Apollo 11 laser experiment set for tech upgrade

The Lunar Laser Ranging experiment saw trays of retroreflectors left on the Moon by the astronauts of the Apollo 11, 14 and 15 missions, and later by two unmanned Soviet missions. Made up of many corner cube prisms, the retroreflectors enable precise laser ranging and exact measurement of the Moon’s distance from Earth. Those measurements have provided a foundation for scientific analysis of the Moon and its interior- including its liquid core – as well as tests of General Relativity.

Now NASA plans to expand the experiment by updating the technology used when it returns to the Moon in the coming years, initially with unmanned spacecraft. As well as building out the existing network, the new instrumentation will provide a 100-fold increase in ranging accuracy. The plan is to add three of these new instruments to the five already in situ on the lunar surface, giving a total of eight retroreflectors.

“Our Next Generation Lunar Retroreflector is a 21st Century version of the instruments currently on the Moon,” said lead scientist Doug Currie, professor emeritus at the University of Maryland and part of the team that designed the original instruments left by the Apollo missions.