NASA and ESA To Demonstrate Earth-Moon Laser Communication 74
cylonlover writes with this news bite about a cool new ground to space laser communication system from NASA and ESA: "Space communications have relied on radio since the first Sputnik in 1957. It's a mature, reliable technology, but it's reaching its limits. The amount of data sent has increased exponentially for decades and NASA expects the trend to continue. The current communications systems are reaching their limits, so NASA and ESA are going beyond radio as a solution. As part of this effort, ESA has finished tests of part of a new communications system, in preparations for a demonstration in October in which it will receive a laser data download from a NASA lunar orbiter."
SETI (Score:3, Insightful)
Maybe this is part of the reason why SETI hasn't picked up anything yet...
Re:SETI (Score:4, Funny)
Maybe this is part of the reason why SETI hasn't picked up anything yet...
And it explains the focus effect of quasars, they are just intergalactic long distance...
wonder what the plan lock in period is on a supermassive black hole?
Also, who do you call for an unlock at the end of the contract?
If it's the vendor, it may be a bad idea to bug someone that sets up black holes on demand...
ET Laser Home? (Score:2)
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It'll be handy for communicating with those Nazis in their moon base.
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I first saw the headline as saying "NASA and ESA To Demonstrate Earth-Moon Laser Cannon", before I got my glasses on.
I was thinking this was covered in a Warner Bros. cartoon....
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I have not seen it myself, but I hear the Nazis do have a moon base... Iron Sky [imdb.com].
Re:NASA (Score:5, Insightful)
Re:NASA (Score:5, Interesting)
Destructively "bouncing" a laser is easy. Just point it in the general direction, and apply power until there's too much extra energy for the target to handle.
Communication is more difficult, because not only do you have to point in exactly the right direction, from far further away (or have ridiculously more power), but you then have to modulate the laser appropriately to transmit data, and do so in such a way that atmospheric or other line-of-sight disturbances won't be too much of a problem, and you have to keep doing it long enough to send all you data through, and ideally even have a matching receiver to pick up the return direction.
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I'm replying to this high-scoring comment not only because I want to be noticed and get mod points, but because I have expertise and experience in the field.
As long as you know the characteristics of the optical medium, you can with some certainty use techniques similar to these [wikipedia.org].
-- Ethanol-fueled
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We already have laser reflectors on the moon. Left by Apollo 13 or so I believe.
It is regularly used for distance measuring.
It is not really hard to point one laser to lunar and another one from there to earth. A data link is absolutely trivial. Hint: a laser beam going to the moon is widening to roughly 100km diameter. Not hard at all to hold the aim.
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Um, Apollo 13 never made it to the Moon.
Apollo 13 article on Wikipedia [wikipedia.org]
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True, forgot about that. the first one was set by Apollo 11, the next two by Apollo 14.
http://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment [wikipedia.org]
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Why can't scientists do something about that?
My sources tell me that's not going to happen until 2208.
Practical problems (Score:2, Redundant)
Re:When ... (Score:5, Interesting)
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Coincidentally, a "space engineer" whose blog I read recently mentioned something similar as a way to generate revenue from the early phase of a lunar mining operation. [wordpress.com] I'm not sure I buy the numbers, but it's an interesting concept:
I can immediately generate revenue from the use of the laser communications system. Utterly secure, 25 gigabits/sec communications with an unhackable data server would easily be worth $150-250m/year in revenue to the U.S. government, based on the cost of the Advanced EHF and other wideband military satellites. The yearly cost to support this is $1-2m dollars, thus my first infrastructure payload for mining is already generating strongly positive cash flow.
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Ill be ok with spending tons of money on space when our sick are taken care of instead of left dying for lack of coverage. .. really .. till then it's just shaming us all .
Ill be ok with spending tons of money when the elderly are taken care of properly , same with our war veterans we abandoned.
Ill be ok with it then
Do you have any idea how much we spend on healthcare and on NASA??
Re:When ... (Score:4, Interesting)
Ill be ok with spending tons of money on space when our sick are taken care of instead of left dying for lack of coverage. Ill be ok with spending tons of money when the elderly are taken care of properly , same with our war veterans we abandoned. Ill be ok with it then .. really .. till then it's just shaming us all .
Stop spending trillions on "defense" and you can take care of the sick and elderly, educate the young, feed the hungry, pave the roads and repair the bridges., and still have enough left over to explore space.
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We have massive debt because we keep cutting taxes while increasing spending. The majority of the debt Obama put on the books is the iraq war, and a couple of tax cuts used to stimulate the ecomomy.
The problem is we cut taxes, and the economy still wasn't stimulated to grow, so we did it again and again.
Also GDP has no bearing on government spending. the GDP is to government spending as the dow jones index is to your personal wealth. The two only line up very very rarely.
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Really ?:
https://www.cia.gov/library/publications/the-world-factbook/rankorder/2034rank.html?countryname=United%20States&countrycode=us®ionCode=noa&rank=19#us [cia.gov]
Awesome! (Score:2)
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illuminating (Score:4, Funny)
I was too lasey to read the article, so it would have been nice if the video was more illuminating, but at least its coherent.
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tax dollars at work (Score:1)
we have known for centuries now that you can communicate using light or other visual signals in real time
we have been bouncing a laser off the moon since the late 60's
now, taking those two concepts and combining them, NASA is spending god knows how much time and money to communicate to the moon, WHERE THERE IS NOTHING TO RESPOND
can we please for the love of god end the multimillion dollar experiments that a 12 year old does on instructables?
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we have been bouncing a laser off the moon since the late 60's
And receiving back only a few photons out of billions, making any meaningful data transfer impossible, unless you consider 1 bps meaningful.
can we please for the love of god end the multimillion dollar experiments that a 12 year old does on instructables?
Can we please educate people enough so that they understand that shining a light across a room is much easier than detecting it from 250,000 mies away?
Too bad; We should put multiple sats in GEO orbit (Score:2)
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In the near future... (Score:3, Funny)
...don't look at the moon with your remaining eye.
We Are About To Begin Phase 2 (Score:2, Insightful)
This is the phase where we put a giant "laser" on the Moon. As you know, the Moon rotates around the Earth like so *spins moon globe around earth globe*. When the Moon reaches it's appropriate Lunar alignment, it will destroy Washington DC. You see, I've turned the Moon into what I like to call a "Death Star". Anyway, the key to this is the giant laser. It was invented by the noted Cambridge physicist Dr. Parsons. Therefore we shall call it The Alan Parsons Project
Rockets and radio. (Score:2)
How about submarines? (Score:3)
This may seem out of left field, but I was recently pondering the efficacy of lasers for submarine communications.
Only the very lowest radio frequencies penetrate a short distance below the surface of the ocean. The broadcasting equipment for those are enormous multi-megawatt monsters which can only transmit a minuscule amount of data, amounting to maybe a sentence per hour.
But with certain wavelengths of lasers, you can get penetration up to ~115 meters.
http://www.laseroptronix.se/techinfo/Waterabsorption.pdf [laseroptronix.se]
Even if the range is less, I'm sure submarine fleets would appreciate the option of laser-based two-way communications with satellites, without needing to surface.
Other than strategically placed buoys, is there even any other option for modernizing submarine communications past our current circa 1960s methods?
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Probably the most physically challenging aspect, if trying to communicate from submarine to satellite, would be aiming the uplink through the water surface that will be moving quite drastically and changing the angle the beam is refracted. And it is possible to have wave shapes that will make it difficult to get a connection for moments at a time (effectively momentary dead spots), although that could probably be over come with short bursts of communications assuming the first issue was overcome. You woul
VALIS (Score:1)