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NASA Space Transportation Science Technology

NASA To Demonstrate Largest-Ever Solar Sail in Space 91

Zothecula writes "NASA's upcoming Technology Demonstration Missions are intended to 'transform its space communications, deep space navigation and in-space propulsion capabilities.' Three project proposals have been selected for these missions, which should be launching in 2015 and 2016. One of those projects will involve demonstrating a mission-capable solar sail. While NASA has recently tested a solar sail measuring 100 square feet (9.29 square meters), this one will be the largest ever flown, spanning a whopping 409 square feet, or 38 square meters."
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NASA To Demonstrate Largest-Ever Solar Sail in Space

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  • Is this something that Neil Armstrong would be disappointed about? I think this is some pretty cool news myself, even though I don't exactly believe it to be the best use of government funds ATM.
    • by khallow ( 566160 )
      While fiscal prudence should be happening in all government agencies, including NASA, the solar sail is a very interesting piece of technology that should have been explored decades ago. I would suggest that it would be a much more effective use of funds, restricted to NASA, than the SLS (Space Launch System) heavy lift proposal that was aired a couple of weeks ago.

      The key advantage is that the propulsion system doesn't run out of fuel. As long as it is exposed to sunlight, one can maneuver it around the
    • by Ogive17 ( 691899 )
      So should the government cut all funds to science research and development? We really didn't need those jobs anyway.
      • Last time I checked, NASA isn't the only agency that does science. NOAA [noaa.gov] comes to mind as well as the NSF [nsf.gov] just to name a few. I my point is that there are terrestrial concerns that are a tad more pressing for the immediate term. Drop the hyperbole.
        • by M8e ( 1008767 )

          Not Safe For GOVernment?

        • Oh, so as long as there's just one agency, science and employment will grow just fine. That is your hyperbole - or rather hypobole.

          Look, why don't you concentrate on the $TRILLIONS in military/intel expenses and the $TRILLIONS in rich people tax cuts that are actually killing our budgets and economy, instead of the fractions of a percent that are the good reasons we have anything left to work with.

          • I don't think I stated that "defense" spending or tax cuts for the "job creators" wasn't a huge waste of taxpayer dollars and is in fact sinking our economy in an almost criminal fashion. I didn't advocate nixing NASA, but I think that our sights should be set a little closer to home. Again, jumping to the ultimate conclusion of any statement is hyperbole and you have just engaged in it yourself.
            • You need to look up the definition of hyperbole [reference.com].

              I didn't say you said anything about military spending or tax cuts. What I said is that nickel/diming the most productive public investments is a waste, when those other sources of crisis are begging for attention. Every minute you spend talking about cutting NASA is a minute you're not talking about cutting military/intel or collecting taxes from rich people. If you can link to somewhere you've asked for that real benefit somewhere in the past month or six, I

    • that is the estimated combine budgets of every form of government in the United States. Federal, state, and local.

      and people seem to have a never ending list of wants, yet it is so very disappointing what little we are getting for that expenditure. So little of the money goes to non-vote buying schemes that we become desperate to find dollars to spend on something right.

      There is no best use of government funds atm because atm the Congress controls nearly fou trillion of it, a good amount that doesn't even e

    • by thed8 ( 1739450 )
      Disappointed is right. China launches a new part of a lab now, and maybe possibly in 10 or 12 years we get to launch Humma Kavula's nose rag..... Achoo
  • by Covalent ( 1001277 ) on Thursday September 29, 2011 @10:40AM (#37553812)
    At this size (0.000038 km^2) the amount of thrust generated by this sail will be 0.0003477N. If the total mass of sail and attached spacecraft is 100kg, then the acceleration will be 3.477E-6 m/s^2. After a month at this acceleration, the craft will be traveling at 9m/s. That's only about 20mph. Not very fast, but an important proof of concept.
    • by rolias ( 2473422 ) on Thursday September 29, 2011 @11:52AM (#37554762)
      Except that the article is wrong. The sail will be 38m wide, or 1444m^2. That's 0.013N: 2 * (38m)^2 * 1368W/m^2 / (300,000,000m/s)
    • Yes, but the point is that it will add another 20mph the next month and so on in a cumulative fashion...and light speeds the limit (in theory)...and it could be combined with other propulsion tech such as ion energy or gravity assists.

