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Is a Laser Data Link 1.5 Million Kilometers Feasible?
An anonymous reader writes "On the Canary Islands last week, a team from Oerlikon Space demonstrated the feasibility of a laser link across a distance of 1.5 million kilometers for the first time ever. In the future, laser links like this one will be able to transmit data across huge distances through the universe far more rapidly and efficiently than is possible using conventional radio links today."
I'm assuming that in space, the problem will not be weather conditions, but "aim"
Hi,
It seems to me that this would be especially useful to reduce the amount of induced radio noise when communicating with L1 (etc) radio telescopes or other instruments potentially sensitive to the normal radio frequencies used for communication, eg keep the comms out-of-band of what is being measured as far as possible.
Rgds
Damon
http://m.earth.org.uk/
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Can't you also make a laser out of radio waves? I know they have microwave "lasers" called masers, so do "rasers" exist?
laser are not focussed they are coherent... sheesh.
Well, while I thought the same thing you did at first, I suspect they mean that the actual data rate will be higher due to lower noise on the channel and/or other factors.
and what sort of receiver setup is needed?
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It doesn't sound like you know much about mathematics. Please check the relation between the diameter of the laser spot and the power/area ratio, then rethink what the inverse square law actually says.
we have the Gas engine... it works.. lets forget about all this crazy hybird and electric car talk...
While we're at it, Coal Plants do a good job at producing energy and they work too... lets forget about all that fandangled alternate energy source stuff...
While were at it.. smoke signals work too.. no need for complicated technology like telephone and email...
okay.. now that my sarcasm limit has been reached... because something works is not a good reason for ignoring technology that can potentially supercede it...
Why? And, basically the same question, less than 70kb per what?
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"Back onto the radio front, we have Voyager 1 which is 15 billion miles away, proven with radio, that would seem good enough for me"
The issue is not whether you get data at all, but whether you can transmit at broadband speeds. I am pretty sure that at this point of
its flight Voyager does nothing else but send a few byte pings every once in a while.
The problems laser links would solve would be in the order of streaming HD video from Mars to Earth.
"Who would have thought that light could travel such a long distance?"
Who would have though the Canary Islands are that big?
-Charlie
Well you could also fix this by setting up a redundant set of transmissions. If your target is going to have a latency of a couple of minutes you could transmit data x a couple of times so that the if for whatever reason the first or second instance of the data is bad there will be a third copy sent. This will increase the amount of data sent but will help ensure correct data rather than having to depend on the target to yell back that the data is corrupted. It's kind of like if you set up a network based on UDP and for every n bytes you send you send redundant packets of those n bytes. In the best case scenario those extra packets won't be needed but in the event of a bad route you have 10 chances to recover good data. This would work best for high latency networks.
If I recall, one of the requirements for the new Lunar X Prize is the shooting of some high-def video from the lunar surface. (For some *very* pricey stock footage!) I imagine it would be much easier to do that with a high-capacity link, such as what you'd get with a laser. This is the sort of technology that the X Prize (and NASA) should be supporting.