NASA's Lunar Atmosphere and Dust Environment Explorer, or LADEE, ended its mission last week with a planned impact on the Moon but just before the impact it performed another successful laser communication with ESA's ground station at a stunning speed of 80 megabits per second (Mbps). Achieved data speeds are like those used by many to watch movies at home via fibre-optic Internet.
Today, spacecrafts beyond close Earth orbits and their ground control communicate via radio transmitters and giant satellite dishes on Earth. Laser communications in the near-infrared, demonstrated by LADEE, may be the way of the future when it comes to downloading massive amounts of data from spacecraft orbiting Earth, Mars or even more distant planets.
Laser Lunar Communication Demonstration or LLCD is the first dedicated system of two-way communication using laser instead of radio waves but its demonstration was not LADEE's only mission. The spacecraft ran its science instruments almost non-stop right up to impact the evening of April 17, 2014, in an effort to gather as much low-altitude data as possible.
Further study of the returned data will reveal what the instruments saw just a few kilometers above the surface. Early results suggest that LADEE was low enough to see some new things, including increased dust density and possibly new atmospheric species. In an incredible race with time, LADEE’s Real Time Operations team queued and downloaded all science files just minutes prior to LADEE's impact.
LLCD made history on October 18, 2013 when it made the first-ever laser transmission from lunar orbit. It demonstrated pulsed laser beam data transmission over the distance of 384 000 km (239 000 miles) at a record-breaking download rate of 622 Mbps. In addition, an error-free data upload rate of 20 Mbps was transmitted from the primary ground station in New Mexico to the Laser Communications Space Terminal aboard LADEE.
Featured image: NASA - LADEE / LLCD