NASA to attempt high-speed laser transmission to the Moon
August 30, 2013
NASA plans to find out if two-way laser communication beyond Earth is possible. If NASA’s Lunar Laser Communication Demonstration (LLCD) mission succeeds, 3-D high-definition video transmissions in deep space could become possible in the future.
Radio frequency (RF) communication has been the communications platform in space used so far. But RF is reaching its limit just as demand for more data capacity continues to increase.
“LLCD is designed to send six times more data from the moon using a smaller transmitter with 25 percent less power as compared to the equivalent state-of-the-art radio (RF) system,” said Don Cornwell, LLCD manager. “Lasers are also more secure and less susceptible to interference and jamming.”
The LLCD experiment, developed by MIT, is hosted aboard NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) — a 100-day robotic mission designed, built, integrated, tested and to be operated by NASA’s Ames Research Center. LADEE will attempt to confirm whether dust caused a mysterious glow on the lunar horizon astronauts observed during several Apollo missions and explore the moon’s tenuous, exotic atmosphere.
Launch of the LADEE spacecraft is set for September aboard a U.S. Air Force Minotaur V rocket from NASA’s Wallops Flight Facility on Wallops Island, Va. It will take 30 days to reach the lunar orbit, when LLCD will begin operation for 30 days.
Hundreds of megabits/second laser transmission
LLCD’s main mission objective is to transmit hundreds of megabits of data per second from the Moon to Earth. This is equivalent to transmitting more than 100 HD television channels simultaneously. LLCD receiving capability will also be tested, as tens of megabits per second are sent from Earth to the spacecraft from NASA’s White Sands Complex in New Mexico,
Recently, an image of Leonardo da Vinci’s painting, the Mona Lisa, was transmitted to NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft orbiting the moon via laser. “But this was done at about 300 bits per second,” [1970's acoustic-modem speed] said Cornwell. “LLCD will be the first dedicated optical communication system and will send data millions of times faster.”The European Space Agency already has successfully demonstrated laser communication between satellites in Earth orbit. Recently they launched Alphasat to demonstrate laser transmission between a low-earth orbit satellite and a satellite in geostationary Earth orbit. LLCD’s laser link from the moon will be ten times farther away.
NASA is looking at laser communication as the next paradigm shift in future space communication, especially deep space. “We can even envision such a laser-based system enabling a robotic mission to an asteroid,” said Cornwell. “It could have 3-D, high-definition video signals transmitted to Earth providing essentially [time-delayed] ‘telepresence’ to a human controller on the ground.”