NASA’s Lunar Laser Communication Demonstration (LLCD) experiment made history yesterday as it beamed data back to Earth from lunar orbit at previously unheard of speed for a space mission. Operating from the LADEE lunar orbiter, the LLCD used lasers to transmit data to Earth at 622 megabits per second (Mbps) as a demonstration of a technology that NASA hopes will one day not only keep up with the communications demands of future missions, but also greatly enhance their capabilities.

Space exploration is dealing with an increasingly difficult bottleneck when it comes to communications. Up until now, NASA and other space agencies have relied on radio frequency (RF) communications, which have worked well, but have only limited bandwidth.

Over the years, the demands for greater data bandwidth have grown and RF is reaching its practical limits, but lasers have a much greater bandwidth capacity and their ability to produce a narrow, coherent beam means that they use less power over longer distances – a prime concern for spacecraft that often have to make do with power levels usually associated with incandescent bulbs.

LLCD optical module (Image: NASA)

The LLCD transmitted the record-breaking download across a quarter of a million miles using a pulsed laser beam picked up by the main LLCD ground station in New Mexico, which is one of three set up in the United States and Spain. In addition to the 622 Mbps download, LADEE also received an upload of data from Earth at a rate of 20 Mbps.

The LLCD is one of the experiment packages aboard NASA’s unmanned Lunar Atmosphere and Dust Environment Explorer (LADEE), which was launched from NASA’s Wallops Flight Facility on Wallops Island, Virginia on September 6 and went into orbit around the Moon on October 6 as part of a 100-day mission to study the almost non-existent lunar atmosphere and the presence of dust that may be kicked up from the lunar surface by solar activity.

According to NASA, lasers will not only allow communications technologies to keep up with demand, but may one day also allow for the transmission from space of images with greater resolution, 3D video from deep space, or even enable telepresence operation of surface rovers by orbiting crews..

NASA says that whereas the LLCD is a short-duration experiment, it paves the way for the long-duration demonstration Laser Communications Relay Demonstration (LCRD) slated to launch in 2017.

The video below outlines the LLCD experiment

Source: NASA

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