Talk:Ion thruster

CAT

The CAT is listed as having an ISP of 690. With Iodine (which is what the reference assumes), its ISP is now known to be closer to 800, and either the propellant should be changed to just Iodine or the ISP should be listed for other propellants. I can provide numbers and sources for the second option.

Pioneer

Who put this german scientisct as pioneer of rocketry? Tsiolkovsky, russian scientist is a pioneer of rocketry and space travel.

Electric propulsion not ion thruster

Hi i think it would be better if the main page for ion thrusters was electric propulsion. This is how it is done in major engineering books on the subject - see Sutton, Rocket Propulsion Elements, or Stark, Fortescue etc, Spacecraft systems engineering. Then electric propulsion is divided into 3 categories; 1. electrostatic propulsion 2. electromagnetic propulsion 3. electrothermal propulsion

Then the different types of electric propulsion (they are many!) are listed in their relevent categories. So ion thrusters would be in electrostatic propulsion, whilst arcjets would be in electrothermal propulsion. Is it ok with ppl if i do this? Can i do this?! Charlie

Since ion propulsion is really the only form of electric propulsion that has actually been used, I think it deserves it's own article. We could have another article that discusses other possibilities for electric propulsion, but this article should stay as it is.--Mars2035 19:42, 5 May 2007 (UTC)

There are some types of electric propulsion engines which are not ion engines (i.e., utilize ions) such as resistojets and arcjets which have flown. I think this is addressed in the general EP article --Allen314159 00:02, 3 July 2007 (UTC)

Hello again i think this page should not contain the scientific backround to spracesraft electric propulsion - that should be contained on the 'electric propulsion' page. It is not right at all to characterise electric propulsion used on spacecraft as ion thrusters, and is a little misleading - for example colloid thrusters are not ion thrusters, as they do not use ions as the propellant, but charged droplets, much larger than an individual ion. This page should focus more specifically on on the classic electrostatic ion thruster, as used on deep space 1. And i guess a short piece on the fictional use of ion thrusters would be appropriate. It should not be the main page that lists the different type of spacecraft electric propulsion - that should be the 'spacecraft electric propulsion' page - a page that currently called the slightly misleading 'electric propulsion'. Cheers --nasalcherry

Craft charge

Question:

Why is it important that the Ion thruster driven space engine stays electrically neutral? I tend to think that in an almost perfect vacuum (outer space) electrical charge doesn't matter. Because charge is relative to its surroundings - basically nothing in space.

Or is there still too much dust around in "empty" space?

Or is there electrical attraction to be expected from really far away objects (say, a planet)?

Charge isn't relative: like mass, it's a property of the object, whether or not there's anything nearby to be affected by it. Also, ion drives are being used in places that are, in terms of particles, far from empty, like near-Earth space. Vicki Rosenzweig 11:59, 29 Sep 2003 (UTC)

The problem with needign to remain electricalyl neutral is that if the chassis becomes too electrically negative, then the device must perform extra work to remove the extra electrons adn ionize the workign fluid, plus the exhaust beign still ionized would be attracted to the highly negative chassis instead fo open space, producing no thrust. Its far more complex than that but the explanation should suffice.

What would happen to the craft if the beams were not neutralized what would be the danger? -verusgenbree

Nothing good. The exhaust would come out the back slower and would slow down more even after that due to the voltage difference between it and the vehicle. The vehicle would develop corona at any sharp points and so forth.- (User) Wolfkeeper (Talk) 18:03, 28 January 2009 (UTC)

Deep Space 1

Also it needs to be noted in here that DS-1 will NOT be using an ION engine it will be using a HALL EFFECT engine, the difference is technical but ion drives are no longer used for future designs.

Au contrare! DS-1 used the xenon ion thruster developed under the JPL NSTAR program, it was definitely a gridded ion thruster, not a Hall thruster.

