Talk:Variable Specific Impulse Magnetoplasma Rocket

message: Phobos is a moon of Mars.  Phobos has a tiny gravity field so only a small thrust is needed for launches and landings.  A suggestion has been made that electric propulsion Earth-Mars transfer vehicles carrying cargo land at a base on Phobos.  The cargo can be building material for the base, return propellant for Earth-Mars manned spacecraft, supplies for the underground base and supplies for astronauts on Mars.  Mars supplies would be sent to the planet by moving them to a chemical propulsion Mars lander.  An example 1MW, 60% efficient VASIMR 100 tonne OTV vehicle may be able to get to Phobos if it has extra large solar panels.
Due to its odd shape Phobos's equatorial surface gravity varies between 0.0084–0.0019 m/s² and has an escape velocity of 11.3 m/s (40 km/h, 25.3 mph).
The gravity is applying a force on the OTV of up to F = m a = 100,000 * 0.0084 = 840 Newtons (N)
Using an Isp of 1000 thrust T = 2 * P * e / (Isp * g) = 2 * 1,000,000 * 0.60 / (1000 * 9.81) = 122 N
To hover on Phobos the OTV needs an Isp = 2 * P * e / (T * g) = 2 * 1,000,000 * 0.60 / (840 * 9.81) = 145.6 
If launch requires more thrust than the VASIMR in the Orbital Transfer Vehicle (OTV) can generate a RCS able to supply the thrust for 3 - 4 km can be specified.  Equipping the base's hanger with a robot arm should permit ground parking of the vehicle.
Andrew Swallow (talk) 10:48, 28 October 2009 (UTC)
thread_title:  Phobos Base launch and landings 

message: The proposed lifters for the Space Elevator will be carrying photovoltaic panels that supply about 3 MW  to 4 MW of electrical power and similar sized cooling panels.  Switching this solar power from the wheel motors to a VASIMR would not be difficult.
Space Elevators are good at raising payloads from planetary surfaces to Geostationary Orbit (GEO) and above.  They can also be used for landings providing the spaceship docks at GEO point.  From higher up the ribbon cargoes can be thrown towards the Moon or Mars but it is a slow trip and there is little control over where the cargoes lands.  A VASIMR thruster able to produce at least 100 Newtons of force is able to supply the velocity and accuracy needed.
VASIMR plus Space Elevator would provide a low cost solar electric space transportation system that starts on the Earth's surface.  An annual check to see if the Space Elevator is being built may be worth while.
Andrew Swallow 04:27, 15 June 2007 (UTC)
thread_title:  Sharing Power and Cooling with the Space Elevator 

message: Hall effect thrusters are increasing their efficiencies by using the metal bismuth as a propellant.  Will the same trick work with a VASIMR?
Andrew Swallow (talk) 02:13, 10 December 2007 (UTC)
thread_title:  Bismuth as propellant 

message: A Unique Selling Proposition (usp) is basically what your product can do but your competitor's product cannot do.  
: "An OTV (space tug) powered by a single VF-200 engine would be capable of transporting about 7 metric tons of cargo from Low Earth Orbit (LEO) to Low Lunar Orbit (LLO) with about a six month long transit time. {snip}"
The Delta IV heavy can launch 6,275 kg to geosynchronous orbit (GEO), so the payload figures are too close to make a unique selling point.  However a small tug that can lift 8 or 12 tonnes to GEO or LLO does have a use.  The small OTV will not have a rival until the project Constellation's Earth Departure Stage (EDS) is built.  Even then the small OTV  and say Falcon 9 is likely to be cheaper than the EDS + Ares V.  The 9 months or 1 year trip time will be a disadvantage but if that is the only way of launching a 10 tonne GEO satellite then the customer will have to do it that way.
Larger satellites and lunar landers can use a EELV or J-120 and the big OTV.
Andrew Swallow (talk) 01:33, 18 March 2009 (UTC)
thread_title:  Unique Selling Proposition of VASIMR OTV 

message: I have cleaned up the article and removed the __cleanup__ tag. Please respond it you think that this was in error. Kind regards SimonHarvey (talk) 04:51, 18 January 2008 (UTC)
thread_title:  Article cleanup 

