9 ms·

A Laser Message from Space

225 points by cromulent 12y ago

jumpwah 12y ago
Ah for a second I thought this is it, we're all doomed. Still a pretty cool demonstration though.
skierscott 12y ago
I'm guessing that this is way harder than the article makes it sound. The satellite is moving very fast and has to hit an extremely precise target, but adding on another layer of complexity, the atmosphere and temperature differences effect the transmission.
- mnw21cam 12y ago
  Affect. The laser effects the transmission, but the atmosphere affects it. But not much. The laser was aimed with an accuracy of 0.01 degrees. Astronomical seeing (the distortion due to atmospheric disturbance) is on the order of an arcsecond, or 36 times smaller than this.
  - kordless 12y ago
    > the atmosphere and temperature differences "caused or brought about" the transmission. Sometimes I wonder if the subtleties of English are worth the effort and frustrations of dealing with it day to day.
    - mnw21cam 12y ago
      Nonsense! It's wonderful fun.
  - easytiger 12y ago
    Indeed, but the mount the projector and receiver on must be constantly calibrating movements and adjusting smoothly. In achievement terms this is almost all software (once you take putting stuff in space for granted). Think of proving it to work in theory, ground based prototypes etc. Error detection is also interesting (though mostly solved but with many options available). High bandwidth laser comms have been around for a while. Originally developed for the financial industry for intra city comms.
    - mnw21cam 12y ago
      To be honest, it's probably less difficult than the tracking that a compact disc player has to achieve to play an off-centre bent wobbly CD. The error correction would be fairly similar too. How long have CDs been around now?
- bsilvereagle 12y ago
  Kind of related fun fact, when astronauts take images of Earth they have to rotate the camera while taking the photo to compensate for the ISS moving so quickly. I think there are now computer controlled gimbals that account for that automatically.
  - sitkack 12y ago
    Same as a sports photographer tracking a race car.
bsilvereagle 12y ago
This is a pretty big deal. At the moment there are two main methods to communicate with the ISS, TDRSS and UHF. UHF can only be used when the ISS is over the US. TDRSS is a shared satellite network between several government agencies. NASA receives "allotments" of time with the network. So if the ISS is outside of UHF range, and another agency has the TDRSS the ISS goes black - we lose all comm with it. A network of laser receivers across the globe could potentially eliminate the current "black outs" NASA has when communicating with the ISS.
- furyg3 12y ago
  I find this kind of surprising. First off, I'd figure that NASA would set up a few UHF stations around the world in locations with decent internet access (friendly countries or military bases), and route comms via that. Maybe you don't have total coverage, but at least you don't have to wait an hour before it's back over the US. Secondly, there many more options available than TDRSS or UHF. Amateur radio enthusiasts frequently make contact with astronauts (2 meter and 70cm bands, IIRC). While that doesn't really solve the blackout problem, I find it hard to imagine that there isn't a lower-frequency radio which could maintain voice contact with the ISS.
  - _delirium 12y ago
    I believe NASA does have a few UHF stations elsewhere, or at least used to. As of a 1998 document about the shuttle program [1], they listed 6 UHF air-to-ground stations, 3 of them in other countries. The U.S.-based ones were in Guam, Hawaii, and Florida; and the others were in Ascension Island (a British dependency halfway between Africa and South America), Bermuda (a British dependency off the east coast of Canada), and Dakar, Senegal. [1] http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-jsc-comm.html http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/s...
    - jdmichal 12y ago
      Just a clarification: Bermuda is not really close to any major coastline, and certainly not the Canadian one. https://www.google.com/maps/place/Bermuda/@31.2546129,-41.5200126,4z https://www.google.com/maps/place/Bermuda/@31.2546129,-41.52...
numlocked 12y ago
And it got to the ISS via a Space-X Dragon! Lasers, privately funded spaceships, hello world...too much fun :)
- damon_c 12y ago
  finally, the future!
  - HNJohnC 12y ago
    It will never be the future until I have a flying car, sorry.
    - agildehaus 12y ago
      Give Elon some time, damn.
    - alex_doom 12y ago
      We can't have flying cars till we can figure out autopiloted cars. I don't want drunk flying :(
    - saraid216 12y ago
      I'm honestly impressed at someone so self-centered as to claim the future is unachievable unless and only unless he gets his own personal toy.
      - HNJohnC 12y ago
        It's a common "meme" from the past, perhaps you're too young to get it.
throwaway_yy2Di 12y ago
