The locations of lunar retroreflectors left by Apollo (A) and Luna (L) missions.

Retroreflectors are devices which reflect light back to its source. Six were left at six sites on the Moon by three crews of the Apollo program, two remote landers of the Lunokhod program, and one by the Chandrayaan program.[1] Lunar reflectors have enabled precise measurement of the Earth–Moon distance since 1969 using lunar laser ranging.[2]

Several unsuccessful attempts to land retroreflectors on the lunar surface have been made, and several future attempts are planned.

Successfully placed reflectors

Operator Mission Name Date Location Coordinates Size Status Comment
NASA Apollo 11 LRRR 21 July 1969 Mare Tranquillitatis 0°40′24″N 23°28′23″E / 0.6734°N 23.4731°E / 0.6734; 23.4731[3] 46×46 cm[4] Operational [5]
Soviet Union Luna 17 Lunokhod 1 17 November 1973 Mare Imbrium 38°18′55″N 35°00′29″W / 38.3152°N 35.0080°W / 38.3152; -35.0080[3] 44×19 cm[1] Operational Rediscovered in 2010[6][7][8][9]
NASA Apollo 14 LRRR 31 January 1971 Fra Mauro formation 3°38′39″S 17°28′43″W / 3.6442°S 17.4786°W / -3.6442; -17.4786[3] 46×46 cm Operational [10]
NASA Apollo 15 LRRR 31 July 1971 Hadley–Apennine 26°08′00″N 3°37′43″E / 26.1334°N 3.6285°E / 26.1334; 3.6285[3] 105×65 cm Operational [11]
Soviet Union Luna 21 Lunokhod 2 15 January 1973 Le Monnier crater 25°49′56″N 30°55′20″E / 25.8323°N 30.9221°E / 25.8323; 30.9221[3] 44×19 cm[1] Operational [12][13]
ISRO Chandrayaan-3 Vikram 23 August 2023 Between Manzinus C and Simpelius N 69°22′03″S 32°20′53″E / 69.367621°S 32.348126°E / -69.367621; 32.348126 5.11 cm diameter[14] Operational [15][16][17][18]

Attempted and planned reflectors

Operator Mission Name Date Location Coordinates Status Comment
SpaceIL, IAI Beresheet Beresheet 11 April 2019 Mare Serenitatis 32°35′44″N 19°20′59″E / 32.5956°N 19.3496°E / 32.5956; 19.3496 Crashed [19][20][21]
ISRO Chandrayaan-2 Vikram 6 September 2019 70°52′52″S 22°47′02″E / 70.8810°S 22.7840°E / -70.8810; 22.7840 Crashed [22][23]
Moon Express Lunar Scout MoonLIGHT on MX-1E July 2020 Malapert Mountain 84°54′S 12°54′E / 84.9°S 12.9°E / -84.9; 12.9 Cancelled [24][25]
Astrobotic Mission One LRA on Peregrine May 2023 Lacus Mortis Aborted,
Controlled Re-entry 		[26]
Roscosmos Luna 25 Luna 25 August 2023 Boguslawsky (crater) Crashed [27][28][29]
Intuitive Machines IM-1 LRA on Nova-C IM-1 February 2024 Malapert (crater) Planned [30][26]

