NASA sends the Mona Lisa to the Moon via space laser
NASA has digitized one of mankind’s most celebrated paintings, Leonardo da Vinci’s Mona Lisa, and fired it at the Moon using lasers. While you probably wanted to hear that NASA used lasers burn the work of art into the lunar surface, the reality of what happened is just as cool in a sci-fi sense.
NASA recently tested its ability to use lasers as deep-space communications tools by transmitting a digital image of the Mona Lisa to the Lunar Reconnaissance Orbiter (LRO), which is currently some 240,000 miles (386,000 km) away from Earth.
Scientists at the Goddard Space Flight Center’s Next Generation Satellite Laser Ranging (NGSLR) transmitted the digital image though laser pulses that are normally used to track the spacecraft. Unlike most satellites, the Lunar Orbiter can be tracked using a laser altimeter instead of radio waves, making it the perfect test subject for planetary-distance laser communications.
Before sending the image, researchers had to encode the image into a 152-by-200-pixel array. Each pixel was translated into a shade of gray represented by a number between zero and 4095. Although the image was sent at the speed of light, the complete image was transmitted at a data rate of about 300 bits per second.
The image the spacecraft received was also packed with quite a few errors thanks to turbulence in Earth's atmosphere, which caused some transmission errors. Scientists corrected the artifacts by employing the Reed-Solomon coding that’s normally used in CDs and DVDs.
Once the upload was completed, the LRO confirmed that it received the image by sending it back to Earth though its radio telemetry system. NASA says this is the first step towards a high-data-rate laser-communication system that will be utilized in the next Moon mission, the Lunar Atmosphere and Dust Environment Explorer.