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Japan Successfully Deploys First Solar Sail In Space

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."

53 of 284 comments (clear)

  1. come sail away by 54mc · · Score: 3, Funny

    I thought those crazy japanese were angels, but much to my surprise, they climbed aboard their starship and headed for the skies.

    --
    Joy! Beautiful spark of the gods!
  2. It's my childhood future... by History's+Coming+To · · Score: 4, Interesting

    Jetpacks? No. Flying cars? No. Sentient robots? No.

    Solar sailing? Oh yes! I love this, it's one of the signals that we're living in the future, if you grew up on Clarke, Asimov et al. Required reading: Clarke's "A Wind From The Sun", Stross's "Accelerando".

    --
    Please consider this account deleted, I just can't be bothered with the spam anymore.
    1. Re:It's my childhood future... by pluther · · Score: 4, Informative

      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?

      --
      If the masses can keep you down, you're not the Ubermensch.
    2. Re:It's my childhood future... by chill · · Score: 2, Informative

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

      --
      Learning HOW to think is more important than learning WHAT to think.
    3. Re:It's my childhood future... by Topwiz · · Score: 2, Interesting

      The book version of Planet of the Apes has one.

    4. Re:It's my childhood future... by Sir_Lewk · · Score: 3, Interesting

      I'll second that recommendation for Accelerando. That's the book that convinced me solar sails are way way cooler than chemical rockets.

      It's even available as a free ebook, though I of course recommend picking up a hard copy.

      --
      "linux is just DOS with a UNIX like syntax" -- Galactic Dominator (944134)
    5. Re:It's my childhood future... by cp.tar · · Score: 2, Informative

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

      --
      Ignore this signature. By order.
    6. Re:It's my childhood future... by mcgrew · · Score: 2, Insightful

      They had jetpacks in the late '60s. Not very utilitarian, but they had them

      The Wright Brothers invented the flying car in 1903 when my grandmother was a baby.

      Sentient robots? Nope, not unless we ever figure out what sentience is and how it works.

  3. Focus by AnonymousClown · · Score: 5, Insightful
    Did anyone else have the thought that, here are the Japanese, designing and building spacecraft to further explore our Universe and progress mankind's knowledge.

    Here are we, the US, once the leaders of space exploration, have spent billions of dollars to go back and relive some glory (Moon shot) and canceled that, we have canceled the Shuttle program with no other vehicle to replace it, and in the process put a halt to much basic research.

    We're kind of like that pathetic ex High School jock that's trying to relive his glory days.

    --
    RIP America

    July 4, 1776 - September 11, 2001

    1. Re:Focus by Anonymous Coward · · Score: 5, Funny

      We're kind of like that pathetic ex High School jock that's trying to relive his glory days.

      But we threw 4 touchdowns in one game, man. IN ONE GAME!

    2. Re:Focus by 0xdeadbeef · · Score: 4, Informative

      Can you count?

    3. Re:Focus by Charliemopps · · Score: 2, Insightful

      I can count the number of non-scientists excited about those projects on 1 hand. Does that count? If NASA continues only to accept projects that do not interest the general public they are going to completely lose funding within a few decades.

    4. Re:Focus by Symbha · · Score: 3, Insightful

      I will only point out that Hubble would have been a complete failure, without the shuttle.
      The reason to have a manned space program, is entirely about the unforeseen.

      When we do need to send Bruce Willis up to the asteroid to blow it out of the way, we are really going to wish we had a suitable manned space program.

    5. Re:Focus by BJ_Covert_Action · · Score: 5, Informative

      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.

    6. Re:Focus by 0xdeadbeef · · Score: 2, Insightful

      No, you can't, because the highest you can go is 0x1F.

    7. Re:Focus by sexconker · · Score: 2, Interesting

      Seems to me that the US and Russia (and the Germans working on both sides) did all of the leg work in the field.

      Seems to me a satellite, however fancy, is orders of magnitude simpler than manned space travel.

