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ESA Moves Forward on New Electric Engine
museumpeace writes to tell us the ESA is reporting that they have confirmed the principle behind a new space thruster. Plasma Double Layers, first discovered by Australian researchers Christine Charles and Rod Boswell, may help to develop a new electric engine that gives more thrust than traditional engines while still maintaining efficiency. From the article: "In essence, a plasma double layer is the electrostatic equivalent of a waterfall. Just as water molecules pick up energy as they fall between the two different heights, so electrically charged particles pick up energy as they travel through the layers of different electrical properties."
Does this mean we won't be needing the space elevator? :-)
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My work here is dung.
No I'm not. I really want to know how big of an impact people think this new design will have.
My work here is dung.
"In essence, a plasma double layer is the electrostatic equivalent of a waterfall. Just as water molecules pick up energy as they fall between the two different heights, so electrically charged particles pick up energy as they travel through the layers of different electrical properties." Like, one metal to another??
Purple, because ice cream has no bones.
Because these are very low thrust engines, they can't hold a candle to gravitational forces. Where they shine in interplanetary and stationkeeping (orbit and orientation) applications.
-everphilski-
Would the article submitter PLEASE not call ion engines "traditional thrusters"?
Now back to thrusting my girlfriend traditionally.
--- Eat my sig.
I can't wait to put one of these bad-boys in my Civic!
In essence, a plasma double layer is the electrostatic equivalent of a waterfall. Just as water molecules pick up energy as they fall between the two different heights...
Water molecules do not pick up energy as they fall. There potential energy is simply converted into kinetic energy. However, they had the energy all along in the form of potential energy.
Energy source for the SSME is combustion (Hydrogen and Oxygen)
4 3.html ... even 10*5 times more thrust is only 5 newtons (read: not much). Scale it up to a SSME sized engine and your talking maybe 25-50 newtons. SSME thrust is measured in MILLIONS of newtons.
Energy source for this engine is electricity, or rather an energy potential... solar cells, nuclear power plant, etc.
Two different concepts. Two different ballparks. While the article states that this method will deliver "many times more thrust" than ESA's "SMART-1" thruster (70 mN, thats mili-newtons) http://www.aoe.vt.edu/~cdhall/Space/archives/0003
So basically, different tech that won't scale to drive a vehicle out of a gravity well. But it is useful for orbital/stationkeeping/interplanetary maneuvers if you have the time.
-everphilski-
i believe this device only provides enough thrust to navigate in a near-weightless enviroment.
more bad science.... and from the official esa too *tsk* *tsk*
-everphilski-
There not really "Electric Engine"s either are they?
Calling them Electric Engines would mean calling pretty much every engine around an electric engine.
Plasma or Ion engine's would be more descriptive in my opinion.
LOL! Mod +5 Funny! Slashdotter with a girlfriend! That's rich!!
flowerp: I am now thrusting you traditionally.
SexyAnGeL_69: Talk geeky to me.
flowerp: I just read on Slashdot about a new electric engine.
SexyAnGeL_69: Oh wow! I'm....oh yes! Traditionally thrust me you bad boy!
Read about this on the BBC article, with diagram This morning... Sounds like it's greatest use will be in deep space missions. It still hold potential for other use if we can find a more efficient way to use it.
-Khyras
The real question is: How do these thrusters stack up to MPDTs (Magnetoplasmadynamic thrusters)? The article is light on technical details like Isp, engine life, potential design issues, fuels, etc. MPDT is a great upcoming technology. But if this new tech can best it by having a shorter development track and equivalent performance, then let's leapfrog the MPDT technology altogether! :-)
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You don't HAVE a girlfriend.
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I would hesitate to call this a "very low thrust" engine, since 100kw is somewhere around 140 horsepower. It may not be enough to escape earth's gravity (if not, maybe the mars or the moon?), but I wouldn't discount the possibility immediately without more information (like what do these thrusters weigh, and how much propellant do they need to carry).
The hardest part would be providing a 100kw power source, but this is the same problem as supplying power to the space elevator climbers, and it might be solvable with wireless power transmission (big lasers and solar panels).
And Mr. Scot is no longer among us.
he did, however, live long and prosper
A feeling of having made the same mistake before: Deja Foobar
...can it go to Ludicrus Speed?
Its not bad terminoligy its bad science. Energy is conserved. First law of thermo. That statement clearly breaks conservation. Therefore it breaks the first law of thermodynamics. Therefore...