Limits to specific impulse

My understanding of ion engines is that they can increase their specific impulse simply by increasing the grid voltage. However, they normally only operate with an isp of about 3000 because higher isp values would require too much power to produce a decent thrust. Is there any practical limit to how high the grid voltage and isp can get if power supply is not a problem? Could an ion engine vary its isp over a wide range of values by changing the ratio of power being used to ionize fuel to the power being used to accelerate the fuel?--Todd Kloos 23:01, 9 Jun 2004 (UTC)

Yes and no; ion drives have problems with ions striking electrodes and eroding the electrodes. If you just crank up the voltage, the ions will start to wreck the electrodes. Other problems may also occur; I'm guessing, but you may also have to avoid arcing and corona discharge in the ion stream, and there may be other concerns as well. But certainly power consumption is a major design issue: you have to trade off the mass of fuel required against the mass of the power generation equipment. For very large delta-v (comparable to the specific impulse) improving specific impulse is a very big win. But if delta-v is relatively small compared to exhaust speed, then the reaction mass is not very large, so boosting specific impulse may require you to increase launch weight to generate enough power. This becomes worse when you want to travel far from the sun; power generation gets more difficult, and if it requires an expendable resource, you might as well throw the expended resource out the back as extra reaction mass. --Andrew 06:53, 11 Jun 2004 (UTC)

Thank you for replying. I know that the current generation of ion thrusters (HiPEP) has very significant advantages in thruster lifetime compared with previous ion engines. Presumably this would also allow higher voltages without wrecking the electrodes? Anyway, I know that higher specific impulse is not always better. However, for many missions using a constant isp value is not the most efficient way. I have seen profiles for optimized VASIMR missions to Mars where the spacecraft will start out with an isp of 3000, but the isp will slowly rise during the trip (sometimes reaching a peak as high as 50,000) before going back down to 3000 at the end of the trip. If ion engines can go through a similar variation of specific impulse, it should allow them to increase efficiency shorten mission durations considerably.--Todd Kloos 08:05, 11 Jun 2004 (UTC)

Scotty Quote

Uh, unless my understanding of wikipedia format is totally off, the quote by Scotty is not appropriate

Personally, I'd like to know which episode that was. 65.60.222.179 11:24, 15 January 2006 (UTC)

So what happened to the star trek reference? It was widely cited in the press in the coverage of the Deeps Space 1 probe. It was the Spock's Brain episode. Here are some relevent references.[1][2][3]. Unless someone has a meaningful objection I am going to restore some kind of reference to this. It is notable enough to mention and there is a long history of interaction between the space program and SF especially Star Trek. Rusty Cashman 04:18, 28 September 2007 (UTC)

Probably because it's meaningless buzzwords in Star Trek and the depiction of the the ion drive bears little relationship to what ion drives are, or how they behave.WolfKeeper 11:58, 28 September 2007 (UTC)

Freelancer Speculation

The following quote from the fiction section of the article is gibberish to me:

The engine exhaust is visible (relatively) low frequency energy pulses and some fans theorize this could be achieved with a form of electromagnetic flux compression to ramp up the power output of the reactor.

If it's gibberish to someone else (ie, it's not just me), could it be simply deleted?

What they're describing is a pulsed fusion reaction, where you increase the magnetic confinement field's strength to compress the plasma, which substantially increases the rate of fusion. I'll try to clean it up. --Christopher Thomas 16:08, 6 January 2006 (UTC)

Delta V?

From the article, under missions: "Of all the electric thrusters, ion thrusters have been the most seriously considered commercially and academically in the quest for interplanetary missions. Ion thrusters are seen as the best solution for these missions as interplanetary trajectories require very high delta V (the overall change in velocity, taken as a single value) that can be built up over long periods of time (years)." This seems wrong. What's important is a very high _average_ velocity, and that can be built up over many years. A high average acceleration doesn't come into it except in that it in turn implies a high average velocity.

You seem to have misunderstood slightly. Delta-v isn't acceleration. Delta-v is (basically) the total speed change the vehicle would get if you were to accelerate it in a straight line, without gravity, until you run out of fuel.

Also actual velocity isn't right at all. For example, as a vehicle climbs higher and higher in an orbit around the Earth or the Sun or whatever, it actually slows down. It's all a bit counterintuitive; but as you drop into lower orbits the speed goes up, as you climb it goes down. But you're spending delta-v to do either manouever.

Sorry, bet that's clear as mud.WolfKeeper 17:19, 3 October 2005 (UTC)

There are numerous mentions of speed in this article that actually refer to Delta-v. I will fix them. Mtpaley (talk) 23:47, 16 March 2014 (UTC)

Imperial Units

Please clear the article of them or at least make SI units the primary unit.

Illustration

Would this one be worth using as a base for an illustration here? Scoo 21:53, 14 December 2005 (UTC)

TIE Fighters?