      Seems to me Japan doesn't exactly a military to waste money on, on account of that whole World War II thing. Or two current wars. Or failed banking and auto industries. Or morans who bought houses they couldn't afford. Or...

      Seems to me the US is shying away from public space exploration, while the private industry prepares to take over.

      You show a complete lack of understanding of the situation. You might as well post about how Japan has better residential internet speeds than the US.

    8. Re:Focus by Sycraft-fu · · Score: 4, Insightful

      Certainly does seem that way. There just seems to be a subculture of Americans, of which Slashdot has more than normal, that love to hate on America. Whatever America does, it's bad. They see the nation in a continually bad light. The flipside of that is usually that they look at other nations with rose coloured glasses. They see only the good, they don't see any down side. The fail to see that there are problems with any nation, as nations are made up of people and we are all flawed.

      For some I think it is just because the see that America may be sliding from a position of dominance and they take that to a nihilist extreme where it means America will become nothing, a 3rd world hellhole or worse. For some reason it never occurs to them that there have been other places like, say, England, or France that once were superpowers and now are just very nice places to live.

      Whatever the case, it does get rather annoying. Criticizing the problems America has is healthy, and necessary. Only though looking at the faults and trying to correct them can you get better. Just hating on America all the time is stupid and unproductive.

    9. Re:Focus by revjd909 · · Score: 2, Informative

      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: http://pinktentacle.com/2010/06/futuristic-mega-projects-by-shimizu/

      --
      *** once i really listened, the noise just went away. -liz phair
    10. Re:Focus by sunspot42 · · Score: 4, Insightful

      It would have been cheaper to launch a fleet of Hubble Space Telescopes than to support the Shuttle program. Hubble cost something in the neighborhood of $2.5 billion. Shuttle missions are somewhere between $500 million and $1.5 billion each, depending on how you handle the accounting. We'll have spent about $200 billion on the Shuttle program by the time it ends. That's around 80 Hubble Space Telescopes.

      Getting humans, their life support equipment and their supplies into space is outrageously expensive using chemical rockets - especially the Shuttle, which has ridiculous per-pound launch costs compared to other boosters. Manned spaceflight is impossible to justify on a cost basis. Robots can do more, cheaper, and that'll continue to be the case unless and until we can develop some better way to get people, their habitats and their supplies into orbit. Which is one of the main things NASA should be focused on.

    11. Re:Focus by ZirconCode · · Score: 2, Insightful

      There just seems to be a subculture of Americans, of which Slashdot has more than normal, that love to hate on America.

      Do you want to know why so many people hate Americans? It's because Americans are so full of themselves that they can't imagine a non-American English speaker.

    12. Re:Focus by Anonymous Coward · · Score: 5, Funny

      And now we sell shoes, Peg.

    13. Re:Focus by UK+Boz · · Score: 2, Insightful

      Why does Japan's Success have to mean America's failure?

      --
      www.boznz.com Simple solutions to complex problems.
    14. Re:Focus by gstoddart · · Score: 2, Interesting

      That's around 80 Hubble Space Telescopes.

      As true as those numbers are, it ignores the fact that without people going into space, Hubble would be floating up there blind as a bat.

      It may come to pass that we can put Really Complex Things up into space and have them work and stay working. For now, Hubble could never have happened without manned space flight.

      Besides, maybe it's because I'm old and have a romantic attachment to it, but I do think it's a shame that I both remember the beginning and the end of the Shuttle program. When the first ones launched, they used to stop classes and watch it live.

      I'm sure it is cheaper and safer. I just seems somehow, less cool. :(

      Oh, but kudos to the Japanese for deploying a frickin' solar sail!! That rocks! Go Team!

      --
      Lost at C:>. Found at C.
    15. Re:Focus by osu-neko · · Score: 4, Insightful

      That's around 80 Hubble Space Telescopes.

      As true as those numbers are, it ignores the fact that without people going into space, Hubble would be floating up there blind as a bat.

      ...and we wouldn't care, because we'd be getting perfectly good images from most if not all of the other 79 of them.

