Talk:Solar sail

message: I revised the introduction, beginning of a major overhaul suggested by several viewers.  This will be done at an irregular pace, mostly top to bottom.  Readers and editors are asked to comment, especially where I might violate Wiki standards. SpaceSailor 22:04, 19 May 2012 (UTC)
replies: text: The section has been removed.  In addition to the above, the section is a recap of a paper by Vulpetti, and thus goes against the Wiki rule against including research results. SpaceSailor 15:54, 18 July 2013 (UTC)

text: Right. At the time I write this, the wind's dynamic pressure is 0.8 nPa, so solar radiation pressure to solar wind pressure is ~11,000. Solar sails are driven by photonic pressure.  Period.  The solar wind has no discernible effect on performance.  Telling readers that the wind is effective is a disservice. If a design effort yields a characteristic acceleration of exactly 1. under radiation pressure, that is the value used in performance analyses and simulations, not 1.00009. SpaceSailor 22:28, 30 June 2013 (UTC)
thread_title: Overhaul of article

message: Can someone please do the appropriate math and come up with a maximum speed for a solar sail using the sun only (no laser)? Assume a mass, let's say, of 18,000 metric tonnes for the ship itself (manned spaceflight)...what percentage of the speed of light could one reach using the sun only? Could you do 10%? 90%?71.80.232.252 (talk) 06:16, 4 March 2012 (UTC)
replies: text: With a hypothetical high-performance solar sail, which we cannot now build and don't really know how to build, it would leave the Solar System at about 0.001c, probably less than you were hoping for--with a very small payload at that.  That is why Bob Forward went to sails pushed by giant lasers, which we really, really don't know how to build.  Its hard to fully appreciate just how difficult interstellar travel actually is. SpaceSailor 20:18, 18 May 2012 (UTC)
replies: text: The effect of a payload is to reduce the speed by a simple formula based on the mass of the sail, the terminal speed is proportional to the square root of the ratio of the total mass to the sail mass, thus if the sail has a mass of M and the payload is 3M, the speed will be half that of the sail alone. The speed can therefore be made arbitrarily close to that of the bare sail by making the sail arbitrarily large so that its mass is much greater than that of the payload. The bare sail speed depends on how close it can get to the light source which in turn depends on its maximum temperature. That in turn depends on how much heat is absorbed from the source and the emissivity of the dark side. The dark side can be assumed to be close to a black body and the heat absorbed depends on the reflectance and hence the chosen material. It also depends on the orientation to the source. The sail can get much closer at grazing incidence, the limit probably being where the plane of the sail is aligned with the limb of the sun or star. I agree, it would be useful to include the equations that lead to your quoted maximum and perhaps a table of values for different materials and normal/grazing incidence but is there a third-party source for that? My own calculations suggest the limit speed would be closer to 1%c for aluminium than the 0.1% you quote, but your figure is probably more practical while mine disregards engineering limitations. George Dishman (talk) 21:41, 19 January 2013 (UTC)
replies: text: When I get back to work on the mission section, I will include some hard data on escape speeds and the physics of solar swingbys.  There have been a lot of distractions for me, but I didn't realize I had not done any work in a year. SpaceSailor 22:45, 30 June 2013 (UTC)

text: Vulpetti's very detailed simulations of fast solar sails show escape speeds of about 0.0003 c with areal densities approaching 1 g/m2, close to some of my early trials, but better quality.  Those are very difficult design challenges.  Payload has to be included in that value.  So, I think my estimate of 0.001 c might be an essentially unachievable upper limit. SpaceSailor 13:59, 13 July 2013 (UTC)