Should some mention of Ion Thrusters in fiction be made? Like, you know, the TIE Fighter. Twin Ion Engine - TIE. Not sure if it's appropriate, but it is a significant cultural thing (Star Wars, not Ion thrusters). --Phant 21:49, 2 June 2006 (UTC)

The 'ion drives' that are depicted show little if anything in common with the real thing.WolfKeeper 12:00, 28 September 2007 (UTC)

Seems pretty in common to me. Using ion engines to propel vessels through the vacuum of space. Perhaps it could be in the See Also section.(Myscrnnm 23:27, 5 November 2007 (UTC))

Close, but it might be real boroska boy from mars exclaims that the martians used ion engines for solar system travel or interplanetary travel.--64.9.237.64 (talk) 04:04, 9 January 2010 (UTC)

Video of Running Ion Drive

I did some google searching and looking on here and no where on the internet can I find any video of an ion drive actually running. I am personally very curious on how the beam of particles looks in motion, and if there is any wobble or anything else of that matter. If anyone has a link to a video, has a video themselves, or knows someone who does, please put it on the net and on Wikipedia as well.

Found this, it's timelapsed and no sound and real bad quality. http://nmp.jpl.nasa.gov/ds1/tech/ds1_ips.mov If I find another one I'll add that. -62.220.161.10 06:55, 31 August 2006 (UTC)

Here are two more, both a bit more recent: N2e (talk) 20:10, 2 February 2011 (UTC)

• VASIMR rocket on the Science Channel
• VASIMR VX-200 full-power stability test, 25 second burn, November 2010

Ion thruster page edits

Hi, I'm a student at the University of Wisconsin - Madison and I'm editing this page as a project for my technical editing class. I'm also majoring in Engineering Mechanics and Astronautics and I've also done quite a bit of research on ion engines. I would appreciate it if you would hold off on editing things I've changed for a day or so until I'm finished (i'll edit this to let you know). Sorry if I changed your stuff (Wolfkeeper). I'll leave an explanation here as to the major things I've done as well. Thanks a lot. Dmpdpete (talk) 00:23, 20 November 2007 (UTC)

The problem is that this page is a general page on ion thrusters, whereas there's a good page on gridded electrostatic ion thrusters that covers what your edits were referring to. I'll leave off editing from now on though.WolfKeeper (talk) 00:42, 20 November 2007 (UTC)

(I only just saw this, sorry about that. :-( )WolfKeeper (talk) 00:43, 20 November 2007 (UTC)

Somewhere, there's a tag for use when you're making changes, but you prefer others not to edit until you've finished, you should probably dig it up and apply it.WolfKeeper (talk) 00:46, 20 November 2007 (UTC)

No worries and thanks. I think I should be good. Regarding the other pages, I feel the the electric propulsion page is a good general ion thruster page and from what I've read when someone refers to ion thrusters, its an electrostatic one. There's no set definition though. I'm just editing this one as kind of a mix of general and electrostatic specifically and then when I'm done I would probably suggest this and the electrostatic page get merged or something. Dmpdpete (talk) 00:52, 20 November 2007 (UTC)

Thing is, Hall effect thrusters also accelerate ions, and are described as ion thrusters but the cathode consists of an electron cloud.WolfKeeper (talk) 05:16, 20 November 2007 (UTC)

Academic editing of the wikipedia was discussed on the wikien-l list. I think that when an academic assignment involves editing the wikipedia, it's best if the student creates an entirely new article- there are lists of article wanted around. Otherwise you will often find that other users will intermingle their edits, and it becomes harder all round.WolfKeeper (talk) 05:16, 20 November 2007 (UTC)

References for comparisons

I am interested in knowing about the capabilities of electronic thrusters that are actually in use by satellites, but the table of comparisons between different thrusters is completely uncited, so I don't know whether these numbers refer to actual thrusters or lab tests only. Mattski (talk) 22:45, 22 January 2008 (UTC)

Dunno. There's a good table in the seventh edition of Sutton with 30 different EP drives in.- (User) WolfKeeper (Talk) 00:05, 23 January 2008 (UTC)

I am most concerned about the ones listed with extremely high power consumptions and high thrusts. Of the few commercially produced ion thrusters I could find details on (from QinetiQ and Boeing), they were on the order of less than 200mN of thrust per engine. For example the listed MPDT hydrogen ion engine that uses 7500kW (that's 7.5MW!) and produces 60N of thrust is ludicrous, a satellite would need a huge solar array and power storage bank to power it even for a short amount of time, and I would have a hard time believing it was even built in a lab. The applications of a thruster with those specs would be very questionable since they probably could not be used in space. I believe that citations must be provided to verify the numbers claimed in this table, or they should be removed. They are orders of magnitude different from what sources I have been able to locate, and are thus highly misleading if they are not actually accurate. Mattski (talk) 22:09, 5 February 2008 (UTC)