      --
      "Convictions are more dangerous enemies of truth than lies."
    16. Re:Focus by sunspot42 · · Score: 2, Interesting

      Without wasting $200 billion sending men into space, Hubble could have been replaced 79 times over with, presumably, better telescopes. Or we'd have been able to easily afford one or two replacement craft, even better than Hubble, which built on its successes and (hopefully) improved upon its failures.

      Instead we've sunk $200 billion into the Shutles and another $100 billion plus into the ISS, to boldly sit where Skylab has sat before. Manned spaceflight has proven to be a colossal money sink with virtually no scientific returns. Imagine if we'd spent just a tenth of that money on our unmanned space program? You could quadruple the number of interplanetary probes and space telescopes we've launched and still have money to burn.

      You do realize the next generation of telescopes NASA plans to launch won't even be man-serviceable, since they're destined for Lagrange points and other destinations far outside low earth orbit?

    17. Re:Focus by c6gunner · · Score: 2, Funny

      Ah, thanks. I was starting to get worried. When the usual talking points don't get trotted out, I start wondering what kind of crap you're coming up with now.

    18. Re:Focus by delinear · · Score: 3, Insightful

      Plenty of human endeavours have been colossal money sinks, few have given us the ability to make a claim so bold, that we left this little planet of ours under our own speed, even for just a tiny fraction of our history. Even if the universe is teeming with life, I have to believe that spaceflight is still a monumental accomplishment. Certainly one I'd rather leave as our epitaph than "we killed a bunch of people for something as tawdry as resources or religious differences". If the fact that, in evolutinary terms, we were barely out of the trees before we got our kind into space doesn't embiggen the soul, I don't know what will.

    19. Re:Focus by argStyopa · · Score: 5, Insightful

      I found your statement to be amusingly ironic. Only on /. would it be rated 'insightful'.

      First, please understand that Americans are generally staggeringly provincial; most Americans don't (and never will) own a passport. Most will never leave the US, because they don't have to. Most do not speak a foreign language. Contrary to the view of 'world citizens' like many Euros (as well as a significant number of patronizing, elitist Americans), this isn't because the bulk of Americans are stupid hicks, they simply don't need these things. Everything they can do, need to do, and want to do, all can take place within the comfortably-broad confines of US borders. If they're feeling slightly adventurous, they can go to Canada (barely another country) or even Mexico (where most vacation destinations are less hispanic than Laredo, TX anyway).

      So to your point, regarding Americans' 'inability to imagine a non-American English speaker', of course they don't generally assume that, it wouldn't make any sense for them to do so in context.

      Secondly, what other countries seem to interpret as arrogance appears to be some sort of reverse projected narcissism: "OMG you are so self-centered, you never notice me!"...and if you don't get the irony in that statement, well, then you're hopelessly humorless.

      To suggest that lack of regard equals arrogance is naive, presumptuous, and ultimately self-defeating. To then use THAT as a motivation to generically HATE someone, based on nothing more than their country of origin? I'd call that a self-justifying conceit - dare I call it arrogance? - itself.

      Get over yourself - nobody automagically is entitled to that level of importance; not Americans individually, and certainly not you.

      --
      -Styopa
  4. Which force? by icebike · · Score: 4, Insightful

    Centripetal or Centrifugal?

    Spinning creates what is commonly called Centrifugal force, and the tethers of the sails constitute what is generally referred to as the Centripetal force.

    About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....

    --
    Sig Battery depleted. Reverting to safe mode.
    1. Re:Which force? by Fluffeh · · Score: 2, Funny

      About here is where some physicist jumps up and tells me everything I learned in the past is wrong and I should shut up and sit down.....

      Yes. Sit down and shut up. Also, because you didn't pay attention the first time you learned it, I won't waste time explaining it again.

