This is a really interesting new technology that could lead to spacecraft or airplanes that don't need propellant or jet engines: NASA's 'impossible' space engine may actually work | MNN - Mother Nature Network The funny thing about this is that scientists don't yet fully understand how or why it works, but it does. Imagine if SpaceX could apply this technology and scale it up -- they would revolutionize air travel and space flight!
For the moment I remain skeptical. One thing that I think is a bit telling is that the NASA lab measured only 1/1000th of the thrust measured by the Chinese lab. This reminds me of cold-fusion-like measurement error, rather than an actual result. Also the thrust is measured in micro-newtons, so this is not, for the foreseeable future, going to do anything in an atmosphere or getting to orbit. you can get a micronewton by just painting one side of the thing black and the other side white.
Agree ggr. I read the paper (it was just an abstract) and another thing that struck me as a bit odd was that the "control device" which was constructed to not produce thrust also did produce thrust. It doesn't say if it produced the same amount or less...
Yes, a micronewton of force is not very much, but at least this is a start. It remains to be seen if they can scale it to 1 newton+, perhaps using a different configuration or applying more energy. Also they need to change something in their experiment if the control is also generating force, as Johan mentioned.
Also, I couldn't really gather from the abstract how much energy (in the form of electricity I presume) was being put in to the system to yield that micronewton of thrust. What kind of (in)efficiency are we talking here?
I stopped reading at "quantum vacuum virtual plasma". I was too distracted by the cool phrase (and also had other things to get done).
I read the abstract too, and also didn't see any reference as to how much energy was used. It was probably not too great, less than 100 W as my first guess. A little more research is in order I think.
"The idea languished, but a decade later the Chinese Academy of Sciences published a paper saying that it too had built an EmDrive-like which, when fed 2.5kW, generated 720mN of thrust. This got the attention of NASA, which in 2013 commissioned a series of tests on the drive and got some surprising results."
So the energy required is much greater than I thought. They state that the next generation of the EmDrive should be able to get to 30 kN per kW of energy, which is incredible. Here's the link (second paragraph from the bottom): NASA says puzzling new space drive can generate thrust without propellant
"The microwaves are travelling at nearly the speed of light"... well, actually, they should be travelling *at* the speed of light, since microwaves are just light at lower energy. Now, take that 30kN of thrust and use it to accelerate 1 tonne (includes the engine) to 30m/s in one second. The kinetic energy of that is now 1/2*1000*30^2 = 450kJ. A Joule is also a Watt-second, so that one second's worth of thrust at 1 kW used only 1kJ of energy. So the second impossible thing before breakfast is that 449kJ of energy has appeared from nowhere. When we were talking mN, not kN, I was prepared to believe that something was possible, maybe, that we didn't understand. But where's all that energy coming from? I guess whoever wrote this article might be exaggerating, since none of the experiments have come within orders of magnitude of these numbers.
I just realized that if this is correct, we can recover that kinetic energy, and I can sell my shares of LPP! Who cares about spaceflight?
True. I just have one important question: how many alternators does this contraption require? (TMC internal joke: alternators)