This link from 2003 says that MPDT thrusters have never been run stably above 1MW, I would suppose that they've been run in pulsed mode, but that doesn't make them practical thrusters. I'm considering removing all the MPDT above 1MW, based on this source (i.e. all of them!)- (User) WolfKeeper (Talk) 23:18, 5 February 2008 (UTC)

Lorentz Force

I am no expert in ion thruster, and I looked up the article because I wanted to learn about them, but what the article says about the Lorentz force cannot be correct. The Lorentz force is perpendicular to the velocity of the particle, and therefore it does not give energy to the particle, it only deviates it. Someone knowledgeable should look at the explanations regarding the use of magnetic fields. In general the Lorentz Force cannot be used to increase the absolute value of the speed of the ions, which is what you want to propel a rocket. I rarely edit wikipedia, but I thought that if someone sees a mistake, he should still point it out even if he can't fix it.... Ivan Biaggio (talk) 02:25, 9 April 2008 (UTC)

The Lorentz force has two terms, the first term is electrostatic, and does give an increase in speed.- (User) WolfKeeper (Talk) 04:04, 9 April 2008 (UTC)

Yes, it is true that sometimes the forces from both magnetic and electric field are combined and that the total is still called Lorentz force. However, the electric term is the Coulomb force F = q E, and the article explicitly tries to distinguish between Coulomb Force and Lorentz Force (Look at the first paragraph!) as two different things that can accellerate the ions. As a result it is confusing. In addition, it is not uncommon in physics to use the term "Lorentz force" more specifically only for the magnetic component.Ivan Biaggio (talk) 23:31, 14 April 2008 (UTC)

It is well known in physics that a static magnetic field cannot change the energy of a charged particle, Ivan Biaggio (talk) is correct about this point. The article needs to be at least clarified and perhaps corrected on the issue, which arises at several points. I do not know enough about the details of the various types (which are not always very clearly described) to undertake a revision, but the general principle is clear. I agree we have a problem here. Wwheaton (talk) 21:35, 1 February 2009 (UTC)

Merge proposal

I am about to modify the merge proposal with Plasma propulsion engine to point to that article's talk page, so we don't have two separate discussions going. I will propose there keeping the two articles separate, based on the criterion of thermal versus non-thermal operation. But note that if this is accepted the material on plama thrusters that has recently been added to this article will need to be integrated with the plasma thrusters article. Wwheaton (talk) 07:40, 31 January 2009 (UTC)

Proposal closed; removing the tag. Jminthorne (talk) 06:38, 3 September 2009 (UTC)

2nd paragraph is meaningless?

"The thrust created in ion thrusters is very small compared to conventional chemical rockets, but a very high specific impulse, or propellant efficiency, is obtained. This high propellant efficiency is achieved through the very frugal propellant consumption of the ion thruster propulsion system."

So basically low power and low consumption. What's the point? I bet you can achieve 10 times more power at some point between 1 engine with 10 times more consumption or 10 engines with the same individual consumption. Am I missing some basic rule of physics or the quoted paragraph is meaningless or what?

Note that I don't have a clue on Ion thrusters; maybe the paragraph is syntactically near to explain something relevant and could be easily improved by somebody with knowledge about these gadgets.

Regards. --Ermey (talk) 15:29, 13 February 2010 (UTC)

It's basically explaining the trade-offs between chemical and electric propulsion. Chemical rockets are high thrust, low propellant efficiency (specific impulse); ion thrusters are low thrust, high specific impulse. ion thrusters are actually power inefficient when compared to chemical rockets in terms of mass of the entire system. chemical rockets get all their power from the chemical bonds in the propellant, whereas the power for ion engines must be provided from outside of the thruster itself, usually a combination of batteries and solar panels. These require a lot of mass, which basically means that an ion engine cannot even lift itself off the ground. However, for spacecraft already in orbit or especially in deep space (where the craft is not fighting directly against gravity), ion engines are ideal because they use their propellant much more efficiently.

Does this answer your question? I think the paragraph makes sense as long as you don't confuse thrust with power. —Preceding unsigned comment added by 18.33.1.251 (talk) 22:38, 7 February 2011 (UTC)

Missing diagrams in PIT section?

