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The NASA engineer who published this speculative piece did so as an individual, and not with endorsement of NASA itself.
Apparently it should be viewed with some skepticism.
That said, my first impression is that the idea is based upon the confirmed General Relativity "feature" that mass increases as a particle is accelerated.
To summarize (my understanding of) the idea, particles are accelerated in a circular path, and then allowed to transfer momentum to the vehicle in a linear direction. This is a variation on the old (and very popular) perpetual motion design involving vibrating objects and the notion that conservation of momentum is (somehow) not preserved.
In this case, (as I understand the proposal) energy is given to a particle moving in a circular path so that it's mass increases. Then, when the momentum of the particle is transferred in a linear direction to the vehicle, the mass of the particle decreases, and it is (presumably) recovered for another round of acceleration.
The advantage of the design is that it does not require expenditure of mass for propulsion.
However, I'm assuming that whatever power supply is involved is going to consume significant amounts of energy, so that would presumably come from atomic processes.
https://www.yahoo.com/news/nasa-enginee … 00127.html
Edit: After re-reading my impressions above, I realized that it would not matter if the mass of a particle is increased, if the momentum from its slowing is released to the vehicle itself. The vehicle material would experience heating, but the vehicle (as I'm thinking of it now) would experience a net-Zero force with respect to the outside universe. I'll be interested to see other analysis, but I am now inclined to agree with the skeptics, that unless some mass is released to the outside Universe from the vehicle, no propulsion is possible. Even propulsion by electromagnetic wave reflection involves a mass component which transfers momentum to a vehicle.
(th)
Last edited by tahanson43206 (2019-10-12 09:09:34)
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Nasa engineer's 'helical engine' may violate the laws of physics
This is the engine that has no propellant but still creates a force once powered...
Last I remember they were going to test in the void of space to see if it still performed as it did on earth to try and understand what is making the momentum of motion.
maybe if I have time I will look for the other posts to add in to this topic.
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Here is the topic The Impossible Propulsion Drive Is Heading to Space
Not many posts in it but we may have more as single meantions in other topics. since key word microwave, engines, propulsion, ect would point to others.
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For SpaceNut re #3 ...
Thanks for clarifying what you were referencing ...
For the record, the two initiatives are not related, and are quite different in approach...
The EM drive is (as I understand it) based upon exploitation of microwaves.
The 'helical engine" is based upon acceleration of particles to near relativistic mass.
Both are subject to the principle that if you have two reference systems (eg, a space craft and the outside Universe) then the space craft can achieve movement with respect to the Universe by ejecting some mass (particles or photons). If mass is moved around inside the space craft, but never leaves the space craft, then (according to the principle) the space craft cannot experience a movement with respect to the Universe.
Again, I am hoping others in the forum may take an interest in the 'helical engine" paper and share viewpoints. It would be especially helpful (to me at least) if the person who takes this one has the expertise to evaluate the original paper.
(th)
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I see the means to move the particle is different but the results are the same in that we get motion.
Both require large amounts of power.
https://www.popularmechanics.com/scienc … -designed/
A new concept for in-space propulsion is proposed in which propellant is not ejected from the engine, but instead is captured to create a nearly infinite specific impulse. The engine accelerates ions confined in a loop to moderate relativistic speeds, and then varies their velocity to make slight changes to their mass. The engine then moves ions back and forth along the direction of travel to produce thrust. This in-space engine could be used for long-term satellite station-keeping without refueling. It could also propel spacecraft across interstellar distances, reaching close to the speed of light. The engine has no moving parts other than ions traveling in a vacuum line, trapped inside electric and magnetic fields.
https://ntrs.nasa.gov/archive/nasa/casi … 029657.pdf
This implies that the particles are collected and moved to the engine for acceleration. The spiral is distance to gain speed before exit.
The other impossible engine moves particles by excitation to bring about force for the motion of the engine to occur.
Both designs are based on near light acceleration of a part of an atom for speed.
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The effects to move a rocket with power input is what Ion engines do with larger particles called atoms and the heavy the are the faster the momentum change is. With this accelerator the particle is small by the effects are near light speed once they exit which is going to give a net speed increase over time in the same manner that ion engines do. Its that slow build up of speed that is the issue for both.
The accelerator is just working with a smaller amount of fuel to make it happen.
For the lack of a better topic to put this into we are still talking about the levels of power required which can only come from..I will whisper it nuclear....
