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Japan Successfully Deploys First Solar Sail In Space 284

An anonymous reader writes "This morning the Japanese space agency, JAXA, successfully unfurled a solar sail in space for the first time. Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel. The Japanese spacecraft IKAROS created centripetal force by spinning, allowing it to launch the 0.0003-inch-thick sail. While deployment is a challenge in a zero-gravity environment, spacecraft — unlike airplanes — don't have to contend with drag, so with each photon that hits the sail helps the spacecraft gather speed."
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Japan Successfully Deploys First Solar Sail In Space

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  • by pluther ( 647209 ) <pluther@us a . net> on Thursday June 10, 2010 @06:35PM (#32529368) Homepage

    And don't forget Forward's Flight of the Dragonfly in that list.

    So, when can I take the space elevator up and catch a sailship for Mars? And do I have to learn Japanese first?

  • Re:Focus (Score:5, Informative)

    by 0xdeadbeef ( 28836 ) on Thursday June 10, 2010 @06:36PM (#32529382) Homepage Journal

    Can you count []?

  • Re:Which force? (Score:3, Informative)

    by pluther ( 647209 ) <pluther@us a . net> on Thursday June 10, 2010 @06:41PM (#32529450) Homepage
    You are correct. Centripetal force is the force exerted by the tethers holding the sail to the spacecraft. (Force from the edge towards the middle).

    Centrifugal force is what pulls the sail out. (Force from the middle to the edge.)

    Also, there's no such thing as centrifugal force: as explained by, who else, xkcd []

  • Better Articles! (Score:5, Informative)

    by BJ_Covert_Action ( 1499847 ) on Thursday June 10, 2010 @06:52PM (#32529568) Homepage Journal
    Oh for fuck's sake why do we keep linking to Inhabitat for news on space missions? The Ikaros project is, indeed, a newsworthy and exciting piece of nerd information. However, linking to a stupid environmental blog that holds informational gems like:

    "Solar sails offer the best hope for deep space exploration because they eliminate the need to carry fuel." (Hint: No, they don't. They don't do that at all. You need maneuvering thrusters to align your spacecraft before deployment. You need a power source to provide electricity to power your control motors when you get too far away from the sun. Saying solar sails eliminate the need to carry fuel is like saying that a spoiler eliminates the need for a gas tank on a car because it improves gas mileage. That is a completely asinine statement.)

    "spacecraft — unlike airplanes — don’t have to contend with drag," (Also untrue. Depending on what orbit/space environment you are in, you may still have to contend with the drag of Earth's atmosphere. If you are deploying in LEO, this could induce a significant moment on your spacecraft. Also, thank you for pointing out the difference between aircraft and spacecraft...that was really weighing on my mind while reading about a spacecraft mission that is proof-of-concepting a new technology).

    "Of course, aliens aren’t the only reason to want to travel through space without carrying rocket fuel. NASA is also working with solar sails to develop ultra-efficient spacecrafts. " (Aliens and ultra-efficient spacecrafts eh? That's your high-quality independent journalism right there? Give me a break this kind of stupid babbling about a very important mission does nothing but patronize the spacecraft industry and the folks who worked on this particular bird).

    Let me give you a hint Inhabitat readers, if you want to track the progress of an impressive space mission, try going to a news site that actually is focused on space. Maybe you should check out: Centauri Dreams [] or one of JAXA's [] own website's [] regarding the hardwork and impressive design that went into designing this mission. Perhaps you should read and link to some articles that actually contain interesting, relevant, tech-centric discussions of the mission rather than your latest, retarded, three paragraph, juvenile blog whose most interesting mission detail: "....allowing it to launch the .0003-inch-thick sail," borders on painfully irrelevant.

  • Re:Focus (Score:5, Informative)

    by BJ_Covert_Action ( 1499847 ) on Thursday June 10, 2010 @07:01PM (#32529666) Homepage Journal
    Meh, don't bother. It's hard to convince the people who keep posting this kind of shit that the American space industry is anything but dead. Nevermind the fact that NASA still has the most impressive space research facility on the planet (JPL) or that they are working on various lifting technologies that include everything from hypersonics to extremely advanced aerodynamics (AMES research facility). Nevermind the fact that American business are now starting to launch vehicles into space, without existing government contracts, unlike almost any other nation on the planet. Nevermind the fact that Cassini has just detected evidence that methane based lifeforms may exist on Titan. Nevermind the fact that NASA is trying to land a rover the size of a mini cooper on mars.