Reading the PIT section, it's as if the text was simply pasted from another source. There are repeated references to a diagram which is not included on the wiki page. —Preceding unsigned comment added by 142.46.198.27 (talk) 18:35, 10 June 2010 (UTC)

Electrothermal thrusters

Electrothermal thrusters aren't a type of electromagnetic thruster, or even a type of ion thruster. All they do is heat up the propellant so that it has more kinetic energy. It has nothing to do with propelling ions through electrostatic or magnetic means, any ionization is accidental and is not taken advantage of. number 4, VASIMR, looks like an ion engine though. I don't know much about it, but it appears to be mainly an electromagnetic ion thruster that also utilizes the electrothermal effect. However, you can utilize the electrothermal effect on just about any kind of thruster, including chemical. —Preceding unsigned comment added by 18.33.1.251 (talk) 22:13, 7 February 2011 (UTC)

VASIMR is clearly an ion engine, as supported by many sources in Wikipedia user space, mostly in the VASIMR article. But if something is needed in this article, feel free to fix it, or add a source. In Wikipedia, everyone can be an editor.

Re your first point "Electrothermal thrusters aren't a type of electromagnetic thruster, or even a type of ion thruster. All they do is heat up the propellant so that it has more kinetic energy. It has nothing to do with propelling ions through electrostatic or magnetic means, any ionization is accidental and is not taken advantage of." Again, feel free to edit the article to improve it, working within the five core Wikipedia policies. Or if you would rather not edit directly, make more concrete and specific suggestions for small changes here on the Talk page and perhaps some other editor may see you argument and rationale and make the changes themselves. Seems like your input would be helpful to improving the article. Cheers. N2e (talk) 23:54, 7 February 2011 (UTC)

My suggestion would be to remove the electrothermal thruster section from this page, and perhaps give it its own page with links to the first three thrusters. VASIMR could be put under one of the other sections on this page or given it's own section under electromagnetic thrusters. —Preceding unsigned comment added by 18.33.1.251 (talk) 16:34, 8 February 2011 (UTC)

I support your proposal. Based on the claims made in the various sources I've read, the three pure electrothermal thrusters you mention are not ion thrusters at all. So be bold and make the changes in the article. N2e (talk) 16:40, 9 February 2011 (UTC)

Done. However, the way I understand the description of VASIMR, it straddles a really semantic line between electrothermal (conventional) and electromagnetic (ion) propulsion: True, the ionised state of the propellant is critical for the functioning of the containment system, but on the other hand the containment system just replaces the solid walls of chemical rockets with the magnetic fields in a similar shape. At which point we have a two-stage microwave oven. The stream of propellant is not ions as is the case for ion thrusters, it's neutral plasma.

I will thus not note VASIMR in electromagnetic propulsion in the Ion thruster article. However, it is noted in Electrically_powered_spacecraft_propulsion#Electromagnetic, which also has a wider definition for "electromagnetic" that includes the principles used in VASIMR. Jostikas (talk) 22:04, 16 November 2013 (UTC)

BepiColombo...

... will use ion propulsion as well. Added that to future missions. — Preceding unsigned comment added by 145.94.195.138 (talk) 08:08, 1 June 2011 (UTC)

Which types are "these types"?

"...the accelerations given by these types of thrusters is frequently less than one thousandth of standard gravity." is a clause that comes immediately after a discussion of chemical rockets. It is common knowledge that chemical rockets are not limited to less than one thousandth of a standard gravity. To avoid the false interpretation of the clause I will substitute ion thrusters for these types. - Fartherred (talk) 14:32, 9 May 2012 (UTC)

Graphics, units, efficiency ...

The graphics look primitive need not the coloring draftsman but an artist's TLC. I am sure picture details can be obrained as NASA PR, freely. In one graphic, cathode is not explained or shown as a brick not visually informative enough. The units on tables could be spelled out esp. where there is space. or given on the side, make least assumptions on the reader. Efficiency issue is just words. Please spare a column to indicate efficiencies, as this is not Detroit data selling dimentions fabrics and colors. Hydrogen and Li vapor listed on the same list, is it a false comparison of technology I wonder (not sure). This is the future now, please help everyone understand. And on that questin of fiction engines citations and comparisons from sci-fi, with years, it is a definite must which can also be a link only. The pt. is, brain-sci-fi'ific has thrust too. Appreciation has to start somewhere. Thank all who contributed and will contribute. — Preceding unsigned comment added by 69.120.118.254 (talk) 19:01, 6 June 2012 (UTC)

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NEXT new update

http://www.nasa.gov/multimedia/imagegallery/image_feature_2416.html#.UhMwxNJFDoJ I don't know how to write this in the page can someone do it? — Preceding unsigned comment added by 79.24.184.73 (talk) 09:05, 20 August 2013 (UTC)

Exhaust velocity and thrust ion thruster

In the second paragraph article: "Ion thrusters' exhaust velocity are often in the range of 15–50 kilometres per second (1,500–5,100 s), and will have a specific thrust usually below a newton per tonne. Thruster efficiency may reach 60–80%."

