Talk:Space-based solar power/Archive 3

Article Cleanup
Hi everyone, having the history/timeline section up front (in my opinion) is really distracting from the readability of this article. I am moving it to the back of the article. This could be a really great article if it was cleaned up and made more readible. TANSTAAFL (talk) 17:44, 31 May 2011 (UTC)

space solar power in fiction
wath do you think about moving this part in another page ? half of it talks about catastrophes or weapons, it makes sps looks bad--Beaucouplusneutre (talk) 21:29, 17 June 2011 (UTC)
 * I don't think there's enough for a page alone. I also don't think moving as a way to sanitize is a good idea. I do think this section is mostly trivia; except, perhaps, "Die Another Day", none of these have had a huge cultural impact & IMO should be removed.  TREKphiler   any time you're ready, Uhura  21:54, 17 June 2011 (UTC)

mankins view in 2011
mankins report march 2011 at iaa 273 pages http://iaaweb.org/iaa/Scientific%20Activity/Study%20Groups/SG%20Commission%203/sg311/sg311finalreport.pdf — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 12:38, 20 June 2011 (UTC)

let's make this page more graphical with video links
--Beaucouplusneutre (talk) 15:19, 22 June 2011 (UTC)

images
created wikimedia commons can we add the mass driver picture on the o neill section ?, and robonaut for the teleoperated part (project m)? integrate some pictures like shimizu dream page could help too (see lunar ring) wath do you think ? mit have some image with deployment / maintenance bots too also ikaros pictures ? — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 10:29, 23 June 2011 (UTC)

sbsp template
key people, organisation, key technology, and the like could be a good thing,--Beaucouplusneutre (talk) 16:17, 24 June 2011 (UTC) a new category that we use to tag other related pages too — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 16:19, 24 June 2011 (UTC)

baseload/peak - sbsp and fusion
hi everyones, a paragraph on baseload/peak power potential, plus why it can be considered a green/renewable enery,comparaison with other sources of power, plus sbsp vs fusion ( its seems iter will produce nuclear waste ) and why sbsp is interesting because it does not need physics breaktrougth ?--Beaucouplusneutre (talk) 09:16, 26 June 2011 (UTC)

Article on space transport for power satellites
If anyone wants to mine this,http://www.theoildrum.com/node/7898 be my guest. The Oil Drum is one of the few blogs that has responsible editing and can be quoted on wikipedia.

Keith Henson (talk) 04:14, 30 June 2011 (UTC)

move criswell to the building from asteroid /moon ?
new detailled building from space section building from asteroid, building on or with the help of the moon — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 10:34, 30 June 2011 (UTC)

orbital location
leo/meo/geo/lagrangian point (landis proposal and maybee others) to give another perspective — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 10:45, 30 June 2011 (UTC) --Beaucouplusneutre (talk) 10:48, 30 June 2011 (UTC)

comparaison table
how about a comparaison table ?, we can add other tables for every subject that need comparaison, it will help make it clear wath challenges this concept is facing,on a separate page as a sub project

--Beaucouplusneutre (talk) 11:39, 1 July 2011 (UTC)

Predicting the future
I've reverted some recent changes to the intro that seem to introduce a degree of finality to the SBSP concept that isn't really warranted yet.

