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Moon NASA Shark Science

NASA Achieves Laser Communication With Lunar Satellite 99

Posted by Soulskill from the and-i-can't-even-shine-my-penlight-at-airplanes dept.
New submitter EngnrFrmrlyKnownAsAC writes "Communicating with lasers has become the hot new thing. While most researchers are seeking faster throughput, NASA set its sights in a different direction: the moon. They recently announced the first successful one-way laser communication 'at planetary distances.' What did they send? An image of the Mona Lisa, of course. 'Precise timing was the key to transmitting the image. Sun and colleagues divided the Mona Lisa image into an array of 152 pixels by 200 pixels. Every pixel was converted into a shade of gray, represented by a number between zero and 4,095. Each pixel was transmitted by a laser pulse, with the pulse being fired in one of 4,096 possible time slots during a brief time window allotted for laser tracking. The complete image was transmitted at a data rate of about 300 bits per second.'"
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NASA Achieves Laser Communication With Lunar Satellite More

NASA Achieves Laser Communication With Lunar Satellite

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  • where are the space sharks?

  • Comment removed (Score:4, Interesting)

    by account_deleted ( 4530225 ) on Saturday January 19, 2013 @05:09PM (#42635531)
    Comment removed based on user account deletion

  • 300 bits per second? (Score:5, Funny)

    by Ardeaem ( 625311 ) on Saturday January 19, 2013 @05:11PM (#42635545)
    My dream of running a BBS on the moon grows ever closer! Who wants to play tw2002 on my moon server?

    • Re:300 bits per second? (Score:4, Funny)

      by VortexCortex ( 1117377 ) <VortexCortex AT ... trograde DOT com> on Saturday January 19, 2013 @05:49PM (#42635687)

      Who wants to play tw2002 on my moon server?

      I do. 300 Baud is a nice reading speed...
      But First!...

      He who would negotiateth a handshake of that breadth must answer me these questions three, Ere the ATDT ye see...
      0. What is your FidoNet node address?
      1. What number of in & out dials have you?
      2. What is the land area coverage of an unladen local call?

      • Re:300 bits per second? (Score:4, Interesting)

        by dissy ( 172727 ) on Saturday January 19, 2013 @10:06PM (#42636833)

        Would you like to play a game?

        0. What is your FidoNet node address?
        1:226/201

        1. What number of in & out dials have you?
        7 / 1 (8 chans of a frac pri)

        2. What is the land area coverage of an unladen local call?
        About half of the area code, guessing 100 square miles?

        I never understood why some parts of 614 were local but others were long distance, while at the same time a small part of 740 was local to me yet a different area code.
        I had to route mail to another board across town in 614, where he could reach the other half of 614 locally, just to avoid minutely charges.

        My 8 PRI channels were to my home (well, to my parents home at the time) and mostly for dialin. I rocked Oblivion/X by the time I was on fido. One line floated for scheduled callouts, but none dedicated to that.
        Once I discovered the Internet in '89, first one then later two channels were dedicated to PPP.
        By '92 I was getting less than 5 calls a day to the board, and shortly converted my whole frac PRI to be dedicated Internet, and I pretty much gave up the sysop role for good in exchange for EFnet as things turned out. Even ran an efnet server for a short time back in '95 i think it was.

        While I can say for certain that communications have only changed for the better as far as the Internet goes, there is still a lot I miss from those days, even though I wouldn't want to go back to that for anything.

      • I do. 300 Baud is a nice reading speed...

        150 cps isn't even a good typing speed. I've often outtyped 1200 bps modems and I can definitely outread them. I used to hang out on a five-liner with all 1200bps USRs in scruz called XBBS and the modems were agonizing.

        • Cool. Maybe you should contact the Guinness Book of World Records, because you're typing five times faster than the fastest typist in the world!

  • Overkill on detail? (Score:5, Funny)

    by CodeheadUK ( 2717911 ) on Saturday January 19, 2013 @05:16PM (#42635559) Homepage

    > Every pixel was converted into a shade of gray, represented by a number between zero and 4,095.

    Obviously 50 shades of gray wasn't enough..

  • ...considering how tight this beam was, and that you'd have to be pretty much directly in its path to intercept the transmission.
    • Still a faster upload speed than Crashplan.
    • I think I would hold out for at least 1,200 baud.

  • What about Lenna? (Score:5, Interesting)

    by ericcc65 ( 2663835 ) on Saturday January 19, 2013 @05:32PM (#42635623)

    The Mona Lisa? Are you serious? Way to break tradition NASA, my heart weeps for Lenna:

    http://www.cs.cmu.edu/~chuck/lennapg/lenna.shtml [cmu.edu]

    • Ya! Aren't technological advancements driven by porn anyway?

    • I imagine that an environment that isn't all-male wouldn't be so pleased with the idea of "tradition."

      • Re: (Score:1)

        by Anonymous Coward

        I imagine that an environment that isn't all-male wouldn't be so pleased with the idea of "tradition."

        If a person has a problem with the image of a woman from the shoulders up, I'm certain they would also have issues with the current image of a woman from the shoulders up.

        Besides, I doubt anything you could do would please a person who is offended by a picture of a female face, no matter which face it happens to be. They would also likely be offended by just about anything else, including squiggly lines in a stock 60's TV test pattern.

        There's really nothing you can do about such people, they will be offend

    • Re: (Score:2)

      by khallow ( 566160 )
      Indeed. Who is this upstart, Mona? Has anyone even heard of her before?

