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38

EmDrive takes ~300W. You won't get it from a cubesat. You need over a meter of solar panels, or good 56kg of RTG battery. It's been tested on Earth, made with materials and electronics meant to work in Earth ambient conditions: temperature, pressure, radiation. Putting things in space is not as simple as loading them onto a rocket. If they are to work, they ...


16

It's a violation of Newton's 3rd law of motion? This is a fairly complete answer to the question in the absence of any deeper argument by the proponents of the device, but I'll get to those in a minute. Firstly, it's important to recognize that our universe follows a set of predictable and consistent laws. This might have been controversial in the 1700s. One ...


14

UPDATE (12/14/2016): Apparently, aside from the Cannae launch, the EmDrive is actually already in space, according to a recent announcement by China, who claims to be testing it in orbit. No, the media has confused things. Cannae, whose tech is being launched, issued a release clarifying things: There has been a lot of erroneous information in media ...


14

Call me unimpressed. NASA did not "validate" this "impossible" space drive. First off, this was a conference paper, not a peer reviewed scientific journal paper. Even if the results had been published in a peer reviewed scientific journal, I would still not call it "validation." The peer reviewed literature is where science starts, not ends. To be "...


13

The Drive's Impacts If the drive works as described, it could reduce the costs to launch to those in the range needed to commercialize manned flight. They claim to be able to design a 2G shuttle using it for primary thrust. Note that a consistent 0.01G (0.1 m/s² vehicle would be capable of making it to mars in a matter of days rather than months. It would ...


11

We might, it depends on the scale of the project, and if someone proposed a proof of concept mission and is ready to finance it. For a small scale technology demonstration mission such as the ones regularly performed aboard the ISS, it could be, for example, proposed through CASIS as a Physical and Materials Science R&D project, but it likely won't win ...


11

Looking through the linked article, several forces are mentioned, including 720 mN and 30-50 uN. These are extremely low levels, but still can have some use. At first glance, these seem similar to the numbers provided by Ion Drives, and Ion Drives also use a large amount of power, so let's compare the two of them, and see how they compare. From Wikipedia, I ...


10

Yes,you can find the PDF here The abstract: Propellantless propulsion is believed to be the best option for interstellar travel. However, photon rockets or solar sails have thrusts so low that maybe only nano-scaled spacecraft may reach the next star within our lifetime using very high-power laser beams. Following into the footsteps of earlier ...


9

A photon drive (the flashlight example) doesn't use reaction mass, just the momentum of (massless) photons. So if it's supplied with power, e.g. from the sun, it can keep thrusting indefinitely. The most obvious example is a solar sail. However, photon drives have a thrust/power ratio of about 3.34 nN/W, which means that ~300 MW is required for 1 N of thrust....


7

There is a great article by gizmodo, which gives an example of what would be required: Power- 700W Thrust- 88 uN System Mass- 9 kG To get 700W of power would require about 2 square meters of high efficiency solar panels, which is probably beyond most small satellites, but could still potentially be done. Where this could fairly easily be done is the ...


7

NASA's already testing the EmDrive, at the NASA/JSC Advanced Propulsion Physics Laboratory. To have no doubt that the device works, we'd need to see the test results replicated consistently by multiple laboratories. As of early 2016, 3 laboratories have done tests with inconsistent results (different levels of thrust/input power). It'd also be nice to ...


6

There's a timely article at Ars Technica today on this. The conclusion (unsurprisingly to me at least): And the winner is… Physics, without much doubt. Even with a power of just a couple of Watts, the EM-drive generates thrust in the expected direction (e.g., the torsion bar twists in the right direction). If you reverse the direction of the thruster, ...


5

The real information, not the "public news", is what NASA uses. Spinning a mundane negative result into hype, or describing the taking of measurements near the noise level of the instruments and then claiming it's a profound and confusing result, does not fool or impress the real engineers. It does not work. There is no reason to suppose anything fishy is ...


4

For the EM-Drive, the disparity comes from the test results of the different test apparati. at least 5 test run versions have been made: — The 2 test rigs by the developer — The Chinese replication — The NASA test (tested in the same program as two cannae thrusters - see Brady, et al) Each version produces a different thrust. This may be due to non-...


4

I was just researching this now. A working design basically doesn't exist yet, so it's still a question of "send what up?" All the major initial results are far more likely the result of thermal currents, which is obviously the case. Since then, the measurements have mostly been within the range of error. There still appears to be promise, but they're ...


4

Self-interacting Lorentz forces were addressed in section 8, point 3, along with other similar errors: The third error is magnetic interaction, which has the potential for a false positive resulting from dc currents in power cables interacting during test article operation with ambient magnetic fields (e.g., local Earth field, magnetic damper) to generate ...


4

The paper is pretty decent (though the results of the experiment are somewhat disappointingly inconclusive), but the Ars Technica article is insultingly bad, missing quite a few important technical aspects and implications, then loudly proclaiming the author's deep and abiding loyalty to SCIENCE! Why do I say the experimental work done so far was ...


3

There is no theoretical reason to think it would work. Its inventor based it on his fundamental misunderstandings of relativity and basic Newtonian mechanics. (Amusingly, Shawyer's analysis assumes Earth's surface is at absolute rest...he appears to be a geocentrist [1].) Alternative theoretical explanations are at the level of handwaving attempts to explain ...


3

NASA doesn't work like that. It might be quicker, but it's also a lot riskier, and it has very little value. A Cubesat can't carry much instrumentation, so after flying it we'd be no closer to understanding how and why the EM drive works, which is the more important question at the moment. Edit And in 2018 we found out that the EmDrive doesn't work, ...


3

Unfortunately physics is physics, and magic is the most important requirement for an EM drive. A recent experiment, this time with a much better test setup is disproving it The explanation given for the small thrust observed is the earth magnetic field. Note: This is still work in progress, but the conclusion seems inevitable.


2

Why don't we build a cube sat, launch it into orbit and try and push it out to Pluto? Seems like we would get much more useful data much quicker Well, ignoring the details of low earth orbit, lack of space for power and problems of monitoring a small dark object over vast distance ... To traverse 7.5 billion kilometers starting at 0 m/s and using an ...


2

from the report of yang Juan and NASA I computed that EmDrive was reported as 200-1000mN/kW and Cannae Drive as 1.4-5mN/kW since the null reactor of Fetta worked despite Fetta's theory, and since it is about 0.5% of EmDrive measured performance, until new evidence one can consider the possibility that Cannae Drive is a parasitic EmDrive (it works because of ...


2

Newton's 3rd law is empirical, and this observation could in theory be the first black swan. That by itself is unlikely, given the amount of empirical data gathered so far (the historically more likely hypothesis is measurement error; wouldn't be the first case). What I consider more damning is that per Emmy Noether's first theorem, spatial symmetry is ...


2

If it works as advertised, it can have quite an impact on satellites. They need to make small corrections to their orbits every now and then. Over years, it adds up to quite a bit of fuel, which had to be ferried to orbit at launch. This new system's only input seems to be energy, which is plentiful at space. If the power comes from an increase in the size ...


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