    Nah, we can just forget all of the missions that NASA has currently studying the Sun, Mercury, Pluto, Saturn, and just about every other interesting object in our solar system because Obama killed the space industry, dontcha know?

    As old as it gets to see people post this kind of crap all over the internet, there is absolutely nothing that will convince them that America, space industry included, is nothing more than a washed up has been that is wallowing in its own filth these days. It's like trying to talk reasonably to a kid who has his fingers in his ears and is shouting, "La la la la la I can't hear you!" They'll only learn otherwise when they make the conscious decision to remove those fingers and grow up.
  • by SixAndFiftyThree ( 1020048 ) on Thursday June 10, 2010 @07:05PM (#32529694)

    How does it stop? If it accelerates tangentially to the Earth's orbit, which is still the most efficient way to get to another planet, then it can decelerate by tilting the sail the other way. In each case, the acceleration vector will have a component outwards from the Sun; the ways to cancel that include furling the sail and waiting for the Sun's gravity to do the job, using a nearby planet's gravity, aerobraking in a nearby planet's atmosphere, or lithobraking. If none of the above work, then perhaps you can't stop. A bizarre scheme that has been suggested would be to bring a second, smaller sail along and use it to collect light reflected from the main sail towards the Sun (you cut the main sail loose and let it drift ahead of you), thus providing reverse thrust until the main sail is too far away. Hard to be sure how well this would work.

    Debris hitting the sail? A few pinholes will make no appreciable difference to its performance. A real sail would have to be made with some sort of "ripstop" reinforcement.

    Max speed? You have a misconception here: solar sails don't use the solar wind (much), but the pressure of the Sun's light. Since e=mc2, momentum equals e/c. I don't have the formula handy, but the important factors are the thickness of the membrane (thinner is better) and how close to the Sun you start (closer is better, provided the membrane doesn't melt). In theory, solar escape speed is attainable, if you're only pulling a small payload. Significant fractions of the speed of light are not attainable.

    Scooping up the gas would need one **** of a scoop!

  • Re:Focus (Score:2, Informative)

    by revjd909 ( 749913 ) on Thursday June 10, 2010 @07:53PM (#32530216) Homepage Journal
    The part that's most frustrating is "What's the size of the NASA budget?" And how does that compare to the size of our military budget? We could have a colony in space or on the moon by now, if we weren't spending close to $1 trillion/year making war. Here's a little look at more of what Japan's planning: []
  • by chill ( 34294 ) on Thursday June 10, 2010 @07:58PM (#32530246) Journal

    It seems you missed this story [] on the first commercially available jetpacks back in March.

  • by boogahboogah ( 310475 ) on Thursday June 10, 2010 @08:55PM (#32530700)

    Looking at the photos in the referenced article, the fourth picture, showing the solar sail fully extended with all kinds of nice wonderful colors (photo from a perpendicular angle) cannot have been shot from the same camera as the other photos. Different color saturation, different focus, different depth, different starfield luminosity, a rather idealized picture of the earth. Offhand, I think this is an artistic or fictional or Photochop representation, and, it is not labeled as such.

    It's nice that the Japanese have launched a sail, but that hoked up photo just killed it for me.

  • Re:Better Articles! (Score:1, Informative)

    by Anonymous Coward on Thursday June 10, 2010 @10:50PM (#32531290)

    To be quite fair, calling inhabitat an environmental blog is a misnomer as well. They wanted, at one point, to be one, but now they report anything they might find cool, regardless of whether or not it's green. My biggest issue with them is exactly as you said, they lack any scientific (or in some cases basic) logic. I recall them explaining how great this 3d rendering of a grass tunnel is, when in reality, grass is not known for it's ability to grow on the ceiling of a structure, hidden from light...

  • Re:Better Articles! (Score:2, Informative)

    by MMatessa ( 673870 ) on Thursday June 10, 2010 @11:14PM (#32531428)
    I also came here to complain about the poor article. Good coverage comes from the blog of the Planetary Society [], which is working on its own solar sail and actually has people visiting JAXA.
  • by cp.tar ( 871488 ) <> on Friday June 11, 2010 @06:28AM (#32533310) Journal

    I would add Cordwainer Smith’s The Lady Who Sailed The Soul to the list.

  • Re:Patent Time (Score:3, Informative)

    by rossdee ( 243626 ) on Friday June 11, 2010 @08:57AM (#32534120)

    Prior art:

    The Wind from the sun - Arthur C Clarke
    The Mote in God's Eye - Niven/Pournelle
    The Flight of the Dragonfly - Robert L Forward

    Not to mention an episode of DS9 where Sisko recreates a Bajoran solar sail.

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