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NASA Space

NASA Tests Microwave Space Drive 201

Posted by Unknown Lamer
from the onward-to-the-stars dept.
schwit1 (797399) writes with news that NASA scientists have tested the EmDrive, which claims to use quantum vacuum plasma for propulsion. Theoretically improbable, but perhaps possible after all. If it does work, it would eliminate the need for expendable fuel (just add electricity). From the article:Either the results are completely wrong, or NASA has confirmed a major breakthrough in space propulsion. A working microwave thruster would radically cut the cost of satellites and space stations and extend their working life, drive deep-space missions, and take astronauts to Mars in weeks rather than months. ... [According to the researchers] "Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma." Skepticism is certainly warranted: NASA researchers were only able to produce about 1/1000th of the force the Chinese researchers reported. But they were careful to avoid false sensor readings, so something is going on. The paper declined to comment on what that could be, leaving the physics of the system an open problem.
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NASA Tests Microwave Space Drive

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  • KSP (Score:5, Funny)

    by Thanshin (1188877) on Friday August 01, 2014 @08:08AM (#47580387)

    Let's stick to the important consequences. When will this reach KSP? Is a patch/hotfix in development?

    • Re:KSP (Score:5, Funny)

      by NotDrWho (3543773) on Friday August 01, 2014 @08:44AM (#47580563)

      Let's stick to the important consequences.

      How fast can it cook a potato?

      • by gewalker (57809)

        No, the question is how fast can it accelerate the average potato. NASA reported 30-50 mN of thrust., call it 40. The average potato is about 375 grams, call is 400 even so math is real east. F=m*a or a = F / M or 1e-7 m/sec^2. So, accelerate for 1 year and you reach the break-neck speed of 31.5 meters per second or 70.5 mph

        It is going to take a long time to get that potato to Alpha Centauri. Especially considering that you have to also accelerate the mass of the Q-drive unit itself and the energy source to

        • by jythie (914043)
          Even if the efficiency can not be improved much, the people who launch probes have impressive patience. Add a good solar panel or a nuclear source and you could get a nice constant acceleration over a long period.
        • Carry the one (Score:5, Informative)

          by FatLittleMonkey (1341387) on Friday August 01, 2014 @10:34AM (#47581243)

          No, the question is how fast can it accelerate the average potato. NASA reported 30-50 mN of thrust., call it 40. The average potato is about 375 grams, call is 400 even so math is real east. F=m*a or a = F / M or 1e-7 m/sec^2.

          40 mN is 0.04N

          400g is 0.4kg

          a = F/m = 0.04 / 0.4 = 0.1 m/s^2 not 0.0000001 m/s^2.

          Therefore accelerating for 3e7 seconds (one year) results in a velocity of 3000 km/s. About 1% of lightspeed. And a distance of 330AU. You'll hit one lightyear in 19 years. Two lightyears in about 28 years, if you turn your potato around to decelerate, you'll deliver your potato to Alpha Century in 56 years. If you want to cook your potato by skimming one of the stars, it'll only take 38 years.

          • Re:Carry the one (Score:4, Informative)

            by FatLittleMonkey (1341387) on Friday August 01, 2014 @10:46AM (#47581343)

            [gewalker said "mN" so I used milliNewtons. I should have checked the paper, it's 30-50 microNewtons (30-50uN). So drop the velocities by 1000. And ignore the rest.]

          • Unfortunately, even though you wouldn't have to supply propellant, you would still need to supply the energy to accelerate it. After accelerating for one year, your potato's kinetic energy is 1.8e12 Joules. That's a lot of energy. Initially you can stick a solar panel on it to power the drive, but once you're out of the inner solar system that won't work any more.

            • Unfortunately, even though you wouldn't have to supply propellant, you would still need to supply the energy to accelerate it.

              Actually you don't. Any reactionless thruster can be turned into a free energy machine. If force-produced is directly proportional to energy-input (eg, the device in TFA gets 31uN/W) regardless of position in the universe and direction of thrust (**), then the change of velocity per unit time is also proportional to energy-input. Linear. But the kinetic energy available is proportional to the square of total velocity. There's a cross over velocity where the increase in kinetic energy is greater than the ene

              • Wow, that was wrong in so many ways.

