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."

Comments

Never saw this coming

[LiquidCoooled]

Who would have thought that light could travel such a long distance?

In all seriousness, the problem is not the knowledge a laser can travel that far; its whether you can create precise enough targeting equipment.
A radio signal might be more of a splatter, but at least if you point it "over there" with enough power behind it, it will get there.

As they say their simple hilltop to hilltop test failed because of weather conditions, whats going to happen when they do put 'scopes at the lagrange points?

"Oh sorry, we can't get the data today because its cloudy"

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.

Re:Never saw this coming

[vertinox]

As they say their simple hilltop to hilltop test failed because of weather conditions, whats going to happen when they do put 'scopes at the lagrange points?

Huh? The logical thing do to would be have the laser communicators in orbit, and the communication from ground to the laser satellites would be via the conventional means. If its cloudy in your town, then the satellite can talk to another town which isn't cloudy and you can use fiber to talk the rest of the way.

Laser moon and back feet, more like *miles*

[Overzeetop]

Correct, they did put corner cubes on the moon (aka retroreflectors, or three mirrored surfaces all at 90 degree angles to one another).

However, the beam size from a collimated laser is a couple miles across at the moon. Typically, receiving a signal back takes a large telescope which counts single-digit photon returns from a Nd:YAG q-switched laser. It's been almost 2 decades since I worked with the stuff (you might search for Satellite Laser Ranging, Goddard Optical Research Facility and MOBLAS or TLRS) and the units that ranged on the moon cubes were at Mt. Haleakala in Hawaii.

It was neat stuff, but I remember one of the PIs saying the spot on the moon was the size of Georgetown (a section of Washington DC), though I can't remember exactly now. The outgoing laser was about 4" in diameter.