We can say that the plan to make certain things possible, and achieve certain benefits, do sound very feasible, but in the end this really hasn't been extensively tested, so we can't say for sure how it "will" end up working. SBSP is still just a theory, no matter how likely it might seem, and will stay that way by definition until it's been thoroughly proven in practice. Equazcion ( talk ) 17:40, 6 Jul 2011 (UTC)
 * yes, i just wanted to find the right word to describe his benefits.--Beaucouplusneutre (talk) 19:05, 6 July 2011 (UTC)
 * No problem. I'm just being vigilante in curbing the temptation to say how great this WILL be, when we don't really know yet. Equazcion  ( talk ) 23:40, 6 Jul 2011 (UTC)
 * I agree with your objectives, but "could" in this context leaves the impression these things aren't demonstrably true. The issue is, no SPS has been built, not that, frex, collection is highter or SPS is unaffected by weather. I'd rather say something like, "If built, it would..."  TREKphiler   any time you're ready, Uhura  01:47, 7 July 2011 (UTC)
 * We can't say "if it's built we would have these benefits", because we really don't know that for sure. If it's built, or as we approach building it, we could find out that we were wrong about one or several of these projected benefits actually resulting from SBSP. The fact that all these benefits WOULD result from SBSP is not demonstrable, so the sentence introducing the benefits of SBSP should be worded as "could", IMO.
 * Individual demonstrable aspects ARE already worded appropriately so in their list items, eg. collection in space "is" higher, and weather "would" not be an issue.
 * We're hoping all these demonstrable properties will result from SBSP, but we don't know that they all will yet. I hope this is clearer. Equazcion  ( talk ) 03:08, 7 Jul 2011 (UTC)
 * You're introducing doubt where there isn't any. Saying "it could have these benefits" effectively says the fact of, frex, greater insolation isn't a fact. All the enumerated items are demonstrably true, in fact have been demonstrated true in other contexts. The only place they aren't proven is together, in an SPS. I get your aim, & IMO saying the combined benefits aren't proven is covered by "if built". Or do you mean to say the individual factors are, in fact, still in doubt?  TREKphiler   any time you're ready, Uhura  04:07, 7 July 2011 (UTC)
 * The fact that the benefits haven't been demonstrated in an actual SBSP scenario is cause to avoid any definitive language. When speaking of a technology that doesn't exist yet, a respectable publication takes pains in keeping the language relatively humble. Just because it seems like all these benefits would come from SBSP doesn't mean they will, no matter how much it seems that they will. As a far-out example I could say perhaps NASA will discover down the line that certain live vegetation could play some role on an SPS, and controlling its growth would become a factor -- so plant encroachment actually wouldn't be entirely avoided by SBSP, making that listed benefit wrong in the end. Again it's a far-out example but either way we shouldn't be making definitive predictions about how it will work if built, or what benefits it will have if built. As much as it seems we do know, we don't know enough to write that "if it's built, it will have these benefits". That's arrogant language for a respectable information source describing a technology that doesn't exist yet. Equazcion  ( talk ) 12:28, 7 Jul 2011 (UTC)
 * Over the many designs and project, the only problem seems the cost, maybee there is a sense making the comparaison to fusion and other forms of energy, that existed on the sps old page ans seems to have vanished. — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 13:46, 7 July 2011 (UTC)
 * "The fact that the benefits haven't been demonstrated" I'd agree with most of that. My trouble is, as said, is that the chosen wording suggests the individual factors are untrue or in doubt, & they're not. What is, & remains, in doubt is the combination. That an SPS might someday have gardens doesn't make the greater insolation in orbit untrue now. What about "Expected (projected?) benefits are"?  TREKphiler   any time you're ready, Uhura  23:16, 7 July 2011 (UTC)
 * "Projected" seems like an improvement. Feel free to tweak my implementation. Equazcion  ( talk ) 13:30, 8 Jul 2011 (UTC)
 * I think that's got it. Thx. Good doing business with you. :D  TREKphiler   any time you're ready, Uhura  00:05, 9 July 2011 (UTC)

from a diverted asteroid (catching)
integrate asteroid deflecting section ? see Asteroid_deflection_strategies detection and composition of asteroids techniques (telescope, or others ?)--Beaucouplusneutre (talk) 09:21, 11 July 2011 (UTC)
 * ...only if there's a source connecting that to space-based solar power. Equazcion  ( talk ) 10:36, 11 Jul 2011 (UTC)
 * of course--Beaucouplusneutre (talk) 12:12, 11 July 2011 (UTC)
 * check this out (and its old) http://nss.org/settlement/nasa/spaceres/IV-2.html

1 asteroid mining (we have that one) 2 asteroid catching with a mass driver i think this call for a new wiki page with updated info : asteroid catching or asteroid capturing distinct from the mining because of the order of things, asteroid catching then mining as complement of mining then retrieval.--Beaucouplusneutre (talk) 08:46, 15 July 2011 (UTC)

This is wrong...
"Cumulative panel damage could be lessened in space, such as that suffered due to weather, corrosion, and erosion"

In fact, erosion in space is so dramatic that panels are rated for only 12 years, and have to be replaced all the time - as is the case on Hubble for instance. On the Earth, panels produced in the 1970s are still in commercial operation and there is some debate about the actual lifetime of panels, which may be a century. Unless someone has a ref for this claim, I'm going to remove it as being clearly counterfactual. Maury Markowitz (talk) 15:34, 11 July 2011 (UTC)
 * Cite a reference or mark a need for a reference ... ?  99.181.136.35 (talk) 04:38, 12 July 2011 (UTC)
 * 2% degradation a year compared to 0.27% for earth-bound panels. Trivially citable, widely known in the industry. Maury Markowitz (talk) 11:45, 15 July 2011 (UTC)

reference about o neill
hello, i have googled this one with no success, does someone knows where to read this article in full ? i have tried nasa and aiaa ^ O'Neill, Gerard K.; Driggers, G.; and O'Leary, B.: New Routes to Manufacturing in Space. Astronautics and Aeronautics, vol. 18, October 1980, pp. 46-51. — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 11:16, 12 July 2011 (UTC)

some costs estimates
80' design : 10by 5 by .5 km, 5 gw on the ground (10 in space because 50% loss of the mw beam), evaluated at 250 billions in 96

solar disk : 6 km diameter, 5 gw on the ground, mw beam, evaluated at 50 billions $.

