6 ms·

Lasers boost space communications

53 points by feelthepain 13y ago

tlarkworthy 13y ago
funny how FM radio encoding was the technological step forward over radio AM, but now the its laser AM encoding that is the next forward after laser FM.
- noselasd 13y ago
  The intend[1] to use pulse position modulation, which is quite unlike AM. [1] http://cwe.ccsds.org/sls/docs/SLS-OCM/Meeting%20Materials/2012_04_Darmstadt/Presentations/LCRD%20Overview%20for%20IOAG%20-%20Germany%20-%20April%202012.pdf http://cwe.ccsds.org/sls/docs/SLS-OCM/Meeting%20Materials/20...
jlebrech 13y ago
Not a mention of latency in that article, of course you can stream terabytes of data over radio in space but the time for the request to arrive would hamper controlling things in real time.
mathattack 13y ago
Whenever I see something inspired by Clarke, Asimov or Roddenberry, I wonder who is inspiring the kids of today. Which movies or authors? Or will be indebted by the guidance of the early SF authors for the next 100 years? My first guess is Avatar as a grand inspiration, but who are the writers out there standing of the giants before them? Quoting country music usually gets me in trouble, but "Who's gonna fill their shoes?"
- incision 13y ago
  That's an interesting question. My guess is that the original/semi-original stuff they will be inspired by are games like Halo, Mass Effect, Portal, StarCraft, Bioshock, movies like Avatar as mentioned, District 9 and Inception. Anecdotally, I don't see young people reading much and when they are it's wizards or vampires, not science fiction. As best I can recall, there haven't been many strong or particularly popular books, movies or television series in the genre for a good decade now.
- TimSAstro 13y ago
  Well, to name my personal favourites: William Gibson. Neal Stephenson. Paolo Bacigalupi. Ian M. Banks (sadly no longer with us as of late). I'm sure I've missed a great deal more fine authors.
- dragonwriter 13y ago
  > Whenever I see something inspired by Clarke, Asimov or Roddenberry, I wonder who is inspiring the kids of today. Which movies or authors? Even if there were parallels around (and, really, you aren't going to find an Asimov or even a Clarke every generation), the social, economic, and cultural situation of the early 21st century isn't the same as the one of the mid-20th, and doesn't lend itself to the same kind of popular reception for futurism that occurred especially during what might be described as the golden age of the American middle class from the end of WWII through about 1980, and continued later among the people that grew up in that period.
- Valid 13y ago
  Neil DeGrasse Tyson's remake of Carl Sagan's COSMOS series is getting me seriously excited. Link: http://www.youtube.com/watch?v=kBTd9--9VMI http://www.youtube.com/watch?v=kBTd9--9VMI Not SF necessarily, but still inspiring.
binarymax 13y ago
Tens of thousands of kilometers sounds good. But millions of kilometers will be a huge challenge. The advantage of the laser is its pinpoint precision. But when you get to the distance where the speed of light is not fast enough, and the receiving end has moved, you have an interesting problem. You will need to point the laser to where the receiver will be. Also, as you start thinking about even further distances and gravity 'refracting' light it gets complicated very quickly.
- noselasd 13y ago
  It isn't that pinpointed, calculating and tracking the position of something in our solar system relative to earth to a few (hundred) thousand square kilometers precision should be little problem. "For example, a typical Ka-band signal from Mars spreads so wide that when it reaches Earth the diameter of the energy is many times larger than the diameter of the Earth. A typical optical signal, however, will spread only over the equivalent of a small portion of the United States, requiring less energy use and waste." From http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf
  - jared314 13y ago
    Interesting. That would increase the need for more terrestrial transceivers or satellite transceivers to maintain active communication as objects spin.
- mtgx 13y ago
  They're already working on quantum communications between Earth and satellites, too, but it's obviously still very early days. But it will probably be what we'll use for very large distances in the future. http://www.extremetech.com/extreme/152906-european-scientists-propose-worlds-largest-quantum-network-between-earth-and-the-iss http://www.extremetech.com/extreme/152906-european-scientist... http://spectrum.ieee.org/tech-talk/aerospace/satellites/china-unveils-secret-quantum-communications-experiment http://spectrum.ieee.org/tech-talk/aerospace/satellites/chin...
  - 13y ago
nathan_long 13y ago
Given that visible light and radio waves are the same thing except that visible frequency, my first thought was "why don't they focus the radio waves rather than switching to visible light?" I suppose that higher frequency waves can encode more information, but I'd guess they also have a harder time penetrating the atmosphere. Maybe we don't have a mechanism for producing "radio laser?" Can anybody clarify for me?
- marcosdumay 13y ago
  We have MASERs, but they just aren't usefull for that. Because theyr wave-length is bigger, a "radio laser" difuses into a huge area before getting into Earth.
- Symmetry 13y ago
  Higher frequency radiation tends to give you a more focused beam for a given lens size. Here's a run related tool for figuring out how much damage a laser beam will do given frequency, energy, lens size, etc. http://www.5596.org/cgi-bin/laser.php http://www.5596.org/cgi-bin/laser.php
- Sharlin 13y ago
  Yes, actually the "radio laser" (actually, microwave laser [1]) was the first type of *aser invented! The reason they haven't been proposed for deep-space communication is that thus far, unlike lasers, they have required bulky cooling mechanisms and solid-state semiconductor masers have not been possible. The future does look brighter due to a recent breakthough, though [2]. [1] http://en.wikipedia.org/wiki/Maser http://en.wikipedia.org/wiki/Maser [2] http://www.nature.com/news/microwave-laser-fulfills-60-years-of-promise-1.11199 http://www.nature.com/news/microwave-laser-fulfills-60-years...
  - toomuchtodo 13y ago
    I'm expecting, one day, for half the moon to be covered in antenna gear and us using it as one large phased array software-defined radio. Like arecibo observatory, but HUGE.
Sharlin 13y ago
The Mars Telecommunications Orbiter [1], if flown, would have demonstrated laser communications at Earth-Mars distances already in the early 2010s. It was cancelled because the funds had to be funneled to the last Hubble service mission, as well as to the overbudget James Webb Space Telescope and the Mars Science Laboratory (the Curiosity rover). Also, the Mars Reconnaissance Orbiter, capable of working as a relay, was found to have adequate bandwidth to serve the various surface missions. [1] http://en.wikipedia.org/wiki/Mars_Telecommunications_Orbiter http://en.wikipedia.org/wiki/Mars_Telecommunications_Orbiter

