid change in capacitance. Applying a known voltage or current allows you to measure that change in capacitance. The main advantage is that for a viberating system you can integrate the change in capacitance probably more easily than trying to observe a rapidly fluctuating laser beam. I'll have to work out the details when I have the time.
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#2971 by sanman on 26 Jan, 2018 18:40
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Has anyone heard of the use of variable attenuation for production of large energy pulses from a resonant cavity, and could the inverse of this be used to generate a sharper accelerative impulse for better signal-to-noise ratio on the measurement side?
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#2972 by X_RaY on 26 Jan, 2018 18:51
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Capacitive distance sensors are state of the art but i think less useful in such pendulum experiment because of the (distant dependent!) additional force applied by charged capacitor plates.I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
I might have an alternative to bouncing a laser between two mirrors. If you still want to do the pendulum approach to amplify thrust displacement you could use two large capacitor plates. They are large and very flat because you want a large area and small distance of separation ~A/d*k=C. A small change in distance leads to a rapid change in capacitance. Applying a known voltage or current allows you to measure that change in capacitance. The main advantage is that for a viberating system you can integrate the change in capacitance probably more easily than trying to observe a rapidly fluctuating laser beam. I'll have to work out the details when I have the time.
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#2973 by dustinthewind on 27 Jan, 2018 02:44
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Capacitive distance sensors are state of the art but i think less useful in such pendulum experiment because of the (distant dependent!) additional force applied by charged capacitor plates.I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
I might have an alternative to bouncing a laser between two mirrors. If you still want to do the pendulum approach to amplify thrust displacement you could use two large capacitor plates. They are large and very flat because you want a large area and small distance of separation ~A/d*k=C. A small change in distance leads to a rapid change in capacitance. Applying a known voltage or current allows you to measure that change in capacitance. The main advantage is that for a viberating system you can integrate the change in capacitance probably more easily than trying to observe a rapidly fluctuating laser beam. I'll have to work out the details when I have the time.
Edit: I see what your saying.
Good point. I was pondering applying a constant voltage to one plate with AC voltage to the other which would cause it to osculate but not be attracted. Still this applies more force with distance changing osculation behavior.
You can use a very small voltage to minimize force but the change with distance may be a problem.
Edit2: Well hold on a minute. What about keeping one capacitor plate charged at a set voltage and the other plate varying sinusoidally at that voltage between negative and positive. If the frequency is much higher than the frequency of the pendulum there shouldn't be a net force.
Edit3: Nevermind the striked through should not work. I am not sure there is a way to make the plates as equally repulsive as they are attractive.
Correction: My integral of change in charge is off by a multiplier of 2 because for every charge you separate from one plate leaves another positive charge on the other so 2 charges created.
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#2974 by dustinthewind on 28 Jan, 2018 01:21
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I have contacted them in the past. Their instrumentation is capable of measurement at this scale. Very helpful and responded right away to my inquiry.
Exchanged private message with RERT at the time, he provided this link; www.micronewton.co.uk/info.html
This was some time ago, I haven't built anything suitable for experimentation yet...
Nice that it can measure micro-Newtons, but my MEGA Drive weighs 1.4 kg. This load cell can't support the weight of the device AND measure the forces. Any suggestions? It would be nice to have a device that can hang a MEGA and measure such small changes in weight.
Here is anther thought. Two opposing MET drives mounted on a pendulum. One driven in propulsion mode the other in a neutral mode.
The pendulum uses a bounced laser and you operate the drives at the resonant frequency of the pendulum.
https://forum.nasaspaceflight.com/index.php?topic=42978.msg1691070#msg1691070
The pendulum frequency will be much too low. The MEGA is operating at 21.5kHz. I don't think you can make a pendulum that will swing that fast.
Just make the voltage to the M.E.T.'s vary sinusoidal at the lower frequency of maybe 1 hz. Run them at 21.5 khz but turn them on and off (or vary their voltage sinusoidal between min max) at maybe 1 hz or what ever the resonant frequency of the pendulum is. Might help them run more cool.
