Laser-powered farewell to Moon mission

NASA's LADEE mission sends laser data to ESA's Optical Ground Station, testing future deep-space communication technologies

Laser from the Moon

25 April 2014

Just before NASA’s latest Moon mission ended last week, an ESA telescope received laser signals from the spacecraft, achieving data speeds like those used by many to watch movies at home via fibre-optic Internet.

During an intense, three-day effort starting on 1 April, ESA’s Optical Ground Station in Spain received data signals via laser from the Moon at the stunning speed of 80 megabits per second.

The signals were transmitted from NASA’s Lunar Atmosphere and Dust Environment Explorer, or LADEE, from a distance of 400 000 km. LADEE completed its seven-month exploration and technology mission on 17 April in a planned impact on the Moon.

The speed is high enough to transmit an entire movie DVD in about eight minutes and is many times faster than provided by traditional radio links used by today’s spacecraft.

Faster than traditional radio

“We had already achieved 40 Mbit/s in our first round of laser communication with LADEE in October, so we’re pretty happy that the final test transmissions were able to double that,” says Klaus-Juergen Schulz, responsible for tracking station engineering at ESA’s ESOC operations centre.

“We also demonstrated that we could transmit laser signals to LADEE and even obtain highly accurate range data, just like our traditional but much larger radio tracking stations can. Overall, the test series has been a big success.”

ESA’s station in Spain’s Canary Islands was equipped with advanced technology developed in Switzerland, France and Denmark that could communicate with LADEE using infrared laser beams.

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NASA Spacecraft Begins Collecting Lunar Atmosphere Data

NASA LADEE

NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) is ready to begin collecting science data about the moon.

On Nov. 20, the spacecraft successfully entered its planned orbit around the moon’s equator — a unique position allowing the small probe to make frequent passes from lunar day to lunar night. This will provide a full scope of the changes and processes occurring within the moon’s tenuous atmosphere.

LADEE now orbits the moon about every two hours at an altitude of eight to 37 miles (12-60 kilometers) above the moon’s surface. For about 100 days, the spacecraft will gather detailed information about the structure and composition of the thin lunar atmosphere and determine whether dust is being lofted into the lunar sky.

“A thorough understanding of the characteristics of our lunar neighbor will help researchers understand other small bodies in the solar system, such as asteroids, Mercury, and the moons of outer planets,” said Sarah Noble, LADEE program scientist at NASA Headquarters in Washington.

Scientists also will be able to study the conditions in the atmosphere during lunar sunrise and sunset, where previous crewed and robotic missions detected a mysterious glow of rays and streamers reaching high into the lunar sky.

On Nov. 20, flight controllers in the LADEE Mission Operations Center at NASA’s Ames Research Center in Moffett Field, Calif., confirmed LADEE performed a crucial burn of its orbit control system to lower the spacecraft into its optimal position to enable science collection. Mission managers will continuously monitor the spacecraft’s altitude and make adjustments as necessary.

“Due to the lumpiness of the moon’s gravitational field, LADEE’s orbit requires significant maintenance activity with maneuvers taking place as often as every three to five days, or as infrequently as once every two weeks,” said Butler Hine, LADEE project manager at Ames. “LADEE will perform regular orbital maintenance maneuvers to keep the spacecraft’s altitude within a safe range above the surface that maximizes the science return.”

In addition to science instruments, the spacecraft carried the Lunar Laser Communications Demonstration, NASA’s first high-data-rate laser communication system. It is designed to enable satellite communication at rates similar to those of high-speed fiber optic networks on Earth. The system was tested successfully during the commissioning phase of the mission, while LADEE was still at a higher altitude.

LADEE was launched Sept. 6 on a U.S. Air Force Minotaur V, an excess ballistic missile converted into a space launch vehicle and operated by Orbital Sciences Corp. of Dulles, Va. LADEE is the first spacecraft designed, developed, built, integrated and tested at Ames. It also was the first probe launched beyond Earth orbit from NASA’s Wallops Flight Facility on the Virginia coast.

NASA’s Science Mission Directorate in Washington funds the LADEE mission. Ames manages the overall mission and serves as a base for mission operations and real-time control of the probe. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the science instruments and technology demonstration payload, the science operations center and overall mission support. NASA’s Marshall Space Flight Center in Huntsville, Ala., manages LADEE within the Lunar Quest Program Office.

For more information about the LADEE mission, visit:

http://www.nasa.gov/ladee