[Laser] NASA to test laser communications link with new lunar mission

[bernieS]

http://www.itworld.com/370190/nasa-test-laser-communications-link-new-lunar-mission

NASA to test frickin' laser communications link with new lunar mission

The link, faster than most home Internet connections, could deliver 
3D high-def video from space

August 23, 2013, 10:28 AM
By Martyn Williams, IDG News Service

An upcoming NASA mission will test a new laser communications system 
that could one day deliver high-definition 3D video signals from Mars 
and beyond.

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. The LADEE 
spacecraft will orbit the moon and collect information on the lunar 
atmosphere -- technically an exosphere -- for around 100 days. A 
laser communications module is built into the satellite.

"NASA has a need for faster download speeds for data from space and 
that grows everyday, just like it does for the rest of us at home and 
also from work," said Don Cornwell, mission manager for the lunar 
laser communications demonstration. He was speaking at a televised 
NASA news conference on Thursday.

"We'd like to be able to send high-resolution images and movies and 
3D even from satellites that not only orbit the Earth but also from 
probes that will go to the moon and beyond. Communicating with radio 
waves has served us well for the last 50 years but we now have the 
technology to use light waves to communicate more data," he said.

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. Once that happens, communications can begin.

The ground stations are at White Sands in New Mexico, at a NASA Jet 
Propulsion Laboratory site in Wrightwood, California, and a European 
Space Agency site in Tenerife, Spain.

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. Home Internet speeds typically run from several megabits per 
second to several tens of megabits per second.

That's roughly six times the speed that's currently possible with 
radio-based transmission, said Cornwell. As a bonus, the laser 
communications equipment also weighs half that of a radio transmitter 
and costs about a quarter less, he said.

(<https://www.youtube.com/watch?v=UfLgfo5c8AY>See a video version of 
this story on YouTube.)

Cornwell said he hopes the test is the first step in demonstrating 
the usefulness of laser communications and building confidence in its 
use in future missions, including those that go deeper into space. He 
said laser communications systems get more attractive compared to 
radio the further the spacecraft travels from Earth because the 
communications beam can be better focused.

"As you go further out into the solar system, it's a much more 
efficient way to get high bandwidth at low power," said John 
Grunsfeld, NASA's associate administrator for science and a former astronaut.

"We've already been having discussions about how you could do laser 
communications on a rover on the surface of Mars," he said, 
referencing a NASA mission to Mars planned for 2020.

"This is just the beginning of what will be replacing some of the 
radio frequency communication in the future," said Grunsfeld. "I 
think there is no question that as we send humans further out into 
the solar system, certainly to Mars, that if we want to have high-def 
3D video, we're going to have laser communications sending that 
information back."

Martyn Williams covers mobile telecoms, Silicon Valley and general 
technology breaking news for The IDG News Service. Follow Martyn on 
Twitter at <http://twitter.com/martyn_williams>@martyn_williams. 
Martyn's e-mail address is 
<mailto:martyn_williams at idg.com>martyn_williams at idg.com