How close are we to space-based laser ISPs? I imagine that you squeeze terabits of optical bandwidth into a single mirror "dish"..
- kbar13 12y ago
  imagine a world where this was the norm. You wouldn't need to worry about outages due to falling trees or utility poles exploding or people screwing with your wires. Then you step outside to look up at the sky and you lose your eyesight
  - deleted 12y ago
    [deleted]
  - mnw21cam 12y ago
    Day of triffids scenario aside, no you won't lose your sight from a 2.5W laser pointing downwards from 260 miles up. The power level is too small. People think that lasers produce a parallel beam. They don't - they are diffraction limited by the width of the beam. The narrower the beam, the more it spreads out. For example, a 1cm wide beam produced by a perfect laser would spread out to around 20m wide when it hits the ground from 260 miles away. That's assuming visible green light - if it's infra-red (or even just red) then the spread will be wider.
  - kahirsch 12y ago
    But it wouldn't work on a cloudy day, presumably.
- awda 12y ago
  Latency is a real problem. Distances to satellites in orbit are very long. Also, there is a scalability problem. How many ground targets can a satellite simultaneously provide service to? My guess is, not a lot. This could be an incremental bandwidth (but not latency) upgrade over existing satellite internet service to remote areas (by transmitting to a single ground receiver that serves a local area), but that's about it.
logfromblammo 12y ago
Yes, but how do they keep the sharks alive up there? Space-to-ground laser communication is a neat trick, but you still have the problem that you need to have a line of sight to the receiver in order to use it. The good news is that you are not quite as limited by bandwidth during the time that you can see the receiver. It would be nice if we could get the sort of international cooperation that would allow for continuous contact, but unfortunately, the politicians in charge usually don't care that much about space research. We'd probably have better luck with one or more reflector satellites that could bounce the laser signal back to the receiver.
yeldarb 12y ago
Interesting. If a 2.5 watt laser was used for communication from the ISS to Earth what wattage would be needed to send a high-bandwidth message back from Mars (or Titan)? How does that compare to traditional radio-based communication? This point-to-point communication is also interesting in relation to the Fermi Paradox. It seems likely that a sufficiently-advanced race would beam their messages directly to their recipients rather than wasting energy (and privacy) transmitting an omnidirectional signal.
- sosuke 12y ago
  Complete tangent of course, but I wonder if aliens using laser communication methods might be why we aren't being bathed in radio waves.
  - ekianjo 12y ago
    Radio waves go in multiple directions, lasers can only work in short range, unless you find a superb trick to keep the alignment perfect at great distances.
    - talmand 12y ago
      Simple, you just keep tapping it with a rubber hammer until you get alignment.
    - sylvinus 12y ago
      I don't know if you need a "trick"... Just several orders of magnitude more precision?
      - ekianjo 12y ago
        Yeah, and just like for telescopes, when you need several orders of magnitude more precision, you need something huge to do so. Unless we find a way to build huge spaceships in space, it's not coming anytime soon.
    - lutorm 12y ago
3rd3 12y ago
Could we please stop with these headlines that hint at alien life?
- outrightfree 12y ago
  It's the title of the target article.
kator 12y ago
Space-X put took the laser to the ISS... Reminds me of Paul Simon's song "The Boy in The Bubble" [1] ... These are the days of lasers in the jungle Lasers in the jungle somewhere Staccato signals of constant information a loose affiliation of millionaires And billionaires, and baby These are the days of miracle and wonder This is the long-distance call The way the camera follows us in slo-mo The way we look to us all, oh yeah The way we look to a distant constellation That’s dying in a corner of the sky These are the days of miracle and wonder ... [1] http://en.wikipedia.org/wiki/Graceland_(album) http://en.wikipedia.org/wiki/Graceland_(album) EDIT: Added link, not bad prediction considering it was released in 1986
- benihana 12y ago
  It was referring to the violence of apartheid. You left out the opening lines mentioning the shattering of shock windows, the bomb in the baby carriage, and the soldiers on the side of the road, which change the entire meaning of the lines you posted.
  - moheeb 12y ago
    My guess is that those lines didn't remind the author of lasers in space.
woodchuck64 12y ago