But Input power: 1 to 7 kilowatts Exhaust velocity: 20 to 50 kilometers per second Thrust: 20 to 250 millinewtons Efficiency: 60 to 80 percent. Vyacheslav84 (talk) 00:17, 18 March 2014 (UTC)

Energy efficiency and vehicle speed

The term "vehicle speed" in this context is ambiguous, i.e. - vehicle speed relative to what or in which frame? I suspect from the equation citation that it is the speed with respect to the average local velocity of the atmospheric gases in which the vehicle is operating. Given that assumption and that most Ion Drives operate in the vacuum of space, without further clarification it would seem that the aforementioned term is irrelevant. Note that this also makes the figure irrelevant since it depicts the efficiency in an atmosphere, and the rocket can correctly be considered to always accelerate from rest in its own co-moving reference frame, when outside the atmosphere.

If this is true, the paragraph should be rewritten to cite the correct equation for the energy efficiency in a vacuum and remove the spurious reference to vehicle speed.

• And more akin to a car that takes two days to accelerate from zero to 60 miles per hour. Vyacheslav84 (talk) 07:44, 6 July 2014 (UTC)

Quote from Scientific American is wrong! - oops misread units

In the third paragraph article says, "The Deep Space 1 spacecraft, powered by an ion thruster, changed velocity by 4.3 km/s while consuming less than 74 kilograms of xenon." I know it's a quote from a Scientific American article; but it struck me as absurd on the face of it. 4.3 km/s is walking speed. 74kg is the mass of a small person.

Check this NASA article: http://www.jpl.nasa.gov/news/news.php?feature=1468 It says, "After a year Dawn's ion propulsion system will have increased the spacecraft's speed by 5,500 mph while consuming the equivalent of only 15 gallons of fuel." I can believe that, and it stands in stark contrast to what the Wikipedia article now states.

The SA quote is off by more than 3 orders of magnitude. Even if the units of speed were supposed to megameters/sec instead of kilometers/sec or the units of mass grams instead of kilograms, it would still be well short.

I am not sure what the best way to fix this would be. (I think there are reservations about the units the NASA article uses.) However, if no one else does something in the next few weeks, I will edit the page to cite the NASA article.DrHow (talk) 17:51, 20 January 2015 (UTC)

"4.3 km/s is walking speed." You must walk very fast...

The two measures cited are within an order or magnitude of each other and, depending on the assumptions you use, both seem valid to me. ChiZeroOne (talk) 18:43, 20 January 2015 (UTC)

I apologize for my blunder. I was obviously thinking 4.3km/hr; and I feel very foolish, since I was questioning the units. That is a factor of 3600 - just like I said, more than 3 orders of magnitude - but my mistake. Sorry folks. Now I wish I could delete my stupid comment; but that is probably not OK in a talk context.DrHow (talk) 04:57, 21 January 2015 (UTC)

We all make mistakes, at least no-one died. ChiZeroOne (talk) 05:00, 22 January 2015 (UTC)

5500 mph = 2.45 km/s so it differs by about a factor of 2. 15 gallons = 68 liters so this works if the density of compressed xenon is just slightly more than water. Sounds alot but maybe possible. Mtpaley (talk) 18:57, 20 January 2015 (UTC)

Another thought "while consuming the equivalent of only 15 gallons of fuel" does not necessarily mean 68 liters, it might be the energy produced by a generic internal combustion engine burning this volume of petrol. If so then this is sloppy journalism but it is entirely possible. They should specify energy in J and power in W and give the readers enough information to convert this to local units. Mtpaley (talk) 22:58, 20 January 2015 (UTC)

Requested move 09 February 2015

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: not moved. Current title appears to be the common name. Number 57 21:38, 17 February 2015 (UTC)

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Ion thruster → Ion Drive – Edgar Choueiri The Ion Drive - Choueiri, Edgar Y. (2009) New dawn of electric rocket Scientific American 300, 58–65 doi:10.1038/scientificamerican0209-58 Vyacheslav84 (talk) 13:58, 9 February 2015 (UTC)

Survey

Feel free to state your position on the renaming proposal by beginning a new line in this section with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.

