NASA Lunar Probe Will Test Out High Speed Laser Communications

By Wesley Fenlon

If NASA's Lunar Laser Communication Demonstration proves successful, it could serve as a replacement for more conventional radio frequency transmissions.

Outer space? Cool. Outer space and laser beams? Even more cool. NASA's LADEE mission, which will launch during a five-day window starting September 6, will play host to a new laser-based communication system that could provide the bandwidth to beam high-res images back and forth between Earth and lunar orbit. LADEE stands for Lunar Atmosphere and Dust Environment Explorer, and it's a probe that will orbit the moon "to gather detailed information about the lunar atmosphere, conditions near the surface and environmental influences on lunar dust."

Studying moon dust is plenty exciting, but not as interesting as the communications system NASA plans to test out. NASA's website explains that currently "communications with spacecraft beyond close Earth orbits require spacecraft to have small, low-mass, low-power radio transmitters and giant satellite dishes on Earth to receive their messages. However, the LADEE spacecraft will demonstrate the use of lasers instead of radio waves to achieve broadband speeds to communicate with Earth."

Photo credit: NASA

Where RF transmission offers limited bandwidth and can hit interference in Earth's atmosphere, the laser system will be faster, draw less power, and offer up to six times the bandwidth. TG Daily writes that the laser system "is to transmit hundreds of millions of bits of data per second from the moon to Earth. This is equivalent to transmitting more than 100 HD television channels simultaneously. LLCD (Lunar Laser Communication Demonstration) receiving capability will also be tested as tens of millions of bits per second are sent from Earth to the spacecraft."

The only problem: the precision required for point-to-point communications over a distance of 240,000 miles. NASA's mission page states "This pointing challenge is the equivalent of a golfer hitting a 'hole-in-one' from a distance of almost five miles."

Image credit: NASA

Thankfully, NASA has some pretty smart golfers behind it: "Developers at the Massachusetts Institute of Technology's (MIT) Lincoln Laboratory have designed a sophisticated system to cancel out the slightest spacecraft vibrations. This is in addition to dealing with other challenges of pointing and tracking the system from such a distance. We are excited about these advancements."

If successful, the Lunar Laser Communication Demonstration could pave the way for a 2017 program called the Laser Communication Relay Demonstration, which aims to prove "the long-term viability of laser communication from a geostationary relay satellite to Earth."