53 points by feelthepain 13y ago

funny how FM radio encoding was the technological step forward over radio AM, but now the its laser AM encoding that is the next forward after laser FM.

noselasd 13y ago
The intend[1] to use pulse position modulation, which is quite unlike AM. [1] http://cwe.ccsds.org/sls/docs/SLS-OCM/Meeting%20Materials/2012_04_Darmstadt/Presentations/LCRD%20Overview%20for%20IOAG%20-%20Germany%20-%20April%202012.pdf http://cwe.ccsds.org/sls/docs/SLS-OCM/Meeting%20Materials/20...

jlebrech 13y ago

Not a mention of latency in that article, of course you can stream terabytes of data over radio in space but the time for the request to arrive would hamper controlling things in real time.

mathattack 13y ago

Whenever I see something inspired by Clarke, Asimov or Roddenberry, I wonder who is inspiring the kids of today. Which movies or authors? Or will be indebted by the guidance of the early SF authors for the next 100 years? My first guess is Avatar as a grand inspiration, but who are the writers out there standing of the giants before them? Quoting country music usually gets me in trouble, but "Who's gonna fill their shoes?"

incision 13y ago
That's an interesting question. My guess is that the original/semi-original stuff they will be inspired by are games like Halo, Mass Effect, Portal, StarCraft, Bioshock, movies like Avatar as mentioned, District 9 and Inception. Anecdotally, I don't see young people reading much and when they are it's wizards or vampires, not science fiction. As best I can recall, there haven't been many strong or particularly popular books, movies or television series in the genre for a good decade now.
TimSAstro 13y ago
Well, to name my personal favourites: William Gibson. Neal Stephenson. Paolo Bacigalupi. Ian M. Banks (sadly no longer with us as of late). I'm sure I've missed a great deal more fine authors.
dragonwriter 13y ago
> Whenever I see something inspired by Clarke, Asimov or Roddenberry, I wonder who is inspiring the kids of today. Which movies or authors? Even if there were parallels around (and, really, you aren't going to find an Asimov or even a Clarke every generation), the social, economic, and cultural situation of the early 21st century isn't the same as the one of the mid-20th, and doesn't lend itself to the same kind of popular reception for futurism that occurred especially during what might be described as the golden age of the American middle class from the end of WWII through about 1980, and continued later among the people that grew up in that period.
Valid 13y ago
Neil DeGrasse Tyson's remake of Carl Sagan's COSMOS series is getting me seriously excited. Link: http://www.youtube.com/watch?v=kBTd9--9VMI http://www.youtube.com/watch?v=kBTd9--9VMI Not SF necessarily, but still inspiring.

