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Space Transportation Science

Japan To Launch Solar Sail Spacecraft "Ikaros" 138

Posted by CmdrTaco
from the so-that's-what-sailor-moon-does dept.
separsons writes "On May 18th, Japan's Aerospace Exploration Agency (JAXA) will launch Ikaros, a fuel-free spacecraft that relies completely on solar power. The spacecraft's 46-foot-wide sails are thinner than a human hair and lined with thin-film solar panels. After a rocket brings the craft to space, mission controllers on the ground will steer Ikaros by adjusting the sails' angles, ensuring optimal radiation is hitting the solar cells. If the mission proves successful, the $16M spacecraft will be the first solar sail-powered craft to enter deep space."
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Japan To Launch Solar Sail Spacecraft "Ikaros"

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  • Icarus? (Score:5, Funny)

    by Kelson (129150) * on Wednesday April 28, 2010 @01:07PM (#32017438) Homepage Journal

    It's always seemed like a bad idea to name anything after a figure whose claim to fame was that he ignored warnings against exceeding the tolerances of his vehicle, causing it to break up and kill him.

    • Re:Icarus? (Score:5, Funny)

      by Gerafix (1028986) on Wednesday April 28, 2010 @01:09PM (#32017474)
      To be fair the Japanese don't have to do metric/imperial conversions so they should be fine.
    • by drinkypoo (153816)

      This whole thing is so Anime-esque I can barely stand it. Not only does it have an unfortunate name, but it's an English acronym, the name is pulled from classic Greek... Now all we need is some Shirow suits and we've got a movie.

    • Re:Icarus? (Score:4, Funny)

      by srussia (884021) on Wednesday April 28, 2010 @01:31PM (#32017844)
      Talk about misnomer. This thing goes away from the Sun, not nearer it. Or maybe they meant post-wax-melt Icarus.
      • Re:Icarus? (Score:4, Informative)

        by radtea (464814) on Wednesday April 28, 2010 @02:57PM (#32019174)

        This thing goes away from the Sun, not nearer it.

        Nope. Tilt the sail so there is thrust against the direction of orbital motion and the ship will fall inward toward the sun. Think of the spacecraft with the sail at 45 degrees to the radial direction ot the sun, so light is reflected along a tangent to orbit in the direction of motion.

        So long as a solar sail craft is in orbit, it can either raise or lower its orbit more-or-less at will, although it is easier nearer the sun than further out. Once it is out of orbit, however, it can't ever return.

        • Re: (Score:3, Insightful)

          by HiThere (15173)

          Not sure about that. I've seen claims that a lot of the thrust of a solar sail would be due to the solar wind...which would tend to stick, and thus couldn't be tacked against.

          Also, solar cells tend to absorb photons, capturing their momentum, and when they re-radiate it (at a lower frequency) the direction is random.

          If this is correct, then the simple model of solar sails tacking using reflected light is at least an oversimplification, and possibly so much of an oversimplification that it doesn't properly

          • Re: (Score:3, Informative)

            Not sure about that. I've seen claims that a lot of the thrust of a solar sail would be due to the solar wind...which would tend to stick, and thus couldn't be tacked against.

            Those claims are wrong. The force on a solar sail due to solar radiation pressure is about a thousand times that of the solar wind.

            Also, solar cells tend to absorb photons, capturing their momentum, and when they re-radiate it (at a lower frequency) the direction is random.

            The solar cells are going to be absorbing a small fraction of the incoming photons. If the sail is designed properly, the rest will be reflected in a controllable direction.

            If this is correct, then the simple model of solar sails tacking using reflected light is at least an oversimplification, and possibly so much of an oversimplification that it doesn't properly predict the effects.

            Your assumptions are wrong, and the model is correct.

            MESSENGER has used its mostly reflective solar panels to make deliberate course changes. The basic physical principle is already proven, not just in the la

    • Creativity points, though, for coming up with a name whose acronym gives the Greek spelling "Ikaros". I've always hated Latinized spellings or names for Greek mythological characters.