solar tower : 15 km long, 250 mw on the ground,mw beam, evaluated at 15 billions $  (same price as iter) numbers from mankins sert conclusions

canceled demos

iss laser demo mission (on kibo - jem), status ? , no costs , http://registration.istdayton.com/Briefings/In-Space%20Laser%20Power%20Beaming%20Concept(HBCU%20forum).pdf

selene eval costs ? (canceled), no costs

mars laser sps demo(european project ?) canceled, no costs, have forget the ref

latest demo estimate (one from the sd hlv presentation, detail the mission and the payload, but not the costs estimates) http://www.nasaspaceflight.com/2010/07/sd-hlv-early-sps-demonstration-risk-assessment/

another one that give estimates and some detail on the payload at 1,3 billions http://nextbigfuture.com/2011/02/future-in-space-operations-assessing.html — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 07:14, 16 July 2011 (UTC)

nice diagram on mw and laser from nasa
toward the end of the document: http://www.hq.nasa.gov/webaccess/CommSpaceTrans/SpaceCommTransSec38/CommSpacTransSec38.html Figure 3.8.2.2-27. Comparison of Laser and Microwave Power Transmission for Space Station Power

also maybee referencing the lasermotive distance record in history or eleswhere http://www.nasa.gov/centers/dryden/status_reports/power_beam.html http://lasermotive.com/files/20091112_LaserMotive_PressRelease.pdf — Preceding unsigned comment added by Beaucouplusneutre (talk • contribs) 19:42, 16 July 2011 (UTC)

Resource from The Futurist May-June 2011 issue.
Resource from World Future Society's The Futurist May-June 2011 Vol. 45, No. 3 141.218.36.44 (talk) 21:30, 4 August 2011 (UTC)
 * Solar Power from the Moon by Patrick Tucker pp34-38
 * Why we need the moon for solar power on Earth by David R. Criswell page 37 box
 * Finding Eden on the Moon'' by Joseph E. Pelton pp39 - 42.
 * Do you have internet links? 99.181.151.50 (talk) 03:14, 5 August 2011 (UTC)
 * This David Criswell? If so, he is in this article. 99.181.144.107 (talk) 02:16, 7 August 2011 (UTC)

Proposal: split article
For the length of this article, there seems to be relatively little information/explanation to be easily picked up by the uninitiated. It's also by it's nature a large topic that rightfully deserves several pieces to be treated properly. I suggest that it might be best to split some of the larger chunks out (and expand upon them) into articles like Satellite solar power and Lunar solar power or similar, but those entries are already available as redirects to this article. The introductions of which could be transcluded into this overview article. --Belg4mit (talk) 22:19, 7 August 2011 (UTC)

missing elements
hi, power relay satelites, sun sails reflectors, power beming demo sats for moon and mars exploration bases and rovers (as a way to reduce mass sent to these bodies and for exploration purposes), iss demo efforts, laser propulsion for space tugs and space launches (thanks to keith henson suggestion) and many other aspects are described here http://www.nss.org/settlement/ssp/library/1989-SecondBeamedSpacePowerWorkshop.pdf i will try to incorporate this aspects into the article (with pictures too but they are bad quality and not in color, but maybee better than nothing) .Also i think we need a image of a rectenna on earth in color.Schemas of powersats designs could also bee nice (fresh look study have some).--Beaucouplusneutre (talk) 09:46, 2 September 2011 (UTC)

sert launch price in 2000
Earth-to-Orbit (ETO) Transportation. SERT results suggest that recurring launch costs in the range of $100-$200 per kilogram of payload to low-Earth orbit are needed if SPS are to be economically viable.It was the position in 2000, does someone knows if there is a updated number somewhere ? numbers form http://www.nss.org/settlement/ssp/library/2000-testimony-JohnMankins.htm --Beaucouplusneutre (talk) 17:27, 2 September 2011 (UTC)

costs estimates
Should it goes to a section or to each subsections ? nsso studies (10 gw, in 10 years for 10 billions)

updated paper on costs http://www.sei.aero/eng/papers/uploads/archive/IAC-10.C3.1.8.pdf

in 2011 mankins have made a new presentation not needing tens of billions anymore, but i could not find his new price estimate.--Beaucouplusneutre (talk) 09:10, 29 January 2012 (UTC)

