The space terminal for the Lunar Laser Communication Demonstration (LLCD), NASA's first high-data-rate laser communication system, was recently integrated onto the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft at NASA's Ames Research Center, Moffett Field, Calif. LLCD will demonstrate laser communications from lunar orbit to Earth at six times the rate of the best modern-day advanced radio communication systems.
Lunar Laser Communication Demonstration (LLCD) components integrated onto the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft.
"The successful testing and integration of LLCD to LADEE is a major accomplishment," said Donald Cornwell, LLCD mission manager at NASA's Goddard Space Flight Center in Greenbelt, Md. "It demonstrates that this new technology is robust and ready for space. This is the first time NASA has had such a communication system pass all its tests and be certified flight ready."
The LLCD mission will use a highly reliable infrared laser, similar to those used to bring high-speed data over fiber optic cables into our workplaces and homes. Data, sent in the form of hundreds of millions of short pulses of light every second, will be sent by the LADEE spacecraft to any one of three ground telescopes in New Mexico, California and Spain.
The real challenge of LLCD will be to point its very narrow laser beam accurately to ground stations across a distance of approximately 238,900 miles while moving. Failure to do so would cause a dropped signal or loss of communication.
"This pointing challenge is the equivalent of a golfer hitting a ‘hole-in-one' from a distance of almost five miles," said Cornwell. "Developers at the Massachusetts Institute of Technology's (MIT) Lincoln Laboratory have designed a sophisticated system to cancel out the slightest spacecraft vibrations. This is in addition to dealing with other challenges of pointing and tracking the system from such a distance. We are excited about these advancements."
The LLCD mission will also serve as a pathfinder for the 2017 launch of NASA's Laser Communication Relay Demonstration (LCRD). That mission will demonstrate the long-term viability of laser communication from a geostationary relay satellite to Earth. In a geostationary orbit the spacecraft orbits at the same speed as Earth, which allows it to maintain the same position in the sky.
Engineers believe that future space missions will be able to use laser communication technology with its low mass and power requirements, to provide increased data quantity for real-time communication and 3-D high-definition video. For example, using S-band communications aboard the LADEE spacecraft would take 639 hours to download an average-length HD movie. Using LLCD technology that time would be reduced to less than eight minutes.
Prior to shipment from MIT, the LLCD spaceflight hardware was subjected to a rigorous set of flight test simulations such as the strong vibrations expected from a Minotaur V rocket, the launch vehicle for the LADEE mission. The LLCD hardware also had to withstand simulated extreme temperatures and other conditions it will experience within the harsh environment of space. Throughout this stringent battery of tests, LLCD maintained its critical alignment and stable pointing accuracy.
Flight and ground station hardware for LLCD was designed and built at Lincoln Laboratory in Lexington, Mass. NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the European Space Agency are developing the ground stations in California and Spain, respectively.
"This is an exciting time for space communications," said Cornwell. "We are about to make a leap in communications ability that is unmatched in NASA's history."
The LLCD mission management team resides at Goddard under the sponsorship of the Space Communications and Navigation (SCaN) Program at NASA Headquarters in Washington. The LADEE mission is managed by Ames under the sponsorship of NASA's Planetary Science Division within the Science Mission Directorate at NASA Headquarters.
NASA's Science Mission Directorate in Washington funds LADEE, a cooperative effort led by Ames, which is responsible for managing the mission, building the spacecraft and performing mission operations. In addition to managing the LLCD payload, Goddard is responsible for managing the science instruments and the science operations center. NASA Wallops Flight Facility has the responsibility for launch vehicle integration, launch services and launch range operations. NASA's Marshall Space Flight Center, Huntsville, Ala., manages LADEE within the Lunar Quest Program Office.
The LADEE mission, on which LLCD is a hosted payload, is scheduled to launch in August 2013.Dewayne Washington
Dewayne Washington | EurekAlert!
Researchers move closer to completely optical artificial neural network
23.07.2018 | The Optical Society
Reversing cause and effect is no trouble for quantum computers
20.07.2018 | Centre for Quantum Technologies at the National University of Singapore
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
23.07.2018 | Materials Sciences
23.07.2018 | Information Technology
23.07.2018 | Health and Medicine