Gallery

See also

References

  1. ^ a b c Lunar Retroreflectors
  2. ^ Slava G. Turyshev: From Quantum to Cosmos: Fundamental Physics Research in Space (2009), p. 300
  3. ^ a b c d e Wagner, R. V.; Speyerer, E. J.; Burns, K. N.; Danton, J.; Robinson, M. S. (1 August 2012). "Revised Coordinates for Apollo Hardware". The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Copernicus GmbH. XXXIX-B4: 517–521. Bibcode:2012ISPAr39B4..517W. doi:10.5194/isprsarchives-XXXIX-B4-517-2012.
  4. ^ Newman, Michael E. (26 September 2017). "To the Moon and Back … in 2.5 Seconds". NIST. Retrieved 27 January 2021.
  5. ^ "What Neil & Buzz Left on the Moon: A cutting-edge science experiment left behind in the Sea of Tranquility by Apollo 11 astronauts is still running today". National Aeronautics and Space Administration. 20 July 2004. Retrieved 1 August 2012.
  6. ^ "Lost Soviet Reflecting Device Rediscovered on the Moon". Space.com. 27 April 2010. Retrieved 26 January 2021.
  7. ^ "LROC Observation M114185541R". Arizona State University. Retrieved 8 August 2012.
  8. ^ "Lunokhod 1 Revisited | Lunar Reconnaissance Orbiter Camera". lroc.sese.asu.edu. Retrieved 8 October 2019.
  9. ^ "USSR – Luna 17".
  10. ^ "Apollo 14: The Eighth Mission: The Third Lunar Landing: 31 January–09 February 1971". National Aeronautics and Space Administration. Archived from the original on 14 November 2004. Retrieved 8 August 2012.
  11. ^ Archinal, Brent (13 April 2010). "The Apollo 15 Lunar Laser Ranging Retroreflector – A Fundamental Point on the Moon!". Arizona State University. Archived from the original on 13 January 2013. Retrieved 1 August 2012.
  12. ^ "USSR – Luna 21".
  13. ^ "NASA – NSSDCA – Spacecraft – Details". nssdc.gsfc.nasa.gov. Retrieved 8 October 2019.
  14. ^ "Chandrayaan 3 – LRA".
  15. ^ "Chandrayaan-3". ISRO. Retrieved 15 August 2023.
  16. ^ Dhillon, Amrit (23 August 2023). "India lands spacecraft near south pole of moon in historic first". The Guardian. Retrieved 23 August 2023.
  17. ^ "Laser Instrument on NASA's LRO Successfully 'Pings' Indian Moon Lander". Retrieved 30 January 2024.
  18. ^ "Instrument on Chandrayaan-3 lander started serving as a location marker near lunar south pole". Retrieved 30 January 2024.
  19. ^ Beresheet crash caused by manual command, but reflector device may have survived. Georgina Torbet, Digital Trends. 21 April 2019.
  20. ^ Warner, Cheryl (10 April 2019). "Update on First Private Robotic Spacecraft Attempt at Moon Landing". NASA. Retrieved 12 April 2019.
  21. ^ Israeli spacecraft Beresheet crash site spotted on moon, 15 May 2019
  22. ^ "Vikram lander located on lunar surface, wasn't a soft landing: Isro". The Times of India. 8 September 2019. Retrieved 8 October 2019.
  23. ^ Bartels, Meghan (24 March 2019). "How NASA Scrambled to Add Science Experiments to Israeli, Indian Moon Probes". Retrieved 25 March 2019.
  24. ^ Internatioinal Lunar Observatory to offer a new astrophysical perspective. Tonasz Nowakowski. Spaceflight Insider. 12 August 2017.
  25. ^ UMD, Italy & MoonEx Join to Put New Laser-Reflecting Arrays on Moon Archived 22 March 2018 at the Wayback Machine. Lee Tune, University of Maryland. 10 June 2015.
  26. ^ a b Etherington, Darrell (23 January 2020). "NASA reveals the payloads for the first commercial moon cargo deliveries". TechCrunch. Retrieved 2 March 2021.
  27. ^ "Luna-25 (Luna-Glob Lander) Payload". www.iki.rssi.ru. Retrieved 15 August 2023.
  28. ^ "NASA - NSSDCA - Spacecraft - Details". nssdc.gsfc.nasa.gov. Retrieved 15 August 2023.
  29. ^ "Russia's Luna-25 spacecraft crashes into the moon, ending its bid to reach the lunar south pole". Associated Press. 20 August 2023. Retrieved 20 August 2023.
  30. ^ "Intuitive Machines-1 Orbital Debris Assessment Report (ODAR) Revision 1.1" (PDF). Intuitive Machines. FCC. 22 April 2021. Retrieved 24 April 2021.
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