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."

Comments

cool but

[ShaneThePain]

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.

Re:cool but

[dbIII]

I think the construction of a space elevator

Dyson spheres and FTL travel are also very cool too and also have nothing to do with this - the benefit of this ion engine is we can build it now with materials and techniques in use now instead of unobtainium or obtainium-next-year-for-sure.

Re:cool but

[abes]

The space elevator seems okay, but I'm putting my money on the space catapult. The one downside is the giant net you need to catch the 'passangers'.

Re:cool but

[asadodetira]

The low torque is not a big concern. In space you can rotate a spaceship any way you want by using gyroscopes.

Conservation of angular momentum says that if you turn on a gyroscope, the spaceship must start rotating in the opposite sense so the total angular momentum is the same as in the beginning. At some point you stop the gyroscope and the ship stops rotating.

Re:cool but

[Anonymous Coward]

Not torque in that sense, but torque as it is used in an automotive engine. A higher torque means that you can accelerate quickly from lower speeds. These are indeed a very gentle acceleration, but can achieve a very high velocity after a long time I believe these are quite energy effecient, and so can provide accelleration for pretty much the entire trip, unlike conventional thrusters which dump large amounts of fuel. Well, the Ion thrusters would at least be able to accelerate for half the trip, before they're turned around and used to decellerate for the second half (note to pedants: apply negative accelleration just sounds dumb, and it is generally understood that decellerate means to accelerate in such a manner as to reduce your velocity with respect to another object, or arbitrary "fixed" point.)

Re:cool but

[zephc]

The one downside is the giant net you need to catch the 'passangers'

I think you misspelled 'chunks of frozen, red slush'.

Re:cool but

[caridon20]

Even though the parrent was trying to be funny a space catapult is a sensible idea.
It would drasticly reduce the cost to throw things into space.

One idea is to put a linear acellerator on the side of mount kilimanjaro (strategic position near equator)
and use it to "kickstart" rokets. this way you can get more payload from a smaller rocket that uses less fuel. /C

Re:cool but

[caridon20]

Probably wont give much. The friction against the water will make the craft reach terminal velocity rather fast. /C

Don't go getting any ideas

[drrngrvy]

Look, we still can't go faster than light, ok guys?

Re:Don't go getting any ideas

[alxkit]

http://www.news.harvard.edu/gazette/1999/02.18/lig ht.html

oh yeah?

Re:Don't go getting any ideas

[Anonymous Coward]

Aparently we can (in theory) with a large enough magnetic field and by using it to slip in to another dimension. In fact, I think we are rather ingnorant/arogant in thinking that we know that we can't go any faster than light. When people used to discuss speed, it was common knowlege that one could not go faster than 60miles per hour and still be able to breathe properly (or at all). I forsee a day when people will laugh at our naivety in relation to our perception of relativity and quantum physics.

Re:Don't go getting any ideas

[XchristX]

[quote]

Aparently we can (in theory) with a large enough magnetic field and by using it to slip in to another dimension. In fact, I think we are rather ingnorant/arogant in thinking that we know that we can't go any faster than light. When people used to discuss speed, it was common knowlege that one could not go faster than 60miles per hour and still be able to breathe properly (or at all). I forsee a day when people will laugh at our naivety in relation to our perception of relativity and quantum physics.

[/quote]

Sorry, but that is just double naysaying. The above example you cited about the 60mph thing (as well as other claims now disproven, like you cant exceed the speed of sound etc.) was not based on hard facts, but vague conjecture and speculation. Furthermore, the dogma in those claims was obvious from the fact that they were deemed "impossible". Nothing is truly impossible. ButFTL acceleration is not impossible. It is completely meaningless as it simply violates causality. If FTL accn is possible, then our entire understanding of physics is almost completely wrong, and there is ample tangible evidence to suggest that is not so.

Furthermore, as a physicist, I do NOT laugh at the 'naivety' of the physicists of the last century at all, or the century before that. I know they made some mistakes and reached some false conclusions. I am also aware that everything that we know about the natural world today can be traced back to their work. Even quantum and statistical theory could not have been possible without the knowledge of Newtonian Mechanics and classical thermodynamics. If the scientists of the future look back and ridicule us for our efforts, they would be ignorant fools who dont realize that their understanding of physics has improved because of what we have discovered in this time.

I know that real scientists will never be as arrogantly clueless as you, or the folks who modded you up are, though.

Re:Don't go getting any ideas

[Anonymous Coward]

"ButFTL acceleration is not impossible. It is completely meaningless as it simply violates causality. If FTL accn is possible, then our entire understanding of physics is almost completely wrong, and there is ample tangible evidence to suggest that is not so."

I wouldn't say that. What about Quatum tunneling?

http://www.npl.washington.edu/AV/altvw75.html

"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."

Deep Space 1

[saskboy]

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.

Anyone else?

[wmajik]

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.

Nonetheless, I blame John Romero for my own confusion and/or angst, because it makes me feel better. :p

carpool

[User 956]

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?

Increase in the number of grids

[Verloc]

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?

Re:Increase in the number of grids

[Nyeerrmm]

Not really, what the extra grids are doing are focusing the beams more so that they actually proceed through the grid rather than hitting it. Ions hitting the grids and causing them to collapse over time is the primary failure mode for an ion thruster, so being able to focus it more seems to allow more power to be pumped into it so that the stream is accelerated faster. I guess more grids might allow you to focus it more, but I'd guess that its a diminishing returns thing. I'm doing research with these thrusters (trying to show a particular fluid simulation, which is particularly good with parallel processing, is valid), especially for the reasons the article talks about with the testing. I think im going to try this multiple grid situation and see how it acts later.

Re:Increase in the number of grids

[Lord Crc]

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?

If you put a high-voltage grid after a low-voltage one, the ions would be repelled by it, not attracted. The voltage gradient must go in one direction: out of the thruster. I'm no scientist, but I don't think you'd gain much by adding a third couple of grids inbetween the two with a medium-voltage level. It would probably be more fruitfull to simply increase the difference between the high and low levels.

I assume the last two grids are low for the same reason the first two are high, to prevent errosion.

Finally...

[RobTheJedi]

One step closer to my TIE Fighter.

YANAP...

[ArcSecond]

Think momentum, not energy.

Ion engine spacecraft!

[nurhussein]

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?

That's hewey!

[imstanny]

The real question is; do the Europeans have a 'Flux Capacitor'?

Re:gawd the moderation is bad sometimes

[hackwrench]

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.

Re:Old News

[angel'o'sphere]

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 ... From ESA not from good old US of A or NASA. And if you don't mind: its good old Europe, not good old USA ...

angel'o'sphere

Re:cool but... oranges and apples

[Jeremi]

Take the space elevator to orbit, use a little bit of conventional thrust to get out of orbit, then fire up the ion drives and eventually hop to the next planet, where your reverse the process.

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.

Not so dumb.

[imsabbel]

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...

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 :D

Re:Charge accumulation?

[Ruie]

Does anyone know how these engines avoid accumulating a net charge over time?

They have an electron gun that shoots electrons the same way the ions go, so the net charge is close to 0.