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#1220
by
rfmwguy
on 14 Apr, 2016 16:51
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EMDRive launch enthusiasts can probably expect a $5 Mil price tag just to try it out...thus...the absolute need for ground verification tests before fundraising efforts to launch an EMDrive probe.
That's just the launch cost right? Nobody is going to launch a DIY satellite. You'll need at least several million more to build a flight-rated spacecraft that can orient itself by gimbaling the emdrive, has reliable communications, solar arrays and batteries, proper cameras, mission control, etc.
Absolutely, although the launch control and even mission costs could be part of the $5 Mil.
I would envision it being nothing but an Arrow...shot into deep space with only one intent...speed.
No cameras, no directional control...basically a ballistic, accelerating "bullet" with standard telemetry: velocity, acceleration, power consumption, etc. No ground based commands, it would be autonomous.
This would be an engine test only, no need for other scientific payloads.
Cheap, straight forward, no trajectory management, nothing but "the need for speed".
I design satellites for a living and I outlined an EMDrive mission about...3 threads ago 
1KW with a moderate duty cycle, off-the-shelf (my shelf!) hardware & software, NASA will probably pay for the launch costs, but it could get up to $1M as a ride-share - this is all stock stuff, I design these kinds of missions every day. Doppler shift in the telemetry carrier can detect down to mm/s of velocity change, plus on-board accelerometers get you very precise data, so just point it away from the Earth and turn it on 
Give me a working drive and flying it is actually the easy part!!
Vax, IF I reached my power threshold of 18 mN force, are you saying all you need is an S-Level rated engine and you'll do the rest?
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#1221
by
Tellmeagain
on 14 Apr, 2016 17:19
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Vax, IF I reached my power threshold of 18 mN force, are you saying all you need is an S-Level rated engine and you'll do the rest?
He probably would like to verify your 18mN first.
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#1222
by
rfmwguy
on 14 Apr, 2016 17:25
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Vax, IF I reached my power threshold of 18 mN force, are you saying all you need is an S-Level rated engine and you'll do the rest?
He probably would like to verify your 18mN first.
I would, too...makes total sense. My thought is, if 18 mN is presented and validated by whomever, what is the needed condition of the assembly?...i.e. would it need to be S-Level? My thought is it would be and THAT would be quite costly I believe.
Only had a little S-Level work back in my day, but tests back then were temp cycling, shock, vibration, PIND, fine and gross leak. All big $$. Things I'm sure changed in 20 years or so.
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#1223
by
X_RaY
on 14 Apr, 2016 19:43
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I got an simple idea to filter/stabilize the output of a noisy magnetron:
In HF technology it is state of the art to stabilize frequencies using resonant circuits such like stripline-, dielectric- or cavity-resonators. It is possible to use a simple cylindrical cavity resonator as a kind of frequency selective filter. So the suggestion is to build a small simple to calc cavity resonator at 2.45GHz and place it inline between magnetron and antenna of the frustum. The output of this additional resonator will way more stable than the magnetron alone, if one stack two or more the effect increases. Its an effective bandpass filter.
Of course this output costs a part of the power(some dB) but its pretty easy to realize and low cost technic.
In the second pic the visual Field vector represents the E-Field.
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#1224
by
FattyLumpkin
on 14 Apr, 2016 20:21
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X_Ray, the only information I have re the nature of the dielectric is this:
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#1225
by
rfmwguy
on 14 Apr, 2016 20:28
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#1226
by
FattyLumpkin
on 14 Apr, 2016 20:34
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X_Ray, I'm not entirely sure where you found this: FattyLumpkin I used the frustum without dielectric, for dims and frequencies I used the paper of Frank Davies (NASA/EW).
Please check the original schematic and as you can see: "DIELECTRIC FROM TOP MIDDLE" is printed.
Your help with this is greatly appreciated however, irrespective of the occasional miscommunication. FL
PS: Is the device you are referring to above known as a Z-choke or Iris filter? And I take it you saw Shell's clean magnetron signal by use of DC? FL
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#1227
by
VAXHeadroom
on 14 Apr, 2016 20:35
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Vax, IF I reached my power threshold of 18 mN force, are you saying all you need is an S-Level rated engine and you'll do the rest?
He probably would like to verify your 18mN first.
I would, too...makes total sense. My thought is, if 18 mN is presented and validated by whomever, what is the needed condition of the assembly?...i.e. would it need to be S-Level? My thought is it would be and THAT would be quite costly I believe.
