Quote from: TheTraveller on 10/31/2015 01:06 amQuote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...Quick analysis suggest the 20cm big end limitation reduces the Df ( F = (2 Df unloadedQ P) / c ) quite a bit. But working on that limitation I get a highly optimised small end of 14.95cm and length of 15.07cm (mode TE011 @ 2.45GHz), with spherical end plates, using a 20% solid state amp conversion efficiency to Rf and 1kW power input could deliver, at a conservative unloaded Q of 50,000 (25,000 as measured loaded Q) around 40mN, generating say 4mm/sec acceleration with a 10kg mass.Let's get our physics right. 40 mN acting on a 10 kg object would generate an acceleration of 4 mm per second per second. So assuming 1) you could hold spacecraft attitude, and 2) other forces on the satellite are much less than 40 mN your velocity would change (for example) 4 mm per second if you could hold 1 kW for one second. Is that detectable?
Quote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...Quick analysis suggest the 20cm big end limitation reduces the Df ( F = (2 Df unloadedQ P) / c ) quite a bit. But working on that limitation I get a highly optimised small end of 14.95cm and length of 15.07cm (mode TE011 @ 2.45GHz), with spherical end plates, using a 20% solid state amp conversion efficiency to Rf and 1kW power input could deliver, at a conservative unloaded Q of 50,000 (25,000 as measured loaded Q) around 40mN, generating say 4mm/sec acceleration with a 10kg mass.
...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...
How much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?
Vax,A X band 1U EMDrive thruster delivering 2mN of thrust for 12W draw is doable. Depending on the power available the Rf Watts can go up as would the thrust.Do you need constant or short term thrust?What is the desired mN thrust?What is the mass budget for the thruster?How much power can you supply to meet the thrust requirements?Potentially the thrust may be able to be vectored +-10 deg in 2 axis. Is this helpful?
Quote from: Prunesquallor on 10/31/2015 12:35 pmQuote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...I'm not sure where you are going here, mm/s is a velocity, not an acceleration. I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab. What would you conclude from a cubesat test that doesn't give detectable results?I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are...
Quote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...I'm not sure where you are going here, mm/s is a velocity, not an acceleration. I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab. What would you conclude from a cubesat test that doesn't give detectable results?
Quote from: VAXHeadroom on 10/31/2015 12:48 pmQuote from: Prunesquallor on 10/31/2015 12:35 pmQuote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...I'm not sure where you are going here, mm/s is a velocity, not an acceleration. I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab. What would you conclude from a cubesat test that doesn't give detectable results?I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are...Regarding disturbing forces, I calculate that the atmospheric drag that could be experienced by a satellite at 300 km altitude to be around 2 mN/m^2. (Assumes F10.7=150, Kp=5, Cd=2.2). At 400 km it would be down to 0.3 mN/m^2.
Quote from: Prunesquallor on 10/31/2015 01:58 pmQuote from: VAXHeadroom on 10/31/2015 12:48 pmQuote from: Prunesquallor on 10/31/2015 12:35 pmQuote from: VAXHeadroom on 10/31/2015 12:36 am...Quote from: TheTraveller on 10/30/2015 11:04 pmHow much Force do you need a cubesat EMDrive to deliver? Knowing the Force desired then the needed Rf watts can be calculated. Your job to deliver those Rf watts and ensure there is enough primary power available. Can design to many dimensions knowing the Rf drive freq, which will need to real time track lowest VSWR or lowest reflected power to achieve and hold resonance. I assume it needs to fit inside 1 cube being 100mmx100mmx100mm?To fit in a 12u cubesat, large dia can be up to 20cm with length up to 36cm. To accelerate a 10Kg cubesat at 10mm/s would take...what... 100mN? I'm guessing on the math here - too late at night - I'm probably off by some powers of 10... We can give you a KW for several minutes once per orbit, only limit is how hot the batteries get and how far we discharge them. More than a 20% depth of discharge will limit their life, but this is probably a limited life test anyway (not a multi-year mission) so we can maybe run them harder and/or pack in more batteries to give us more instantaneous power...I'm not sure where you are going here, mm/s is a velocity, not an acceleration. I have made my concerns about an amateur space test known previously. In my opinion, the disturbing orbital forces, thermal and EM effects on a satellite this small may not be appreciably smaller than the effects folks are trying to eliminate in the lab. What would you conclude from a cubesat test that doesn't give detectable results?I have made my credentials known, I'm not an amateur, and this would not be an amateur test. The change of velocity resulting from thrust causes the ground to see a Doppler shift in the rf carrier, detectable down to a deltaV of single digit mm/s. This change needs to occur in a pretty short period of time (minutes) to insure a significant signal to noise ratio in the rf shift (if it happens too slowly it can look like thermal drift of the S-Band amplifier). This means all the hard part (large, expensive) of the test and measurement equipment is on the ground. A second means of measurement is using NASA Goddard's laser measurement system - all we really have to do for that is provide a retro-reflector on the spacecraft. They can do both position and velocity measurements out to the moon (they do this for LRO all the time), but I'll have to find out what their measurement and resolution limits are...Regarding disturbing forces, I calculate that the atmospheric drag that could be experienced by a satellite at 300 km altitude to be around 2 mN/m^2. (Assumes F10.7=150, Kp=5, Cd=2.2). At 400 km it would be down to 0.3 mN/m^2. Those numbers look reasonable to me at first glance This would be only about 0.5m^2 for the solar panels and generally they would be body mounted and kept normal to the sun, so they do contribute to the drag for part of the orbit. The satellite body for a 6u or 12u is 30cmx37cm so only about 0.1m^2 in cross section... (caution: ascii art follows )___ ___ ___ _ ___ ___ ___ <-- solar arrays | | | | <-- satellite body ^ | | | sun vectorwe do have a solar array drive available, and if we use it, then the bottom of the satellite can stay pointed at the Earth and the body rotates about the vertical axis (in the drawing) once per orbit. Gives us slightly higher power and provides constant earth pointing...