Japan's SBSP roadmap
A long-form article in the technical publication IEEE Spectrum has a comprehensive story just published on Japan's roadmap in a JAXA proposal. Here's the source: How Japan Plans to Build an Orbital Solar Farm. Whether it ever gets funded development, or built, is always in question. However, the article would be a good source for various statements already made in the article. Cheers. N2e (talk) 04:41, 9 May 2014 (UTC)

Reliable source?
There are 25 places where Wikipedia references theenergycollective. So I guess it is considered (like the now defunct Oil Drum) to be a reliable source.

In which case, if anyone wants to work parts of this into the article, be my guest.

http://theenergycollective.com/keith-henson/485571/power-satellite-progress

Keith Henson (talk) 06:39, 10 September 2014 (UTC)

Disadvantages list removed unsupported claim of 10-year useful lifetime
I removed the following unsupported claim:

System lifetimes on the order of a decade would be expected, which makes it difficult to produce enough power to be economical.

The fact that it's unsupported matters, because an expected lifetime of 10 years would be a killer disadvantage -- it would make the whole concept economically impossible. If true, this would be huge; so this statement needs significant support.

The closest I could find was the solarstorms.org reference from two points above,

"It is expected that solar panels will degrade by about 20-25% during the 10 to 15-year lifetimes of modern GEO satellites."

Even if true (that site seems somewhat polemical), a 25% degradation would not constitute the end of useful life for a powersat, though it would certainly be significant. However, that reference was for communications satellites that cannot be accessed at all once placed in GEO. A solar power satellites would have continuous robotic maintenance available, with human teleoperation support where needed. That could probably fix most problems quickly on a simple, repetitive structure. If not, periodic human inspection and repair certainly could. So I would expect that even a vulnerable design could remain in service indefinitely if desired; the only question is what the maintenance would cost.

Secondly, note that this objection only applies to one proposed design: simple solar cell arrays. The proton bombardment, etc. that solarstorms.org describes would not affect an alternate design of high-efficiency cells with concentrating mirrors (since the cells face away from the Sun and solar wind). Also, none of these effects would matter for the other major proposed design: concentrating-solar thermal plants in space. Howie Goodell (talk) 03:27, 23 January 2014 (UTC)


 * Seems a reasonable bold edit to me. If someone disagrees, they can BRD it and we can discuss it further here.
 * Actually, quite a lot of that material, both advantages and disadvantages, needs sources. N2e (talk) 17:46, 23 January 2014 (UTC)


 * I agree, ten years seems like an unreasonably short lifetime. There are a fair number of communication satellites that have functioned longer. There are also thermal designs clear back to the 70s that should last 50 years. Keith Henson (talk) 06:43, 10 September 2014 (UTC)

