Moon-bound laser beams from Earth enable Wi-Fi hotspot in space
Researchers at MIT and NASA have announced it is possible to post selfies and stream high-definition video from the moon. Kind of.
The two organisations have demonstrated that data communication technology is possible in space. They recently built four separate telescopes at a ground terminal in New Mexico, capable of sending an uplink signal to the moon. A laser transmitter technically sends the information through each telescope as coded pulses of infrared light, resulting in 40 watts of transmitter power.
Using this setup, researchers managed to upload information from Earth to the moon at a rate of 19.44 Mbps. That's equal to basic broadband speeds on Earth. They were also able to download information from the moon at a mind-blowing rate of 622 Mbps, meaning this new laser-powered communication is about 4,800 times faster than radio transmission speeds achieved by RF signals.
The two organisations plan to present their new technology at the CLEO laser technology conference on 9 June in California. Researchers will not only detail how they transmitted data across a 384,633km distance between Earth and the moon at high rates with laser beams but also how they avoided atmosphere turbulence that can bend light and cause dropouts of the signal at the receiver.
The four telescopes actually compensate for this turbulence by transmitting light - or beaming a connection - to the moon through different columns of air, each with different bending effects, in an attempt to increase the chance that at least one of the laser beams will reach the receiver, which is attached to a satellite that orbits the moon, and establish a solid broadband connection.
Less than a billionth of a watt from the 40-watt transmitted signal will hit the satellite, but that's ten times more than needed. Similar to the ground terminal on Earth, the orbiting satellite features a telescope. This telescope doesn't beam lasers but rather collects any transmitted infrared light and focuses it into an optical fibre. A photodetector converts the coded pulses of light into electrical pulses and then into readable data.
With this process, MIT and NASA hope to one day enable data communication for near-Earth missions and eventually deep-space missions.