Quote from: ChrisWilson68 on 10/28/2015 03:53 amDoesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.As far as I can tell, the experiment is just measuring the Lorentz force on a device with a current running through it due to the Earth's magnetic field. They point out in the Appendix that due to different grounding points in the null and resonating cavity tests, the Lorentz force may not have been correctly accounted for in the Eagleworks experiment. This just adds one more possible explanation of experimental error that could be the real cause for the small thrust measured by Eagleworks.This is a paper explaining why the emdrive thrust is just an error in the experiment design. It could use a bit more rigor in parts, but its point is to demonstrate that a significant source of error exists, not to precisely measure the magnitude, which would require them to have access to the original experiment equipment.To reiterate, this paper claims (reasonably) that the measured thrust is an experimental error, and suggests an incorrect calibration of the Lorentz force effect on the setup as the cause of the error.
Doesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.
...And yet the anomalous thrust signals remain...Best, Paul March
Quote from: Star-Drive on 10/31/2015 03:21 pm...And yet the anomalous thrust signals remain...Best, Paul MarchExcelsior!
Vax,Your 10mN at 35W max input power requirements appears to be doable. Going to pulsed op at upto 50mN seems doable. 3kg is heaps of mass budget. All the electronics would be on one cubesat pcb with the frustum mounted and secured to the 1u modules frame. What g and vibration freq rates will the thruster and mounting system need to be designed to handle?What are the processes to move forward, what are the precursor qualification requirements and what are the time frames as an overview?Yes of course I need to do the rotary demo rig. That is a unspoken given requirement. Despite others opinion here, the EMDrive does work and this cubesat thruster is really doable.It is my intention to start commercial sales of EMDrives, so the cubesat project will be done with commercial sales as the objective. It will be a high quality and high fidelity build.
All:I wish I could show you all the pictures I've taken ... but I can't due to the restrictive NASA press release rules now applied to the EW Lab. However since I still can't show you this supporting data ... ... And yet the anomalous thrust signals remain...Best, Paul March
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all. And yet the anomalous thrust signals remain...Best, Paul March
Quote from: meberbs on 10/28/2015 04:48 amQuote from: ChrisWilson68 on 10/28/2015 03:53 amDoesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.All:And yet the anomalous thrust signals remain...Best, Paul March
Quote from: ChrisWilson68 on 10/28/2015 03:53 amDoesn't anyone here have any reply at all to the substance of this paper? Just throwing out insults without providing any justification for the insults isn't very persuasive.
100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"
Quote from: Star-Drive on 10/31/2015 03:21 pmGiven all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all. And yet the anomalous thrust signals remain...Best, Paul MarchPaul,That's wonderful news! I am super excited for you.I do have a question, however. This is going to take a while to ask, so bare with me for a moment.I started following this topic back during thread 2. Then sort of missed out on threads three and four. During thread 2, someone posted a paper published in the 1950's by A. L. Cullen who was studying the behavior of microwaves bouncing around within closed metal containers. He did this with containers of a constant profile, rather than ones of a varying profile such as those used in an EmDrive. However, he ran into the issue of the containers heating up and generating thermal lift. He solved this by placing a ring reflector on each end of his containers, as shown in fig. 12 on page 8 in his paper. The microwaves continued to bounce around within the container, but the issue of thermal lift was no longer a problem.My question is this: In order to solve the thermal lift issue, why hasn't anyone attempted using ring reflectors on the ends of their EmDrives, as Cullen showed that was a viable solution, to this exact issue, without a need to use a vacuum chamber in the 1950's?
Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.
Paul March,Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.
Quote from: meberbs on 10/31/2015 06:28 pmAny thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.Glad to see we agree in principle. Where is your calculation of 3.33 nano-Newtons per Watt ?
Quote from: Notsosureofit on 10/31/2015 05:43 pm100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.Paul March,Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.Thank you.Also, I am glad you are making progress on eliminating sources of error.
Quote from: meberbs on 10/31/2015 06:28 pmQuote from: Notsosureofit on 10/31/2015 05:43 pm100microN, 80W, TM212, should only need Q ~ 12,000 to stay within "No new physics required"Any thrust greater than 3.33 nano-Newtons per Watt would require new physics. I'm always hoping for new physics since it could revolutionize space travel, but unfortunately solid new physics results are pretty rare.Paul March,Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error. Could you please clarify for them that explanations such as this page are accurate descriptions of electrodynamics, and something else (quantum vacuum, gravitational warping, dark matter, or other effects not recorded to date) would be required to explain any anomylous thrust? I think this would help discussion on the emDrive to be much more productive.Thank you.Also, I am glad you are making progress on eliminating sources of error.Notsosureofit:The integrated copper frustum test article's -3dB loaded Q-factor for the 80W / ~100uN test runs or 1.25 uN/W was 7,100. That is 1.25 uN/W / 3.33 nano-Newton (nN) / Watt = ~375.4 times as much thrust as a 100% efficient E&M rocket can produce. Meberbs:"Some people on this thread have been having trouble accepting that the emDrive requires new physics to explain its thrust if it is not experimental error."I concur with your position that Maxwell's Classical E&M can NOT explain the frustum test results we continue to see, because when you sum up ALL of the Maxwell pressure tensors in the frustum due to all the E&M fields bouncing around inside the cavity and their interactions with any interior components like the PE discs and the active copper layer in the frustum's end and side walls, the NET force answer has to be ZERO by definition. In other words classical E&M cannot provide an explanation for conservation of momentum for a closed E&M system that produces a net thrust.