As if that news wasn’t cool enough enough, NASA has trumped itself by sending a copy of the Mona Lisa to the moon by laser.
In an effort to move interplanetary communication forward, NASA experimented last week with sending a message to the Lunar Reconnaissance Orbiter.
The laser is used to keep track of the orbiter’s position but this time it was used to send a digitize image of the Mona Lisa 240,000 miles from the Next Generation Satellite Laser Ranging (NGSLR) station at NASA’s Goddard Space Flight Center in Greenbelt, Md to spacecraft, which was able to receive the message by using its Lunar Orbiter Laser Altimeter (LOLA). NASA sent the image in the form of discrete laser pulses that were decompiled by the Orbiter. Each pulse represented a different pixel of the digitized image.
Precise timing was key. The image was divided into an array of 152 pixels by 200 pixels, and each dot was converted into a shade of gray, represented by a number between zero and 4,095. The pulse had to be fired in one of 4,096 possible timing slots during a brief time window allotted for laser tracking.
In the end, the transmission rate reached a maximum 300 bits per second. To clean up the image, NASA used the tried-and-true Reed-Solomon error correction, which is routinely used in CDs and DVDs.