Tajmar Tests Refutes Emdrive Reactionless Drive and Mach Effect Thruster Claims

Tajmars team at Dresden University of Technology had intensive tests and analysis of three EmDrive variants and measurements refute all EmDrive claims by at least 3 orders of magnitude.

High-Accuracy Thrust Measurements of the EMDrive and Elimination of False-Positive Effects

High-Accuracy Thrust Measurements of the EMDrive and Elimination of False-Positive Effects

The EMDrive is a proposed propellantless propulsion concept claiming to be many orders of magnitude more efficient than classical radiation pressure forces. It is based on microwaves, which are injected into a closed tapered cavity, producing a unidirectional thrust with values of at least one mN/kW. This was met with high scepticism going against basic conservation laws and classical mechanics. However, several tests and theories appeared in the literature supporting this concept. Measuring a thruster with a significant thermal and mechanical load as well as high electric currents, such as those required to operate a microwave amplifier, can create numerous artefacts that produce false-positive thrust values. After many iterations, we developed an inverted counterbalanced double pendulum thrust balance, where the thruster can be mounted on a bearing below its suspension point to eliminate most thermal drift effects. In addition, the EMDrive was self-powered by a battery pack to remove undesired interactions due to feedthroughs. Using a geometry and operating conditions close to the model by White et al that reported positive results published in the peer-reviewed literature, we found no thrust values within a wide frequency band including several resonance frequencies. Our data limits any anomalous thrust to below the force equivalent from classical radiation for a given amount of power. This provides strong limits to all proposed theories and rules out previous test results by more than three orders of magnitude.

Thrust Measurements and Evaluation of Asymmetric Infrared Laser Resonators for Space Propulsion

In addition to the classic EmDrive, Tajmar’s team also analyzed the LemDrive-variation:

“This laser variant of the EmDrive is based on theoretical considerations by McCulloch. In numerous experimental set-ups, we have been able to show that both laser resonators and asymmetrical fiber coils do not show any forces that are above normal photon pressure. His theory (…we limit ourselves here to the laboratory standard and not to his astronomical claims), as well as the experiments cited by him are excluded by 4 orders of magnitude.

Abstract – Thrust Measurements and Evaluation of Asymmetric Infrared Laser Resonators for Space Propulsion
Since modern propulsion systems are insufficient for large-scale space exploration, a breakthrough in propulsion physics is required. Amongst different concepts, the EMDrive is a proposed device claiming to be more efficient in converting energy into propulsive forces than classical photon momentum exchange. It is based on a microwave resonator inside a tapered cavity. Recently, Taylor suggested using a laser instead of microwaves to boost thrust by many orders of magnitude due to the higher quality factor of optical resonators. His analysis was based on the theory of quantised inertia by McCulloch, who predicted that an asymmetry in mass surrounding the device and/or geometry is responsible for EMDrive-like forces. We put this concept to the test in a number of different configurations using various asymmetrical laser resonators, reflective cavities of different materials and size as well as fiber-optic loops, which were symmetrically and asymmetrically shaped. A dedicated high precision thrust balance was developed to test all these concepts with a sensitivity better than pure photon thrust, which is the force equivalent to the radiation pressure of a laser for the same power that is used to operate each individual devices. In summary, all devices showed no net thrust within our resolution at the Nanonewton range, meaning that any anomalous thrust must be below state-of-the-art propellantless propulsion. This puts strong limits on all proposed theories like quantised inertia by at least 4 orders of magnitude for the laboratory-scale geometries and power levels used with worst care assumptions for the theoretical predictions.

With both the EmDrive and the LemDrive, we have achieved a measurement accuracy that is below the photon pressure. That is, even if one of these concepts worked, it would be more effective simply to use a laser beam as a drive.”

In a third paper, the Dresden physicists then describe their research on the “Mach-Effect Thruster”:

“Here we have proven that the Mach-Effect-Thruster (an idea by J. Woodward) is unfortunately a vibration artifact and also not a real thrust.”

