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jueves, 24 de octubre de 2013

NASA : NASA Laser Communication System Sets Record with Data Transmissions to and from Moon

An artist's concept of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft firing its maneuvering thrusters in order to maintain a safe altitude as it orbits the moon.
Image Credit: NASA Ames / Dana Berry

During the recent government shutdown that lasted thru Oct. 16, NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) mission continued to perform critical maneuvers and was captured into its commissioning orbit around the moon. The trajectory correction maneuver (TCM-1) on Oct. 1, set the spacecraft on course to rendezvous with the moon on Oct. 6.
The first Lunar Orbit Insertion maneuver (LOI-1) on Oct. 6, was a real nail-biter for the team, because missing that maneuver would have made it very difficult for LADEE to achieve a lunar orbit and perform the science mission. Fortunately, the LOI-1 engine burn was very accurate, and required no additional course adjustments. This maneuver successfully put the spacecraft in a 24-hour elliptical lunar orbit. The LOI-2 maneuver on Oct. 9, also was very accurate, and placed LADEE in a four-hour elliptic lunar orbit. The third and final burn (LOI-3) occurred on Oct. 12, and put the spacecraft into its current two-hour commissioning orbit at approximately 145-155 miles (235-250 km) above the lunar surface .
After arriving at the moon, the LADEE spacecraft first performed commissioning activites to make sure the spacecraft was operating correctly in that orbit. Those activities are now complete, and the instrument commissioning activities have begun.
All instruments onboard LADEE have covers to protect them during launch and cruise, and are ejected - or deployed - at various times as LADEE travels to the moon. The cover for the Lunar Laser Communications Demonstration (LLCD) was deployed on Sept. 27, in order to perform an early acquisition calibration test. The Neutral mass Spectrometer (NMS) cap was ejected on Oct 3, just prior to LADEE’s arrival at the moon, so that it would not become a hazard to the spacecraft. The Lunar Dust EXperiment (LDEX) and Ultra Violet Spectrometer (UVS) aliveness activities were successfully completed on Oct. 16, with the deployment of both instrument covers.
These instrument cover deployments were the last remaining planned critical events for the mission. This means there are no further show-stoppers before the science phase begins. All of the critical maneuvers and all instrument cover deployments are now completed. The science instrument commissioning and LLCD primary experiment will be conducted through mid-November, at which point the spacecraft will descend to the lower lunar orbit and perform science measurements.
Butler Hine
NASA's Ames Research Center, Moffett Field, Calif.

The Internet is no longer limited by the slow speed of dial-up connections, so why should our satellites be?
LLCD was powered-on, and the signal with LADEE was acquired on September 27th, 2013.
LLCD began to demonstrate the capabilities of laser communications, from the Moon, with the first successful pass occurring on October 18th, 2013.
Still from LLCD Video showing thetransmission of data at 622Mbps to Earth from LLST in lunar orbit.

LLCD will continue to demonstrate the possibilities of laser communications technology and the future of space communications for 30 days.

After LADEE was successfully placed into lunar orbit, the LLGT in White Sands, NM was able to acquire the location of the LADEE spacecraft. After the LLGT connected with the LLST aboard the LADEE spacecraft, their signals were "locked" and data began to flow from the Moon back down to Earth, via infrared laser light.
The LADEE/LLCD mission launched on September 6th, 2013 at 11:27p EDT from the Mid-Atlantic Regional Spaceport (MARS), on Wallops Island, VA.

LADEE succesfully launched on Sept. 6th, 2013
The LADEE/LLCD spacecraft launched aboard the Orbital Science's Minotaur V rocket and was the first planetary mission to launch from the Wallops Flight Facility, located on Wallops Island, VA.

LLCD mission concept artist rendition.

What is LLCD?

Compared to the days of dial-up, today's web-sites load at lightning speed. Just like you need your web-pages load quickly and securely, NASA scientists and engineers want the same quick connectivity with their data-gathering spacecraft. To meet these demands NASA is moving away from their form of dial-up (radio frequency-based communication), to their own version of high-speed Internet; using laser communications.

