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New Ion Engine Being Tested
Dr Cool writes "A new design of spacecraft ion engine has been tested by the European Space Agency which dramatically improves performance over present thrusters and marks a major step forward in space propulsion capability. Ion engines are a form of electric propulsion and work by accelerating a beam of positively charged particles (or ions) away from the spacecraft using an electric field. ESA is currently using electric propulsion on its Moon mission, SMART-1. The new engine is over ten times more fuel efficient than the one used on SMART-1."
Ion engines are high impulse, low torque, so they are appropriate only once your already IN space. even then, there is extremely slow acceleration. I think the construction of a space elevator http://en.wikipedia.org/wiki/Space_Elevator would be a much greater step towards "casual" space flight. even so, very cool.
Fascism is the greatest political ideology ever conceived. Sorry.
Look, we still can't go faster than light, ok guys?
I remember reading about Deep Space 1 and it's Ion engine about 8 years ago. I was most impressed that the thrust is about that felt on your hand by a piece of paper when held on Earth. The key is that it accelerates the ship to a speed much greater than traditional rockets, not how quickly it does that. Besides, you don't want to go from 0 to 60 in .058 seconds, unless you want to be a smear on the bulkhead.
Saskboy's blog is good. 9 out of 10 dentists agree.
You Know You Are A Geek when a /. story with the name "New Ion Engine Being Tested" makes you nearly drop the beer and wonder how a defunct game company is producing new engines.
:p
Nonetheless, I blame John Romero for my own confusion and/or angst, because it makes me feel better.
Ion engines are a form of electric propulsion and work by accelerating a beam of positively charged particles (or ions) away from the spacecraft using an electric field.
Cool. So can I put one on my Hummer and drive in the Carpool lane with all those Priuses?
The theory of relativity doesn't work right in Arkansas.
This innovation came from the addition of another grid (from TFA) used in the process of accelerating the ions. Is there any reason that they couldn't just keep adding grids with varying voltages? And why are the last two voltages both low? Wouldn't it make sense to alternate them?
The test model achieved voltage differences as high as 30kV and produced an ion exhaust plume that travelled at 210,000 m/s, over four times faster than state-of-the-art ion engine designs achieve. This makes it four times more fuel efficient, and also enables an engine design which is many times more compact than present thrusters, allowing the design to be scaled up in size to operate at high power and thrust.
Since KE=(mv^2)/2, wouldn't an ion engine with over four times the exhaust velocity have over 16 times the efficiency, all other factors being equal? And wouldn't an increase in ion KE produce a proportional increase in the erosion rate of the dual low-voltage grids, along with a concomitant shortening of the engine's usable service life?
One step closer to my TIE Fighter.
I am so creative, look at my cry for attention in my sig.
Think momentum, not energy.
I've got a bad attitude and karma to burn. Go ahead. Mod me down.
That's neat! Now if we could hook up two of these babies together, and perhaps add solar panels for additional power, we'd get space craft with twin ion engines. Hrm. Twin ion engines... where have I seen that before?
The real question is; do the Europeans have a 'Flux Capacitor'?
You have a choice. If you mod 'Insightful' we smash your face against the bulkhead. If you mod 'Interesting' we smash the bulkhead against your face.
Whether this is efficient to do depends on the speed of the ions. As the velocity of the ions increases, the mass increases and therefore the energy required to achieve the same level of acceleration also increases. Of course, the grids have mass, as does the energy source, so you increase the amount of force needed to achieve the same acceleration.
The ESA are a lot of things - many of them unprintable - but I am prepared to believe they're smart enough to have done studies on multi-stage accelerators as most European physicists have worked on them. (Many particle accelerators in Europe were of this kind, at one point.) If they're only using one grid for acceleration, there's a good chance they'll have crunched the numbers and decided that a single grid was the best bet.
Unfortunately, politics in European space research is (almost) as bad as in NASA, so it cannot be automatically assumed that the solution adopted actually is the option the engineers and ion engine scientists would have preferred. For that reason, I would certainly encourage anyone who knows the science to offer up guesstimates on what different configurations would be like. I would ALSO encourage CmdrTaco and the Slashdot team to see if they can pester someone at the ESA into giving an interview.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
ESA is using an ion drive on the SMART-1 mission. The SMART-1 probe reached it's final destination in lunar orbit about a year ago. The engine in this news is a new improved version of the one used on the SMART-1 mission.
Also, as an European whose tax money is being spent on these ESA projects, I am slightly annoyed by the assumption that "brits" are the only ones behind ESA. The British contribution to ESA's budget is less than 14.2%, which is the portion Italy (the third biggest contributor) stands for, with the Germans (22.7%) and French (29.3%) being second and first.
Why not just increase the number of ion engines? If one gives for example a 1 m/s thrust, wouldn't 20 of them combined give a 20 m/s thrust? I know its not that simple, but you will see significant increases in acceleration, I am sure. Put together a platform with 50 of them, slap on a crew compartment and storage spage, and you have your first in-system exploration ship to go gadding about in! I'd probably throw in a nuclear plant for the giant frickin lasers myself (purely to clear debris, naturally ;)), but we could build all that right now...
What he can't kill, he has sex on. Trent.
So while the ESA is desperately trying to generate some positive press to help people forget about their recent failings the good old US of A is putting proven and effective technology into getting back to the moon.
Care to point out some of the recent failure sof ESA?
As a sidenote: the currently only ion drive propulsed moon orbiter is a european one
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Actually, in many cases you can get where you want to go with little or no thrust at all, simply by riding the elevator up past the altitude of geosynchronous orbit. The higher above that altitude you go, the greater the centrifugal force from being spun around the Earth, so it's just a matter of calculating when to let go of the elevator.
I don't care if it's 90,000 hectares. That lake was not my doing.