• O P   P     O       S           E, as per moving forward not backwards.

"ion thruster" gets "About 7,920 results" in Scholar

"ion drive" gets "About 1,230 results" in Scholar

GregKaye 17:37, 9 February 2015 (UTC)

• Oppose The common name would appear to be Ion Thruster which in fact the article quoted above supports; "Thruster" and even "Engine" are used more times in it than "Drive". This is particularly true when talking about real technology which the wiki article is primarily concerned with rather than for example terminology from science fiction. ChiZeroOne (talk) 21:42, 9 February 2015 (UTC)
• Strong oppose no evidence of this being the common name, and ion drive does not signify the same thing as ion thruster, since it could signify a device used to drive ions in other applications not related to rocketry. Further fails MOS:CAPS -- 70.51.200.101 (talk) 05:10, 11 February 2015 (UTC)

Discussion

Any additional comments:

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The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Lobying for powerful ion thruster

"U.S. Lawmaker Wants NASA Working on Interstellar Propulsion" [4]. He wants to fund the Asteroid Redirect Mission and develop a 25-kilowatt to 30-kilowatt engine 10x more powerful that that on Dawn spacecrft. BatteryIncluded (talk) 18:59, 25 March 2015 (UTC)

I don't think this is yet notable enough to include in this article....if it does get implemented, however, it would eventually be good info for the Asteroid Redirect Mission article. Cheers! Skyraider1 (talk) 21:49, 25 March 2015 (UTC)

New drive to watch for

Although wp is NOTNEWS, editors here may want to keep an eye out for information on Patrick Neumann's new variation on the ion drive, claimed here to beat HiPEP by 50%, and to do so using recycled magnesium for reaction mass. Though the article doesn't talk about it explicitly, the implication is clear that this would be very useful for cleaning up space junk.LeadSongDog come howl! 21:08, 21 September 2015 (UTC)

Quantities and units

As rocket science is famous for loosing spacecraft due to a mismatch in units and quantities, I'd like to point to ISO/IEC directives, part 2, a document of international standardisation organisations how to draft standards. Annex I "Quantities and units" on page 71f specifies: "The decimal sign shall be a comma." and "International Standards shall use only SI units, [..]". --Gunnar (talk) 18:51, 12 March 2016 (UTC)

Ion thrust use in RORSAT

The page ought to note the Soviet use of ion propulsion in their RORSAT program. Ion propulsion was used in low-orbiting military active radar surveillance satellites to keep their orbits from decaying . This is publicly listed for missions in 1987-1988, but seems to have been used as early as 1975 with Kosmos-723. See also, the TOPAZ and BES-5 nuclear reactors that powered them.Pulu (talk) 21:39, 27 July 2016 (UTC)

References

Clarify ion thruster / plasma thruster

Dear fellow wikipedians,

In my opinion this article overlaps with the article Plasma propulsion engine. Please see Talk:Plasma_propulsion_engine#Better_distinguish_electrostatic_ion_thrusters_vs_electromagnetic_plasma_thrusters.

Ileresolu (talk) 12:14, 18 August 2016 (UTC)

Ion thruster (electrostatics, coulomb force) ≠ plasma thruster (electromagnetic, Lorentz force)

As explained many time in this page without proper action, ions thrusters accelerate positive ions with an electric field. They are electrostatic devices in nature. The fact that someone wrote that all plasma thrusters can be "loosely called ion thrusters" is plain wrong. Such studies date back to the 1960s and keep continuing. Spacecraft electric propulsion is clearly divided into three categories:

• Electrostatic thrusters (ion thrusters fall in this category)
• Electrothermal thrusters (where electricity is mainly used to heat/ionize a propellant to violently expand it out of a nozzle)
• Electromagnetic thruster which accelerates a plasma primarily using the Lorentz force (cross-product of an electric current with a magnetic field, which accelerates ALL species: free elctrons, negative ions, positive ions… and through collisions, also neutral atoms, in one single direction). To be much specific, electromagnetic plasma thrusters exactly refer to any plasma propulsion device using a magnetic field and where the electric field is not in the direction of the acceleration.

Electromagnetic thrusters are NOT ion thrusters. This is well known among specialists and an indisputable fact well sourced in the literature.

