Laser sends Mona Lisa into space

NASA scientists say they beamed an image of the Mona Lisa to the Lunar Reconnaissance Orbiter, in a test of communicating with a satellite using a laser. The iconic image, converted to digital format, traveled nearly 240,000 miles from the Next Generation Satellite Laser Ranging station at NASA's Goddard Space Flight Center in Greenbelt, Md., to the Lunar Orbiter Laser Altimeter instrument on the spacecraft, the space agency reported Thursday. Normally, satellites that go beyond Earth orbit use radio waves for tracking and communication. The LRO is the only satellite in orbit around a body other than Earth to be tracked by laser as well, researchers said. "This is the first time anyone has achieved one-way laser communication at planetary distances," said David Smith of the Massachusetts Institute of Technology, the principal investigator for the altimeter instrument. "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." Scientists divided the Mona Lisa image into an array of 152 pixels by 200 pixels, and each pixel was transmitted by a laser pulse. "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," NASA Goddard scientist Xiaoli Sun said.