NASA Testing Frickin' Laser Communications 108
itwbennett writes "The lunar laser communications demonstration will be part of the agency's Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, which is scheduled to launch on Sept. 6. Here's how the system will work: When the satellite is in orbit around the moon and visible from Earth, one of three ground stations will shoot a laser towards its approximate location. The laser beam from Earth will scan a patch of sky and should illuminate the spacecraft at some point. When that happens, the spacecraft will begin transmitting its own laser towards the ground station and the two will lock on to each other. The technology should allow an upstream data rate, from the Earth to the spacecraft, of around 20Mbps and a much faster downstream rate of 622Mbps. That's roughly six times the speed that's currently possible with radio-based transmission, said Don Cornwell, mission manager for the lunar laser communications demonstration."
Re:A long time coming (Score:4, Interesting)
What's proposed here makes more sense as a technology demonstration than a practical solution. Lasers from Earth to space (and reverse) are unreliable because of clouds and ducks that radio goes right through. But lasers from space to space are excellent. You get more reliable comunications with a relay in Earth orbit to downconvert the laser signal to a microwave frequency. Also because there's no need to get high-res video streaming from the moon for this kind of science experiment.