Disadvantages list missing cost?
I put cost as a disadvantage, but it was removed. Why on earth would you not list the monstrous cost of implementing any industrial-scale SBS effort as a disadvantage? Lifting all hardware to geostationary orbit and assembling it would be prohibitively expensive. Compared to this, the threat of micrometeorites (or other things on the list) is minor. Hermanoere (talk) 16:18, 21 March 2012 (UTC)
 * The problem is that it was an original observation. If you can bring a reliable source that says SBS is prohibitively expensive, and that costs for space travel would have to drop dramatically before it becomes feasible (there may very well be such sources), that claim could be added. Follow the links in my comment to see Wikipedia's policies regarding these issues. Equazcion  ( talk ) 18:53, 21 Mar 2012 (UTC)
 * It's also dependent on design choices. It's easy to imagine a series of smaller SPS, in the 200 ton range, being launched by private contractors at a cost well below NASA's typical cost (which is bloated by needless manpower). So "prohibitively expensive" is very subjective & POV.  TREKphiler   any time you're ready, Uhura  19:35, 21 March 2012 (UTC)
 * Hermanoere's addition may not be true, but it can be supported by a reference already in the article, so I put it back in with the reference - Fartherred (talk) 18:55, 12 May 2012 (UTC)
 * Entering Space (1999) by Robert Zubrin, pp 70-74, calculates that the launch costs alone of SPS are in the order of $3300/W (assuming a price-to-GEO of $40,000/kg, 15% efficiency panels and 12W/kg for the system). All-up cost for a moderate-sized (1000MW) plant would be $6 trillion, some 6000 times the cost of an equivalent natural gas plant. The retail price would need to be at least $114/kWh. Granted, since Zubrin wrote that, we've seen solar panel efficiency increase to about 30%, and SpaceX has (probably) dropped the cost to GEO by a factor of 4. But that still leaves SPS with a 100,000% cost disadvantage to ground-based power. SPS isn't just uneconomic, it's pure unadulterated fantasy.--Yeti Hunter (talk) 06:06, 26 June 2012 (UTC)
 * "pure unadulterated fantasy" Really? How much does a 2km-diameter Mylar mirror & a 5GW turbine rig weigh? At $40K/kg, it damn sure ain't $6 trillion. As said, cost depends on the underlying assumptions.  TREKphiler   any time you're ready, Uhura  06:15, 26 June 2012 (UTC)
 * Forgive my poor sentence structure above - the $6t number was for launch costs AND hardware. FWIW, Zubrin's calculations were for PV panels, and his hypothetical 1GW system would weigh 83,000 tons. 83,000,000kg multiplied by $40k/kg does indeed equal $3.3 trillion. The pro-SPS source in the article, http://www.sei.aero/eng/papers/uploads/archive/IAC-10.C3.1.8.pdf, suggests a 5GW system would weigh 12,000 tons and therefore cost $480 billion to launch (Edit: that's assuming Zubrin's $40k/kg number, not in the source) . As noted, Zubrin was a little on the pessimistic side with both collection efficiency and launch costs, but 12,000 tons for a 314 hectare mylar mirror, and a turbine comparable in size to the largest in the world, is probably optimistic by a similar margin.--Yeti Hunter (talk) 07:13, 26 June 2012 (UTC)
 * I mean, I know I'm breaching WP:NOTFORUM here, but a closed brayton-cycle turbine will need a generator, yes? I've no idea how much a big one of those weighs, but a 1MW wind turbine nacelle typically weighs about 40 tons. Let's be generous and say the generator might be a quarter of that. 10 tons. Hell, call it five tons. We're building to aerospace spec after all. Multiply by 5000 to get to 5GW and that's 25,000 tons just for the generators, more than twice the SEI estimate. Plus the turbines themselves, heat exchangers, radiators, a 5GW laser array (!!!), hundreds of hectares of mylar...... Maybe even Zubrin was being optimistic in his mass calcs.--Yeti Hunter (talk) 08:36, 26 June 2012 (UTC)
 * I think it's fair enough to list cost as a major disadvantage. In reality it is likely the biggest disadvantage, tied to the fact that the idea is based on theoretical and currently non-existent technology. As with most unproven technology, the start up costs for the research and development and to actually get a system running are going to be much higher than any subsequent system. That means the first system is likely going to be incredibly expensive, with cost overruns not to be unexpected, with possible results unknown. More than anything else it's these unknown start-up costs that no government is willing to pay that is the major impediment to bringing something like this about. These unknown costs compared to proven technology with known costs can't be dismissed because they are unknown. It's precisely because they are unknown that they are such a disadvantage.91.182.244.126 (talk) 22:23, 26 December 2012 (UTC)


 * Couple of things, a power sat has to generate 10 GW to put 5 GW on the grid. If you are doing it with turbines, a GE90 engine on a Boeing 777 aircraft puts out 75,000 kW with a mass of ~7500 kg or 0.1 tons per MW. 10,000 MW of turbines at 0.1 tons/MW would mass 1000 tons. The generators may mass more than the turbines. One example is an aircraft 400-Hz generator, 40-50 KVA that massed 15 kg, or .33 kg/kW, or 330 tons per GW, 3300 tons for 5 GW on the ground.  http://books.google.com/books?id=QVlKAQAAIAAJ&q=mil-g-21480/+KVA&dq=mil-g-21480/+KVA&hl=en&sa=X&ei=02rFU5ShOIfwoASF7oKYCw&ved=0CCYQ6AEwAg  But the main point is correct.  Work it from the other direction and you get no more than $200/kg to GEO for power satellites to make economical power.  Fortunately Skylon to LEO and microwave powered VASIMR engines from LEO to GEO look like they will do it.