      • Re: (Score:2, Insightful)

        The Latin spelling is Íkaros. So they are using the Latinized name.

        • by a whoabot (706122)

          I highly doubt the Latins used "Ikaros" very often. Maybe when they were referring to the Greek. Ovid certainly used "Icarus": http://users.telenet.be/daedalus/Ovid/DaedIcar.htm [telenet.be].

          • The spelling "Icarus" is derived from the Etruscan spelling which was Vicare.

            • Re: (Score:3, Interesting)

              by a whoabot (706122)

              That's possible, but I would doubt it. Greek words and names were usually transliterated by the Latins with "c" for Greek kappa (and "us" for cases with Greek second-declension masculine[omicron-sigma/"os"]). And this was done even after Etruscan had gone extinct. Maybe the tradition of transliterating as such came from the Etruscans, I don't know.

      • Re: (Score:3, Insightful)

        by a whoabot (706122)

        Shouldn't your name be "SputnikPanik" then?

    • Re: (Score:1, Offtopic)

      by A. B3ttik (1344591)
      It's correctly spelled iKarOS and pronounced 'eye-car-oh-ess.'
      • Re: (Score:1, Funny)

        by Anonymous Coward

        Isn't that Apple's new product?

      • by Pharmboy (216950)

        iKarOS?

        Sounds like an open source project to replace the faulty code in the oft crashing Toyotas. Using a Darwin kernel.

    • by osu-neko (2604)

      It's always seemed like a bad idea to name anything after a figure whose claim to fame was that he ignored warnings against exceeding the tolerances of his vehicle, causing it to break up and kill him.

      Yeah... "Daidalos" would have been a better name I would think. Or "Daedalus" if you prefer Latin spellings (which I assume you do, since you titled your post "Icarus" instead of the more accurate to the original Greek "Ikaros").

    • Still, it's not as bad as when Gloster produced Britain's first jet fighter, and decided to call it the "Meteor [wikipedia.org]".

      As in, "Those things that, every time you see one, it always seems to be falling out of the sky in a screaming ball of flame before smashing into the ground".

    • Re: (Score:3, Funny)

      Reminds me of the shock I experienced when I found that one of the biggest brand of condoms in the US is called 'Trojan'. It can either refer to the people of Troy that got totally pwned or to the Trojan Horse from which the guys got out once they were inside...
      • by Kiffer (206134)

        Of it can refer to the physically impenetrable Walls of Troy which were only breached through cunning trickery...
        Much like when she takes all your condoms and secretly pokes holes in them through the packaging so that she can have your baby... actually that's more likely to happen the other way round but anyway.

    • by mdielmann (514750)

      Sounds like a reminder, too. "Fly this puppy too close to the sun and your wings will melt off and you'll turn into a rock."

    • by blumpy (84889)
      It should have been named "The Crazy Eddie Probe", Motie technology FTW!
  • Thin sails (Score:2, Insightful)

    by Ricken (797341)
    The spacecraft's 46-foot-wide sails are thinner than a human hair and lined with thin-film solar panels.

    Won't that easily break if something even touches it? (lots of space rock going a few km/s out there, or am i totally off?)
    • Re:Thin sails (Score:4, Insightful)

      by d1r3lnd (1743112) on Wednesday April 28, 2010 @01:20PM (#32017638)

      Well yeah, but you could make it 100x thicker and all that debris whizzing around would still poke holes in it. This way, it's light enough to be a.) cheap to launch and b.) actually efficient enough at harnessing the solar "wind" to move its mass.

      • Re:Thin sails (Score:4, Informative)

        by yariv (1107831) <yariv.yaari @ g m a i l . c om> on Wednesday April 28, 2010 @02:02PM (#32018364)

        ...harnessing the solar "wind" to move its mass.