Never seen one built before.
I am not sure if it might require specialized mirrors unfortunately.
OK never mind it looks like these people built one
Angle amplification for nanoradian measurements
Marco Pisani and Milena Astrua
https://scholar.google.com/scholar?cluster=17562303010736805268&hl=en&as_sdt=0,26QuoteA method to amplify the rotation angle of a mirror, based on multiple reflections between two quasi-parallel
mirrors, is presented. The method allows rotations of fractions of nanoradians to be measured with a simple
setup. The working principle, the experimental setup, and the results are presented.
On second thought I might not recommend using mirrors because the MET's might cause the mirrors to vibrate causing problems with measurements!
Maybe the dual mirrors would work after all. I am guessing you might want to mount the mirrors on damping devices such as a type of rubber maybe so it would absorb vibrations.
I had another crazy thought which was use a set of pezioelectric disks to sense viberations as a 1st layer. The 2nd layer then creates an equal and opposite vibration to actively cancel vibrations to the mirror. Sort of like those sound canceling head phones.
Acoustic damping might be achievable by some devices they already have out for excluding local conversations beyond a range and external noise from beyond the range to the local conversation.
Would be interesting to see the maximum sensitivity achievable.
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#2975 by RERT on 29 Jan, 2018 17:41
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.....
Capacitive distance sensors are state of the art but i think less useful in such pendulum experiment because of the (distant dependent!) additional force applied by charged capacitor plates.
.....
Edit3: Nevermind the striked through should not work. I am not sure there is a way to make the plates as equally repulsive as they are attractive.
Perhaps put one capacitive distance sensor on each side, one tending to rotate the torsion wire clockwise and one anti-clockwise.
If the force from each is constant, you are done - at worst the torsion wire will just settle off-centre if the forces are different. If the forces are non-constant with distance, to first order you probably just change the effective stiffness of the torsion wire a little if the change in force is linear with displacement on each side. -
#2976 by Peter Lauwer on 31 Jan, 2018 11:24
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Hi everybody, a small sign of life from my side, after being almost absend for a few months.
I don't have the cold weather as an excuse, like some Americans on this forum (on the contrary, here in the Netherlands the hottest January 24nd since measurements started in 1901 has been recorded). But my EmDrive project almost got to a standstill because I had to empty my parents house after my mother went to a residential home. Quite a daunting task.
Nevertheless, I recently did some tests with the torsion balance, see the attached pictures. The initial tests I usually do with a paper chart recorder since you have better overview, especially when rotating the wire for zero output and to observe drift. When everything seems to work fine, I shift to using an ADC and LabView software.
The unrest is higher than I had in the past with these electronics and sensors. The frame and portal is a little different, more compact then before. It is placed on the floor for better stability (and also because of too small lab-space, I have to admit ), the cover is a temporary one but should be OK.
The portal should be covered, of course. And maybe the temperature difference between the floor and the top of the cover is too large (of the order of 1 degree Celsius) and I have to add some thermal insulation. The damping is about right, slightly overdamped I estimate from the measurement in the last picture (the step-function force is made with a small bar magnet/solenoid system, force = about 15-20 micronewton. It is not calibrated yet).
So far the torsion balance system, first I am going to do some microwave measurements on the frustum and coupling.
The torsion balance arm which can be seen in the picture, is a symmetrical one for testing purposes of the system only. Another balance arm for holding the microwave cavity (e.g., the frustum shaped one) is under construction.
Cheers,
Peter
Peter -
Very nice build progress! When you have time could you provide more detail on the design of the torsion balance and support system (and my apologies of I missed this earlier). Drawing or sketch perhaps.
And I love the strip chart recorder - excellent especially for initial system tuning. Digital recording is great and useful but something about pen on paper just feels right too. Maybe my age is showing LOL. Big plus for Labview too - it is worth the effort and cost.
We here in Texas would be happy to trade some of that warm weather. We have had several days down to nearly -10C where I live. That has stopped all work here.