 * Adding to what I wrote above, unfortunately VASIMR engines will not do for a LEO to GEO run. They mass so much that it looks like the take out most of the payload.  However, it seems that arcjets, of which there are examples built at least 60 years ago are light enough to do the job.  NASA Ames has a 60 MW unit.  http://www.nasa.gov/sites/default/files/acd04-0124-120.jpg  Keith Henson (talk) 22:27, 13 November 2014 (UTC)

Video animation of transport and construction
I should not add this because I am named in it.

https://www.youtube.com/watch?v=q-Lrj35HcbQ

Be my guest if you would like to add it.

3000 of these, which we could build by the early 2030s, would replace all the fossil fuel being used today.

Keith Henson (talk) 02:54, 24 May 2015 (UTC)

Useless link to Earth's surface
The link to "Earth's surface" in the lead section is not helpful. Even the link to "Earth" is of dubious value as a commonly understood word. If people want an article in depth about the Earth they can find one without a link from the SBSP article. The Earth's surface link just compounds this problem by giving a second link to the Earth article in the second paragraph of the lead and using a redirect to fool readers into thinking that they might be linking to a special article about Earth's surface as it differs from Earth as a whole. So I will remove the Earth's surface link. - Fartherred (talk) 12:45, 18 June 2015 (UTC)
 * Another editor beat me to it. - Fartherred (talk) 12:50, 18 June 2015 (UTC)

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Nitrogen oxides citation request
Belg4mit in the edit of 03:08 hours on the 13th of August wrote in the edit summary: "high-temp combustion in atmosphere by definition forms NOX". This would be the case if fuel were being burnt with atmospheric oxygen which is mixed with nitrogen. Rockets carry their own oxidizer which often contains no nitrogen. If the fuel also contains no nitrogen, no nitrogen oxides are formed in combustion. Exhaust gasses of a rocket are cooled by adiabatic expansion as they exit the expansion nozzle. So if a rocket is traveling forward through the atmosphere with a speed equal to its exhaust velocity, the mixing of exhaust gasses into the atmosphere is a relatively low temperature simple mixing process that produces no nitrogen oxides. It is when the rocket is traveling at low speeds that the high speed exhaust is reheated on contact with the ambient atmosphere and can form nitrogen oxides. This matter is sufficiently complicated that there should be a cited source or the statement about forming nitrogen oxides should be removed. Fartherred (talk) 15:20, 13 August 2011 (UTC)

I've deleted this section. First of all, no one responded to Fartherred's source request. Secondly, this article is not the right place for a discussion of the various advantages and disadvantages of certain kinds of launch methods; there are many. Third, as Fartherred pointed out, a rocket nozzle is specifically designed to lower exhaust pressure. In that process, exhaust temperature drops precipitously. For an example, see http://www.nasa.gov/multimedia/imagegallery/image_feature_1263.html. Last, the vast majority of rocket engines used in large launchers expel either CO2 and H2O (LOX/RP-1) or just H2O (LOX/LH2), so I don't know what the original writer was specifically citing. Voronwae (talk) 16:47, 27 May 2012 (UTC)


 * NOx is a subject that may be of concern for a serious level of power satellite construction. Hypersonic velocity in the atmosphere both going up and coming down generates NOx, which does chew up ozone. However, the NOx is taken out of circulation by water, so that may take care of the problem.  Needs study.  Some of it might be found in the SST work.  Keith Henson (talk) 07:03, 10 September 2014 (UTC)


 * NOAA ran a study that indicates NOx will not be a problem for hydrogen burning Skylon type craft. http://onlinelibrary.wiley.com/doi/10.1002/2016EF000399/full At least if the flight rate stays below a million flights a year.  Keith Henson (talk) 23:26, 29 March 2017 (UTC)

Confusion of terminology
Space-based solar power is also rendered
 * SPS
 * SSPS

and many other ways. There are so many ways that have been used over the years that there is bound to be much confusion Wikkrockiana (talk) 08:27, 4 May 2017 (UTC)

L5 Society
I recall MIT students' advocacy of SBSP through the L5 Society (from the 1980s), and that operation had advocated space colonization along with other innovative solar technologies. The may/must have been numerous others. Is there any way to look for a listing of the various organizational forms early research and advocacy (from the 70s, 80s, and 90s) may have taken? MaynardClark (talk) 20:21, 6 June 2017 (UTC)

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Efectivity
"(55–60%) is lost on its way through the Earth's atmosphere by the effects of reflection and absorption. " Ehm.. wtf? In space it is 1350 w/m2, for example in centre of europe it is 400w/m2 in winter and 1000w/m2 in summer. In centre of europe we get 1 Mwh of sun light per year for m2. In space (permanently on sun) it can be 11,8 MWh/year per m2. On geo orbit it will be 40-50% less becouse shadow of earth. (Probably) So where come from 55-60%?