Okay, here's a dumb question for you: I've got a pretty good idea what would happen to me if I stood right behind a traditional rocket while it was lit. But what would happen to me if I stood right behind one of these while it was running? Instant death? Intense pain? A refreshing tingly sensation?
I don't care if it's 90,000 hectares. That lake was not my doing.
What if you view the speed you're going at as a 4-dimensional vector with the basic 3 axis of space and the axis of time. That way, speed would (should) be a constant, where, if you accelerate more in the space domain in any direction, your speed in the time domain would decrease. Now, if you could accept that travelling faster than the speed of light is impossible only due to this vector being constant in size, you could accelerate until it is on the other side of the timeplane, thereby allowing you to travel through time.
Didn't think about what paradoxes you'd need, and you'd probably bump into yourself at the moment of turnaround, but aside from that...
No research done whether this could be true, but it's an idea I've been playing with.
I realize these ion engines have a low thrust/acceleration as a tradeoff against their better fuel economy, which means they're really meant for the long-duration missions such as to the outer planets, etc. Yet I wonder if this new ion thruster design, and also the Double Layer Helicon Thruster that was also recently tested, will result in ion engines that could take man to Mars?
It would be nice if upcoming unmanned space missions could put these new ion engines through their paces, to see how much performance we can squeeze out of this technology. Let's see how high they can make the thrust go. I read on the newsgroups that ion engines could one day emulate the VASIMR concept which can achieve a wide variety of thrust characteristics.
Or what about a 2-stage rocket design? Just have a regular chemical rocket first-stage with high thrust to escape the earth's gravity, and then from there use ion engines to power the 2nd-stage.
These ideas have been floating around NASA and the defense industry for years.
Ion engines, yes. Dual-Stage ones? I was under the impression that they were new.So why haven't these engines been put into use?
What are you talking about? Dual-Stage ion engines are just being developed, and conventional ion engines are/were in use both on NASA and ESA probes.As a result the only projects suggested were either unmanned deep space probes
You seem to be implying that unmanned space exploration is useless. It is anything but. If at all, the presence of humans in space is of questionable scientific value.they provide very little acceleartion
If you had RTFA, you'ld have seen that this new technology remedies exactly that problem and woud lend itself for Mars missions.Well... on earth, nothing would happen, as this kind of engine only works in vaccuum... The mean free travel lenght of those ions in air would be meassured in mircrometers...
:D
In vaccuum, you would die rather violently, due to shortage of air....
So i dont think this is a practical concern...
Of course, if you were in a spacesuit, there would be an issue...
The process (hitting an object with high energy noble gas ions) is also used on earth, where to precess is used to alter surfaces of materials. Its called "sputtering", or "plasma etching". So i guess you can get a general idea of what it does... It cant penetrate your spacesuit, but will happily kick layer by layer of atoms from its surface.
If you waited long enough, it would open holes/ect, but it you be very damaging to sensor equipment/solar cells even with short exposures.
Think of a very low power slaver desintegrator from the ringworld novels
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Indeed torque can be a big problem in space, even if you have gyroscopes.
If the propulsion engine has a small offset in thrust wrt the center of mass of the spaceship, this generates torque. The gyroscopes can absorb this by accelerating, but only up to a certain amount (because, obviously, they cannot continue to increase their speed indefinitely).
At that point the gyroscopes must be "unloaded" by firing some appropriate thruster and consuming propellant.
They have a similar problem on the ISS (but there the torque is generated by friction with the upper atmosphere and small gas leaks), where the american gyroscopes must be periodically unloaded firing the russian thrusters, using precious propellant (this, of course, isn't due to a fault in the gyroscopes).
One of the good things of ion engines is that they can very finely tuned to not have pratically any off-center thrust: the Smart-1 spacecraft has almost never had the need to use it's gyroscopes to absorb thrust generated by the ion engine.
And, of course, the torque generated by really big motors (e.g.: Space Shuttle or Ariane 5 main engines) must be corrected by the same engines with a closed-loop control, because there is no way a gyroscope can absorb that much torque.
There's a hidden treasure in Python 3.x: __prepare__()
oh wait, never mind. i'm an idiot. :-P
SOL ~= 300,000 km/s, not m/s.
210,000 m/s / 300,000,000 m/s = 0.07% the speed of light
(much more believable)
http://kered.org
Does anyone know how these engines avoid accumulating a net charge over time? If you're emitting a stream of positive ions for a long time, and you're not taking in any negative ions, you would have an increasingly large negative charge. It seems that this would decrease the thrust over time, not to mention electrocuting the vessel upon re-entering an atmosphere.
If you can read this sig, you're too close.
But think about the environmental impact of doing something like that. You are wasting a non-renewable resource that rightly belongs to everyone on Earth. I don't think anyone should be able to do something like that until we are really clear on the impact on Earths like from the rotation slowdown that would happen from this. Even more I think we should impose a ban on any and all fly-by assisted missions.
"In particular, Aichmann and Nimtz have recently transmitted Mozart's 40th Symphony as frequency modulated microwaves through an 11.4 cm length of barrier wave guide at an FTL group velocity of 4.7 c, receiving audibly recognizable music from the microwave photons that survived their barrier passage. The transit time through the barrier was about 81 picoseconds and was observed to be constant for barriers with widths varying from 4.0 cm to 11.4 cm."
Nimtz is a clever PR guy but a lousy physicist. Every physics undergrad should know that both the group and phase velocity of electromagnetic waves can have arbitrary values and that this doesn't contradict special relativity. The important question is how fast information is being transmitted and for this neither the group nor the phase velocity is suitable.
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The earth already is loosing rotaional energy. Quite a bit in fact. It happens naturally. The moon has pretty much lost all its rotational energy.