        I guess you didn't mean this, but just to avoid confusion. There is something called "solar wind", charged particles ejected from the sun, it has nothing to do with this sail. The sail uses light pressure, the pressure of light emitted by the sun.

        • by Chris Burke (6130)

          I guess you didn't mean this, but just to avoid confusion. There is something called "solar wind", charged particles ejected from the sun, it has nothing to do with this sail. The sail uses light pressure, the pressure of light emitted by the sun.

          I'm pretty sure it uses both, seeing as how both light and charged particles will impart momentum to the sail when they hit it. Ihe solar light pressure is larger, so it's accurate to say it's powered by light pressure. But the solar wind does have something to d

    • Re:Thin sails (Score:5, Insightful)

      by natehoy (1608657) on Wednesday April 28, 2010 @01:23PM (#32017700) Journal

      No, I suspect that's an expectation, but if the materials are built right it'll have some rip-stop capability so it'll just make a hole. That will affect the solar sail, but not significantly until you get a lot of them.

      The alternative is to make something that is heavier and less effective, which will still get punctured if a bit of debris goes through it.

      After all, things in space are usually not moving very slowly in relation to each other, so anything that touches it is likely to go right through anyway, regardless of the material. I suppose with something like this, the less resistance the material puts up the less its course is going to be screwed up by a space rock.

      It's also relatively unlikely (though certainly not impossible) for them to have a strike in the first place. Look at how cluttered Low Earth Orbit is with Mankind's crap, and how many active satellites have ever been knocked out of commission by our own cesspool of concentrated garbage in LEO? Two that I recall, and they hit each other. I know there have been occasional stories about impacts, but they aren't terribly common, and the chances of them dwindle off rapidly past LEO and Mankind's junkyard.

      Plus, $16 million?!? for a deep space probe that requires no fuel? That's chicken feed in terms of space travel. The Japanese could probably mass-produce them for $12 million a pop or less given economies of scale, send 10 of them out in different directions, lose 8 of them to debris strikes and whatever, and STILL get better science longer than pretty much anything short of nuclear we could send up today.

      • "Maybe in order to understand Mankind, we have to look at the word
        itself: "Mankind". Basically, it's made up of two separate words -
        "mank" and "ind". What do these words mean ? It's a mystery, and that's
        why so is mankind."

        -Jack Handy
        • Basically, it's made up of two separate words -

          "mank" and "ind". What do these words mean ? It's a mystery...

          Well, I don't know about "ind", but for mank [wiktionary.org]:

          mank

          1. (British, slang) disgusting, repulsive

          When he eats, he never closes his mouth. It's so mank

    • Re: (Score:1, Informative)

      by Anonymous Coward

      Sure, but 46 feet wide is a pretty small target in the vast, empty vacuum of space. Beefing up the thickness wouldn't make it tough enough to resist impacts at the velocities that space rocks would be hitting it at anyway. And if an object with mass hits your solar sail, probably it's better for it to punch clean through and impart as little kinetic energy into your vehicle as possible, so that it doesn't get knocked off course as badly.

    • by drinkypoo (153816)

      I don't know anything about this project, but one strategy for handling micrometeorite impact in large deployed thin-film solar panels (which is what these sails really are... plus "steering mechanisms"... thin-film ion drives?) is to deliver massively more sail area than is required, and to use a grid network design in the sails themselves such that power is carried through highly redundant parallel paths. If you lose a large percentage of the total sail area, you still retain the ability to operate. Nanos

    • Re:Thin sails (Score:5, Informative)

      by AikonMGB (1013995) on Wednesday April 28, 2010 @01:26PM (#32017748) Homepage

      Yes, you are right -- micrometeoroid impacts are definitely an issue that you have to deal with when you are using thin-membrane materials in space. Hopefully the engineers will design features called "rip stops" (among other names) into the sail to prevent tears from spreading through the sail. These are usually accomplished by putting a grid of perforations throughout the sail -- when a tear encounters one, the circular shape spreads the tensile stresses across the adjacent material, reducing the likelihood that the tear will propagate. This way a micrometeoroid impact won't ruin your entire sail, just the local grid element.

