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."

Comments

A question for the physicists ...

[eldavojohn]

Ok, I RTFAed so don't be mad at me. I'm still not clear on something though stemming from this excerpt from the article:

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.

Is this saying that the energy used to propel the shuttle can now be deferred to depending on an electric source (for the 100kW)? I'm wondering if I should be excited about this new technology or if I should just give them a pat on the back for finding a different and possibly slightly better way to power an engine? I guess it's comparable in size but can rely more on electricity instead of solid fuel for thrust, correct?

MPDT

[AKAImBatman]

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! :-)

Exactly how is this different from the Ion Engines

[alexfromspace]

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.

So, how does this compare...

[wjsteele]

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