message: The recent press release - http://www.adastrarocket.com/Release%20040308final.pdf glowing over 2007 AdAstra achievements also seems to highlight in_between_the_lines two (possibly related?) issues that appear to be stumbling blocks:
- delays with superconducting magnets: "in order to give Scientific Magnetics of Culham, UK. the needed time to complete its certification of the superconducting subsystem."
- problems with heat generated as a by-product of plasma creation and speed-up: "addressing the challenging thermal management aspects of the VASIMR™ engine"   &   "generated new patents in the efficient production of high speed plasma jets and associated thermal management
technologies. These are necessary in order to achieve the overall performance of which these engines are capable."
=> I guess 70% efficiency also means that 1/3 of that (relatively) enormous power ends up to be waste heat!
70kW+ of heat generation sounds like a serious problem! (for VX-200)
Anybody has knowledge in the area of heat management?
How can they cope with this?
Is it going to add a lot of weight to the engine?
=> has anybody seen these patents they talk about? Perhaps some interesting info there...
83.7.204.254 (talk) 17:09, 9 March 2008 (UTC)
replies: text: Looking through Nautel website http://www.nautel.com/Resources is appears that their analog AM transmitters (solid state) have 84% efficiency. Since the RF transmitter for VASIMR has much simpler job (after all it can do away with all music modulation...) than perhaps their claimed 90% efficiency for ion generation is credible. 83.7.204.254 (talk) 17:09, 9 March 2008 (UTC)
thread_title:  The Devil is in the Heat !?  -  2008 development issues 

message: It would be helpful if a sentence or so could be added to show how this technology is different from ion thrusters. As far as I can tell, the difference is that this adds more energy to the atoms, but it'd be good to make it explicit. A comparison of specific impulse outputs would also be helpful.  ·:· Will Beback  ·:· 21:59, 8 August 2008 (UTC)
thread_title:  Comparison to ion thruster 

message: This article could also be helpful for getting information: http://dsc.discovery.com/news/2008/08/07/plasma-rocket.html --62.214.214.39 (talk) 10:46, 9 August 2008 (UTC)
replies: text: Very nice article, thanks for the heads up. I'll put it on my to-do list. — Huntster (t • @ • c) 15:49, 9 August 2008 (UTC)
thread_title:  new article 

message: I wonder if anybody has some inside why Ad Astra chose 200kW as design baseline.
I have found references to specific power being 1,5 kg/kWh -e.g. VF-200 having mass of 300kg
Given the trust of 5 - 8 N - that gives ratio of max. 0.0026 x  . 
But if, for instance, VF-1200 improves specific power to 0,625 kg/kWh or by factor of 2,5, 
than trust to weight ratio (while still no competition for chemical rockets) would improve to 0.0065 x 
And what is the theoretical limit on specific power? is the limiting factor the ICRF magnet or helicon?
A new section in the article about future developments of the engine and possibilities of improvement should include discussion about this.
Awatral (talk) 12:10, 26 March 2009 (UTC)
replies: text: I imagine this is a situation of "start small and build from there". When developments occur, I'm sure such a section will be added. — Huntster (t • @ • c) 03:38, 27 March 2009 (UTC)
replies: text: The 200kW design baseline was chosen as that's the power necessary to move the ISS. I read it on Slashdot. --198.49.180.40 (talk) 00:42, 6 October 2009 (UTC)
thread_title:  future optimum trust level & specific power -> trust to weight ratio 

message: There is a substantial new article about VASIMR, Chang Diaz, Ad Astra, etc. in the June 2009 issue of IEEE Spectrum, a general interest technical magazine for Electrical Engineers.  Here is the link: http://www.spectrum.ieee.org/aerospace/space-flight/rockets-for-the-red-planet/0 N2e (talk) 19:25, 4 June 2009 (UTC)
thread_title:  Another new article -- in IEEE Spectrum 

message: I'm not a plasma physicist, but in reading this article and other articles about ion propulsion, I have the following question about VASIMR: What happens to the electrons? In other ion thrusters, it seems that electrons are injected into the thrust separately, to prevent the build-up of charge on the vehicle. This doesn't seem to be the case with VASIMR. 
It seems to me that the electrons would be free in the cold plasma, and would still be in the hot plasma, they just wouldn't be heated by ICH. What doesn't make sense to me is how or if they will be accelerated by the magnetic nozzle. If they are precessing in the opposite direction from the positive ions, would they not be accelerated in the opposite direction (i.e. into the vehicle)? --Dbuijs (talk) 15:35, 23 December 2009 (UTC)
thread_title: Charge balance