text: I ran a few quick simulations and found areal density of 0.02 g/m2 gives about 300 km/s = 0.001 c = my earlier guess on best possible. SpaceSailor 15:56, 16 July 2013 (UTC)
replies: text: Below 40nm, aluminium starts to transmit rather than reflect so a practical limit is around 0.11gsm for solid sheet. The perihelion distance and hence the terminal speed is then set by your choice of maximum sail temperature, what are you assuming? George Dishman (talk) 10:15, 6 October 2013 (UTC)
replies: text: I agree, an Al sail 'bottoms out' around 0.1 g/m2, while lithium bottoms out around 0.02 g/m2, something I have long been interested in.  I recently added a bit on lithium in Materials.  I generally assume 0.20 AU for close approach for Al sail, but much farther out for Li.  An all-Al sail has no emission coating and suffers a lower emissivity value, affecting its temp (I do not know what e values might be for this case, hence don't know temp values).  Usable emissivity values are empirical because thin-film effects dominate; bulk emissivity values do not hold up in these cases because material thickness is much thinner than the emitted wavelengths. Radiation degradation is always a serious issue (sail can darken), and must be considered along with temperature and structural loads in a close swingby.  Radiation and loads may be more limiting than temperature.  So the closest practical approach remains a big unknown--I consider 0.20 AU a reasonable estimate for the present for Al, recognizing it might be off substantially one way or the other.  Li is highly reactive with oxygen and has a low melt point, so it must be fabricated in orbit above oxygen levels, and might not be usable much inside of 1 AU. SpaceSailor (talk) 16:27, 7 October 2013 (UTC)
replies: text: One of the key advantages of aluminium is that it retains its reflectivity to below 200nm. I haven't been able to find a reflectivity graph for lithium, it would be useful if that could be added to the graph on the reflectivity page. George Dishman (talk) 15:31, 30 January 2014 (UTC)
thread_title: max speed with sun only?

message: I think perhap we should modify the initial sentence to state that solar sails are a proven technique of spacecraft propulsion.  I need to do some research and get a cite to verify that existing test data is considered adequate to prove the concept as applicable to spacecraft.
There was early experience with the Echo balloons being pushed off orbit by solar wind.  I do not know if the light pressure was influential (reflection provides 2 times the photon mass thrust adjusted for vector dot products) or negligable compared to the momentumm of absorbed ions in the  solar wind.
There was an asteroid or comet rendezvous proposed.  I do not remember if it was scrubbed while still conceptual or failed on deployment.
Anyway, the issue is manufacturing technology and spacecraft design.   Nobody argues AFAIK that the method will not work provided our spacecraft design and manufacturing technology gets good enough to deploy and use the sails.
There have been tests with laser light pressure:
http://spaceflightnow.com/news/n0007/06lasersail/
http://www.eps.org/aps/meet/SHOCK01/baps/abs/S250.html
Planetary society site may have latest informtion:
http://www.space.com/businesstechnology/technology/solar_sail_update_010723.html
http://www.planetary.org/solarsail/suborbital.html
This article
http://www.quinion.com/words/weirdwords/ww-sol1.htm
that NASA used light pressure on Mercury Mariner probes in approximately 74 timeframe to extend usefulness of the probe 's data collection period.   I have been unable to verfiy this from an independent reputable source.
If true, IMHO, this is clearly successful solar sailing.  Just as a crippled power boat or raft will drift or "sail" with ambient wind.  A sail boat is designed to generate and use the thrust more efficiently but it exists in the more primitive application of technology.
Opinions, insight, queries or sources anybody?
user:mirwin
:The revised intro should take care of this issue.  Doubters overlook the fact that every successful interplanetary spacecraft is another demonstration of solar pressure predictions. Mariner 10 experience was written up in AvWeek and described in Space Sailing.  I met with the guys who did it and got to review their telemetry printouts. SpaceSailor 13:31, 20 May 2012 (UTC)
thread_title: Old message

message: My understanding is that not all the criticism of solar cells is empty or based on misunderstandings of the technology. Not so the article's. Can someone clean up the section, so it sounds less gung-ho about the technology it is criticizing? -173.3.112.55 (talk) 00:26, 10 November 2009 (UTC)
thread_title: Critcism

message: The section on 'current progress' mentions the Japanese prototypes launched in August. Could somebody add something about what happened to them, and whether they were successful? The Singing Badger 17:10, 30 Sep 2004 (UTC)
replies: text: They tested deployment, not propulsion, so I imagine after popping out, they re-entered. Added a ref. SeanCollins (talk) 07:51, 24 April 2008 (UTC)
thread_title: What happened to the Japanese prototypes?

