Retroreflectors are devices which reflect light back to its source. Seven retroreflectors were left at seven sites on the Moon by three crews of the Apollo program, two by remote landers of the Lunokhod program, one by the Commercial Lunar Payload Services program and one by the Chandrayaan program.Lunar Retroreflectors Lunar reflectors have enabled precise measurement of the Earth–Moon distance since 1969 using lunar laser ranging.Slava G. Turyshev: From Quantum to Cosmos: Fundamental Physics Research in Space (2009), p. 300
There have been several additional attempts to land retroreflectors on the lunar surface which were unsuccessful, and several future attempts are planned.
Successfully placed reflectors
Operator Mission Name DateLocation CoordinatesSizeStatusCommentNASA Apollo 11LRRR 21 July 1969Mare Tranquillitatis 46×46 cmSoviet UnionLuna 17Lunokhod 117 November 1970Mare Imbrium44×19 cm Rediscovered in 2010NASA Apollo 14LRRR 31 January 1971Fra Mauro formation 46×46 cmNASA Apollo 15LRRR31 July 1971Hadley–Apennine 105×65 cmSoviet UnionLuna 21Lunokhod 215 January 1973Le Monnier crater44×19 cmISROChandrayaan-3Vikram23 August 2023Statio Shiv Shakti5.11 cm diameterUniversity of MarylandBlue Ghost Mission 1Next Generation Lunar Retroreflectors (NGLR) on Blue Ghost Mission 12 March 2025Mare Crisium near Mons Latreille17x13x12 cm
Attempted and planned reflectors Operator Mission Name DateLocation CoordinatesStatusCommentSpaceIL, IAIBeresheet Beresheet 11 April 2019Mare Serenitatis Beresheet crash caused by manual command, but reflector device may have survived. Georgina Torbet, Digital Trends. 21 April 2019.Israeli spacecraft Beresheet crash site spotted on moon, 15 May 2019ISRO Chandrayaan-2Vikram6 September 2019Moon ExpressLunar ScoutMoonLIGHT on MX-1EJuly 2020Malapert MountainInternatioinal Lunar Observatory to offer a new astrophysical perspective. Tonasz Nowakowski. Spaceflight Insider. 12 August 2017.UMD, Italy & MoonEx Join to Put New Laser-Reflecting Arrays on Moon . Lee Tune, University of Maryland. 10 June 2015.AstroboticMission OneLRA on Peregrine May 2023Lacus MortisRoscosmosLuna 25Luna 25August 2023Pontécoulant G craterIntuitive MachinesIM-1LRA on Nova-C IM-1February 2024 Malapert (crater)Intuitive MachinesIM-2LRA on Nova-C IM-26 March 2025 Mons Mouton
Gallery
See also Lunar Laser Ranging experiment List of artificial objects on the Moon List of missions to the Moon
References