      There are probably other methods of implementing rip stops, but I haven't read any significant literature on them. Anything bigger than a micrometeoroid, and you have bigger problems -- but in this case, a traditional satellite would have just as big a problem.

      Aikon-

    • by yariv (1107831)

      Macroscopic objects are extremely rare (even microscopic objects are rare). Space is mostly, well, empty. The craft will cover some space, so it's expected to encounter something, but nothing big. The Sail can't be thicker, the sail area to mass ratio is what defines the efectiveness of the sail. As long as tiny holes in it won't cause it to collapse in some way or tear down, I can't see any problem.

      Even if it's destroyed, it's very cheap...

    • There is not much air resistance in space. A way would be to operate a radar actively detecting incoming objects and flap-down or rotate the whole sail in less than seconds?
    • Re: (Score:2, Insightful)

      by SnarfQuest (469614)

      I believe that "Saran Wrap" is about this thin, but you still trust it to protect you from the mold growing on the leftover beans in your fridge. Thin doesn't mean it has to be extremely fragile.

    • by GungaDan (195739)

      You're thinking about it wrong. They've seriously reduced the odds of side-impact damage with this clever thinner-than-hair technology. Glass half full, right?

  • meh (Score:5, Funny)

    by jt418-93 (450715) on Wednesday April 28, 2010 @01:14PM (#32017546)

    the bjorans did this centuries ago :)
    repeat

    • the bjorans did this centuries ago

      While I enjoyed this episode of DS9, it really wasn't clear to me how this Bajoran ship left Bajor's surface, did a de-orbit burn to start its journey into space and then did a re-entry onto Cardassia. They conveniently glossed over that piece.

      • Re: (Score:3, Insightful)

        by H0p313ss (811249)
        They call it science-FICTION for a reason. And this is Trek you're talking about.
        • That's true, but even in terms of Trek, you can't help but wonder why when Sisko recreated a Bajoran lightship, he had the ship launch from a space station, instead of the surface of Bajor. He was supposedly going for a almost genuine (with the exception of zero g) experience afterall.

      • by Pharmboy (216950)

        If you want overly technical scifi-babble about the technology and methods used in Star Trek, I suggest you watch Voyager instead. The stories aren't nearly as good, but they use lots of $2 words.

      • The point was that Bajorans have made it to Cardassia long before either species had developed warp technology.
        Kinda like as if Ikaros would suddenly made it to Alpha Centauri in a matter of minutes. And found Na'vi there.

        Whether Bajorans used chemical rockets, space elevators or giant catapults to get their solar-sail ships to space in the first place is rather irrelevant compared to that.

    • And NASA first used light pressure in an interplanetary probe decades ago... Mariner 3 [wikipedia.org] and Mariner 4 [wikipedia.org] both used light pressure to assist in controlling attitude during the trans Martian cruise phase of their flights. (That's what the paddles on the end of the solar arrays are for.)

      It wasn't used on later Mars missions because the craft became too large and heavy to use that method.

      Which is the real drawback of light pressure sails - from a purely mathematical standpoint they're the most eff

  • by decipher_saint (72686) on Wednesday April 28, 2010 @01:19PM (#32017616) Homepage

    Very cool project, I can't wait to see this baby in action!

    That said, someone already mentioned the project vehicle name, but we all know it should have been Odin: Photon Sailer Starlight.

    I suddenly feel very nerdy, much more so than normal.

    • Re: (Score:3, Funny)

      by Yvan256 (722131)

      I suddenly feel very nerdy, much more so than normal.

      Are you suddenly speaking more fluently in Javascript or Klingon?

  • "The craft's 46-foot sails come equipped with solar cells thinner than a human hair. When solar particles hit the cells, they generate power for Ikaros. Mission controllers on the ground will steer the craft by adjusting the sails' angles, ensuring optimal amounts of radiation are reaching the solar cells."