But cost.. make solar panel cost cca 34 dolars per m2, selling for 70-700 dolars per m2 (no kidding). Double efective panels cost 4x or more. (If you even can buy it) It weight is more then 1kg per 1kwp. Get 1kg to orbit cost cca 14 000 dolars. So 340 vs 14000 is 1:41 but top efective is only 1:11,8. This is reason why we hav 0 orbital solar powerplants. 91.221.212.116 (talk) 09:23, 24 August 2017 (UTC)

If we could get a source to this statistic maybe it would help clear up the confusion? Aaronvoth (talk) 02:11, 17 October 2017 (UTC)

No mentions of dangers in SBSS in article
I am not sure if mention about this belongs in the article.

An SBSS facility would only be useful if it provided large amounts of energy, which would be dangerous to life in case of malfunction or hijacking of a transmitter. — Preceding unsigned comment added by 62.249.66.155 (talk) 19:37, 2 March 2016 (UTC) I agree with the statement above, which makes me question who would be allowed access to this for maintenance? Aaronvoth (talk) 02:30, 17 October 2017 (UTC)

i wonder if this new technology is capable to unite the world. decentralisation of the distribution of power provided as such is a political problem.

the powers that are at the moment wont allow it, unless they can benefit from it. also concider the loss of economics in power industry today. lots of people will lose their jobs worldwide.

ther will be much less use for feul and oil. the change in worldwide economics as a result from orbital power, is a scary aspect for the few who control energy today. an answer might be to start an international company that is financially maintained by a worldwide funding from tax and run by an international board.

quit a task to make such a movement happening, expect resistance from those who gain from nucliar power, like the monsantos and the rotschilds — Preceding unsigned comment added by 2A02:1812:2E1F:A900:91D:B93:DBCC:E87C (talk) 14:30, 31 October 2016 (UTC)

Political role
Maybe mention how the current world leaders view this idea and if there is any overall agreement Aaronvoth (talk) 02:38, 17 October 2017 (UTC)

could this potentially weaken bonds with other countries or could it create more conflict than we already have?Aaronvoth (talk) 02:38, 17 October 2017 (UTC)

if access to this amount of energy fell into the wrong hands would there be preventative measures taken to keep them from using it incorrectly?Aaronvoth (talk) 02:38, 17 October 2017 (UTC)

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"Outer space"
I've always considered "outer space" to be, at the very least, interplanetary space, or space way, way beyond the Earth and the Moon. Really I generally consider outer space to be outside the solar system. I'm not sure whether it is a term which is completely scientific or not, perhaps having been used by many amateurs for so long. Not that I'm an expert!

I had thought that a generic word for what's just beyond our atmosphere was just "space". As in "space station" not "outer space station" and "interplanetary craft" or "space craft" not "outer space craft". Also the title of this article is "Space-based..." rather than "Outer Space-based..." Common dictionary definitions do seem to define "outer space" as anything above our atmosphere, but I'm just wondering if we should be a little more accurate with this term. 75.177.79.101 (talk) 01:03, 20 January 2018 (UTC)
 * ♠Actually, in the trade (& among space & SF buffs), you almost never hear the term; it's usually reserved for uninformed news weenies...
 * ♠In this instance, GEO or cislunar would be more apt. (I'm not sure Lagrange points qualify as GEO...). Or just use Lagrange point.
 * ♠Beyond Luna's "interplanetary" space; beyond the heliopause, interstellar: both technically, "outer", but...  TREKphiler  any time you're ready, Uhura  02:14, 21 January 2018 (UTC) (Post scriptum:  Yes, I am showing off a bit.)


 * I'm in agreement. However, I understand that Wikipedia needs to cater somewhat to the everyone and that not everyone understands the nuances involved.


 * That being said, Wikipedia also seeks to inform people of facts. Therefore, in this instance, "outer space" is surely inappropriate. I would personally prefer to use the term "space". Unfortunately, I see that the disambiguation page for space points to an article titled "Outer space" which, by my understanding, describes the term a little erroneously. Perhaps we should move to change the title of the article Outer space, or at least make a note on the correct usage... assuming we can find academic or scientific citations? --75.177.79.101 (talk) 00:21, 24 January 2018 (UTC)
 * As peculiar as I find the use of "outer space" as a term, in encyclopedic usage, it's sensible to distinguish between astronomic & geographic. That being true, it's probably best not to tamper with "outer space" as a pagename; I'm not sure everyone defaults to it, so it may well not be the most likely-searched use of "space" (& that's the governing criteria for "primary article", which it would become).  TREKphiler  any time you're ready, Uhura  09:42, 24 January 2018 (UTC)