Okay, how big is the video and what exactly was the bandwidth? Can't understand why they won't put the basics in the article. So I illegally downloaded the video from YouTube; it appears to be 2657084 bytes, so 2657084/3.5 is 759166 bytes per second or 6073328 bits or 5.8 megabit per second. Reporting that as a maximum rate of 50 megabit seems ... a little "Comcastic". Or am I missing something? Update: I see another article calling it a 175 megabit transmission so if that took 148 seconds that's an average rate of 1.2 megabit. It's a mystery to me why average throughput is just not interesting to the author of the original article. And presumably the downvoting I'm getting is from a similar sense of vapid apathy about intriguing detail.
- CountHackulus 12y ago
  They said that the video was transmitted repeatedly over the course of the test.
- dozy 12y ago
  conceivable that the 3.5 seconds includes some overhead related to getting the thing powered up and pointed in the right direction. Also conceivable that it peaked at 50mbps for just a moment. I'll also throw in that whatever protocol they're using...I'm guessing it's not bit torrent over HTTP over TCP :)...has overhead as well to account for errors and OUTER-SPACE related nuances! anyways I'm willing to give them the benefit of the doubt.
- maxerickson 12y ago
  I wouldn't expect the bits coming down from YouTube to be a meaningful representation of what they transmitted. This page describes the mission goal as 10 megabits-per-second or higher, I guess they aren't making that up: http://www.nasa.gov/mission_pages/station/research/experiments/861.html http://www.nasa.gov/mission_pages/station/research/experimen...
  - woodchuck64 12y ago
    Why wouldn't YouTube be meaningful? It would make sense for the video to be stored and transmitted as h264 and then uploaded as is to YouTube. I doubt YouTube recompresses h264.
damon_c 12y ago
They don't mention this anywhere, but for light based communication with more distant targets where the laser would need multiple seconds to reach its target, would they need to "lead the target" with the lasers pointing in both directions? Also, what about the complications due to interspersed massive bodies creating gravitational lensing?! I guess this can all be accounted for in the aiming software... but it's not very simple!
- mnw21cam 12y ago
  At the multiple seconds travel time level, gravitational lensing is completely insignificant. Come back when you have a round trip time of a million years past a massive galactic supercluster.
tempodox 12y ago
So we have our first ad from space. Mankind will never be the same again.
- saraid216 12y ago
  Best reasoning for claiming that mankind will never be the same again: claiming that mankind is being the same.
Achshar 12y ago
Why is radio communication slower than visible light based ones? 0s and 1s should be the same speed no matter what the wavelength.
- icegreentea 12y ago
  It's not about latency, its about bandwidth. Your data transfer rate is directly proportional to the frequency of the carrier wave. Visible light has a shorter wavelength (higher frequency) than RF, therefore can carry more information in any period of time.
- _mulder_ 12y ago
  Think about it, wavelength (or frequency, they're effectively the same measurement here) determines how fast you can transmit those 1's and 0's. It's not slower, it's just that you can't transmit as much information in the same time period. Also, laser light for Telecoms is not normally Visible, it's usually Infrared which has a wavelength shorter than Microwave radio but longer than visible light. Another bonus fact; in a vacuum, Radio and Light waves travel at the same speed. However, when light travels down an optical fibre it is slowed down by the glass so Fibre Internet is actually slightly slower than radio.
  - dm2 12y ago
    So the speed of all fiber and radio is basically the same and it's the capacity that's different? Does that mean that saying "internet connection speed" is a faulty term? We should all be saying "capacity" or data-rate?
Sir_Cmpwn 12y ago
A more appropriate use for "Hello, world!" than I have ever written in a new programming language.
- louthy 12y ago
  At least yours has the correct punctuation.
dynode 12y ago
Link to the JPL project page with more detail <http://phaeton.jpl.nasa.gov/external/projects/optical.cfm> http://phaeton.jpl.nasa.gov/external/projects/optical.cfm> Interestingly this is a Phaeton project. Phaeton projects are designed for early career engineers to jumpstart their experience. Very cool. <http://phaeton.jpl.nasa.gov/external/ProgramOverview/home.cfm> http://phaeton.jpl.nasa.gov/external/ProgramOverview/home.cf...
ccamrobertson 12y ago
Congratulations to rwitoff and team at JPL for pulling it off!
fakeyfake 12y ago
If you are a fan of videos I definitely recommend their YouTube channel for brief news updates. The first thing I thought when I saw this video was definitely about the tech Li-Fi, there was a new quite long video about it recently here: https://www.youtube.com/watch?v=WRG9iXZbuAc https://www.youtube.com/watch?v=WRG9iXZbuAc
pocketstar 12y ago
>Unlike normal data transmissions, which are encoded in radio waves, this one came to Earth on a beam of light. >radio waves >beam of light Radio waves are light...