  • by Cornwallis ( 1188489 ) on Thursday September 29, 2011 @10:43AM (#37553864)

    Whopping? That's only about four times larger. Certainly not "whopping".

    • by Anonymous Coward

      Whopping? That's only about four times larger. Certainly not "whopping".

      That's what she said

    • by LWATCDR ( 28044 )

      Sorry you are wrong. In the Slashdot system of universal measurements you only have to have a 2x expansion to == a whopping. An 8x or greater requires the addition of the prefix great and a 64x an additional prefix of huge as in a huge great whopping. You transition to hugenormus once the surface area == one standard library of congress rendered in courier 10 point font, double sided on A4 sized paper, at standard temperature and pressure.
      Hope that cleared it up for you.

      • Thanks for the clarification, but I have one other question on a recently used measure:

        What about ton? ("I have a ton of iso/mp3s")

        • We need to know which "ton" you're speaking about. Is it a shit-ton, a metric shit-ton or a butt-ton?
        • by LWATCDR ( 28044 )

          A ton of digital data is that can not fit on common mass storage costing less than $60. That is the the technical use. So in say 1983 it would have been about two mega bytes using Elephant floppies at around 177k each In the colloquial use. Today it is about 1 TB. Also anything large fraction of a SLOC "Standard Library of Congress" would be a ton of. The less formal use means "so much I have no idea what I have", "I have a netfix account and rip and send", or "I have more than you do".

      • by AlecC ( 512609 )

        Unless it is expressed in football pitches, or maybe micro-Belgiums, how can I possibly understand it?

        • by LWATCDR ( 28044 )

          Football pitches? What are you a 10 year old girl or a sissy EU type. This here board was started in Michigan in the U.S. of the freaking A. We use football fields here! micro-Belgiums? Well since everything in Europe is small and frankly unimportant a micro-Belgium== a smige.

    • Well, how big is YOUR solar sail?

      • Don't need one. I use two swallows with a string tied under the dorsal guiding feathers. I made small air tanks from empty coconuts. Rocket science, meh.
  • by cobrausn ( 1915176 ) on Thursday September 29, 2011 @10:44AM (#37553888)
    If Sim City is to be believed [mastermarf.com], I expect this to go into production as a viable energy source around 2020. As long as they don't cut funding. They would regret that.
  • Ok I know I RTFA. But just 409 sq. ft.? (and no I don't think they meant 409 ft. square, they also said 38 sq. meters). I'm really hoping that's a journalistic error because 409 sq. ft. is just 20x20 feet! I think the sun shield used on the hopefully-not-to-cancelled JWST is bigger than that. And there are 5 layers!

    In terms of size there are lots of things solar sail-ish that are bigger than that. Like the solar arrays on the ISS. Or how about Echo 1, a giant slivered balloon that was put into orbit

    • by rolias ( 2473422 )
      The Gizmag article was... imprecise. The sail will be a square 38m wide, with an area about 1400 m^2. It's based on a 20m wide sail L'Garde built and tested for NASA in 2005. More info here: http://www.nasa.gov/offices/oct/crosscutting_capability/tech_demo_missions.html [nasa.gov]
      • Thank you very much, that was a MUCH more informative link.

        I especially like the "station keeping" applications, over the poles or at pseudo-lagrangian points. Someday, they could perhaps use this technology for station keeping directly over the SUN!

        Alas, I'm afraid that thanks to the debacle of the space shuttle and ISS, space exploration may have been sent back by a generation (maybe longer if you consider the loss of "momentum" in political will). What I had hoped to see in my lifetime will now only be

        • by rolias ( 2473422 )

          Glad to help. Yeah, a sufficiently large (thrust) and lightweight (acceleration) sail could counteract and even exceed the sun's gravity. A sail mass/area of ~1.5 g/m^2, which accelerates at ~6 mm/s^2 at Earth would achieve this. Lower performance sails could still linger over the sun in "halo" orbits.

