Why did NASA shoot a laser at the moon?


Using a laser, NASA has beamed data between the moon and Earth -- 239,000 miles -- at a record-shattering rate.

The download rate that got NASA scientists so excited was 622 megabits per second. We asked an expert to break it down.

“This download rate is six times faster than the most recent state-of-the-art radio system from the moon,” Don Cornwell, manager of the Lunar Laser Communication Demonstration told The Times by email on Wednesday.


PHOTOS: ISS crews and images from space

Up to this point, NASA has used radio frequency communication. But it’s limited, and scientists want more than that.

One issue is crowding: There’s only so much room in the electromagnetic spectrum, NASA explains, and the radio and microwave portions are nearly chock-full. Meanwhile, NASA has rapidly ramped up its transmission of data. A laser can sizzle along in a roomier part of the electromagnetic spectrum.

Laser communication would mean better image resolution, NASA says, and make it feasible to transmit 3-D video to Earth from deep space.

Cornwell put it this way: “The demonstrated bandwidth of 622 Mbps could support up to 30 HD video channels from the moon.

“NASA has no plans to start its own cable network,” he wryly noted, but “we could use that bandwidth to send down many more high-resolution images (and videos for human space flight) than we can now.”

For the LLCD experiment, data was transmitted between a ground station in New Mexico and the Lunar Atmosphere Dust Environment Explorer, a spacecraft now orbiting the moon. Next is the Laser Communications Relay Demonstration, launching in 2017.

“LCRD is going to test the ability to relay data from one ground station at White Sands, N.M., to another at NASA JPL through a laser communications terminal in geostationary orbit,” 22,000 miles above the Earth, Cornwell said.

Like NASA news? Follow me @AmyTheHub


Taking a balloon into near space

Your cat’s poop could be a public health threat

High school student found youngest crested dinosaur fossil