BTW -best wishes for your mother and you in the new living arrangements - having gone through that recently myself that can be a very traumatic and stressful process. Family comes first but it can be very challenging.
Best Wishes,
Herman
graybeardsyseng
Hello Herman,
Well, thank you very much! I see the temperatures are a bit higher now in Texas.
I will post some more details about the torsion balance soon (say the coming weeks).
Cheers,
Peter -
#2977 by Peter Lauwer on 31 Jan, 2018 11:55
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EmDrive research at Naval Research Lab
In the meantime, I learned from one of my sources () that the Naval Research Lab in the US also uses contactless microwave signal coupling in their EmDrive experiments.
They are using a kind of "stripline finger" to couple directly into the cavity under research.
It seems to me that they must be using a very rigid measurement instrument (torsion balance), because such a stripline will not enable movements of... probably smaller then 1 mm.
On the other hand, the stripline is probably more wideband than the "cavity coupling" I am using [see https://arxiv.org/abs/1706.04999].
Peter -
#2978 by Rodal on 31 Jan, 2018 14:48
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SSI to begin releasing videos of the 2017 Advanced Propulsion Workshop
http://ssi.org/advanced-propulsion-workshop-2017/QuoteLast November Space Studies Institute NASA Innovative Advanced Concepts (NIAC) Team Principal Investigator Dr. Heidi Fearn and Team Consultant Dr. James Woodward invited a group of friends and colleagues to discuss updates in engineering and testing of Propellant-less Propulsion, The “Woodward Effect,” The Machian Principle and other advanced physics and propulsion engineering topics.
Greg Meholic of The Aerospace Corporation, a presenter at the 2016 Estes Park Breakthrough Propulsion Workshop, offered an excellent space for this gathering in the Sally Ride Board Room at The Aerospace Corporation’s El Segundo, California headquarters.
The Space Studies Institute recorded the three day event and we are proud to begin releasing the full-length videos of the presentations starting this week on the SSI YouTube Channel
https://www.youtube.com/c/SSISpaceStudiesInstitute
There were a few papers about the EM Drive presented at this workshop...
For example, this one by Prof. Martin Tajmar that was just posted a few minutes ago:
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#2979 by X_RaY on 31 Jan, 2018 21:57
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SSI to begin releasing videos of the 2017 Advanced Propulsion Workshop
Thanks Jose', the presentation is very enlightening and i am very happy you was there to ask the right questions as well as to trigger important points to discuss things related to the subject.
http://ssi.org/advanced-propulsion-workshop-2017/QuoteLast November Space Studies Institute NASA Innovative Advanced Concepts (NIAC) Team Principal Investigator Dr. Heidi Fearn and Team Consultant Dr. James Woodward invited a group of friends and colleagues to discuss updates in engineering and testing of Propellant-less Propulsion, The “Woodward Effect,” The Machian Principle and other advanced physics and propulsion engineering topics.
Greg Meholic of The Aerospace Corporation, a presenter at the 2016 Estes Park Breakthrough Propulsion Workshop, offered an excellent space for this gathering in the Sally Ride Board Room at The Aerospace Corporation’s El Segundo, California headquarters.
The Space Studies Institute recorded the three day event and we are proud to begin releasing the full-length videos of the presentations starting this week on the SSI YouTube Channel
https://www.youtube.com/c/SSISpaceStudiesInstitute
There were a few papers about the EM Drive presented at this workshop...
For example, this one by Prof. Martin Tajmar that was just posted a few minutes ago:
A special thanks goes to SSI.org for supporting the whole theme in this way.
I would be happy to be present at the next (scheduled?) conference.
So please keeping on your great work, it's nice to follow (as well right now
).
Prof. Martin Tajmar and his students (as well as many others!) are doing a great job in regard to detect the small forces involved and he gave a honest report of the work that was done as well as the future callenges . I like the ideas like the liquid metal coaxial contacts, very nice work.
), the cover is a temporary one but should be OK.
).