NASA has reportedly completed the transfer of an image — Leonardo Da Vinci’s Mona Lisa — from Earth to the moon. The latest mission led by the U.S. space agency has led some to wonder why NASA is directing its attention to blasting lasers toward the moon.
The short answer has to do with interplanetary space travel, according to the agency.
The latest test, which involved shooting lasers at the Lunar Reconnaissance Orbiter (LRO) – the robotic spacecraft that creates gravitational maps of the moon — is the most recent attempt by NASA to test a new form of communication that relies on laser technology, rather than conventional radio transmission technology.
“This is the first time anyone has achieved one-way laser communication at planetary distances,” says NASA principal investigator, David Smith of the Massachusetts Institute of Technology. “In the near future, this type of simple laser communication might serve as a backup for the radio communication that satellites use. In the more distant future, it may allow communication at higher data rates than present radio links can provide.”
Typically, satellites that go beyond Earth orbit use radio waves for tracking and communication. LRO is the only satellite in orbit around a body other than Earth to be tracked by laser as well.
“Because LRO is already set up to receive laser signals through the LOLA instrument, we had a unique opportunity to demonstrate one-way laser communication with a distant satellite,” says Xiaoli Sun, a LOLA scientist at NASA Goddard and lead author of the Optics Express paper, posted online today, that describes the work.
The U.S.-based space agency, which has not been shy about its goal of sending astronauts to Mars and possibly beyond, has repeatedly said that it hopes to have a better way to send data across space. Speaking earlier this week, NASA officials said the latest test was groundbreaking for the agency, noting that no one has ever achieved one-way laser communication at planetary distances. Theoretically the speed and amount of data that can be transferred via laser is an order of magnitude greater than the rates currently attainable with radio waves. According to NASA, a laser-based communication system has the potential to transfer data 10 to 100 times faster than radio systems with the same mass and power.
While the newly devised laser data transfer system could one day replace radio transmission, NASA did note that its Mona Lisa trial did not go off without a few problems of its own. According to NASA, the first attempt to transfer the image to the LRO resulted in a distorted, degraded image — likely due to atmospheric conditions. In addition, the data rate of 300 bits per second achieved by the agency is far slower than current cable or radio rates. The agency says it is now working on developing a new experimental laser they hope will be capable of transmitting 600 million bits per second.
It remains unclear whether NASA will have the laser communication system ready to go ahead of its upcoming missions. The space agency has vowed to send astronauts to a nearby asteroid, the moon, and to Mars, leaving little doubt that developing a reliable, laser-based form of communication would be beneficial. The agency has already announced plans to launch the Laser Communications Radar Demonstration into orbit aboard a commercial satellite in 2017, marking their first attempt at a full, beam-based communication system.