message: This must be the umpteenth time I have had to change "altitude" back into "attitude". Yes, "attitude" is perfectly correct, it controls the direction the spacecraft is turning. There is little need for "altitude" control in space, for one, because there isn't really a "height" in space - its all subjective, but certainly attitude is needed because direction is far more important. Solar sails aren't really meant to be manoeuvred through the atmosphere, where altitude applies, either. Can you people please stop doing this? Its VERY VERY EXASPERATING. "Attitude" IS a valid word for spacecraft. -- Natalinasmpf 14:14, 22 Jun 2005 (UTC)
replies: text: How about putting some HTML comments  into the text at places where "attitude" keeps getting changed, explaining that the usage is correct? That way any editor who goes in to change it will definitely see it. I've used this approach before in other articles and it seems to work pretty well. Bryan 06:34, 23 Jun 2005 (UTC)
thread_title:  Please note, "attitude" is correct, stop changing it 

message: I removed the following:
"Aspiring engineer Kyle Caskey has proposed to use designs of manned spacecraft with solar sails as the main means of propulsion for a small pleasure crafts, somewhat like yachts. These solar sail yachts could move small groups of family and friends between the Moon and Earth and other destinations at varying speeds."
Text from an aspiring engineer shouldn't really be included in this case. kmccoy (talk) 21:08, 13 July 2005 (UTC)
thread_title:  Removed yacht text 

message: What kind of acceleration are we talking about, here?  It would be great if we could translate some of the mechanisms, etc, above into measures that the average sci-fi fan can grok.  Do solar-sailed craft whiz about the solar system, or just kinda putter?  If HAL had been sail-powered, how long would it have taken Dave to get to Jupiter?  Thanks!
:: I agree that it would be nice to put acceleration, earth-to-mars time, earth-to-jupiter time, etc. into the article. --70.189.75.148 00:54, 29 July 2005 (UTC)
replies: text: I enthusiastically also agree. Therealhrw 00:23, 29 December 2005 (UTC)
replies: text: Specific acceleration would depend on the design of the individual spacecraft and its payload/mass and sail area.  Perhaps some detailed design discussions at http:\\www.wikiversity.org school of engineering would be appropriate.  In general the current state of the art with solar sails implies "puttering" not performance records compared to other propulsion methods.  Lazyquasar 05:44, 25 September 2007 (UTC)
thread_title:  Question : What kind of acceleration are we talking about, here? 

message: Critics of the solar sail argue that solar sails are impractical for orbital and interplanetary missions because they move on an indirect course. However, when in Earth orbit, the majority of mass on most interplanetary missions is taken up by fuel. A robotic solar sail could therefore multiply an interplanetary payload by several times by reducing this heavy fuel mass, and create a reusable, multiimission spacecraft. Most near-term planetary missions involve robotic exploration craft, in which the directness of the course is simply unimportant compared to the small fuel mass and fast transit times of a solar sail. For example, most existing missions use multiple gravitational slingshots to reduce fuel mass, because even though these are terribly indirect they save years of transit time.
This entire first paragraph in the second section, excepting the first sentence, is very unclear.  The second sentence appears to begin dealing with one situation ("in Earth orbit") then suddenly move to another ("interplanetary missions") without addressing the first.  I replaced "heavy" with "significant" in the third sentence since it seemed redundant; multiimission in the same sentence is spelled incorrectly, but I do not know the correct spelling.  I tidied up the second last sentence, as it sounded awkward, but the last sentence I could not decide how to improve, though it currently bothers me.  —Preceding unsigned comment added by Mywikinick (talk • contribs) 21:32, 15 September 2007 (UTC)
thread_title:  Awkward and confusion "Misunderstandings" section 

message: I'm just expressing concern that this article isn't neutral. I didn't add a POV tag because it isn't that bad yet but the article seems to have a "criticism" section but it's only called "misunderstandings", it shouldn't be called that because that's only what PR people write when they want to change people's mind about things and an encyclopaedia's job is to just mention it and not necessarily to change people's minds. Jeffrey.Kleykamp 21:11, 22 September 2007 (UTC)
replies: text: The section "Misunderstandings" actually appears to attempt to correct common misunderstandings about how a solar sail would work.  The theoretical basis for solar sails is well understood.  I did a college paper on solar sails about twenty years ago.   Critics of the approach are unconvinced the engineering and manufacturing details provide a better approach than other alternatives, the science is uncontroversial.  A section for critics should cite some technical engineering studies and describe why solar sails were not used in specific missions.  Usually technical development risk but probably some schedule, sail development and travel too long for mission profile.  I deleted the last paragraph in this section because it claimed it was a misunderstanding that a solar sail would have to tack and then proceeded to describe how it would tack.  Perhaps the paragraph could be restored and revised for useful placement elsewhere.  Lazyquasar 06:03, 25 September 2007 (UTC)
thread_title:  NPOV , Criticism section called misunderstandings, 2007 

message: I cannot find any reference online regarding any "doppler shift" related to Dr. Gold's contention that solar sails will not work because of application of the Carnot Rule.  Further, I cannot find any serious work, analysis, reference, etc. that indicates space scientists and engineers take his contention seriously enough to refute it with published mathematical physics.  Perhaps we should delete references to Dr. Gold's contention solar sails will not work?  Too bad Cosmos-1 crashed that would settle it definatively.   Personally I find the too refutations I have added both convincing.  Lazyquasar 07:38, 25 September 2007 (UTC)
thread_title: Bad science?