                1. There is no such thing as a "free energy machine".

                2. No one is claiming this device is a "free energy machine". You have to put energy in as electricity, and you don't get more energy out than you put in.

                3. No one is claiming this device is "reactionless". There's ongoing discussion about the exact mechanism (assuming it actually works). They suggest it may be pushing against space itself, somewhat analogously to how a swimmer pushes against the water they're swimmi

                • 1. There is no such thing as a "free energy machine".

                  And that's why skeptics are skeptical of the claims made for the EmDrive.

                  2. No one is claiming this device is a "free energy machine".

                  Skeptics are, because all reactionless drives are free energy machines.

                  You have to put energy in as electricity, and you don't get more energy out than you put in.

                  However, the power input is constant for the thrust out (Newtons-per-Watt), therefore power input is constant for acceleration (m/s^2-per-Watt), therefore energy input is constant for delta-V (m/s-per-Joule). But the energy out (kinetic energy) is proportional to the square of total velocity (Ek=1/2mv^2). Therefore energy-in increases more slowly than the energy-out

                  • 2. No one is claiming this device is a "free energy machine".

                    Skeptics are, because all reactionless drives are free energy machines.

                    That's doublespeak. No one who believes in it claims it's a free energy machine. Ok, you are free to announce, "It's a free energy machine, therefore it can't exist!". But since you don't have any evidence to support your claim, that's meaningless. Either it works or it doesn't. If it does work, it almost certainly is not a free energy machine. No one has presented any evidence to indicate it doesn't conserve energy. If you make that claim anyway, it just shows you're making claims that aren't based

      • by freeze128 (544774)
        "All hands, prepare for burrito blast!"
    • http://steamcommunity.com/app/... [steamcommunity.com]
      "ishanda --- Kerbal Space Program Apr 17, 2013 @ 2:29am; If you REALLY want Star Trek Style impulse engines why not mod them yourself? All you really need is to make copies of the relevant part files, change the name of the Xenon Tank to "Deuterium" and change the Ion Engine to "Impulse Engine" and then change a few values to make them super efficient. Done."

      Still looking forward to seeing how the real device pans out though... Just like I'm still wondering about all the cla

  • Bad summary (Score:5, Informative)

    by Anonymous Coward on Friday August 01, 2014 @08:13AM (#47580405)

    Skepticism is certainly warranted: NASA researchers were only able to produce about 1/1000th of the force the Chinese researchers reported. But they were careful to avoid false sensor readings, so something is going on. The paper declined to comment on what that could be, leaving the physics of the system an open problem.

    The physics of the system has two explanations, one relativistic relying on a classical radiation pressure, and one quantum relying on virtual particles, and is not an "open problem". These are things that were designed, not things that just work but we can't explain why. The EmDrive site will give you the relativistic model; the paywalled Chinese article presumably gives the quantum model. The NASA researchers produced 1/1000th of the force of the Chinese & English drives because they used a different design, which reduces the Q factor of the waveguide - again, this is explained on the EmDrive site. Now Chinese, English and American teams have all measured "anomalous" thrusts from this type of device, so skepticism is not really warranted on that basis, nor on the basis of a presumed anomaly in thrust magnitude when in fact that's all well understood.

    • Bad summary (Score:3, Informative)

      by Anonymous Coward

      No. The NASA team have found unexplained faults in their test apparatus. The null experiment ALSO produced the tiny thrust.

    • Re:Bad summary (Score:5, Informative)

      by Sockatume (732728) on Friday August 01, 2014 @09:23AM (#47580781)

      Unfortunately in this instance they measured the anomalous thrust on a version of the instrument designed and built by its own inventors in such a fashion as to not produce thrust at all. I'm inclined to believe that the anomalous thrust is some sort of weird ideomotor effect related to the fact that they had to manually control the frequency of the RF excitation as the test ran.