-everphilski-
The ion engines rely on the same principle of accelerating propellant through its electromagnetic properties. Plasma is an ionic gas, and propellant is gas too. The only difference I could imagine is that the method of ionization itself produces thrust. Is this indeed the source of higher energy efficiency? The description of two levels sounds like two varying magnetic fields which cause magnetically charged particles (plasma) to accelerate, and the divergence sounds like magnetism applied to aerodynamics. Perhaps this is another source of higher efficiency. If so, this really is groundbreaking.
There is no english word 'alot'. The phrase is 'a lot'. This always bugs me.
I thought articles that got to the front page were screened/checked? Am I wrong?
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You must be new here.
Yes, you are wrong.
I wonder if it could be used to extend the life of optical reconnaissance satellites.
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So, is this the first version of the glowy spaceship engines we see in movies? 'bout time we came up with it...
There not really "Electric Engine"s either are they?
Why not? Electricity is used to create an electric or magnetic field, which then accelerates plasma/ions. Electric sounds like a reasonable name to me. Ion or plasma is fine too, but most people don't understand what that means and they do understand what electric means.
Calling them Electric Engines would mean calling pretty much every engine around an electric engine.
I'm not sure I follow. Not all engines require electricity to run. Rocket engines make no use of electricty at all, apart from maybe some pumps. The difference in this case is that electrical power is the primary source of power to create the thrust. Find a way to generate electrical power (nuclear reactor, solar cell) and you can save a lot of propellant weight.
AccountKiller
a new space thruster. Plasma Double Layers, first discovered by Australian researchers Christine Charles and Rod Boswell, may help to develop
Anyone else notice that these names seem like code references for the Rosecrutians and Roswell? Duh. I've seen TV, I know what's going on, here.
Don't disappoint your bird dog. Go to the range.
Plasma needs to come from somewhere. Even if you have some renewable energy source like a solar panel, eventually you will run out of ions to exhaust.
I think that's the point of the design. The ions can be accelerated without the need for being attracted by cathode plates or wire mesh at the back, as is done now.
Of course, they're still chemical rockets, which inherently suck. But they're not nearly as shoddy as you make out.
So we're talking more of a game of blackjack as opposed to a crap shoot? Sticking with the gambling theme that is.
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Find a job you like and you will never work a day in your life.
ion engine accelerates propelland through ELECTRIC MESHES. the principle is similar to CRT, except you have many cathodes and many annodes (they are both meshes, in reality)
... double layer (sorry, but that's what they are called) in the plasma that need to be accelerated out, saving the mesh but now you need to have some containment for the plasma: magnetically trapped electrons. (the meshes served as a electrostatic trap in ion engines)
double layer creates a
Electricity is what gives the energy that's being used - the fuel is just reaction mass - unlike chemical engines where your fuel is both your energy source and (once reacted) the reaction mass.
I am trolling
Great! Now that we've got these, how long till I can put a hyperdrive in my Mazda?
What about cetrifugal/gyroscopic force generators there are tons of patents on these types of devices and tons of claims that they work, but .. are they all full of it? i mean it seems if such a device actually did work it would surely be used in place of this new engine because they dont require fuel (only electricity from solar panels) and supposedly apply more thrust
The principle was popular in particle accelerators for a while - I worked at Daresbury some time back, which was a 20 MeV tandem accelerator. It's cheap and easy. A variant, only with reversed electrical fields, was used in old-fashioned thermionic valves. In that configuration, they were termed deflection grids. CRTs use the same technology to steer electrons towards the correct place on the screen.
Not sure why anyone would need to prove the idea would work in space, since we already use the technology in vaccuum and we already know tandem accelerators can produce greater acceleration than a single grid.
I would be much more interested in knowing if it were practical to ionize oxygen then use this technique to improve the oxygen/nitrogen ratio in the engine. If you could, it would improve engine efficiency and may help in reducing the complexity of the engine electronics and mechanics.
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From TFA: "The concept is an ingenious one, inspired by the northern and southern aurorae...led to a patent on a promising new electric propulsion device called an Electronegative Plasma Thruster" Obligatory gripe about patenting basic science. Geez, they patented the aurorae borealis! It does point out the gray area between a basic physical property of matter and something patentable though. This seems to me like a reasonable idea to protect, although I'm not sure what the ESA is going to do with the intellectual property rights here. Do they license this technology to Klingons or something?
(Astronomers are, as a rule, mystified by plasma-dynamic events, leading them to talk about "hot gases", "stellar plumes", "galactic jets", "magnetars", "dark matter", "dark energy", and worse. For most, their only exposure to anything like plasma in school was an unphysical mathematical construct called MHD, so they are worse off than if they'd skipped class. (Hawking is often quoted, with no trace of irony, saying "the greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.") For those of us even a little more familiar with real plasma effects, astronomical press releases are no end of hilarity.)