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Current researchers
Though they are all mentioned, there are three current researchers John Mankins, Lt. Col. Peter Garretson and Paul Jaffe who are not covered by a BLP on Wikipedia. I have previously written stubs on a few people so I could do one or two of them. Anyone else interested? Keith Henson (talk) 01:46, 1 October 2018 (UTC)

Critique-free article?
The article seems to only praise the great advancements and chances in SBSP - and just reeks of propaganda. I'm missing two matters in particular:

- Sunlight/Wattage that would otherwise never arrive on the planetary surface will arrive using this technology. That will by definition heat up the planet - especially when applied at a world-wide scale comparable to fossil fuel (terra Watts per year). This makes SBSP renewable, but not environmental. In the long run even problematic. The Safety section instead claims "The long-term effects of beaming power through the ionosphere in the form of microwaves has yet to be studied, but nothing has been suggested which might lead to any significant effect." without sources. Now I've put up the argument above, it is even false too.

- The possibility to weaponize a system which beams energy to the surface: Basically SBSP exists of a space based energy cannon. It will only be competitive to earth based solar if the power to area ratio at the receiver becomes as much greater to an Earth based solar array as the difference in costs and atmospheric loss. This implies at least Giga Watt installations smaller then current Mega Watt ground based arrays. What if the receiving end is a targeted person or city? How will or can anyone ensure that this cannot be done on purpose, or even by accident (because of a space impact moving or shaking the satellite)?

The Safety section sort-of addresses the second, but the basis of the entire text is as about as well sourced as this Talk comment: it references, but it doesn't actually reference any of the assumptions made. The Safety section also brushes over any concerns without even mentioning the word "weapon", as does the entire article. "Nothing to see here people, move along". — Preceding unsigned comment added by 2001:1c00:b0d:3500:b492:c8f9:5f80:f5ce (talk) 06:11, March 1, 2021 (UTC)


 * A lot of these criticisms are probably specious. Large scale surface-based solar farms will warm the Earth and disrupt global climate as well, and achieving the energy density of a beam enough to use it as a weapon sounds extremely unlikely. But if there are reliably sourced criticisms of SBSP, they should be included in the article. Geogene (talk) 19:52, 1 March 2021 (UTC)


 * This seems to be the case of the uninformed talking to each other. The huge problem with space-based power is the cost for the amount of energy generated, I do agree the article pretty much ignores this and it should be fixed, with arguments in both directions.
 * OP is not understanding how trivial the energy we use is compared to the energy received from the Sun on Earth. The heat from actual generated energy being turned into heat is pretty much irrelevant, and would apply equally to burning fossil fuels or nuclear energy, both of which are taking energy stored as something other than heat and eventually converting it to heat. The second poster seems to have missed the fact that space based solar power is in fact taking energy that would not have hit the Earth at all and sending it to Earth, which is a difference from ground solar power, which is what the OP was complaining about, though it is still too small to be of any concern.
 * It also is not really a problem to make the system impossible to focus the beam to a weapon. In fact a huge problem is that the size of the receiver antenna is actually a lot larger than a solar power field generating the same amount of energy (it might be less expensive though as it is a sparse field of wires rather than a solid surface of solar panels).

Spitzak (talk) 20:10, 1 March 2021 (UTC)
 * The second poster seems to have missed the fact that space based solar power is in fact taking energy that would not have hit the Earth at all and sending it to Earth And, what you are missing is that Earth-based solar power decreases the planetary albedo. Geogene (talk) 20:20, 1 March 2021 (UTC)

Unexplained technical Abbreviation: "GW Scale"
This sentence seems obscure to me because there is no explanation of what "GW" stands for, so it is hard to tell what "GW scale" means.

"Microwave optic requires GW scale due to Airy disk beam spreading."

174.21.14.131 (talk) 16:54, 27 October 2021 (UTC)
 * GW could mean Gigawatt, as in you need to overbuild capacity (scale) of the installation. Just a guess though; it isn't clear. Geogene (talk) 03:49, 28 October 2021 (UTC)

Energy return on investment
Basic information to add to this article: the possible/likely range of energy return on investment from such schemes. 173.88.246.138 (talk) 16:13, 19 October 2021 (UTC)

Yeah these are essential in serious discussion, and would be a great addition if someone can dig them out Eric Lotze (talk) 21:39, 15 March 2022 (UTC)