The Lunar Laser Communication Demonstration (LLCD) is NASA's first high-rate, two-way, space laser communication demonstration.
NASA is venturing into a new era of space communications using laser communications technology and it's starting with the LLCD mission. For decades NASA has launched and operated satellites in order to expand our understanding of Earth and space science. In order to sustain this vision, satellites have increased their data-capturing capabilities and have had to send data over greater distances. Each of these advancements have required increases to data downlink rates and higher data volumes. Just as your home computer struggled to download large multimedia files in the past, NASA's communication networks may soon reach the same complications as data volumes continue to grow. In an effort to address these challenges and enhance the Agency's communications capabilities, NASA has directed the Goddard Space Flight Center (GSFC) to lead the Lunar Laser Communication Demonstration (LLCD).
Mission Components
The LLCD mission consists of space-based and ground-based components. The Lunar Laser Space Terminal (LLST) is an optical communications test payload flying aboard the LADEE Spacecraft. The LLST is demonstrating laser communications using a data-downlink rate that is five-times the current communication capabilities from lunar orbit. The ground segmentconsists of three ground terminals that will perform high-rate communication with the LLST aboard LADEE. The primary ground terminal, the Lunar Laser Ground Terminal (LLGT) is located in White Sands, NM and was developed by MIT/Lincoln Laboratory and NASA. The ground segment also includes two secondary terminals located at NASA/JPL's Table Mountain Facility in California and the European Space Agency's La Teide Observatory in Tenerife, Spain.
 NASA Laser Communication System Sets Record with Data Transmissions to and from Moon
NASA's Lunar Laser Communication Demonstration (LLCD) has made history using a pulsed laser beam to transmit data over the 239,000 miles between the moon and Earth at a record-breaking download rate of 622 megabits per second (Mbps).
LLCD is NASA's first system for two-way communication using a laser instead of radio waves. It also has demonstrated an error-free data upload rate of 20 Mbps transmitted from the primary ground station in New Mexico to the spacecraft currently orbiting the moon.
"LLCD is the first step on our roadmap toward building the next generation of space communication capability," said Badri Younes, NASA's deputy associate administrator for space communications and navigation (SCaN) in Washington. "We are encouraged by the results of the demonstration to this point, and we are confident we are on the right path to introduce this new capability into operational service soon."
Since NASA first ventured into space, it has relied on radio frequency (RF) communication. However, RF is reaching its limit as demand for more data capacity continues to increase. The development and deployment of laser communications will enable NASA to extend communication capabilities such as increased image resolution and 3-D video transmission from deep space.
"The goal of LLCD is to validate and build confidence in this technology so that future missions will consider using it," said Don Cornwell, LLCD manager at NASA's Goddard Space Flight Center in Greenbelt, Md. "This unique ability developed by the Massachusetts Institute of Technology's Lincoln Laboratory has incredible application possibilities."
LLCD is a short-duration experiment and the precursor to NASA's long-duration demonstration, the Laser Communications Relay Demonstration (LCRD). LCRD is a part of the agency's Technology Demonstration Missions Program, which is working to develop crosscutting technology capable of operating in the rigors of space. It is scheduled to launch in 2017.
LLCD is hosted aboard NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), launched in September from NASA's Wallops Flight Facility on Wallops Island, Va. LADEE is a 100-day robotic mission operated by the agency's Ames Research Center at Moffett Field, Calif. LADEE's mission is to provide data that will help NASA determine whether dust caused the mysterious glow astronauts observed on the lunar horizon during several Apollo missions. It also will explore the moon's atmosphere. Ames designed, developed, built, integrated and tested LADEE, and manages overall operations of the spacecraft. NASA's Science Mission Directorate in Washington funds the LADEE mission.
The LLCD system, flight terminal and primary ground terminal at NASA's White Sands Test Facility in Las Cruces, N.M., were developed by the Lincoln Laboratory at MIT. The Table Mountain Optical Communications Technology Laboratory operated by NASA's Jet Propulsion Laboratory in Pasadena, Calif., is participating in the demonstration. A third ground station operated by the European Space Agency on Tenerife in the Canary Islands also will be participating in the demonstration.
For more information about LLCD, visit:
For more information about the LADEE mission, visit:
For more information about LCRD, visit:
For more information about SCaN, visit:
Guillermo Gonzalo Sánchez Achutegui

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