message: I wonder if this section should be moved a separate article/stub similar to http://en.wikipedia.org/wiki/Force_field_%28science_fiction%29 and then linked.  To me it adds little to a serious understanding of Solar Sail technology towards which the rest of the article is aimed.  Lazyquasar 13:33, 25 September 2007 (UTC)
replies: text: Fair question, but there is at least one fictional instance that is relevant - Robert L. Forward, one of the designers of the concept, gives a fairly detailed description in Rocheworld and its sequel Return to Rocheworld, including the use of the sail for braking. Philcha (talk) 11:42, 2 January 2008 (UTC)
thread_title: Solar Sails in Fiction

message: I think I'm right when I say that there should be a continuous variation possible between what we call a solar sail and a solar cell.  If you have a perfectly efficient solar cell and use its power to produce a beam of light, that's the same as a mirror.  Half the pressure comes with the absorption of the light and half with its emission.  Even an inefficient solar cell, or one powering a load, should work almost the same way, if you can cunningly design your heat sinks to send most of the infrared radiation a certain way.  If you have power to spare I suppose you can even use refrigeration methods to concentrate all the heat in a very defined way.  It would seem to follow, then, as one considers a technologically advanced future, that eventually the ships should use vast membranous solar cells as their solar sails, arranging to do something with all that power before releasing it into space from structural elements designed for the purpose. 70.15.116.59 (talk) 17:21, 19 December 2007 (UTC)
replies: text: Should a wheel be considered a both an electric motor and a generator?  75.45.71.133 (talk) 05:27, 14 February 2008 (UTC)

text: To add to the thrust, the heatsink has to emit the radiation back towards the source, but it will also absorb heat from the source hence you get into complex questions of thermodynamic balance. Basically any energy you extract as useful work detracts from the kinetic energy gained by the craft. George Dishman (talk) 09:29, 14 August 2010 (UTC)
thread_title:  Solar sail vs. solar cell 

message: NASA is to launch NanoSail-D in a month: http://science.nasa.gov/headlines/y2008/26jun_nanosaild.htm?list1097511 (at the moment I just put it in "External Links". —Eickenberg (talk) 00:37, 28 June 2008 (UTC)
thread_title:  NanoSail-D 

message: ive heard of one mission that is to launch next year. its a polish nanosatelite. and according to the info i found, it's a solar sail so i sugest that some of the imfo i found could be added to this article. http://space.skyrocket.de/index_frame.htm?http://space.skyrocket.de/chrono.htm--Nrpf22pr (talk) 23:43, 20 December 2008 (UTC)
thread_title:  PW-Sat 1 

message: The Interstellar Flight profiles needs reworking. I'm trying to build a coherent summary of Forward's proposals.  And after spending an obsessive day over the first sentence in the article, I decided I would have to spend some quality time with the whole article first before deciding how to work this section.
Ecualegacy (talk) 02:13, 2 April 2009 (UTC)
thread_title:  Interstellar Flight 

message: Somebody should link this article to a list of science fiction novels dealing with solar sails.   Dexter Nextnumber (talk) 22:13, 27 November 2009 (UTC)
thread_title:  Solar Sails in science fiction 