message: This interview was just released and mentions, among other things, the Ad Astra goal of testing the VASIMR technology, in space, by early 2011, on the International Space Station, and the theoretical potential of a 39-day trip to Mars using this technology, per Franklin Chang-Diaz, who is clearly an authorized spokesman for Ad Astra.  This is the early half of the "2011-2012" statement now in the article.  The link is from a space news blog, but I suspect the vid could also be located at Ad Astra, if a more acceptable source is desired. N2e (talk) 19:45, 27 February 2010 (UTC)
replies: text: Jeez, is that what's responsible for the hundred-fold increase in traffic? Was it on national tv, or something? 91.84.208.36 (talk) 15:50, 2 March 2010 (UTC)
replies: text:  NASA performing an official study on using Ad Astra's VASIMR as the engine on a lunar tug [url]http://www.parabolicarc.com/2010/01/25/nasa-studying-ad-astras-vasimr-engine-lunar-tug[/url] may have also triggered some of the extra traffic. Andrew Swallow (talk) 01:12, 4 March 2010 (UTC)
replies: text: That's a very nice uptick in visitors. The term "VASIMR" has found it's way into 371 new stories in the past week, according to Google News, with a sizeable number of those being non-English. — Huntster (t @ c) 05:10, 4 March 2010 (UTC)

text: May 4, 2010 article from Discovery Channel  at MSNBC. Thrust per mass compared to ion engines would be useful in this article. Edison (talk) 22:16, 4 May 2010 (UTC)

text: The MSNBC article mentioned a possible 2017 trip to an asteroid.  That is interesting.  The power drops off the further the asteroid is from the sun.  I wonder how close the design is to being a general purpose tug?  Andrew Swallow (talk) 04:47, 5 May 2010 (UTC)

text: (outdent) The June 2010 Aviation Week article I mention below says 2014 for testing on the ISS. N2e (talk) 11:43, 17 June 2010 (UTC)
thread_title:  2011 target date for testing in space on the ISS 

message: Think I fixed the dreaded "present tense-ness" of the article. I wish people wouldn't write that way! :) But someone might check my work. Nice article.
Mydogtrouble (talk) 20:55, 27 February 2010 (UTC)
replies: text: Good work! I'm hoping to improve this article significantly. This deserves to be a WP:Good article, but it's a long way off yet. Anxietycello (talk) 17:11, 1 March 2010 (UTC)
thread_title:  Tense of the article 

message: :"It can also be seen as an electrodeless version of an arcjet, able to reach higher propellant temperature by limiting the heat flux from the plasma to the structure. Neither type of engine has any electrodes. The main advantage of such designs is elimination of problems with electrode erosion."
The above text appears to contradict itself. Perhaps its meaning could be clarified by better wording? Anxietycello (talk) 17:08, 1 March 2010 (UTC)
thread_title:  Apparent contradiction 

message: A new article, full of technical detail on improvements in the latest testing phase over the past six months, was published in Aviation Week on June 16th.  I've added a link to the Additional resources part of the VASIMIR WP article, but have not had time to cull substantial new info from the source to improve the article.  Have at it. N2e (talk) 11:41, 17 June 2010 (UTC)
thread_title:  June 2010 Aviation Week article 

message: The citation from Help:Interlanguage links#Bots and links to and from a section:
“The activity of the bots also requires that interlanguage links are only put from an article to an article covering the same subject, not more and not less. It is technically possible to make an interlanguage link from an article to a section of an article, just like any link to a section. The bots can handle this. They will not try to link back from a section to the article that links to it. Maintaining such a link by hand, however, is complicated, so linking to a section is still not recommended.” 
The german article has interwiki to plasma propulsion engine. Русские идут! (talk) 16:52, 8 November 2010 (UTC)
replies: text: Yes, but the German article has a section on VASIMR, which is what the interwiki links to. Your quote above specifically allows for it. It just means that the German article won't automatically be linked back to this one. — Huntster (t @ c) 21:29, 8 November 2010 (UTC)
replies: text:  Doesn't it should be avoided? Русские идут! (talk) 22:31, 8 November 2010 (UTC)
replies: text: No, it says that bots can detect and handle interwikis with section links; they simply will not link back to the local article from the other language article (since that article as a whole isn't about our local topic). — Huntster (t @ c) 03:14, 9 November 2010 (UTC)
replies: text: could this be achieved by using a new redirect page on the de.wiki, linking to the sub-section? Just an idea. regards, Lynbarn (talk) 12:25, 9 November 2010 (UTC)
thread_title:  Interwiki 

message: Does anyone have a citation for the claim: "Another issue was waste heat management (60% efficiency means about 80 kW of unnecessary heat) critical to allowing for continuous operation of VASIMR engine."?  Has anyone done research on what would be required to dissapate into space 80 kW of heat?  How big would such a system be?  How much would it weigh?  What fraction of the ISS total waste heat dissipation budget is this?  Cheers.  N2e (talk) 20:18, 9 December 2010 (UTC)
replies: text: That one is conservation of energy and basic maths.  200kW * (100% - 60%) / 100% = 80 kWThe size of space radiators depends on the fourth power of the temperature. Andrew Swallow (talk) 05:49, 10 December 2010 (UTC)