Abstract – The SpaceDrive Project – Mach-Effect Thruster Experiments on High-Precision Balances in Vacuum
Concepts for propellantless space propulsion are carefully investigated using high-precision balances in the framework of the SpaceDrive Project. The Mach-Effect-Thruster, an original design from Woodward that relies on the particular vibration of an asymmetric, piezoelectric stack actuator to produce thrust, is one concept that was extensively tested. In an attempt to validate the results published in peer-reviewed literature, several MET devices were tested on two different types of balances in vacuum conditions: a torsion balance and an inverted counterbalanced double pendulum, as well as on a rotating apparatus. The instruments are characterized by background noise lower than 5 nN after averaging and are calibrated using laser interferometry and a voice coil with a high-resolution current source. Encased in grounded mu-metal shielding on the balance, and powered by dedicated amplifiers, the device was swept with a frequency between 20 and 50 kHz in order to identify the operating range with the largest beam deflections. Measurements with the torsion balance from a previous campaign seem to indicate vibration artifacts, thermal noise and changes in the experiment’s center of mass at specific resonance frequencies. These measurements were repeated with different device orientations on the double-pendulum balance, and deflections of similar magnitude that can be explained by thermal expansion and device resonance were also observed. Recording both balance beam displacements with a sampling rate of up to 25 MHz revealed a significant vibration when exciting the actuator around its longitudinal resonance, regardless of the mounting and isolation. Calculations and simple modeling of the resulting pulsed force from the vibrations confirms the hypotheses made from balance measurements. Additional tests were performed on a rotating apparatus to investigate the presence of mass fluctuations in a centrifugal force field without having to synchronize with a push-pull force. Our tests reveal the presence of mechanical artifacts but no thrust.

SOURCES- Dresden University, Conference: Space Propulsion 2020+1
Written By Brian Wang, Nextbigfuture.com

8 thoughts on “Tajmar Tests Refutes Emdrive Reactionless Drive and Mach Effect Thruster Claims”

  1. "The DARPA NLM project is currently funded until May 2021. Mike McCulloch
    is the current DARPA EmDrive project leader. Mike presented some
    interim results in an embedded video below."

  2. I mean, we all WANT amazing wonder tech that runs on magical unicorn farts but none work so far. That's probably why the snake oil salesmen keep inventing them.
    No big surprise here. Would have been nice, but the concept really never made sense.

  3. Yes, no great surprise here, although I will admit to wanting McCulloch's QI theory to prove correct. As cool as it would be, we don't need reactionless wonder-drives or perpetual motion machines to build an amazing future.

  4. I expected a null result from the EM Drive test. We can finally put this behind us. I am disappointed with the Mach Effect results, given that Woodward and Fern have recently made a small breakthrough. We shall see in the next year or so how this pans out.

  5. Well, the fun is over.

    Because it was mostly an entertaining notion and speculation what kept this ongoing, and the all too human desire that something like this exists.

    I still suspect that any such effect, if weak and near the noise floor, will only be proven (or easily discarded) in an age when there are enough people living and working in space, preferably in deep space; where they can test it by throwing it out an airlock and see if it budges by itself even a little bit.

    That age is approaching, but we're not quite there yet.

  6. Exactly, there probably was an enormous amount of wishful thinking involved, an almost religious desire to believe.
    Unfortunately, the universe cannot be bothered by our wishful thinking.
    In a way, courageous that Tajmar published this, since he was deeply involved in this issue for a long time. This is science at work.

  7. It was back in the 1800's that Cavendish measured the gravitational force between two lead balls in a lab. At this point, any competent scientist ought, if taking care, to be able to measure the photon thrust of an LED powered by a 9V battery.

    I've thought all along that these experiments looked like people subconsciously desperate not to disprove the effect, the setups were typically so marginal. Haven't I been saying all along, "Use a torsion balance in vacuum"?

    So, I'm not surprised here. It never made much sense to think the EM drive was real.

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