message: :There are two sources of solar forces. The first is photonic pressure which is small but relatively consistent, and the second is due to solar winds which at times are less predictable, but far more powerful.
It's time to remove the last part of this statement, which was in the section "Physics".  You can look it up anywhere you want, the pressure due to photons is much larger than the pressure due to massive particles. For example: The sunlight amounts to 1368 watts per square meter outside the Earths atmosphere. See for instance Sun, section "Sunlight", or, for more detail, see Sunlight, section "Solar Constant".
Consider the force exerted by this radiation on a black body with a perpendicular area A during a time period of duration t. You can compute the radiation pressure like this:
:P=F/A; p=F*t so F=p/t; p=E/c; E=I*t*A
where P=pressure, F=force, A=area, p=momentum, E=energy, c=velocity of light, t=time duration, and I="irradiation" in the sense of (absorbed) energy per unit time and per unit area - this is the given number 1368 W/m2. Substitute these equations into each other and get P=F/A=(p/t)/A=((E/c)/t)/A=((I*t*A/c)/t)/A=I/c, or
:Pphotons = I/c = 1368 / 3*108) Pa = 4.6*10-6 Pa.
(If you feel unsure about the relationship p=F*t, just consider a body of mass m, subject to a force F during a time t. Apply Newton's second law, F=m*a, where a is the body's acceleration due to the force. Since acceleration is velocity change per unit time, a=v/t, the body gains a velocity v=a*t assuming we start at rest. Then we get p = m*v = m*a*t = m*(F/m)*t = F*t.)
You may also look up Radiation Pressure, which gives both numbers in the lead: 1370 W/m2 and 4.6 μPa.
On the other hand, the material particles flowing from the Sun are usually given as a particle density of 8.7 protons per cubic centimeters, see http://pluto.space.swri.edu/image/glossary/solar_wind.html.   Since the flow is 95% protons by mass, we may disregard other particles in a first approximation.  The same source gives the average velocity as 468 km/s. Consider a volume V that is 468000 m long times 1 m2 cross section. This volume flows across a surface A of one square meter in time t one second. Each cubic meter has 100*100*100 cubic centimeters, so the particle density becomes n = 8.7*106/m3. Use the proton mass mproton=1.673*10-27 kg. The computation becomes
:Pwind = F/A; F=p/t; p=m*v; m = N*mproton; N=n*V; V=v*t*A, 
:Pwind = n*v2*mproton = 8.7*106 * 4680002 * 1.673*10-27 Pa = 3.2 nPa.
assuming the particles are absorbed, not reflected. N is the total number of protons in the volume V.
The numbers in this article are not that different: 6.7 billion ton ejected from the Sun per hour, assuming American billions 109, velocities 400km/s for two thirds and 750km/s for a third of the flow (see section Components in this article), a distance of 150 million km (Sun), and using the surface of a sphere A=4*π*r2 gives 3.4 nPa.  
Conclusion: photonic radiation pressure is more than 1000 times stronger than non-photonic wind pressure.Cacadril (talk) 02:13, 26 April 2010 (UTC)
replies: text: That solar wind is stronger is a common layman's misconception, so feel free to rewrite and expand the Physics section as you have outlined. Including the math would also be valuable, in which case you should probably translate it to LaTeX (see Help:Displaying a formula). And don't forget to properly reference the secondary sources to prevent reversion. --IanOsgood (talk) 15:30, 26 April 2010 (UTC)
thread_title:  Radiation pressure is stronger than wind pressure 

message: I just removed the Criticism section as it does not contain anything of merit. The claims that solar sailing breaks Carnot rule, etc, is a kind of misunderstanding that rather indicates lack of normal intelligence or more likely willful misunderstanding.  If you like, you may write about it in an article about the New Scientist magazine or about how to fill magazine pages with pointless spin or fake controversy, making the reader feel clever because the misunderstanding is so stupid.  As a real misunderstanding it is implausible.
(To exaggerate a little: it is like rebutting in an article about Cleveland, Ohio, the belief that the Earth is flat and America's discovery was a hoax.)
The section also contained some explanations that may be included in other sections, such as the redshift/blueshift of reflected radiation. This illuminates the principle of conservation of energy, and may have some merit, but should be rewritten to fit in an appropriate section, perhaps the physics section. This is perhaps better handled in a more general physics article.
It shows in this talk page that a couple readers were surprised to discover that light can have momentum.  This is quite natural, but the proper place to write about that is in articles about momentum, about light (photons, electromagnetic radiation, etc), or other basic articles. Of course the talk pages are always OK.Cacadril (talk) 11:00, 26 April 2010 (UTC)
thread_title:  Removed "Criticism" section 

message: There has been a new development in this field, and it is proposed that the optical lift discovery may be used to help on self-alignment and steering of solar sails. It will be nice for someone familiar with the solar sail article to incorporate this.  Cheers, --BatteryIncluded (talk) 04:27, 9 December 2010 (UTC)
thread_title:  Optical lift 