binarymax 13y ago

Tens of thousands of kilometers sounds good. But millions of kilometers will be a huge challenge. The advantage of the laser is its pinpoint precision. But when you get to the distance where the speed of light is not fast enough, and the receiving end has moved, you have an interesting problem. You will need to point the laser to where the receiver will be. Also, as you start thinking about even further distances and gravity 'refracting' light it gets complicated very quickly.

noselasd 13y ago
It isn't that pinpointed, calculating and tracking the position of something in our solar system relative to earth to a few (hundred) thousand square kilometers precision should be little problem. "For example, a typical Ka-band signal from Mars spreads so wide that when it reaches Earth the diameter of the energy is many times larger than the diameter of the Earth. A typical optical signal, however, will spread only over the equivalent of a small portion of the United States, requiring less energy use and waste." From http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf http://www.nasa.gov/pdf/742122main_LCRDFactSheet3.pdf
- jared314 13y ago
  Interesting. That would increase the need for more terrestrial transceivers or satellite transceivers to maintain active communication as objects spin.
mtgx 13y ago
They're already working on quantum communications between Earth and satellites, too, but it's obviously still very early days. But it will probably be what we'll use for very large distances in the future. http://www.extremetech.com/extreme/152906-european-scientists-propose-worlds-largest-quantum-network-between-earth-and-the-iss http://www.extremetech.com/extreme/152906-european-scientist... http://spectrum.ieee.org/tech-talk/aerospace/satellites/china-unveils-secret-quantum-communications-experiment http://spectrum.ieee.org/tech-talk/aerospace/satellites/chin...
- 13y ago

nathan_long 13y ago

Given that visible light and radio waves are the same thing except that visible frequency, my first thought was "why don't they focus the radio waves rather than switching to visible light?" I suppose that higher frequency waves can encode more information, but I'd guess they also have a harder time penetrating the atmosphere. Maybe we don't have a mechanism for producing "radio laser?" Can anybody clarify for me?

marcosdumay 13y ago
We have MASERs, but they just aren't usefull for that. Because theyr wave-length is bigger, a "radio laser" difuses into a huge area before getting into Earth.
Symmetry 13y ago
Higher frequency radiation tends to give you a more focused beam for a given lens size. Here's a run related tool for figuring out how much damage a laser beam will do given frequency, energy, lens size, etc. http://www.5596.org/cgi-bin/laser.php http://www.5596.org/cgi-bin/laser.php
Sharlin 13y ago
Yes, actually the "radio laser" (actually, microwave laser [1]) was the first type of *aser invented! The reason they haven't been proposed for deep-space communication is that thus far, unlike lasers, they have required bulky cooling mechanisms and solid-state semiconductor masers have not been possible. The future does look brighter due to a recent breakthough, though [2]. [1] http://en.wikipedia.org/wiki/Maser http://en.wikipedia.org/wiki/Maser [2] http://www.nature.com/news/microwave-laser-fulfills-60-years-of-promise-1.11199 http://www.nature.com/news/microwave-laser-fulfills-60-years...
- toomuchtodo 13y ago
  I'm expecting, one day, for half the moon to be covered in antenna gear and us using it as one large phased array software-defined radio. Like arecibo observatory, but HUGE.

Sharlin 13y ago

The Mars Telecommunications Orbiter [1], if flown, would have demonstrated laser communications at Earth-Mars distances already in the early 2010s. It was cancelled because the funds had to be funneled to the last Hubble service mission, as well as to the overbudget James Webb Space Telescope and the Mars Science Laboratory (the Curiosity rover). Also, the Mars Reconnaissance Orbiter, capable of working as a relay, was found to have adequate bandwidth to serve the various surface missions. [1] http://en.wikipedia.org/wiki/Mars_Telecommunications_Orbiter http://en.wikipedia.org/wiki/Mars_Telecommunications_Orbiter