    What could possibly go wrong?

    • by RevWaldo (1186281) on Wednesday April 28, 2010 @01:53PM (#32018246)
      Possible outcomes:

      1) try > succeed > learn

      2) try > fail > learn

      Given the amazing low price tag for the mission, both are good outcomes.
    • by Sir_Lewk (967686)

      Uhhhh, not much? If the craft fails then they are only out a few million, same thing that happens when any other spacecraft fails (except they are usually far more expensive).

      Generally we try to reserve the "What could possibly go wrong" meme for things that reek of a bad idea, like making walking titanium skeletal robots, giving them machine-guns and Austrian accents, then turning over control of them to google. Space sails are a pretty simple and much discussed idea, and lack any particularly bad failur

      • by HiThere (15173)

        Well...

        If they're large enough you could use them to burn down cities and wipe out food supplies, but I guess we already have pretty effective ways of doing that.

  • Preparation (Score:5, Funny)

    by gmuslera (3436) on Wednesday April 28, 2010 @01:23PM (#32017704) Homepage Journal
    In the case it or one of its successors are launched to another solar system, i suggest that it carry scaled down versions of the ninja turtles, so if some come back to this mote in god's eye will never figure how we really are.
  • You know the only reason the Japanese named it Ikaros instead of Icarus is so they could finally laugh at us mispronouncing something for once. Wow, the Abbot and Costello routine around this one almost writes itself....

    • by renrutal (872592)

      You would be right if they were aiming for the name in english. Íkaros is his name in latin.

      At least its easier to write than greek: , which Slashdot can't even parse...

      • by Opyros (1153335)
        Actually, "Icarus" (or rather "ICARVS") is the Latin form of his name, see e.g. Ovid's Metamorphoses [thelatinlibrary.com]. "Ikaros" is a direct transliteration of the original Greek form.
  • ...is so infested with bad JS I can't view the actual text in FF. Anyone have a working link?

  • A Mote in Gods Eye (Score:2, Informative)

    by monkaru (927718)
    This reminds me of the novel "A Mote in Gods Eye" by Larry Niven and Jerry Pournelle. Who knows, maybe one day we'll be that "mote". http://en.wikipedia.org/wiki/The_Mote_in_God's_Eye [wikipedia.org]
    • by bFusion (1433853)

      Man I hope not, those Moties were pretty terrifying.

      Fantastic book though, I should read that one again.

  • I would like to see the verification on all of these statistics from another source. I am hesitant to believe this because it costs about $450 MILLION [nasa.gov] just to launch a space shuttle once. If the article has more basis than mere rumor, this price tag cannot possibly include deployment. Maybe it's $16M on materials alone? Maybe salaries alone? Consider also that they plan on spending around $2B over the course of ten years, which is just $.3B more than the pricetag on a single Space Shuttle. I will be surpris
    • by cowscows (103644)

      I'm thinking that $16M does seem rather low, but I would expect the cost to be significantly less than a shuttle launch. The shuttle is pretty big, very heavy, and also has to carry and keep alive a bunch of people through launch, orbit, and return. This solar sail is designed for a much simpler set of tasks, and likely weighs in at a small fraction of what a shuttle orbiter does.

    • by Imrik (148191)

      As the article implies, the $16M price tag is the price of the ship, not including the price of using it. Given that it's being sent up as a secondary launch for another mission the price of using it should be pretty low.

    • Building the Ikaros alone probably accounts for the $16M. I think JAXA HIIA launch cost is probably on the order of $100M (U.S.) although that cost could be shared as they can launch multiple satellites at a time (bounded by space and weight constraints).
  • by wisnoskij (1206448) on Wednesday April 28, 2010 @02:02PM (#32018370) Homepage

    Now all we have to do is find a tachyon eddy and we could be on Cardasia in no time.