message: The spacecraft Helios 2 has (had?) a top speed record of 67.042 km/s, making it faster than Voyager 1 at 17.06 km/s.
Thangalin (talk) 09:20, 15 July 2011 (UTC)
thread_title:  Speed Record 

message: In the sail parameters section...is the size some sort of length (edge or diagonal) or an area?  As it appears now the units of size are not clear.  — Preceding unsigned comment added by 128.158.1.164 (talk) 22:44, 30 August 2012 (UTC)
replies: text: Explanations of the dimensions have been added.  Thanks. SpaceSailor 01:43, 4 July 2013 (UTC)
thread_title:  question about the units of size for sail parameters 

message: Some topics need to be moved out of this section and into the previous section. IKAROS appears to be mentioned twice.Kortoso (talk) 19:13, 2 July 2014 (UTC)
thread_title:  Projects in development or proposed 

message: Deeds a precise ref plz might consider removing this ...
How do we know that Verne had specifically light pressure on a spacecraft in mind?—172.56.35.133 (talk) 17:57, 26 November 2014 (UTC)
thread_title:  Jules Verne? 

message: The Summary states "The total force exerted on an 800 by 800 meter solar sail, for example, is about 5 newtons (1.1 lbf) at Earth's distance from Sol,"  5 newton meters is equal to 3.7 (rounded) foot pounds.  Can someone please check the reference and determine which value is actually correct?  5/3.7 or 1.5/1.1 newtons/lbf respectively?
EAGreene (talk) 00:40, 17 December 2014 (UTC)
thread_title:  Error in Summary 

message: The reference cited (1925) is, according to the Wikipedia biography of F. Zander, and just as its title suggests, about the problems with using rockets for interstellar travel.  It is clear to me that it is not about using solar sails, but I don't know if solar sails are mentioned in it. This would need to be verified, I am challenging it. Robert Forward (1984) cites Zander's 1924 paper on solar sails. It is NOT the same paper, I believe the 1925 citation is wrong.  I searched google scholar for Zander for the period '23 -'26 and one paper I found say this about Zanders 1924 paper:"There is an analogy between the RPDA mechanism and the “Light Sail” scheme for spacecraft propulsion. This scheme, which uses the photon momentum transfer to the light-sail, has been proposed by F. A. Zander in 1924 [5]."  (from arxiv.org pdf of paper). The citing paper is:Unlimited Energy Gain in the Laser-Driven Radiation Pressure Dominant Acceleration of Ions; S. V. Bulanov, E. Yu. Echkina, T. Zh. Esirkepov, I. N. Inovenkov, M. Kando, F. Pegoraro, and G. Korn,Physics of Plasmas (1994-present) 17 (6), 063102, 2010. {note: a similar article in the same year is behind a pay wall:Unlimited Ion Acceleration by Radiation Pressure, Phys. Rev. Lett. 104, 135003 – Published 2 April 2010 but is in a main stream (more accessible) journal.} 
and Zander's paper is: [5] F. A. Zander, Technika i Zhizn, No. 13, 15 (1924) [in Russian]. or the Russin citation: Ф. А. Цандер. Перелеты на другие планеты. Техника и жизнь. 1924. No 13. C. 15-16.  which seems to translate (I read zero Russian) to "F.A.Zander, Flights to other planets. Tech and Life (maybe Tech Life(?), its the journal's name)
I propose changing the reference to this but I don't know which to cite...Oh, I think we should add the year 1924 to the prose in the article (and perhaps correct the spelling of his last name, ie Zander (aka Tsander)).Abitslow (talk) 20:44, 11 January 2015 (UTC)
thread_title:  Edit request Friedrich Zander (spelled Tsander ) 

message: CNUSAIL-1, a 3U CubeSat from Korea, was launched on 12 January 2018 on a PSLV rocket together with other 30 nanosatellites.  It is a solar sail cubesat intended to fly for at least 3 months. BatteryIncluded (talk) 15:11, 24 January 2018 (UTC)
thread_title:  CNUSAIL-1 in orbit 

message: A small table to summarise deployed sails by the delta-V they gained ?
: Name, date deployed, end of mission, delta-V achieved, notes ?
: IKAROS, 2010, still operating?
: Lightsail-2, 23 July 2019 to 17 November 2022.
: - Rod57 (talk) 10:51, 24 January 2024 (UTC)
thread_title:  Can we summarise deployed sails by the delta-V they gained