text: Yup - it seems that too little R&D attention is paid to space radiators. I believe that ISS is using radiators build by LOCKHEED MARTIN utilizing liquid ammonia. This is hardly state of the art hence it requires huge surface area to radiate. The capacity of the system has to account for ALL of electrical energy generated by ISS solar panels plus give or take 6x 100W (human body heat) - one way or the other that electricity ends us as waste heat. So actually with VASIMR operating the demand for heat rejection WILL BE LOWER so it improves ISS cooling budget by 120kW during the 15 minutes bursts that VASIMR will operate. Awatral (talk) 13:23, 4 January 2011 (UTC)
replies: text:  I am curious - can anybody point me to some worth while research regarding high temperature radiators? Awatral (talk) 13:23, 4 January 2011 (UTC)
thread_title:  Waste heat management 

message: As I read the article today (25 Jan 2011), I cannot find the article making an explicit claim of the maximum specific impulse, either for any particular AdAstra prototype, nor for the theoretical limits thought to be associated with VASIMR technology.  Am I just missing it?  Or is this an oversight?
I searched for all the instances of "specific impulse" as well as "ISP".  I find a couple of mentions of optimum (throttled-back?  on the low end of the "variable range"?  in the middle of the "variable range"?—it is not clear) Isp of 3000 to 5000 s.  I can also find mention of some numbers here on the Talk page.  But I think the article itself ought to have some explicit (and well sourced) claims about something so important.  And a cited claim for the useful operating range of ISP and the minimum ISP of the "variable" design would also be quite useful to our readers.  N2e (talk) 17:28, 25 January 2011 (UTC)
replies: text: The slides presented by Ad Astra in mid-January at the FISO colloquiam (see citation below, in next section, pp 10) show that the design point for good efficiency on the VX-200 is 50 km/s exhaust velocity, or an Isp of 5000 s.  This is for a thruster efficiency of 70% (which Ad Astra is explicit now that this is achievable) yielding an overall system efficiency (DC electricity to thruster power) of 60% (since the DC to RF power conversion efficiency exceeds 95%). N2e (talk) 04:32, 31 January 2011 (UTC)
replies: text: I have updated the article, per the source mentioned above.  It does not appear that Ad Astra's design orientation is to achieve the "maximum" Isp, as there would likely be tradeoffs in engine life, propellant usage, etc.  They seem to be going for "optimum."  With these updates, at least for me, the fuzzy Isp problem in the article has been eliminated.  Others feel free improve further as you wish.  N2e (talk) 04:21, 2 February 2011 (UTC)
thread_title:  Fuzzy specific impulse specification(s) 

message: Ad Astra Director of Development Tim Glover presented to the (industry/academic/NASA) Future in Space Operations (FISO) Colloquium on 19 Jan 2011.  I found the presentation extremely informative on the development and testing of the current VX-200, with a number of good images and charts, and specifics on use of such a device on a future Mars mission.  The slides are available online at the URL given here:  
VASIMR VX-200 Performance and Near-term SEP Capability for Unmanned Mars Flight, Tim Glover, Future in Space Operations (FISO) Colloquium, 2011-01-19, accessed 2011-01-31. Cheers.  N2e (talk) 04:17, 31 January 2011 (UTC)
thread_title:  AdAstra presentation at 19 Jan 2011 FISO colloquiam 

message: I am puzzled by the text, "VASIMR is not suitable to launch payloads from the surface of the Earth due to its low thrust to weight ratio and its need of a vacuum to operate." I have not seen arguments as to why vacuum is required. If-only I had sufficient electrical power, could I not strap one of these onto a vehicle? Could I not propel a scramjet this way? -- 99.233.186.4 (talk) 23:17, 3 February 2011 (UTC)
thread_title:  Vacuum 

message: Is there a specific reason why name VASIMR gets spelled as VASIMIR? (apart from the Russian pronunciation likeness)
1 time in the article (in the criticism section), 5 times in this discussion, and also here: Exoplanet Atlas (although they've managed to mess the Celsius scale too)  — Preceding unsigned comment added by 118.160.199.71 (talk) 05:51, 9 December 2011 (UTC)
replies: text: I've not heard a particular reason, but almost certainly because the "MR" part is typically pronounced as "MEER" or "MUR". Nothing to worry about...just fix it in the article if/when you find an instance. — Huntster (t @ c) 09:35, 9 December 2011 (UTC)
thread_title:  Name controversy 

