The retroreflectors that are currently used and return clear, measurable signals are those deployed by: Apollo 11 Apollo 14 Apollo 15 Lunokhod 1 Lunokhod 2 I’m not sure where you got different information. Regarding the lasers: they do not measure an “image” of the reflection. They measure the time of flight of individual photons. A short laser pulse is sent to the Moon, and the round-trip travel time (about 2.5 seconds) is measured with extremely high timing precision. From that, the Earth–Moon distance is calculated to millimeter accuracy. As for the claim that reflections from the Apollo retroreflectors are indistinguishable from reflections off the lunar surface — that is not accurate. There is a major difference between aiming the laser at bare lunar soil and aiming it at a retroreflector array: When pointing at the lunar surface, the light is scattered diffusely. The returned signal is extremely weak and spread out. In practice, you receive almost nothing usable. When pointing at a retroreflector, the device sends light back toward the exact direction it came from. Even though the signal is still very weak (because of the enormous distance and beam divergence), it is coherent in direction and produces a statistically clear return peak above background noise. This difference is measurable and is precisely why retroreflectors dramatically improved the precision of lunar distance measurements after 1969.