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Mit Figures Out How to Give the Moon Broadband--Using Lasers
An artist's concept of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft seen orbiting near the surface of the moon.
Credit: U.S. National Aeronautics and Space Administration
Massachusetts Institute of Technology researchers have developed a system that can give a satellite orbiting the moon faster Internet access than many U.S. homes get.
The researchers are working with the National Aeronautics and Space Administration's Lunar Atmosphere and Dust Environment Explorer (LADEE) project, which recently launched a satellite that is now orbiting the moon. LADEE is equipped with a laser communications module for use in the high-speed wireless experiment.
The experiment, called the Lunar Laser Communication Demonstration, can transmit data from LADEE to Earth at 622 Mbps and from Earth to LADEE at 19.44 Mbps, eclipsing the fastest-ever radio communication to the moon by a factor of 4,800.
The most difficult part of sending data to the moon by laser is getting through the Earth's atmosphere, which can bend light and cause it to fade or drop out. The researchers solved this problem by using four separate telescopes, each of which sends its beam through a different column of air. The researchers say the optical link has provided error-free performance in both darkness and bright sunlight, through partly transparent thin clouds, and through atmospheric turbulence that affects signal power.
From IDG News Service
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