NASA Will Flight Test a Nuclear Rocket by 2024 and Other High Tech NASA Projects
For Nasa this is the holy grail to getting to mars with nuclear thermal reaction. The plans for using it are part of the DRM 5.0 which we do have a topic for. Nasa while it works slowly does so while pincvhing pennies from everything to be able to work concepts forward over time.
Of course the methods of the engine are not as important as to the use of nuclear as the means to opening up space for man. Nasa has been working on the energy generating and storage issues for making mission for 0g travel less of an issue.
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SpaceNut-I've long been a supporter of Nuclear Thermal propulsion systems, dating back to NERVA, and the Kiwi rocket motor. As Zubrin correctly points out--the outer solar system is essentially inaccessible by chemical propulsive means for human space travel due to long transit times, measured in not just years, but decades. Nuclear Thermal offers Isp of 850-925 seconds, depending on the source referenced. No bipropellant needed, and only Hydrogen without oxidizers.
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Just about any gas that can liquify can be used for fuel not just hydrogen as the ion engines can use kyrpton, argon, xenon gas, ammonia and nitrogen can be used as propellant plus a few others have been tried in the past.
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After decades of research and development, the only practical replacement for a conventional chemical rocket engine that we've found for human space flight purposes seems to be a more energy dense heat engine that ejects a lighter reaction mass particle. We seem to keep coming back to where we were in the Apollo Program in the 1970's. In the interest of actually doing something worthwhile, we could simply accept current technological reality and get on with the process of designing / building / testing hardware, such as nuclear thermal rockets, that could take us to other planets while we continue to try to figure out what the next best propulsion technology will be. I think Dr. Zubrin has talked about the "Do we want to go to the moon or do we want to go to the moon?" issue at some length.
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kbd512-
I concur. I'm a believer in evolutionary design principles, and Nuclear Thermal is simply the "next step." Then we can fantasize about various ion propulsion systems--once we have sufficient energy available.
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Doesn't the energy to accelerate the particles also have mass? So if you had a self contained system that was accelerating and decelerating ions, the mass of the ions would change, but the mass of the system as a whole would not. Hence, moving it back and forth would not generate a net thrust.
Use what is abundant and build to last
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For Terraformer ....
That's how I'm interpreting the situation right now, pending a strong argument/demonstration otherwise.
I suspect these are simply more sophisticated Perpetual Motion Machine designs. The one that tries with Relativistic Physics is interesting, but without transfer between reference frames, the vehicles will (most probably) just jiggle in place.
(th)
Doesn't the energy to accelerate the particles also have mass? So if you had a self contained system that was accelerating and decelerating ions, the mass of the ions would change, but the mass of the system as a whole would not. Hence, moving it back and forth would not generate a net thrust.
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Anyone else here who remembers Rube Goldberg? Makes a complicated and sophisticated machine to accomplish a trivial task--which tended to hide the fact it was totally worthless??!!
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Worthless in that it could not be used for anything else but the one task it was laid out for.
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Extract from New Scientist: 'It would also need to be big – some 200 metres long and 12 metres in diameter – and powerful, requiring 165 megawatts of power to generate just 1 newton of thrust, which is about the same force you use to type on a keyboard'
That's a lot of power for not much thrust. If you are generating that much power, the photon pressure from the waste heat radiators will rival what this drive is able to produce.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Thrust in that range would be virtually impossible to measure being applied to such an enormous system. Statistically ZERO.
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Don't believe anybody who tells you that he can avoid application of the law of conservation of momentum!
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I second the motions of Oldfart1939 and Elderflower. There are 3 conservation laws, and 3 laws of thermodynamics.
There's no "proof" of any of them, except that NO confirmed exceptions have ever been observed for over 3 centuries now.
If somebody claims something that violates one of those 6 things, then very extreme skepticism is well-warranted.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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How about using interstellar ions as propellant? Two thin meshes one positive, one negative, will impart force on any charged ions between them, generating thrust. Of course, you still need to generate power to do it.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Multiple mesh which are switched on and off to pull in the particle so as to be able to push it out would seem to fit that bill with different spacings between the grids in order to make for different levels of power being placed onto them. So gathering them in a large enough quantity to get anything useful from them seems to be the issue...
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This seems to explain why it wouldn't work.
So, let's just state up front: this drive won't work. The problem is that, even though the author does a very nice simulation, he has left out the fields that do the accelerating. When we accelerate ions using a magnetic or electric field, the ions push back on the field. There is an equal and opposite force exerted on the electrodes and coils that produce the fields, and those just happen to be in the spaceship, too.
Use what is abundant and build to last
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