225 points by cromulent 12y ago

Ah for a second I thought this is it, we're all doomed. Still a pretty cool demonstration though.

I'm guessing that this is way harder than the article makes it sound. The satellite is moving very fast and has to hit an extremely precise target, but adding on another layer of complexity, the atmosphere and temperature differences effect the transmission.

mnw21cam 12y ago
Affect. The laser effects the transmission, but the atmosphere affects it. But not much. The laser was aimed with an accuracy of 0.01 degrees. Astronomical seeing (the distortion due to atmospheric disturbance) is on the order of an arcsecond, or 36 times smaller than this.
- kordless 12y ago
  > the atmosphere and temperature differences "caused or brought about" the transmission. Sometimes I wonder if the subtleties of English are worth the effort and frustrations of dealing with it day to day.
  - mnw21cam 12y ago
    Nonsense! It's wonderful fun.
- easytiger 12y ago
  Indeed, but the mount the projector and receiver on must be constantly calibrating movements and adjusting smoothly. In achievement terms this is almost all software (once you take putting stuff in space for granted). Think of proving it to work in theory, ground based prototypes etc. Error detection is also interesting (though mostly solved but with many options available). High bandwidth laser comms have been around for a while. Originally developed for the financial industry for intra city comms.
  - mnw21cam 12y ago
    To be honest, it's probably less difficult than the tracking that a compact disc player has to achieve to play an off-centre bent wobbly CD. The error correction would be fairly similar too. How long have CDs been around now?
bsilvereagle 12y ago
Kind of related fun fact, when astronauts take images of Earth they have to rotate the camera while taking the photo to compensate for the ISS moving so quickly. I think there are now computer controlled gimbals that account for that automatically.
- sitkack 12y ago
  Same as a sports photographer tracking a race car.

bsilvereagle 12y ago

This is a pretty big deal. At the moment there are two main methods to communicate with the ISS, TDRSS and UHF. UHF can only be used when the ISS is over the US. TDRSS is a shared satellite network between several government agencies. NASA receives "allotments" of time with the network. So if the ISS is outside of UHF range, and another agency has the TDRSS the ISS goes black - we lose all comm with it. A network of laser receivers across the globe could potentially eliminate the current "black outs" NASA has when communicating with the ISS.

furyg3 12y ago
I find this kind of surprising. First off, I'd figure that NASA would set up a few UHF stations around the world in locations with decent internet access (friendly countries or military bases), and route comms via that. Maybe you don't have total coverage, but at least you don't have to wait an hour before it's back over the US. Secondly, there many more options available than TDRSS or UHF. Amateur radio enthusiasts frequently make contact with astronauts (2 meter and 70cm bands, IIRC). While that doesn't really solve the blackout problem, I find it hard to imagine that there isn't a lower-frequency radio which could maintain voice contact with the ISS.
- _delirium 12y ago
  I believe NASA does have a few UHF stations elsewhere, or at least used to. As of a 1998 document about the shuttle program [1], they listed 6 UHF air-to-ground stations, 3 of them in other countries. The U.S.-based ones were in Guam, Hawaii, and Florida; and the others were in Ascension Island (a British dependency halfway between Africa and South America), Bermuda (a British dependency off the east coast of Canada), and Dakar, Senegal. [1] http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts-jsc-comm.html http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/s...
  - jdmichal 12y ago
    Just a clarification: Bermuda is not really close to any major coastline, and certainly not the Canadian one. https://www.google.com/maps/place/Bermuda/@31.2546129,-41.5200126,4z https://www.google.com/maps/place/Bermuda/@31.2546129,-41.52...

numlocked 12y ago

And it got to the ISS via a Space-X Dragon! Lasers, privately funded spaceships, hello world...too much fun :)

damon_c 12y ago
finally, the future!
- HNJohnC 12y ago
  It will never be the future until I have a flying car, sorry.
  - agildehaus 12y ago
    Give Elon some time, damn.
  - alex_doom 12y ago
    We can't have flying cars till we can figure out autopiloted cars. I don't want drunk flying :(
  - saraid216 12y ago
    I'm honestly impressed at someone so self-centered as to claim the future is unachievable unless and only unless he gets his own personal toy.
    - HNJohnC 12y ago
      It's a common "meme" from the past, perhaps you're too young to get it.