          I think it's an opportunity when large organizations fail do do something new. They get out of the way, giving more flexible and innovative parties have a chance. I think expansion into space has, in part, bee

    • Oh, by the way, the name of the story was "The Wind from the Sun".

      • Thanks for posting that. I loved A.C.C.'s stories when I was a kid, but I don't remember reading a story about a solar sail race to the moon. I was about to search for it (it sounds interesting), but you've saved me the work :)
    • Both Echo 1 and Echo 2 experienced solar sail effects. Anything, regardless of size or shape, will experience solar sail effects. However the effects are generally negligible unless the object has a huge area relative to its mass.
  • "Press Has Forgotten Five-Year-Old NASA Promise"

  • In July 2010 the Japanese deployed IKROS [wikipedia.org] with a surface area of almost 2200sq.ft. That is almost 5.5 times the size of this sail. Maybe Gizmag should learn to use Google.

    • by Wingfat ( 911988 )
      for one that is a Wiki site.. on the 2nd note, it says it was the first? lies.. the Russains were the first in 1993. and the Russians were the ones that came up with the idea of it. just like the light bulb.. we invented it.. they make it better.
      • by rolias ( 2473422 )
        The Russians deployed the Znamya [space.ru] space mirror from a Progress resupply ship in 1993, and tried a second time in 1999. The Progress propelled and steered it to reflect a spot of light down on the Earth, so it didn't do actual solar sailing. IKAROS [www.jaxa.jp] has that distinction. This new mission [nasa.gov] will actually test a 38m x 38m sail, so it will be the largest.
      • just like the light bulb.. we invented it.. they make it better.

        You're British?

        • by Wingfat ( 911988 )
          Scott/Irish/Norse/NativeAmerican - you pick. Swan did make one first.. but Edison made the long lasting Filament
          • Scott/Irish/Norse/NativeAmerican - you pick. Swan did make one first.. but Edison made the long lasting Filament

            Swan who? Edison's cohort? Not by a long shot. People were making incandescent light bulbs before Swan was even born. But why let a few stray facts spoil such a pervasive American Myth.

    • Gizmag is wrong, but not in the way you think. The sail is 38m in width, 1444m^2 area or 15,542.6089sq.ft

  • I always thought Solar sails would be awesome after seeing the DS9 epsiode where Commander Sisko constructed his own lightship and took his son, Jake Sisko, along for the maiden voyage. http://www.startrek.com/database_article/bajoran-solar-sail-vessel [startrek.com]
  • Complete story (Score:2, Informative)

    by Anonymous Coward

    For the complete story, see the NASA announcement from August 22nd: http://www.nasa.gov/offices/oct/crosscutting_capability/tech_demo_missions.html

    The sail is 38x38m. Two 20x20m sails were developed for NASA in 2005 by L'Garde and ATK. The thrust on the sail is approximately: 2 * (38m)^2 * 1368 W/m^2 / c ~= 0.01 N

  • A small thrust like this can be used to keep the station up permanently and even to adjust the orbital attitude as needed.

    This will save those missions to send up maneuvering fuel from time to time and save lots of $$

  • Like NASA will still be funded then. I don't think NASA will make it past 2013 if even FEMA funding is in question.

  • spanning a whopping 409 square feet, or 38 square meters.

    That's not "whopping". In microgravity and near vacuum, "whopping" would be a square kilometer, or a dozen square kilometers. Accelerating probes into outer solar orbits in a few years, dropping network nodes along the way, charging fuel stations for planetary exploration, eventually capturing asteroids for making machines that exploit other planets' resources, eventually colonizing the whole system. The future of inhabiting space is long, but there's little reason to wait for a truly "whopping" sail to get

  • I sure am glad they are going to demonstrate it in space!

    Demonstrating it here on Earth would cause all kinds of problems.
  • The Planetary Society should get kudos for getting the ball rolling early on this: http://www.universetoday.com/44551/planetary-society-to-launch-three-separate-solar-sails/ [universetoday.com]

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