Only had a little S-Level work back in my day, but tests back then were temp cycling, shock, vibration, PIND, fine and gross leak. All big $$. Things I'm sure changed in 20 years or so.
If you can prove 18mN/KW (especially in a vacuum) people will be throwing money at projects to fly it. HOWEVER, that test regime is probably $200K(ish) (I think the facility is about $30K/day IIRC) and the hardware can be built for <$2M (that's pretty good HW, but we need it to work for quite a while) so the whole mission is <<$5M even including launch and flight ops. Probably a 27u CubeSat mission. RTG won't give you enough power (Curiosity rover's RTG only produces 100W!)
https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator So solar panels are really the only way to go. TransLunar or TransMartian injection is probably the best test for a system with that small a thrust, but a geo transfer orbit (just to get it WAY out of the atmosphere) is probably workable...
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#1228
by
FattyLumpkin
on 14 Apr, 2016 20:42
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Rfmwguy interesting you just posted about Cannae as I was poised to post this re the satellite station keeping and mini Emdrive discussion
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#1229
by
X_RaY
on 14 Apr, 2016 20:50
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X_Ray, I'm not entirely sure where you found this: FattyLumpkin I used the frustum without dielectric, for dims and frequencies I used the paper of Frank Davies (NASA/EW).
Please check the original schematic and as you can see: "DIELECTRIC FROM TOP MIDDLE" is printed.
Your help with this is greatly appreciated however, irrespective of the occasional miscommunication. FL
PS: Is the device you are referring to above known as a Z-choke or Iris filter? And I take it you saw Shell's clean magnetron signal by use of DC? FL
Yes it's comparable with the z-choke (and it's an similar possibility! z-choke is also usable) but more general its a filter technic. The z-choke also connects 2 single cavities to each other using an iris in this case, therefore your statement is quite legal. For choke coupling one has to define the position, shape and the width of the window between the cavities. My suggestion includes simple stub antennas and a defined mode. The length of these antennas defines the coupling conditions and can be used to optimize the coupling factor and get impedance match. In the past I explore this option experimentally within the K-band, it works as well.
I will do some calculations using the EW dims for the dielectric after I finished the current calculations, maybe tomorrow, now its bed time in my time zone
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#1230
by
rfmwguy
on 14 Apr, 2016 21:10
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Vax, IF I reached my power threshold of 18 mN force, are you saying all you need is an S-Level rated engine and you'll do the rest?
He probably would like to verify your 18mN first.
I would, too...makes total sense. My thought is, if 18 mN is presented and validated by whomever, what is the needed condition of the assembly?...i.e. would it need to be S-Level? My thought is it would be and THAT would be quite costly I believe.
Only had a little S-Level work back in my day, but tests back then were temp cycling, shock, vibration, PIND, fine and gross leak. All big $$. Things I'm sure changed in 20 years or so.
If you can prove 18mN/KW (especially in a vacuum) people will be throwing money at projects to fly it. HOWEVER, that test regime is probably $200K(ish) (I think the facility is about $30K/day IIRC) and the hardware can be built for <$2M (that's pretty good HW, but we need it to work for quite a while) so the whole mission is <<$5M even including launch and flight ops. Probably a 27u CubeSat mission. RTG won't give you enough power (Curiosity rover's RTG only produces 100W!) https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator So solar panels are really the only way to go. TransLunar or TransMartian injection is probably the best test for a system with that small a thrust, but a geo transfer orbit (just to get it WAY out of the atmosphere) is probably workable...
Yes, I figured a 2.5 kW power budget...ala Deep Space 1's solar array. After it gets outside the sun's influence (have to look that distance up), the 2.5 kW RTG kicks in and the solar panels and batteries get ejected. The Soviets had a 3 kW unit, think the US is hovering around the 1.5 kW area.
Whatever gravity assist is available, but assume this adds complexity ($$) to mission. You're the man on this stuff, but probably wouldn't be a bad idea to archive a rough plan somewhere and hope the costs go down.
18 mN/kW will only be testable in ambient on a torsion setup by me...If this is achieved, it all depends on by how much, for my assumption is the vacuum degrades performance...unless it is built to contain a pressurized atmosphere, which I have already thought about.
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#1231
by
FattyLumpkin
on 14 Apr, 2016 21:32
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Orion spacecraft with all four "wings" extended from service module generate 11 kilowatts (presumably in near earth orbit) after that hello inverse square.
