The Apollo 15 Lunar Laser Ranging RetroReflector (LRRR) array deployed on the Moon in 1971.
Credit: NASA/David Scott

China has successfully made its first Lunar Laser Ranging measurements, making use of the Apollo 15 Lunar Laser Ranging RetroReflector (LRRR) array – equipment deployed on the Moon in 1971.

The applied astronomy group from the Yunnan Observatories measured the distance between the Apollo 15 retro-reflector and the Yunnan Observatories ground station.

Results of Lunar Laser Ranging (LLR) measurements are valuable in the study of astro-geodynamics, Earth-moon system dynamics and lunar physics. China’s LLR program joins the United States, France and Italy in harnessing the capability.

Focus on science

Apollo 15’s Falcon lunar module was piloted by David Scott and James Irwin to a landing spot at Hadley Rille.

Apollo 15 was the ninth piloted mission in the United States’ Apollo program, the fourth to land on the Moon. It was the first of what were termed “J missions” – long stays on the Moon, with a greater focus on science than had been possible on previous missions. That Apollo mission was first to utilize a lunar rover for increased mobility of moonwalkers on the surface.

NASA’s Lunar Reconnaissance Orbiter acquired this image of the Apollo 15 landing site. Lunar Laser Ranging RetroReflector (LRRR) is circled.
Credit: NASA/GSFC/Arizona State University

Far side lander

The LLR was conducted in the context of China preparing to launch the Chang’e-4 lunar probe this year that will attempt the first soft landing on the far side of the Moon.

“In the near future, China will plant its own retro-reflector on the Moon, which will further boost the development of LLR in China,” said Li Yuqiang, an associate researcher with Yunnan Observatories, as reported by the Xinhua news agency.

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