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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."
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.
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! :-)
Javascript + Nintendo DSi = DSiCade
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.
Not really. It requires a constant power level (100MW, according to the article) to operate, plus fuel. Now the upshot is that it requires less fuel since the energy is input from power source. But if you plan on having your power source off of the craft and "beam" the power, beware, because it becomes really inefficient at long distances...
I'm not trying to be a critic, I'm just trying to show where the applications are. Imagine if Voyager had this kind of propulsion system - it could have made its mission in record time and still be making maneuvers today.
-everphilski-
I think you're comparing the 815 pound weight of Smart-1 (which is the weight of the whole probe including thrusters, fuel, batteries, scientific equipment, etc...) to the 7,774 pound weight of SSME, without fuel.
Also, the SSME is built to lift a very heavy space shuttle (and worse, its 4 million pounds of fuel) to orbit. Of course it needs a lot of power. Presumably, this new thruster does not need to carry as much propellant because it expells it at a higher velocity. If this thruster is light enough that it can lift its own weight, plus that of its propellant and energy source, then it can carry objects to orbit. It doesn't need 12 million horsepower if it doesn't weigh 4.5 million pounds.
You're probably right that it isn't strong enough, but I don't think your comparison is sound. I also agree that this would be a wonderful way to cruise around the solar system. (It might even be a good way to push heavy things like meteoroids around).
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!
Dude. Hank is so gonna kick your ass for posting that, as soon as you leave town. Karl told me so.
David Gould
main(i){putchar(340056100>>(i-1)*5&31|!!(i<6)<< 6)&&main(++i);}
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?
Sort of, except there aren't any metal grids. No grids, not so much chance for them to erode away and your engine to break. Apparently you can get a lot more thrust out of it too.