It should be noted however that a particular case are Hall effect thrusters, which are hybrid electrostatic–electromagnetic accelerators, as the Hall effect make electrons drift (so the electronic current and its collisions with heavy species is not anymore directed along the electric field lines, while positive ions are free to accelerate downstream along the applied electric field. Still, the electric field is directed along the axis of the thruster and ions are electrostatically accelerated, so it is indeed an ion thruster.

cf. the absolute classical bible in this field: "Physics of Electric Propulsion" by Robert G. Jahn (McGraw-Hill Book Cie 1968, reprint Dover 2006). A summarization of what I said has been done by the author in this paper freely available.

Therefore many parts of the article, related to purely electrothermal and electromagnetic thrusters, has to be removed and detailed in the specific subsections of the pages Electrically powered spacecraft propulsion and Plasma propulsion engine. — Tokamac (talk) 17:32, 4 April 2018 (UTC)

X3 Ion Thruster Paper Link

Stumbled on this link which relates to a paper presented to 2013 33rd electrical propolusion conference. It details info about the nested X2 and X3 Ion thruster. Unsure if this info is covered in other links although I couldn't see or find any and noted (news articles only) the hall effect thruster in the main artical was missing a citation which this paper may be appropriate to cover. I'll leave the link here for a more expereienced editor to review and incorporeate or discard:

https://apps.dtic.mil/dtic/tr/fulltext/u2/a595910.pdf Sirrob01 (talk) 22:59, 2 January 2019 (UTC)

Update to experimental thrusters section.

Spacex recently launched the first 60 of their starlink satellites, they use a krypton ion thruster. https://spaceflightnow.com/2019/05/24/spacexs-first-60-starlink-broadband-satellites-deployed-in-orbit/

Therefore i suggest that the section with experimental thrusters should be updated and corrected.

The Starlink V1 and V1.5 sats use krypton, and now the V2-mini Starlinks use argon thrusters. Need a ref to confirm Hall-effect. - Rod57 (talk) 08:20, 7 October 2023 (UTC)

Arsenic Speed

What is that? I have looked for it on the internet but there is no info. It would be helpful if there was a link to what it means???? — Preceding unsigned comment added by 173.172.158.168 (talk) 19:19, 28 March 2020 (UTC)

Gridded electrostatic ion thrusters explanation

This explanation is too oriented to xenon ion Thrusters. Today we have already different types of propellents and it's nice to have a general explanation. Also gridded electrostatic ion thruster research is not at all actualized.

? NSTAR and NEXT are gridded ? - Rod57 (talk) 22:04, 20 November 2021 (UTC)

In Goddard's wikipedia bio it looks like he was the first to suggest this:

n September 1906 he wrote in his notebook about using the repulsion of electrically charged particles (ions) to produce thrust.[22]:13 From 1916 to 1917, Goddard built and tested the first known experimental ion thrusters, which he thought might be used for propulsion in the near-vacuum conditions of outer space. The small glass engines he built were tested at atmospheric pressure, where they generated a stream of ionized air.[34]

Seems like this should be mentioned in the article.

Propose combine the comparisons table(s) and add status/TRL column

Propose combine the comparison table and add status column, since hard to maintain and some thrusters seem to be in the wrong table - eg X3 hasn't flown yet so should be in the experimental table ? Could add a status/TRL column (theory, built-in-development, vacuum chamber tested, selected to fly, flown) ? - Rod57 (talk) 22:03, 20 November 2021 (UTC)

Also, propose adding a type column to the table

Type column : To confirm which are Hall-effect and which are various types of gridded ion thruster. - Rod57 (talk) 08:13, 7 October 2023 (UTC)

2020 review and summary - useful ref

Ion thrusters for electric propulsion: Scientific issues developing a niche technology into a game changer Kristof et al. has lots of detail, eg table 1, also seems to consider Hall[-effect] thrusters as distinct and not a subtype of ion thruster. - Rod57 (talk) 18:29, 4 December 2021 (UTC)

Please add SI metric

Nobody outside of the United States uses Specific Impulse to specify the performance of propulsion systems. Please either replace the ISp column with one for effective exhaust velocity or add a column for effective exhaust velocity. Since the key point of any propulsion system is to effect a velocity change, and the Rocket Equation specifies that this is the effective exhaust velocity times the natural logarithm of the mass ratio, what really is the point of ISp? It has the odd units of seconds because it uses two different meanings of the English word "pound", one of this is a force and the other is a mass. That is it conceals the fact that an arbitrary acceleration of 32.1740 ft/s^2 is hidden inside the calculation! Why that magic number? It would make as much sense to include the verb "pound" meaning "to strike a horizontal surface forcefully" in the definition. Jamescobban (talk) 00:30, 28 June 2024 (UTC)