message: Does anybody have some source of news regarding Ad Astra? - They have been awfully quiet for over half a year now. 
Do they continue to work on VF-200 or are there financial problems hindering VASIMR development?  — Preceding unsigned comment added by 62.121.115.9 (talk) 10:29, 15 February 2012 (UTC)
thread_title:  2012 news 

message: The are three sentences in the section
1) "... VASMIR is less efficient than other electric based thrusters which are now operational." - is not correct.  System efficiency of VASIMR (as measured in VX-200) is more than 60% (http://www.adastrarocket.com/Ben_IEPC11-156.pdf) which is more or about the same as other electric thrusters.
2) "Zubrin also believes that electric propulsion is not necessary to get to Mars and therefore budgets should not be assigned to develop it." and 3) "His second point of criticism concentrates on lack of suitable power source." - are related to Electric Propulsion in general and can be transfered to the corresponding page.
:Note:  the above comment has no date, and is not signed.  Don't see any replies to it as of Dec 2013.
:For interest, here is an essay published in SpaceNews that is critical of VASIMR: SpaceNews, July 2011. I am currently agnostic on the claims, but think they ought to be able to be seen and read by other editors as well.  N2e (talk) 17:28, 30 December 2013 (UTC)
replies: text: While both sides should be presented, it really does seem to be a case of Zubrin screaming out in every venue he can get into, which seems to be rather UNDUE. I mean, the criticism section was renamed to specifically name Zubrin because he's the only real voice out there! I'm not sure what should be done, but I'm not comfortable with the status quo. — Huntster (t @ c) 00:50, 31 December 2013 (UTC)
thread_title:  Criticisms of VASIMR section should be removed 

message: The second paragraph of the Design and Operation section ends with the sentence,
"The second phase is a strong electromagnet positioned to compress the ionized plasma in a similar fashion to a convergent-divergent nozzle that compresses gas in traditional rocket engines."
I believe this expresses an incorrect idea about convergent-divergent, or De Laval nozzles in conventional rocket engines.  As I understand it, gasses in a De Laval nozzle are everywhere expanding, not compressing.  It might be more accurate, in this context, to replace the word "compresses" with the word "accelerates".  The problem with this is that I do not know the physics of VASIMR.  Correcting the misstatement about De Laval nozzles might have the effect of creating a misconception about VASIMR.  I need someone with knowledge of both sets of physics to suggest a better way of expressing what this sentence is trying to say. 7802mark (talk) 16:20, 25 August 2015 (UTC)
thread_title: Nozzle Misstatement?

message: People saying you can 3d print solar cells don't know what they're talking about, and the references basically talk about 3d printing the trusses. (itself of dubious usefulness)88.159.64.160 (talk) 00:02, 12 July 2017 (UTC)
thread_title:  3d printing solar cells. Nope.  

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thread_title:  External links modified (January 2018) 

message: As far as I can tell, "variable specific impulse magnetoplasma rocket" should be lower case, per Wikipedia:Manual of Style/Capital letters. It is not a proper noun, not a trademark. It should not, heaven forfend, be capitalized to indicate the origin of the acronym VASIMR. It is self-evidently a generic technical description, like "magnetic resonance imaging". 
It does not matter how it was (or was not) capitalized in the original source.  It does not matter how it is capitalized in the majority of Google hits or company press releases or primary academic papers.  What matters is how it is capitalized in the majority of independent, reliable sources (Wikipedia:Reliable sources). The reference list suffers from a dearth of those; the only one I saw in a quick scan that obviously qualifies is the IEEE Spectrum piece (http://spectrum.ieee.org/aerospace/space-flight/rockets-for-the-red-planet/0).  And that does indeed style it lower-case.
@Eejit43, can you assess on that basis?  If you do indeed find a preponderance of independent, reliable secondary sources that capitalize it, that would be grounds for keeping the caps. Gould363 (talk) 04:30, 13 February 2023 (UTC)
replies: text: @Gould363 I think a full RM should be opened, there seems to be a fair amount of usage in both capitalization variations, with sources such as NASA as well as Ad Astra, who appear to be the original developer, use the capitalized version, "Variable Specific Impulse Magnetoplasma Rocket". I'd say that version should be kept, however I am not that knowledgeable about this specific topic. ~ Eejit43 (talk) 04:41, 13 February 2023 (UTC)
replies: text: I'm sorry, I'm afraid I don't know how to do that.  Thank you anyway. Gould363 (talk) 04:25, 14 February 2023 (UTC)
replies: text: @Gould363 If you'd like to, see WP:PCM. Thanks :) ~ Eejit43 (talk) 12:28, 14 February 2023 (UTC)
thread_title:  Caps