Plasma double layers aren't mysterious. They develop naturally as the diffuse particles containing ions tend toward equilibrium. Variation in composition, ionicity, and density in a diffuse plasma gather at boundary layers between regions, making the space between the boundaries much more uniform, and concentrating mass, electric fields, and current flow. Highly-stressed double layers tend to explode; on the sun they call it a "coronal mass ejection". On another star it may be called lots of things.
In one of those plasma ball toys, you can see double-layer tubes connecting the electrode in the center with the transparent ball. You see them because the current density is high enough to put the plasma it runs through in "glow-discharge" mode, exactly as in a neon sign or St. Elmo's Fire. The other two modes are "invisible" and "arcing". The former is common throughout the universe (and detectable only indirectly, as you might imagine) such as between the earth and the sun, between star systems, and even between galaxies. The latter is what you see in a lightning bolt, on the surface of the sun, or in one of those spotlights they used to use at movie premieres. Astronomical glow-discharge events (with the exception of earth's polar aurorae) are usually confused with "shock waves".
The most beautiful astronomical glow-discharging double-layer structure I know of is M2-9 in Ophiucus. "In this image, neutral oxygen is shown in red, once-ionized nitrogen in green, and twice-ionized oxygen in blue."
In essence, a plasma double layer is the electrostatic equivalent of a waterfall.
Ok, I'm no physicist, but do we really need a double layered plasma engine to throw rockets over the side of a cliff?
Also, doesn't a waterfall transfer the energy back to the earth when those water molecules collide with the ground (minus losses). It doesn't create energy, and the net gain is zero. If if wasn't, you could create a perpetual motion machine by harnessing the energy of the falling water to carry more water back up the cliff/hill. So either I'm misunderstanding something, or the waterfall is a horrible analogy, because it takes as much (theoretically) or more (practically) energy to lift the water to the elevated state than you could gain by harnessing the energy of it falling.
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you sir, owe me a N3w keyb0ard! this should be +5
to the Variable specific impulse magnetoplasma rocket?
What I'm thinking about is that this "new" Ion engine has a higher thrust and/or a higher specific impusle than a standard Ion engine (like the one on Deep Space 1.) But how does it actually rate against the VASIMR style engine and does it have the flexibility of it? (That is, can it adjust it's SI/Thrust depending on the situation - orbital maneauvering vs. cruising.)
Bill
It's my Sig and you can't have it. Mine! All Mine!
The big list of engines that aren't electric engines:
Gasoline engines
Diesel engines
Steam engines
Jet engines
Liquid-fueled rocket engines
Solid-fueled rocket engines
The big list of engines that are electric engines:
Ion thrusters
I'm probably missing a few in both categories, granted.
Ewige Blumenkraft.
so can I build myself a TIE fighter yet? are these ion engines powerful enough?
"Evil will always triumph because good is dumb." -- Dark Helmet
Rod Boswell and his plasma thruster. He's slow, but he get's 'em there!
Supposedly this engine is supposed to have much higher thrust than normal Ion engines... but I can't find anywhere that gives the thrust levels is is theorized to achieve. Low Thrust engines are limited to certain types of interplanetary missions - if this thing can give a higher thrust at a comparable Isp (i.e. fuel efficiency) that would open up all sorts of new uses for electric propulsion (manned mars missions, missions to the outer planets, etc)
has anyone found a quote for the thrust levels they expect? something on the order of 0.1-1 N would be revolutionary... something less and I don't know what all of the fuss is about (cuz then it just seems like a new type of Hall thruster).
There are 10 types of people in this world, those who can count in binary and those who can't.
Cassini has to fire its main engines once every 400 days in order to flush corrosion from the cat beds that might clog the lines otherwise... This has never been much of a problem to do as small maneuvers can be planned without messing up the interplanetary trajectory.
Actually for interplanetary missions chemical rockets are far less risky than low thrust systems. This is because chemical rockets instantly change you from one safe trajectory to another.. low thrust engines make this change over several days and as a reult there are often periods where if the engine fails the spacecraft would be left on an unstable orbit that is likely to crash into something or be thrown into an escape trajectory. JIMO and Dawn both had major problems trying to design trajectories that always left enough time to recover from possible engine failures without crashing.
It all comes down to control authority... bigger thrust gives you more control authority and you can much more easily recover from unexpected trajectory perturbations.