throwaway_yy2Di 12y ago

How close are we to space-based laser ISPs? I imagine that you squeeze terabits of optical bandwidth into a single mirror "dish"..

kbar13 12y ago
imagine a world where this was the norm. You wouldn't need to worry about outages due to falling trees or utility poles exploding or people screwing with your wires. Then you step outside to look up at the sky and you lose your eyesight
- deleted 12y ago
  [deleted]
- mnw21cam 12y ago
  Day of triffids scenario aside, no you won't lose your sight from a 2.5W laser pointing downwards from 260 miles up. The power level is too small. People think that lasers produce a parallel beam. They don't - they are diffraction limited by the width of the beam. The narrower the beam, the more it spreads out. For example, a 1cm wide beam produced by a perfect laser would spread out to around 20m wide when it hits the ground from 260 miles away. That's assuming visible green light - if it's infra-red (or even just red) then the spread will be wider.
- kahirsch 12y ago
  But it wouldn't work on a cloudy day, presumably.
awda 12y ago
Latency is a real problem. Distances to satellites in orbit are very long. Also, there is a scalability problem. How many ground targets can a satellite simultaneously provide service to? My guess is, not a lot. This could be an incremental bandwidth (but not latency) upgrade over existing satellite internet service to remote areas (by transmitting to a single ground receiver that serves a local area), but that's about it.

logfromblammo 12y ago

Yes, but how do they keep the sharks alive up there? Space-to-ground laser communication is a neat trick, but you still have the problem that you need to have a line of sight to the receiver in order to use it. The good news is that you are not quite as limited by bandwidth during the time that you can see the receiver. It would be nice if we could get the sort of international cooperation that would allow for continuous contact, but unfortunately, the politicians in charge usually don't care that much about space research. We'd probably have better luck with one or more reflector satellites that could bounce the laser signal back to the receiver.

yeldarb 12y ago

Interesting. If a 2.5 watt laser was used for communication from the ISS to Earth what wattage would be needed to send a high-bandwidth message back from Mars (or Titan)? How does that compare to traditional radio-based communication? This point-to-point communication is also interesting in relation to the Fermi Paradox. It seems likely that a sufficiently-advanced race would beam their messages directly to their recipients rather than wasting energy (and privacy) transmitting an omnidirectional signal.

sosuke 12y ago
Complete tangent of course, but I wonder if aliens using laser communication methods might be why we aren't being bathed in radio waves.
- ekianjo 12y ago
  Radio waves go in multiple directions, lasers can only work in short range, unless you find a superb trick to keep the alignment perfect at great distances.
  - talmand 12y ago
    Simple, you just keep tapping it with a rubber hammer until you get alignment.
  - sylvinus 12y ago
    I don't know if you need a "trick"... Just several orders of magnitude more precision?
    - ekianjo 12y ago
      Yeah, and just like for telescopes, when you need several orders of magnitude more precision, you need something huge to do so. Unless we find a way to build huge spaceships in space, it's not coming anytime soon.
  - lutorm 12y ago

3rd3 12y ago

Could we please stop with these headlines that hint at alien life?

outrightfree 12y ago
It's the title of the target article.

kator 12y ago

Space-X put took the laser to the ISS... Reminds me of Paul Simon's song "The Boy in The Bubble" [1] ... These are the days of lasers in the jungle Lasers in the jungle somewhere Staccato signals of constant information a loose affiliation of millionaires And billionaires, and baby These are the days of miracle and wonder This is the long-distance call The way the camera follows us in slo-mo The way we look to us all, oh yeah The way we look to a distant constellation That’s dying in a corner of the sky These are the days of miracle and wonder ... [1] http://en.wikipedia.org/wiki/Graceland_(album) http://en.wikipedia.org/wiki/Graceland_(album) EDIT: Added link, not bad prediction considering it was released in 1986

benihana 12y ago
It was referring to the violence of apartheid. You left out the opening lines mentioning the shattering of shock windows, the bomb in the baby carriage, and the soldiers on the side of the road, which change the entire meaning of the lines you posted.
- moheeb 12y ago
  My guess is that those lines didn't remind the author of lasers in space.

woodchuck64 12y ago

Okay, how big is the video and what exactly was the bandwidth? Can't understand why they won't put the basics in the article. So I illegally downloaded the video from YouTube; it appears to be 2657084 bytes, so 2657084/3.5 is 759166 bytes per second or 6073328 bits or 5.8 megabit per second. Reporting that as a maximum rate of 50 megabit seems ... a little "Comcastic". Or am I missing something? Update: I see another article calling it a 175 megabit transmission so if that took 148 seconds that's an average rate of 1.2 megabit. It's a mystery to me why average throughput is just not interesting to the author of the original article. And presumably the downvoting I'm getting is from a similar sense of vapid apathy about intriguing detail.