      • Who is this upstart, Mona? Has anyone even heard of her before?

        I think she was a White House intern or something.

        ({[ yes I know that's not the right name. Go away, silly nitpickers ]})

    • Very Simple.

      If they missed the moon, and it instead went straight on out into space to be picked up at random by an alien species. I suspect they want to display a false front.

  • Shouldn't have been Lena?

  • They have mirrors on the moon, that we routinely bounce lasers off of to measure distances and do Relativity experiments with. It's suddenly difficult to transmit information via laser? Why so slow? Why was this an accomplishment?

    • Re: (Score:3)

      by tyrione ( 134248 )

      They have mirrors on the moon, that we routinely bounce lasers off of to measure distances and do Relativity experiments with. It's suddenly difficult to transmit information via laser? Why so slow? Why was this an accomplishment?

      To demonstrate a line of sight transmission, from any possible point of orbit? Think about it. They are developing towards a true subspace solution.

    • Re: (Score:1)

      by Anonymous Coward

      Because with lunar ranging, you have a big receiver antenna (telescope) on the ground, which is impractically large to put on a spacecraft.

  • Fermi Paradox (Score:5, Interesting)

    by yanom ( 2512780 ) on Saturday January 19, 2013 @07:43PM (#42636291)
    If laser communication overtakes radio for our own space equipment, it might explain the Fermi paradox - we cannot detect alien civilizations because the communicate with lasers (emitting no radio signals at all), making them undetectable to those not in the path of the beam.
  • Friggin sharks communicating with friggin laser beams on their heads.

  • PPM? (Score:2)

    by dohzer ( 867770 )

    So that's Pulse Position Modulation, yeah?

  • Why not use 2 different wavelength lasers (Or even 3 or more)
    For two lasers (let it be greeen and blue) it would be binary transmission,
    "4096" fits into 13 bits. Image transmission would be 315 times faster.

  • And that's why SETI will never find the aliens (Score:3, Interesting)

    by Anonymous Coward on Saturday January 19, 2013 @08:42PM (#42636519)

    As I've been saying for years SETI doesn't have a hope in h**l finding the aliens because they use the much more efficient point to point message casting as opposed to the broadcasting in every direction used here on earth. Why use the inefficient method sending your message/data/... everywhere when it is really only destined for 1 place.

    I think in 100 years we'll look back and see that the use or radio and the inefficient broadcasting methods was a short segment in our history. It will likely be the same for other developing races.

    I recall a few years back they actually found something that looked like real alien communication. It couldn't be captured again. Of course it coul'n't be found again. We were no longer behind the target of the message beam.

    • Re: (Score:1)

      by Tablizer ( 95088 )

      But aren't laser pulses that coincidentally point our way detectable? If you have gajillion satellites and spaceships all about, then every now and then one will line up with Earth.

      • Re: (Score:2)

        by QQBoss ( 2527196 )

        Are you assuming that the satellites are transparent, or that such a sufficiently advanced civilization will miss their target so frequently?

      • Re: (Score:2)

        by Jeremi ( 14640 )

        But aren't laser pulses that coincidentally point our way detectable? If you have gajillion satellites and spaceships all about, then every now and then one will line up with Earth.

        Will the aliens' laser have spread out enough to cover a significant part (or all) of Earth by that point, or will it still be pretty small? It's no good having the laser light land in New Zealand if your receiving equipment is in Australia, after all...

      • Re: (Score:2)

        by cusco ( 717999 )
        Only if you're looking for them. Optical SETI has barely begun, and only with a fraction of the (miniscule) resources that radio SETI has. We at least *think* we know how to do radio search, but there are so many bizarre natural sources in the optical range that I don't think they're sure what to look for.

    • This is the one you're thinking of:
      http://en.m.wikipedia.org/wiki/Wow!_signal [wikipedia.org]

    • Why use the inefficient method sending your message/data/... everywhere when it is really only destined for 1 place.

      I think you're forgetting about broadcast transmissions. You know, TV, trunked mobile communications...messages that will reach multiple locations simultaneously. Now the distances involved and the spreading loss, that's another issue. There is only so much coherent integration that can be done usually.

  • They want their Hayes Smart Modem 300 back.

  • So, the moon, which is 409,073 kilometers away at its furthest is "planetary distances"? What does that make the distance to Venus, which is 41 million kilometers at its closest or Mars, which is 56 million kilometers at its closest. Seems to me that this is only over about 1% of the shortest distance you could actually consider "planetary distances".

    • No. Planetary distances are distances as found on planets. Like, from New York to Moscow. From Earth to Venus would be an interplanetary distance.

      Of course, laser communication on planetary distances is not new, as there are tons of fiber used for exactly that.

      • Re: (Score:2)

        by tragedy ( 27079 )

        Either way, the term "planetary distances" that was used is clearly not accurate, whether it's two orders of magnitude too small or two orders of magnitude too big.

  • You just know when you click it, it's gonna be a lame banana store site or something.

  • who is completely underwhelmed by this "feat"?

  • They way they're doing it is too damned easy. I'd throw a little challenge into it by requiring that low bits must transmitted by bouncing them off the Apollo laser reflectors. Might require spinning up LRO to about 3000 rps unless it has two sensors.

  • How wide is the beam when it reaches the craft? What are the theoretical limits of the width per distance?

  • We could see laser flashes just as easily as hear radio waves from parabolic dishes. http://www.cusabio.com/pro_11.html [cusabio.com]

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