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Communications Space Technology

Ground Crew Back In Touch With LightSail Solar Spacecraft 56

Yesterday, we noted that the Planetary Society's solar-sail powered craft had lost radio contact with its controllers here on Earth; Engadget reports that the group has issued an update, and the news is good. From the Society's release: "The solar sailing spacecraft test mission, a precursor to a 2016 mission, has now resumed contact after a suspected software glitch affected communications. The LightSail team will soon determine when to attempt deployment of the spacecraft’s Mylar solar sails."
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Ground Crew Back In Touch With LightSail Solar Spacecraft

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  • would be nice if everything works, when all the tests are done, to put the sail in a continuos orbit around the sun and get as much speed as possible and then send it to alpha centauri and let it take some pictures from there
    • by Crystal Shepard ( 4115237 ) on Sunday May 31, 2015 @12:18AM (#49807909)
      It would be nice. That way our descendents four or five generations from now can think "how cute!" as they pass it in the RamJets.
      • by KGIII ( 973947 )

        I am not sure if RAM jets (or SCAM jets) would work so very well in space unless they carried their own oxygen and, even still, I am not immediately seeing how this would provide propulsion for any length of time.

        • Re:just a though (Score:4, Informative)

          by meerling ( 1487879 ) on Sunday May 31, 2015 @12:34AM (#49807941)
          Wrong Ramjet
          Try checking out http://en.wikipedia.org/wiki/Bussard_ramjet
          • by KGIII ( 973947 )

            Ah, some theoretical thing with a name similar to an already real jet. I thought I must be missing something because it made no sense to me. Thanks for the link!

            • "Jet" can be, and has been, applied to a lot of technologies, but there's no way that NASA could even try to develop it on their budget. So far we haven't even gotten a manned mission to Mars, so one to Alpha Centauri, or any other star system, is pretty much a moot point.
              For now it's just science fiction until somebody will lay apply the necessary resources.
            • No, I'm pretty sure it's the other way around - there's now a real jet which adopted the name of a theoretical fusion engine that had been designed decades before.

              • by KGIII ( 973947 )

                Decades before 1913? I am not entirely sure that I believe you and I am to search. So, yeah, I think you might be making stuff up.

                • Hmm, my mistake - the ramjet does appear to predate Doctor Bussard considerably - clearly my avionics history is lacking.

                  On the other hand, Arthur C. Clarke credits "L'Autre Monde: ou les États et Empires de la Lune" (1657) as both being the first example of rocket-powered space flight and for inventing the ramjet. Though I would imagine they probably discussed something similar to a conventional ramjet, fusion having not yet been imagined. (http://en.wikipedia.org/wiki/Ramjet#Cyrano_de_Bergerac)

                  • by KGIII ( 973947 )

                    Now that is interesting. The ramjet I was thinking about and linked to would probably get someone into space if one had enough fuel. They are not very complex and work best at high speeds. The V1 had a lot in common with a ramjet as well IIRC. They scale well is my understanding but I do not know how well they would do in space with the added weight penalty from having to carry their own oxygen.

                  • by KGIII ( 973947 )

                    Also, I just read my earlier post... Wow... I blame weed.

        • Re:just a though (Score:4, Informative)

          by thesupraman ( 179040 ) on Sunday May 31, 2015 @01:21AM (#49808025)

          1 - as others have pointed out, you are barking up the wrong tree - these are bussard ramjets, not the type you are thinking of.
          http://en.wikipedia.org/wiki/Bussard_ramjet

          2 - normal ramjets are alive and well and very functional thank you very much - not even new tech.
          Several countries have been using RAMJETS for some time: http://en.wikipedia.org/wiki/BrahMos

          3 - what I suspect you are thinking about SCRAMjets (supersonic combustion..), while rare, are also functional now and have passed
          the point of being considered a scam as they once were, for example you can watch one here: https://www.youtube.com/watch?v=6K_rzuSuqIg
          The Russians and Indians seem quite happy with their SCRAMJETS : http://en.wikipedia.org/wiki/BrahMos-II

      • by Tablizer ( 95088 )