      *smirk*

      *sips coffee*

      --
      Moved to http://soylentnews.org/. You are invited to join us too!
    2. Re:Which force? by Anonymous Coward · · Score: 5, Funny

      Obligatory xkcd:

      http://xkcd.com/123/

    3. Re:Which force? by pluther · · Score: 2, Informative
      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

      --
      If the masses can keep you down, you're not the Ubermensch.
    4. Re:Which force? by sammyF70 · · Score: 2, Funny

      What exists when people forget Newton's first law is a Darwin Award contender (possibly with a posthume leading role in the next anti-drug campaign movie).

      --
      "DRM is like the Ford Pinto: it's a smooth ride, right up the point at which it explodes and ruins your day."-C.Doctorow
  5. Commence Whining by RobinEggs · · Score: 4, Insightful

    Commence whining about the death of the US Space program, the US falling behind other nations, and how it's all the (Pick one: Obama, Bush, Clinton, Bush Sr.) administration's fault in 3.....2......1....blastoff.

    Don't get me wrong, it's all basically true; it's just tiresome whining to listen to.

    1. Re:Commence Whining by geekoid · · Score: 3, Informative
      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
    2. Re:Commence Whining by Nyeerrmm · · Score: 3, Interesting

      It's a common theme -- but I think its a little misguided. It occurs to me that part of the problem is that NASA thinks of Apollo-level funding as the rule rather than the exception.

      Done right, we could do quite a bit with the current Human Spaceflight (HSF) budget. Given that the post-Apollo budget levels are relatively consistent, it seems that current funding level is the politically sustainable level, without external influences (i.e. Cold Wars). If there had been no space race, I can't help but think that NASA would be much better at doing impressive things on the HSF side on their more modest budget.

      $17B is a pretty good chunk of change, and the fact that its been increased despite an across-the-board budget cut on other non-defense discretionary spending shows that there is some significant support for it. We (the space community) tend to think of 1% GDP as the "correct" amount that should be spent on space exploration. Maybe if we get used to the idea that what we have now is closer to normal, we'll be much better off.

  6. Deploying Pierce Brosnan in 3...2...1 by Firehed · · Score: 3, Funny

    Seriously. If you're going to make a real-life attempt at a Bond plot, at least change the name of your giant solar sail.

    --
    How are sites slashdotted when nobody reads TFAs?
  7. 1st step in something useful for deep exploration. by hadesan · · Score: 3, Insightful
    One question, how does it stop with no fuel (aka an ability to brake?)

    Also, how well does the membrane hold up to minuscule debris? Is it durable for extended voyages (outer solar system, extra solar)?

    What is the maximum velocity it could reach with the available solar wind prior to it ending at the heliosheath?

    If they could combine it with something to scoop up stellar gas, along with something to process the gas into energy for steering and braking, you would have something useful.

    And please no Uranus comments for my subject line...

  8. Better Articles! by BJ_Covert_Action · · Score: 5, Informative

    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.)

    And:
    "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).

    And:
    "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.

    /endnerdrage

    1. Re:Better Articles! by MMatessa · · Score: 2, Informative

      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.

  9. Ya! The US has done nothing! by Sycraft-fu · · Score: 5, Insightful

    I mean they most certainly didn't recently deploy two rovers to Mars that WILDLY exceeded expectations. They didn't then also deploy another, fixed, lander which while not as wildly successful exceeded it's planned mission significantly. Nope, none of that happened...

    Oh wait, yes it did.

    Please, while the US space program is not without troubles, it isn't as though it is at a standstill. NASA continues to do some amazing work, and much of it like the landers are pure science, to further our knowledge.

    Stop with the US hate that is so popular on Slashdot. The US is not perfect, no nations is, indeed no human endeavor is. There's plenty to criticize and that includes in the space program. However trying to pretend as though they accomplish nothing of note is silly. Two successful recent Mars missions shows that. No, they weren't manned, neither is this Japanese craft. Putting people in space is dangerous and often not worth the expense. We can learn a lot with remote operated equipment.