      • In 1989 Fleischmann and Pons published a paper showing evidence of cold fusion. No one, other than a team atmTexas AM, of course, was able to replicate. The lab where I worked had a preprint of he TAM paper andmeveryone unformly decides it was crapbduebto lack lack of experimental detailed procedure. I am told the FP paper had the same issues. Though millions was thrown t the problem in 1989 and 1990 nothing came of this discovery that gviolated all known science. Mather AM people denied fraud by claimin
        • Moreover, Fleischmann and Pons were getting energy out of what they were doing, so they did have experimental results. Some other people were confirming it as fusion, and were later exposed as people who had no clue how to use a neutron detector. Since then, I've been dubious about results like this (didn't stop me from trying to figure out how to put FTL neutrinos into Special Relativity, though).

    • Re:Bad summary (Score:4, Insightful)

      by Immerman (2627577) on Friday August 01, 2014 @12:41PM (#47582419)

      We have two competing theories being advanced by people who've built this family of thruster, both of which are also widely regarded as containing flawed physics (if not necessarily well-examined), and many other provisional theories having been advanced by scientists unconvinced that the effect is real. Meanwhile, NASA tests a related apparatus and does in fact detect thrust, but of a magnitude inconsistent with the theory upon which it is constructed.

      By what stretch of logic do you propose they can responsibly claim either theory is accurate? The most that they can confirm is that they did in fact measure anomalous results. Addressing the specific physics in play was far beyond the scope of the experiment they performed, and thus would be pure speculation on their part. The proper response is to do exactly what they did: not endorse any specific explanation, but confirm that a repeatable phenomena unexplained by broadly accepted physics does appear to exist. That bolsters the legitimacy of anyone exploring the phenomena without endorsing a particular theory that they lack the data to confirm (aka making a statement of "faith" or "opinion").

      • Well, if you want to teach the scientists something about science, get at least the magnitude thing correct.
        They where not off by one magnitude, but by three :D

        • by Immerman (2627577)

          It's perhaps an easy mistake to make if you're not well-versed in the terminology of the field, but you are describing order-of-magnitude, a term having nothing to do with magnitude itself, which (in this context) specifies the "length" or "absolute value" of a vector value such as displacement, velocity, force, etc.

          For example speed is an always-positive scalar (single-number) value that specifies the magnitude of velocity, which is a vector (multi-number) value independently specifying the speed along eac

          • If we have X, and something is an(one) order of magnitude bigger than X, then it is 10x bigger than X.
            If it is 100x bigger than X then this is two orders of magnitude and if we are talking about 1000x smaller or bigger, as in this case: it is three orders of magnitudes.

            • by Immerman (2627577)

              Yes. That is what an order of magnitude means. But that is not what magnitude means - it has its own definition separate from that one particular usage: size. Try reading that in the context of what I wrote:

              >Meanwhile, NASA tests a related apparatus and does in fact detect thrust, but of a -magnitude- size inconsistent with the theory upon which it is constructed.

              I say nothing about orders of magnitude. I only refer to the size of the effect, and note that the size is inconsistent with the theory. Th

              • We did not talk about magnitudes, we talked about orders of magnitudes.

                I don't know why you wanted to bring that topic up :) So I corrected your previous post and pointed out that our parent was wrong with the orders of magnitudes ...

                So, why do you bring up this topic? A sudden urge to educate strangers? Then perhaps tell me something I don't know?

                Or don't we have a common parent and it was you I answered to? Then simply make your posts more clear :) instead of trying to weasel yourself out: " oh I never sa

                • by Immerman (2627577)

                  Perhaps your interpretations have been polluted by a set of sibling posts I never saw.

                  But you seem to have a problem with my specific usage of magnitude, despite explanations, so I think perhaps you are being willfully obtuse, I am doing a poor job of explaining it to you, or possibly you aren't as well-versed in english technological vernacular as you think - you do imply you speak German, perhaps you are in that uncomfortable situation where the similarities with your mother tongue are just enough to occa

                  • Ah, so we did not talk about your post but about the ACs one ... so I'm not that Alzheimered as I feared.