        Or EM drives

      • the thing is that if you leave the solar sail orbiting the sun for enough time, it might be theoretically possible for it to achieve near light speed velocity, I haven't done any calculations and so it's almost whishful thinking, but at 10% c it would arrive in just 40 years
      • Probably not a conventional ramjet
        "In a ramjet, the high pressure is produced by "ramming" external air into the combustor using the forward speed of the vehicle"
        https://www.grc.nasa.gov/WWW/k... [nasa.gov]

        Perhaps you mean the Bussard ramjet or ramscoop
        "The Bussard ramjet is a theoretical method of spacecraft propulsion proposed in 1960 by the physicist Robert W. Bussard, popularized by Poul Anderson's novel Tau Zero, Larry Niven in his Known Space series of books, Vernor Vinge in his Zones of Thought series, and refe

        • It has long been proven that the drag of accumulating the hydrogen greatly exceeds the possible thrust. It's more like a parachute than it is an engine.

             

          • by Lumpy ( 12016 )

            Proven? when did they run that experiment? You have to get up to about 0.05% C to even get them to start working and nobody has launched a test craft.

          • No, it's been shown that one particular hypothetical design based on one particular set of assumptions would not be viable. Not that the fundamental concept is flawed. There's a post a few pages up that gives more details.

    • Land it on Mars and use the mylar sail to cover a cave entrance. A great habitat would be waiting for the colonists. Sure, there are a couple of techincal challanges with either idea - but that can be worked out in the software.
    • by jkabbe ( 631234 )

      You'd never get to see the pictures in any case (nor would any human anytime soon).

  • by Anonymous Coward on Sunday May 31, 2015 @12:31AM (#49807935)

    SourceForge, the code repository site owned by Slashdot Media, has apparently seized control of the account hosting GIMP for Windows on the service, according to e-mails and discussions amongst members of the GIMP community—locking out GIMP's lead Windows developer. And now anyone downloading the Windows version of the open source image editing tool from SourceForge gets the software wrapped in an installer replete with advertisements.

    Link to original source [arstechnica.com]
    The GIMP developers aren't happy at all about this. They say that Sourceforge impersonated the GIMP developers, and abused the trademarks owned by the GNOME foundation [gnome.org].

    • by aardvarkjoe ( 156801 ) on Sunday May 31, 2015 @01:28AM (#49808039)

      It's funny, the Slashdot editors used [slashdot.org] to [slashdot.org] be [slashdot.org] aware of the Streisand effect. Apparently they still haven't learned not to try to hide something that's already been publicized widely on the internet.

      • by nadaou ( 535365 ) on Sunday May 31, 2015 @05:19AM (#49808445) Homepage

        From a technical standpoint (and that's why we're here isn't it?) the Streisand Effect is actively trying to supress a nibble of information that wants desperately to be free. Which isn't really the case here. Here we have the editors silently ignoring an up-rated story on the firehose in the hope that if it goes away they won't get shit from their corporate overlords. They aren't filing public documents to make it so. Presumably they already have got the shit come down from on high and they don't feel that they're completely irreplaceable.

        You want to stir the shit? Get the quashing story on Soylent News or wherever people with a beef hang out.

        As for me, just another journalistic straw broken in my respect for the good 'ol site.

        • Actually, the Streisand Effect is where something becomes known to people specifically because of the efforts to suppress it. Or in other words, the efforts to suppress something bring attention to something that likely would have otherwise been overlooked and ignored.

    • by Anonymous Coward

      "Most of the Apache Foundation's projects—including Allura, Derby, Directory Studio, the Apache HTTP server, Hadoop, OpenOffice, Solr, and Subversion;"

      This is absolutely fucking disgusting. Have all the fucking ads you want on your site, but DO NOT FUCKING TOUCH THE DEV ACCOUNTS AND MODIFY BINARIES

      This is evil incarnate. I hope someone takes the initiative and sues the living shit for damage to reputation.

      • please make it so, the roots of this disease go deep, and the creeps responsible must be purged.

      • This is evil incarnate.

        So... Hitler was reborn as Slashdot? That explains why this place is so obsessed with karma.

    • SourceFarce MUST allow reporting and discussion of it's actions here on SlashOwned, or we WILL know the reason why?

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