CountHackulus 12y ago
They said that the video was transmitted repeatedly over the course of the test.
dozy 12y ago
conceivable that the 3.5 seconds includes some overhead related to getting the thing powered up and pointed in the right direction. Also conceivable that it peaked at 50mbps for just a moment. I'll also throw in that whatever protocol they're using...I'm guessing it's not bit torrent over HTTP over TCP :)...has overhead as well to account for errors and OUTER-SPACE related nuances! anyways I'm willing to give them the benefit of the doubt.
maxerickson 12y ago
I wouldn't expect the bits coming down from YouTube to be a meaningful representation of what they transmitted. This page describes the mission goal as 10 megabits-per-second or higher, I guess they aren't making that up: http://www.nasa.gov/mission_pages/station/research/experiments/861.html http://www.nasa.gov/mission_pages/station/research/experimen...
- woodchuck64 12y ago
  Why wouldn't YouTube be meaningful? It would make sense for the video to be stored and transmitted as h264 and then uploaded as is to YouTube. I doubt YouTube recompresses h264.

damon_c 12y ago

They don't mention this anywhere, but for light based communication with more distant targets where the laser would need multiple seconds to reach its target, would they need to "lead the target" with the lasers pointing in both directions? Also, what about the complications due to interspersed massive bodies creating gravitational lensing?! I guess this can all be accounted for in the aiming software... but it's not very simple!

mnw21cam 12y ago
At the multiple seconds travel time level, gravitational lensing is completely insignificant. Come back when you have a round trip time of a million years past a massive galactic supercluster.

tempodox 12y ago

So we have our first ad from space. Mankind will never be the same again.

saraid216 12y ago
Best reasoning for claiming that mankind will never be the same again: claiming that mankind is being the same.

Achshar 12y ago

Why is radio communication slower than visible light based ones? 0s and 1s should be the same speed no matter what the wavelength.

icegreentea 12y ago
It's not about latency, its about bandwidth. Your data transfer rate is directly proportional to the frequency of the carrier wave. Visible light has a shorter wavelength (higher frequency) than RF, therefore can carry more information in any period of time.
_mulder_ 12y ago
Think about it, wavelength (or frequency, they're effectively the same measurement here) determines how fast you can transmit those 1's and 0's. It's not slower, it's just that you can't transmit as much information in the same time period. Also, laser light for Telecoms is not normally Visible, it's usually Infrared which has a wavelength shorter than Microwave radio but longer than visible light. Another bonus fact; in a vacuum, Radio and Light waves travel at the same speed. However, when light travels down an optical fibre it is slowed down by the glass so Fibre Internet is actually slightly slower than radio.
- dm2 12y ago
  So the speed of all fiber and radio is basically the same and it's the capacity that's different? Does that mean that saying "internet connection speed" is a faulty term? We should all be saying "capacity" or data-rate?

Sir_Cmpwn 12y ago

A more appropriate use for "Hello, world!" than I have ever written in a new programming language.

louthy 12y ago
At least yours has the correct punctuation.

dynode 12y ago

Link to the JPL project page with more detail <http://phaeton.jpl.nasa.gov/external/projects/optical.cfm> http://phaeton.jpl.nasa.gov/external/projects/optical.cfm> Interestingly this is a Phaeton project. Phaeton projects are designed for early career engineers to jumpstart their experience. Very cool. <http://phaeton.jpl.nasa.gov/external/ProgramOverview/home.cfm> http://phaeton.jpl.nasa.gov/external/ProgramOverview/home.cf...

ccamrobertson 12y ago

Congratulations to rwitoff and team at JPL for pulling it off!

fakeyfake 12y ago

If you are a fan of videos I definitely recommend their YouTube channel for brief news updates. The first thing I thought when I saw this video was definitely about the tech Li-Fi, there was a new quite long video about it recently here: https://www.youtube.com/watch?v=WRG9iXZbuAc https://www.youtube.com/watch?v=WRG9iXZbuAc

pocketstar 12y ago

>Unlike normal data transmissions, which are encoded in radio waves, this one came to Earth on a beam of light. >radio waves >beam of light Radio waves are light...