Mona Lisa goes to outer space

You've got to admit, the lady certainly gets around in style.

 

The US National Aeronautics and Space Administration (NASA) took Leonardo da Vinci's famously enigmatic lady, the Mona Lisa, for a ride —via laser, no less— to an orbiter around the Moon.

 

“This is the first time anyone has achieved one-way laser communication at planetary distances,” said David Smith of the Massachusetts Institute of Technology, according to the Smithsonian Magazine.

 

Smith is the Lunar Orbiter Laser Altimeter’s principal investigator. The laser journey involved a distance of about 240,000 miles.

 

NASA's experiment in laser communication had scientists at its Next Generation Satellite Laser Ranging (NGSLR) station at the Goddard Space Flight Center in Greenbelt, Maryland, beam a digital image of the Mona Lisa to the Lunar Reconnaissance Orbiter (LRO).

 

LRO is a satellite that has been orbiting the moon and mapping its surface since 2009.

 

It is the only spacecraft outside of Earth’s orbit that is capable of receiving lasers, and can be tracked using both lasers and radio.

 

During the experiment, a digital image of the Mona Lisa rode “piggyback” on laser pulses that are regularly beamed at LRO to follow its position in space.

 

Before this, NASA scientists had used radio waves to track and communicate with satellites traveling outside of Earth’s orbit.

 

They are considering using lasers, which are faster and can transmit more data.

 

Xiaoli Sun, a scientist at NASA Goddard and lead author of a recent paper about the project in Optics Express, said they chose the Mona Lisa for the journey because of its subtleties.

 

“We chose the Mona Lisa because it is a familiar image with a lot of subtleties, which helped us to see the effect of transmission errors,” Sun said.

 

Transmission errors

 

To compensate for transmission errors introduced by the Earth’s atmosphere, Goddard scientists applied Reed-Solomon error correction.

 

Sun and colleagues divided the Mona Lisa image into an array of 152 pixels by 200 pixels.

 

Every pixel was converted into a shade of gray, represented by a number between zero and 4,095.

 

A laser pulse transmitted each pixel, with the pulse being fired in one of 4,096 possible time slots during a brief time window allotted for laser tracking.

 

The complete image was transmitted at a data rate of about 300 bits per second.

 

The satellite then pieced together the full image and then sent it back via radio waves.

 

However, the portrait was not transmitted perfectly as the natural disturbance of the laser as it passed through the Earth’s atmosphere account for the blank pixels in the image.

 

More experiments

 

There will likely be more similar experiments, researchers said.

 

“This pathfinding achievement sets the stage for the Lunar Laser Communications Demonstration (LLCD), a high data rate laser-communication demonstration that will be a central feature of NASA’s next moon mission, the Lunar Atmosphere and Dust Environment Explorer (LADEE),” said Goddard’s Richard Vondrak, the LRO deputy project scientist.

 

Past experiments

 

In 2005, a group of researchers from the University of Amsterdam analyzed Mona Lisa’s famous smile by running a scanned reproduction through “emotion recognition” software.

 

That software claimed Mona was precisely 83 percent happy, 9 percent disgusted, 6 percent fearful, 2 percent angry, 1 percent neutral—and completely unsurprised.

 

In 2010, scientists in France used X-ray fluorescence spectrometry on the painting and found that da Vinci applied layers of glazes and paints to achieve the subject’s flawless complexion.

 

Last year, Italian archaeologists exhumed the skeletal remains of Lisa Gherardini, the suspected sitter for the portrait, in Florence to identify the real Mona Lisa. — TJD, GMA News