There are 10 types of people in this world, those who can count in binary and those who can't.
Yes, but they generally use electricity to accomplish their goals. This means they can use batteries or nuclear generators or solar or whatever.
The question that the OP was asking was is this just a better ion engine or is it a real replacement for a chemical engine akin to methane/O2 engine.
IOW, the OP is simply trying to determine if this is an incremental improvement or major improvement.
I am not qualified to answer it, but I am sure that others here are. But from what I have read here and elsewhere this is a good deal more than an incremental.
I prefer the "u" in honour as it seems to be missing these days.
Once you're in orbit, the amount of thrust becomes a reasonably insignificant detail. The overriding concern is whether or not your craft can produce the necessary Delta-V to reach the required escape trajectory. Since it seems unlikely that the ESA would be investigating these devices as a replacement for ION engines if their performance was sub-par to IONs, it stands to reason that these engines will have no difficulty reaching the required Delta-V.
Delta v is the main concern, but thrust is important too, in that low thrust spacecraft take forever to get anywhere, and the engines are so feeble that they have a lot of trouble when third body effects pose a danger of crashing the spacecraft (i.e. orbiting asteroids or at Jupiter or Saturn). If this engine has significantly higher thrust than gridded Ion engines and hall effect thrusters and even 1/3 of the fuel efficiency (i.e. specific impulse) then this would indeed be a major breakthrough and will open up the solar system to a major exploration effort.... however, I can't find the thrust levels quoted anywhere so I don't know if this is something amazing or just some research group self-promoting and slight improvement to a hall thruster.
There are 10 types of people in this world, those who can count in binary and those who can't.
MW? No, the article says 100 kW. Here is the relevant passage (unedited).
"Calculations suggest that a helicon double layer thruster would take up a little more space than the main electric thruster on ESA's SMART-1 mission, yet it could potentially deliver many times more thrust at higher powers of up to 100 kW whilst giving a similar fuel efficiency."
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If you don't know much about the ion engine used in Deep Space I, look here before posting.
The article mentions that this new thruster design's "fuel efficiency" is comparable to the ion engine. This means that it has to propel about the same amount of ionized gas away to get the same amount of thrust (presumably at a similar velocity). However, I didn't see anything about "energy efficiency". Does it require a lot more electricity to get the same amount of thrust? For a space probe, 100kV is a LOT. The Deep Space I probe had solar panels that generated 2.5kV, and it didn't even have enough electricity to run its ion thruster simultaneously with most of its other systems. Sure it would be nice to have the option to accelerate more quickly, but will there be enough electricity available to take advantage of it for long periods of time?
So are you going to show us the formula for transparent aluminum now?
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I would just like to say that, up until this point, I haven't seen a post by that guy with the anoying sig:
Why yes, I AM a rocketscientist.
For the perfect anti-Unix, write an OS that thinks it knows what you're doing better than you do and let it be wrong.
Just as water molecules pick up energy as they fall between the two different heights,
They are not picking up anything, they are just transforming potential into kinetic energy.
Life is just nature's way of keeping meat fresh.
Still I fail to see fundamental difference between this 'invention' and 30 years old ion beam sputtering technology.
What can you do with this that you can't do with good ol' reaction wheels and gyros powered by solar panels?
You can raise and lower your orbit with nothing but electric motors if you've got moveable masses and electricity. I seem to recall it's done rather commonly in existing satellites.
Forget rocket engines, when are we going to see a "Phased plasma rifle in the 40-watt range"? I wonder how far a supersonic jet of plasma could travel through regular air.
Karma: Nonnegative
If this thruster works, the VASIMR people could stop messing around with their ICRH (resonant ion heater) in the expanding section of their plasma. VASIMR creates a helicon plasma, lets it flow out one end (a one-sided magnetic mirror), and adds ion heating in the expanding plasma. The 'double layer' forms due to expanding a plasma in a one-sided magnetic mirror. I don't know is the VASIMR people have looked for a double layer, but they probably would find one if they tried. The hoped-for improvement of VASIMR is that you can gain additional ion energy, over the double-layer voltage, through conservation of the magnetic moment. It's maybe not so easy to single-pass heat ions, however. One issue with both concepts: I think that they assume a very high ionization fraction; efficiency per input gas is pretty important here. Additional issue with the double-layer idea: I've never seen a power balance -- I don't know how the input RF power is converted to directional ion momentum. But I might be ignorant. I (thereby) don't know how you can control the double-layer, and thereby the thrust and SI).