Lunar mission to test space laser
WALLOPS ISLAND, Va. – With the launch of NASA’s moon-orbiting Lunar Atmosphere and Dust Environment Explorer (LADEE) this fall, the space agency ventured toward what it hopes will be the next paradigm shift in future space communication, especially in deep space.
LADEE is a robotic mission that will orbit the moon to gather detailed information about its atmosphere, conditions near the surface, and environmental influences on lunar dust. Aboard LADEE is technology associated with NASA’s Lunar Laser Communication Demonstration (LLCD), the space agency’s first attempt to show that two-way laser communication beyond Earth is possible.
LLCD’s main mission objective is to transmit hundreds of millions of bits of data per second from the moon to Earth, the equivalent of transmitting more than 100 high-definition TV channels simultaneously, NASA said. Its receiving capability will also be tested as tens of millions of bits per second are sent from ground stations on Earth to the spacecraft. The demonstrations will prove that the technology for increased bandwidth is possible for future missions, something that could one day allow for 3-D high-definition video transmissions in deep space to become routine.
Artist’s depiction of NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) observatory
as it approaches lunar orbit. Photo courtesy of NASA Ames/Dana Berry.
“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.”
In the past, NASA has experimented with sending low amounts of individual pulses to cameras on far-away space probes near Jupiter, Mars and Mercury.
Recently, an image of Leonardo da Vinci’s “Mona Lisa” was transmitted to NASA’s Lunar Reconnaissance Orbiter spacecraft orbiting the moon. “But this was done at only hundreds of data bits per second,” Cornwell said. “LLCD will be the first dedicated optical communication system and will send data millions of times faster.”
The European Space Agency (ESA) has successfully demonstrated laser communication between satellites in Earth orbit. The ESA recently launched Alphasat to demonstrate laser transmission between a low-Earth orbit satellite and a satellite in geostationary Earth orbit, but LLCD’s laser link from the moon will be 10 times farther away.
The short LLCD mission is a precursor to NASA’s long-duration demonstration, the Laser Communications Relay Demonstration, which is scheduled to launch in 2017.
The goal of the LLCD experiment, Cornwell said, “is to validate and build confidence in this technology so that future missions will consider using it. We can even envision such a laser-based system enabling a robotic mission to an asteroid. It could have 3-D, high-definition video signals transmitted to Earth, providing essentially ‘telepresence’ to a human controller on the ground.”
The LADEE mission is scheduled to last approximately 160 days: 30 days to travel to the moon, 30 days for checkout and 100 days for science operations. The mission will attempt to confirm whether dust caused a mysterious glow on the lunar horizon that astronauts observed during several Apollo missions, and to explore the moon’s tenuous, exotic atmosphere.
NASA’s Ames Research Center in Silicon Valley, Calif., designed, developed, built and tested the spacecraft and will manage the 100-day science mission.
For more information, see ‘Lunar Orbiter Lasers Mona Lisa to Moon,’ www.photonics.com/a52820.
- A kind of spectrograph in which some form of detector, other than a photographic film, is used to measure the distribution of radiation in a particular wavelength region.
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