  10. Thank you Slashdot. by CrazyJim1 · · Score: 2, Interesting

    I want to hear stories like this. I want to know if Solar Sails are viable. Back in highschool I wondered about a space ship propulsion device. My theory was to make particle accelerators to get the maximum propulsion out of hydrogen atoms and fire them out the back of the craft. The problem was you could run out of hydrogen. Its not something serious, but just trying to figure out something better than rockets. The solar sail sounds like it is plausible, and I'll be excited to hear this story develop. The last thing I was excited about was the Mars Rovers. How cool were those.

    1. Re:Thank you Slashdot. by TooMuchToDo · · Score: 2, Interesting

      Why not use magnetic fields to scoop hydrogen from in front of your craft and accelerate them out the back using a particle accelerator/cyclotron. This could be powered via solar near our/other suns, or nuclear RTGs further out. Similar to an ion drive, but without the need to carry the propellant.

  11. Re:1st step in something useful for deep explorati by SixAndFiftyThree · · Score: 5, Informative

    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!

  12. Re:1st step in something useful for deep explorati by DowdyGoat · · Score: 4, Interesting

    NASA had a proposed "Interstellar Probe" mission that was to use a 200 meter diameter solar sail to travel 200 AU in 15 years (the heliosheath, or edge of the solar system, is about 100 AU from the Sun). It was thought they could keep contact until 400 AUs distance. Link (go to the Interstellar Probe Report link there):

    http://interstellar.jpl.nasa.gov/

    This mission, as well as a proposed follow up mission (I think called Interstellar Probe 2) that would have had a bigger sail, gone twice as fast, and reached around 1000 AU, were both shelved quite a while ago. (There was a single NASA page on that second mission a long time ago, but I cannot find it now.)

    You could use probes like these to sort of act as galactic weather probes, testing the interstellar space that our solar system would encounter in coming decades/centuries and seeing how that "interstellar weather" affects the Sun the the Earth's environment as we pass through it.

    A theoretical improvement on a solar sail would be a "light sail"--you could set up satellites with powerful laser systems orbiting the Sun and use that focused and powerful light to push sails much faster. Some folks have hypothesized reaching 10% to 30% the speed of light using techniques like this if the lasers were powerful enough and coordinated enough. Assuming success, you could possibly send an unmanned probe to Alpha Centauri in a matter of decades. In this instance, you could theoretically use a solar sail to use the solar wind/light of the Alpha Centauri system to slow down once you started nearing it (although that could potentially add more travel time).

    Things like these could be a relatively fast, cheap, and safe (as compared to nuclear) way to explore our external solar system (Kuiper Belt) and nearby interstellar space (Oort Cloud), and get a good handle on how our surrounding interstellar space affects our solar system. Very interesting stuff. I hope more of it happens!

  13. Re:1st step in something useful for deep explorati by blueg3 · · Score: 5, Funny

    Lithobraking is an ingenious term for "fuck it, we'll just crash into the planet".

  14. Re:warp drive is better by Nyeerrmm · · Score: 2, Insightful

    Somehow I think it will be easier to get some form of suspended animation working than to develop a functioning FTL drive.

  15. Re:0.0003-inches ?! by ArbitraryDescriptor · · Score: 4, Funny

    Seven point six two micron: Full Metal Ja- er, sorry, just 7.62 microns.

  16. Anybody else notice the fake photo ? by boogahboogah · · Score: 2, Informative

    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.

  17. Solar sails. Huh. That's nothing. by fyngyrz · · Score: 2, Insightful

    The ship in Poul Andersen's The Makeshift Rocket uses beer for propellant.

    You can't top that. You're always on the right heading, see? Heading froth into the stars!

    Solar sails, indeed. [sniff!]

    --
    I've fallen off your lawn, and I can't get up.
  18. Re:0.0003-inches ?! by bmo · · Score: 2, Funny

    You don't know how thick it is?

    If they said .00762mm, you still wouldn't have been able to visualize it anyway.

    This is how you visualize it:

    It's 1/10 the thickness of a human hair. Now get out.

    --
    BMO

  19. Re:Patent Time by rossdee · · Score: 2, Informative

    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.

  20. Two words: by copponex · · Score: 2, Funny

    Ron Jeremy.