Nowadays, we transmit most of the wireless data using radiofrequency (RF). However, due to the huge number of applications that already exist in this band (satellite communications, wi-fi, maritime radio, TV, radio astronomy,…) we are arriving to the limits of capacity. This, added to the need to increase the download speed rate while communicating in space, encouraged NASA to launch in September 2013 the LLCD (Lunar Laser Communications Demonstration) mission, to revolutionize space communications using lasers.
Two main elements compose the communication link of the mission: the spacecraft called LADEE (which is orbiting around the moon) and the ground segments (three stations on Earth responsible for the communication with the spacecraft). Its first aim was to establish a new way to communicate in space, emitting in the near-infrared of the electromagnetic spectrum, and the result of this is a download data rate of 622 Mbps, which is about 5 times quicker than we do today from lunar distances.
Another reason for which NASA decided to communicate with lasers, and thus to start the LLCD mission, was to create more efficient and secure space communications. As lasers have smaller wavelengths than RF, their beams cover a narrower area. Thus, their receiving antennas are going to be reduced in size for the ground segments as well as for the aircraft. Therefore, with this new way of communication we have quicker, safer and less powered communications and also a reduced mass and size of the satellite, so a considerably save of costs.
The first positive results have already been obtained, so maybe in a not very far future, we will be able to watch a 3D-High definition video from the Moon or communicate in real-time with Mars or even beyond the Solar System, who knows… ?