                    Yes, we can agree that the word 'magnitude' has slightly different meanings, depending if other words like 'order' precede it.

                    Regarding english vs. german that is indeed a big problem, that is why I encourage you in any legal case regarding both languages to hire a professional interpreter (hint: the literal translation from german to english would not be interpreter but translator) e.g. words like event

  • Zaphod? (Score:5, Funny)

    by fuzznutz (789413) on Friday August 01, 2014 @08:15AM (#47580413)

    Theoretically improbable, but perhaps possible after all.

    Actually, it's infinitely improbable, therefore finitely probable. All they need is a heart of gold.

  • Ugh (Score:5, Interesting)

    by Anonymous Coward on Friday August 01, 2014 @08:19AM (#47580421)

    Don't be deceived by vacuum chamber: the device was placed inside a chamber designed to be evacuated, but the experiments were conducted at atmospheric pressure. Ionization effects of air were not considered, and to demonstrate force at pressure and not in vacuum does nothing to establish the utility of such apparatus for extra-atmospheric purposes.

    • Nor were convection effects considered.
      You don't need much airflow to generate 50 micronewtons.

    • Yeah, that paper should be rejected. The results are totally useless. I wonder how many people went "WTF?" upon reading "...within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure."
  • by MyLongNickName (822545) on Friday August 01, 2014 @08:44AM (#47580561) Journal

    Fact 1: The NASA team has measured approximately 30-50 micronewtons of thrust in the experiment
    Fact 2: The NASA team experienced a similar thrust on a test item that was NOT design to experience any force.

    It is pretty obvious that there was a systematic error in NASA's experiment.

    • Re: (Score:2, Funny)

      by Charliemopps (1157495)

      Fact 1: The NASA team has measured approximately 30-50 micronewtons of thrust in the experiment
      Fact 2: The NASA team experienced a similar thrust on a test item that was NOT design to experience any force.

      It is pretty obvious that there was a systematic error in NASA's experiment.

      Or the midichlorians were just screwing with them for fun.

    • by Sockatume (732728)

      The relevant quote:

      Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the “null” test article)

    • The big problem I have with their "test" is that they did it at atmospheric pressure. So, they're supposing the force is pushing off quantum vacuum virtual plasma. That's one possibility. The other possibility is it's pushing off THE FREAKING AIR IN THE CHAMBER.

      Don't get me wrong, I would love to see a reactionless drive. A reactionless drive could get us to the stars. But it generally involves violating conservation of momentum, and that's unlikely.

      • Why do people always make such stupid claims: ... it generally involves violating conservation of momentum, and that's unlikely. Why would a drive using microwaves to utilize a quantum effect violate impulse conservation? Your ship gets a momentum in one direction ad said quantum effect thrust holds the other half of the momentum ... obviously!

        • If the thing works, it's not that it violates conservation of momentum, it's that it's doing something we don't understand, which appears to violate the conservation of momentum because we don't know how it works.

          I'm sure many people would love to see this turn out to work because it would be a really cool real-world effect based on some of the the really bizarre and incredibly abstract physics going on these days. Like many people here I'm sure, I'm fascinated by the advances in modern physics in the last

    • How do you explain the discrepancy between the two tests?

  • Is useless drivel. Its a one page abstract that reads like a news media comentatry of the test. There are not even graphs of measurments taken, no specifics on the test setup. Nothing. Its not even Science by my definition. Lets move along, nothing to see here.
  • Can someone explain to me again why this couldn't be modified, scaled up and used as a micro thrust system for satellites and such? And why is a microwave resonant chamber "better?"

    • Can someone explain to me again why this couldn't be modified, scaled up and used as a micro thrust system for satellites and such?

      Can you explain how it could be modified, scaled up, and used as a micro thrust system?

      First problem: it goes round and round, but doesn't produce net thrust in any one direction.

      • Can someone explain to me again why this couldn't be modified, scaled up and used as a micro thrust system for satellites and such?

        First problem: it goes round and round, but doesn't produce net thrust in any one direction.

