NASA released now, seemingly positive, results of their tests of the EMDrive over the weekend. The EMDrive is an electromagnetic thruster that does not use a conventional propellant. The suspected thrust signals, to date, have been low. In the vacuum of space even a small amount of thrust applied constantly can get an object moving very fast. The data from the most recent NASA release puts am EMDrive about on par with a chemical rocket for reaching Mars - but makes a return trip a whole lot easier.
The EMDrive is controversial. Sealed cans should not be able to move on their own accord. A number of theories have been proposed. Leading ones involve some kind of relativistic action with spacetime and pushing some form of virtual particle out of one end. At least one recent test by a DIY engineer (engineer building a test article as a hobby) in Germany has detected an unknown emission coming out of the drive opposite to the direction of expected thrust. The unknown emission interfered with the path of a laser between fixed points, possibly suggesting some kind of gravity ripple. If true this would indicate that the EMDrive is not a closed system and does not violate conservation of momentum (which makes it a hell of a lot more likely to actually work).
On Saturday a member of the team at NASA released comments on a pre-publication third party paper calling the NASA tests into question. The release indicates NASA is still detecting an anomalous thrust from the device and had already compensated for the proposed source of error. The team has sacled up the force up since the last public release of information and are attempting to scale if further.
A small team of engineers at NASA has been working on the device – part time at last report – for a little over a year. One of the researchers made a comment about potential spacetime effects. This spurred a storm of reports that NASA was working on a warp drive. Higher ups at NASA told the team to shut up unless they wanted to find themselves in a position where they better either actually have a warp drive or find another job. Last week a paper was released on a pre-publication website suggesting that the initial NASA tests might have resulted from magnetic fields in the device interacting with a magnet within the measuring apparatus. The news embargo NASA has put on the project allowed the team to comment on the prepublication of the paper. The response has now hit the press, so I’m not going to get anyone in any more trouble by posting it here.
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper [author’s reddit handle], on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, 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 until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
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...
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A follow-up clarified that the integrated test article is a aluminum EMDrive which they are at the point of pumping significantly more than 80 watts into, but has not yet been tested in a vacuum.
Release of the statement has kicked off attempts to organize a test of the EMDrive in orbit, most likely launched on a cubesat either from the ISS or as an additional payload on some other launch. One employee, at a different part of NASA, has estimated the total cost of an orbital test at around one million dollars and is attempted to line up outside funding sources. Additionally, one of the DIY engineers working on the device (who unlike others holds a license from the British inventor/patent holder of the drive) seems to be in the initial stages of forming a company to produce cubesat sized EMDrive thrusters.
I can’t help but wondering if now would not be a good time for more public and/or venture capital money to become involved in developing this device.