  • by BetterSense (1398915) on Wednesday April 28, 2010 @02:35PM (#32018882)
    I haven't really payed much attention to Japan's space program in the past...heck I didn't really know they had a space program. But they recently landed a probe on an asteroid, and returned it to earth with asteroid rocks. When I read that it was like, "Oh. Japan has a space program, and they actually did something scientifically interesting". It seems like space programs are all about bitching about government funding and endlessly redesigning ancient rocket designs and speculating about manned missions to other planets, and meanwhile Japan went to an asteroid and brought back rocks. So when they say they are going to make this solar sail thing, I believe that they are going to make this solar sail thing.
    • Re: (Score:1, Interesting)

      by Anonymous Coward

      That's an excellent attitude and it (unsurprisingly) mirrors my own thoughts on Japan's space program. They're doing *cool stuff* that can spark the imagination. And they're doing it for amazingly reasonable sums of money.

    • But they recently landed a probe on an asteroid, and returned it to earth with asteroid rocks

      Well, not exactly. They sent a spacecraft to an asteroid to hover above the asteroid, shoot a pellet at it, scoop up some debris, and come back. Instead, part of the system failed. The spacecraft landed to preserve its health while possible fixes were discussed. The landing caused the pellet shooting system to fail so no asteroid debris was collected for sure. The Japanese decided there was still some chance that something, somehow, ended up in the collection bin. They uploaded some patches to the spacecra

  • Inhabitat Articles (Score:4, Insightful)

    by BJ_Covert_Action (1499847) on Wednesday April 28, 2010 @02:42PM (#32018976) Homepage Journal
    This is a bit offtopic but it's becoming more prevalent and frustrating on slashdot. Is there a chance we could stop posting so many Inhabitat stories to slashdot? More often than not they aren't even stories so much as single paragraph posts that say, "Look at this really cool technology! Isn't it cool and, more importantly green?" They never even bother to go into a decent amount of technical detail about the really cool technology. Hell, in this case, the wikipedia article [wikipedia.org] has more relevant technical details than the Inhabitat article. It's not like we put a post to slashdot every time a new wikipedia article on technology opens up. For that matter, if we are just posting links to websites about really cool technology, we could easily go digging through websites that are dedicated to the particular technology to get the really juicy bits of interest. For instance, when talking about Ikaros, why don't we try looking it up on one of the dozens of websites dedicated to cataloging spacecraft? Well that's not news is it? That's just cataloging interesting technology which, as far as I can tell, is all Inhabitat does.

    I guess what I am getting at is that just because Inhabitat stumbled upon something cool they didn't know existed, it doesn't mean there is any news regarding that particular item. Now, if Ikaros launched recently, or if it's mission was underway, or if it was experiencing some technical difficulties, that would be something. The fact that the mission exists in the first place is neither a recent development nor particularly newsworthy. It seems like the firehose is getting clogged with Inhabitat submissions and frankly its starting to seem like slashvertising for the blog.
  • I wonder how much speed it picks up after a few months/years? I think I remember reading that these things go quite fast eventually, due to the perpetual acceleration. Speaking of which, is there any way to slow it down?
  • I'm surprised that there hasn't been a single EVE reference to this project yet.

    Soon as I saw this project, I thought, "It's like they're developing a Minmatar frigate [eveonline.com] of some sort!"

    With that in mind, I genuinely hope that this project exceeds expectations, and that we may see more projects like this in our near future. Good luck and best wishes.

  • Name FAIL

  • Calling it the Ikaros is sort of like calling a new ship you build "The Titanic". It doesn't do a lot to inspire confidence.

    Here's to hoping to works for them though, it's definitely ambitious and way cool.

  • spacecraft will be the first solar sail-powered craft to enter deep space

    Depends on your definition of "deep space". I understood that to mean outside the solar system. A quick googling shows two definitions: 1. interstellar 2. interplanetary and beyond. So definitely not clear. In any case, it's somewhat moot since there's never been any solar sail-powered craft, ever, that succeeded in deploying its sail. Even in Earth orbit.

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