        Second problem: it doesn't work in a vacuum. Those bulbs are partially evacuated - too much atmosphere, and it doesn't work, too little, and it doesn't work. Which points to this being some kind of expansion-contraction thermal effect rather than some kind of spacey photon-momentum thing.

        Point of interest: I've also heard that if you put one of these things in a freezer you can get them to run backwards...

        • I've also heard that if you put one of these things in a freezer you can get them to run backwards...

          So that's what Cameron should've done with his dad's car!

    • If the effect is real, it could be. The question is whether the effect is real.

  • by tbg58 (942837) on Friday August 01, 2014 @10:55AM (#47581411)

    The Wired article speaks of Shawyer's EMDrive, which has been around for some time, and at first appears to confuse the EMDrive with a different technology Dr. Harold "Sonny" White of NASA has been working on for some time.

    The tech report clears things up a bit. The test results are showing anomalous thrust, however NASA is reticent to attribute the thrust to Shawyer's theory of how it operates, which would violate conservation of momentum (hence the "impossible" in the title.

    What the technical report says is something far more interesting. Dr. White has been working with several different test articles which use electromagnetic forces to increase the rate of virtual particle pair production in the quantum vacuum, then using the virtual particles during their very short time of existence as reaction mass. In other words, it is a reaction drive, but instead of carrying reaction mass in the tank, the investigators are trying to use mass borrowed from quantum vacuum plasma to generate a small, but measurable, amount of thrust.

    The final sentence of the technical report contains the salient material:

    "Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma. Future test plans include independent verification and validation at other test facilities."

    Coypu

    • attribute the thrust to Shawyer's theory of how it operates, which would violate conservation of momentum
      No, it does not violate the law of conservation of momentum, why should it?
      Hint: http://en.wikipedia.org/wiki/E... [wikipedia.org]

      • by HiThere (15173)

        Well, if you threw away both halves of the virtual pair, you would transfer momentum to them. If they then recombined what would happen to the momentum?

        • Nothing of course ... it is conserved obviously, but perhaps you lost me somewhere :D
          Does the EMDrive create virtual pairs? Was not aware of that ...

          • by tbg58 (942837)

            Neither did Shawyer suggest the EM drive created virtual pairs, but the last sentence from the technical report says that since no known electromagnetic phenomenon can account for the observed thrust, the EM drive may be demonstrating "an interaction with the quantum vacuum virtual plasma". The quantum vacuum virtual plasma is the reference to vacuum fluctuation, or virtual particle/anti-particle pairs. If I understand the report correctly I believe he is suggesting that virtual particles may be providin

  • From TFS:

    If it does work, it would eliminate the need for expendable fuel (just add electricity).

    Always left out of these discussion is just how much electricity they need to produce useful thrust. While in theory, even a micro-Newton can eventually get you anywhere you want to go, practical considerations (E.G. the desire to not spend months in the Van Allen while spiraling outward, or the need to decelerate to enter planetary orbit) usually dictate a higher thrust level.

    Power is, for example, a huge Achi

    • People often miss that the problem with ion drives and other electrical drives is that the exhaust velocity is too HIGH, not too low.

      The higher the exhaust velocity, the more power you need for the same thrust. Making high specific impulse drives is easy - a microwave source can be ~80% efficient and has an exhaust velocity of the speed of light. The problem is that the power requirements are enormous.

      Sure, energy from the sun is "free", but the mass of the solar cells to collect that energy is not free.

  • the vacuum is electrically neutral; the virtual charged particles
    created by quantum fluctuations will be in oppositely charged
    pairs (e.g. electron / positron). Won't this drive send these pairs
    in opposite directions? So the whole thing will have zero thrust

    this thought is the product of complete ignorance of how this
    drive is actually supposed to work however :)

    • by HiThere (15173)

      I don't know the design, but couldn't you use the charge difference to separate them a bit, and then throw both away in the same direction? This seems implied by the comment that it violates conservation of momentum, because if the virtual pair then recombines momentum would seem to have disappeared.

      A question is whether you could do this without using enough energy to stabilize the virtual pair as actual particles. It not then it would be extremely inefficient energetically.

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