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#1232
by
Monomorphic
on 14 Apr, 2016 21:54
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Cannae website back up and running w/a 4/10/16 update: http://cannae.com/cannaes-superconducting-test-lab-is-up-and-running/
They've definitely been spending some $$$ on CG renderings...
From the site: "We recently completed successful demonstration of a 2nd generation superconducting prototype. We are planning a news release regarding our demonstration results.
Cannae now has demonstrated the ability to numerically model, design, manufacture and test superconducting RF thrusters. A next generation superconducting Cannae Drive prototype is in the design phase now."
The deep space probe is interesting. Looks like they are stacking their drives.
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#1233
by
FattyLumpkin
on 14 Apr, 2016 22:07
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Huh-um, look familiar? Wonder if the RF moves from cavity to cavity? Hmmmm
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#1234
by
Monomorphic
on 14 Apr, 2016 22:10
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Huh-um, look familiar? Wonder if the RF moves from cavity to cavity? Hmmmm
They're definitely connected. I bet that pipe is a waveguide.
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#1235
by
rfmwguy
on 14 Apr, 2016 22:18
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Cannae website back up and running w/a 4/10/16 update: http://cannae.com/cannaes-superconducting-test-lab-is-up-and-running/
They've definitely been spending some $$$ on CG renderings...
From the site: "We recently completed successful demonstration of a 2nd generation superconducting prototype. We are planning a news release regarding our demonstration results. Cannae now has demonstrated the ability to numerically model, design, manufacture and test superconducting RF thrusters. A next generation superconducting Cannae Drive prototype is in the design phase now."
The deep space probe is interesting. Looks like they are stacking their drives.
Im a little suspicious that the black discs are thermal radiators for an RTG and not stacked drives...could be wrong, but this is a typical way to axially locate an RTG power source.
Also, not one to criticize new propulsion ideas too much, but saying they've tested without formal presentation, videos, data or papers leads me to think its still in fundraising mode. Could be very wrong about this, but demonstrating any product or service publicly is critical to market acceptance.
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#1236
by
Mark7777777
on 14 Apr, 2016 22:31
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Yes. Logically though you could think it's a lot of time and effort for Guido unless he had seen real results himself from his experiments?
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#1237
by
flux_capacitor
on 14 Apr, 2016 22:41
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Cannae website back up and running w/a 4/10/16 update: http://cannae.com/cannaes-superconducting-test-lab-is-up-and-running/
They've definitely been spending some $$$ on CG renderings...
From the site: "We recently completed successful demonstration of a 2nd generation superconducting prototype. We are planning a news release regarding our demonstration results. Cannae now has demonstrated the ability to numerically model, design, manufacture and test superconducting RF thrusters. A next generation superconducting Cannae Drive prototype is in the design phase now."
The deep space probe is interesting. Looks like they are stacking their drives.
Im a little suspicious that the black discs are thermal radiators for an RTG and not stacked drives...could be wrong, but this is a typical way to axially locate an RTG power source.
Also, not one to criticize new propulsion ideas too much, but saying they've tested without formal presentation, videos, data or papers leads me to think its still in fundraising mode. Could be very wrong about this, but demonstrating any product or service publicly is critical to market acceptance.
No Dave, they are indeed stacked Cannae drives, read
what they say on their web site under the picture:
There are 10 Cannae Drives included in the design.
5 x 50 MHz Thruster cavities (continuously powered)
3 x 1 GHz Steering cavities (powered as needed)
2 x 1.5 GHz Roll-control cavities (powered as needed)
The 5 Cannae Drive thruster cavities provide continuous acceleration of 8.66 x 10-3 m/s2 to the probe. This is equivalent to accelerating at 1/1132 G. The small acceleration is constantly applied in one direction throughout the life time of the probe, continually increasing the velocity of the probe with respect to the Earth reference frame. The total thrust developed by the 5 thruster cavities is 85.5 newtons.
The three medium sized Cannae Drive cavities provide steering for the probe. These cavities are intermittently powered to provide course corrections or for flight maneuvers.
The two small Cannae Drive cavities are used to modulate the roll rate of the space probe. These cavities are also used intermittently.
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#1238
by
FattyLumpkin
on 14 Apr, 2016 22:44
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If you read the text it state "5 x 50 MHz Thruster cavities"...I suspect not cavities.
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#1239
by
Monomorphic
on 14 Apr, 2016 22:50
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Some quick sims of stacked emdrives before heading out to dinner. My dims (TE311), different size holes between frustums, and far right using square waveguide.
