Lunokhod 1 Retroreflector Returns 2,000 Photons After 39 Years Silent
Updated
Updated · spacedaily.com · May 25
Lunokhod 1 Retroreflector Returns 2,000 Photons After 39 Years Silent
1 articles · Updated · spacedaily.com · May 25
Summary
Apache Point Observatory hit Lunokhod 1 with a laser in April 2010 and got a strong return, reviving a reflector that had been effectively lost since the rover fell silent in 1971.
NASA’s Lunar Reconnaissance Orbiter had narrowed the rover’s position from several kilometers to about 100 meters in March 2010, making a targeted ranging attempt practical for the first time in decades.
The first return delivered about 2,000 photons, versus roughly 750 from Lunokhod 2 at its best, suggesting Lunokhod 1 was oriented unusually well toward Earth and had suffered little degradation.
That unexpectedly strong signal turned the French-built reflector into one of the most valuable lunar ranging targets, improving measurements used for general relativity tests and tracking the Moon’s gradual recession from Earth.
How did a Soviet device, lost for 40 years on the Moon, end up outperforming its more modern counterparts?
What can this 50-year-old lunar relic teach us about building permanent scientific outposts on other worlds?
From Lost to Legacy: The Scientific Revolution Sparked by Lunokhod 1’s Retroreflector in Lunar Laser Ranging
Overview
Lunar Laser Ranging (LLR) remains a vital tool for lunar science, using lasers bounced off retroreflectors on the Moon to precisely measure the Earth-Moon distance. This technique has revealed that the Moon is slowly moving away from Earth and provides essential data for understanding the Earth-Moon system. Recent advancements, such as new retroreflector technologies and improved lander positioning, have increased measurement accuracy. LLR data is shared with the scientific community, supporting ongoing research. The enduring performance of both new and legacy reflectors highlights the importance of robust engineering and international collaboration in lunar exploration.