Editing Retroreflector (section)

====In satellites{{anchor|In Earth orbit}}====
{{Further|Satellite laser ranging}}

Many [[artificial satellites]] carry retroreflectors so they can be tracked from [[ground stations]]. Some satellites were built solely for laser ranging.
[[LAGEOS]], or Laser Geodynamics Satellites, are a series of scientific research satellites designed to provide an orbiting laser ranging benchmark for geodynamical studies of the Earth.<ref>{{cite journal |last1=Pearlman |first1=M. |last2=Arnold |first2=D. |last3=Davis |first3=M. |last4=Barlier |first4=F. |last5=Biancale |first5=R. |last6=Vasiliev |first6=V. |last7=Ciufolini |first7=I. |last8=Paolozzi |first8=A. |last9=Pavlis |first9=E. C. |last10=Sośnica |first10=K. |last11=Bloßfeld |first11=M. |title=Laser geodetic satellites: a high-accuracy scientific tool |journal=Journal of Geodesy |date=November 2019 |volume=93 |issue=11 |pages=2181–2194 |doi=10.1007/s00190-019-01228-y|bibcode=2019JGeod..93.2181P |s2cid=127408940 }}</ref> There are two LAGEOS spacecraft: LAGEOS-1<ref>[https://ilrs.cddis.eosdis.nasa.gov/missions/satellite_missions/current_missions/lag1_general.html NASA.gov]</ref> (launched in 1976), and LAGEOS-2 (launched in 1992). They use cube-corner retroreflectors made of fused silica glass. As of 2020, both LAGEOS spacecraft are still in service.<ref>{{cite journal |last1=Zajdel |first1=R. |last2=Sośnica |first2=K. |last3=Drożdżewski |first3=M. |last4=Bury |first4=G. |last5=Strugarek |first5=D. |title=Impact of network constraining on the terrestrial reference frame realization based on SLR observations to LAGEOS |journal=Journal of Geodesy |date=November 2019 |volume=93 |issue=11 |pages=2293–2313 |doi=10.1007/s00190-019-01307-0|bibcode=2019JGeod..93.2293Z |doi-access=free }}</ref> Three [[Starshine (satellite)|STARSHINE]] satellites equipped with retroreflectors were launched beginning in 1999. The [[LARES (satellite)|LARES]] satellite was launched on February 13, 2012. (See also: [[List of laser ranging satellites]].)

Other satellites include retroreflectors for orbit calibration<ref>{{cite journal |last1=Kazmierski |first1=Kamil |last2=Sośnica |first2=Krzysztof |last3=Hadas |first3=Tomasz |date=2017-11-06 |title=Quality assessment of multi-GNSS orbits and clocks for real-time precise point positioning |journal=GPS Solutions |volume=22 |issue=1 |pages=11 |bibcode=2018GPSS...22...11K |doi=10.1007/s10291-017-0678-6 |doi-access=free}}</ref> and orbit determination,<ref>{{cite journal |last1=Bury |first1=Grzegorz |last2=Sośnica |first2=Krzysztof |last3=Zajdel |first3=Radosław |date=2018-04-19 |title=Multi-GNSS orbit determination using satellite laser ranging |journal=Journal of Geodesy |volume=93 |issue=12 |pages=2447–2463 |bibcode=2019JGeod..93.2447B |doi=10.1007/s00190-018-1143-1 |doi-access=free}}</ref> such as in [[satellite navigation]] (e.g., all [[Galileo satellites]],<ref>{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Prange |first2=Lars |last3=Kaźmierski |first3=Kamil |last4=Bury |first4=Grzegorz |last5=Drożdżewski |first5=Mateusz |last6=Zajdel |first6=Radosław |last7=Hadas |first7=Tomasz |title=Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes |journal=Journal of Geodesy |date=February 2018 |volume=92 |issue=2 |pages=131–148 |doi=10.1007/s00190-017-1050-x|bibcode=2018JGeod..92..131S |doi-access=free }}</ref> most [[GLONASS satellites]],<ref>{{cite journal |last1=Zajdel |first1=Radosław |title=A New Online Service for the Validation of Multi-GNSS Orbits Using SLR |journal=Remote Sensing |date=14 October 2017 |volume=9 |issue=10 |pages=1049 |doi=10.3390/rs9101049|bibcode=2017RemS....9.1049Z |doi-access=free }}</ref> [[Indian Regional Navigation Satellite System|IRNSS satellites]],<ref>{{Cite web|url=https://ilrs.cddis.eosdis.nasa.gov/missions/satellite_missions/current_missions/irns_reflector.html|title=IRNSS: Reflector Information|website=ilrs.cddis.eosdis.nasa.gov|archive-url=https://web.archive.org/web/20190325175546/https://ilrs.cddis.eosdis.nasa.gov/missions/satellite_missions/current_missions/irns_reflector.html|archive-date=2019-03-25|access-date=2019-03-25}}</ref> [[BeiDou]],<ref>{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Zajdel |first2=Radosław |last3=Bury |first3=Grzegorz |last4=Bosy |first4=Jarosław |last5=Moore |first5=Michael |last6=Masoumi |first6=Salim |title=Quality assessment of experimental IGS multi-GNSS combined orbits |journal=GPS Solutions |date=April 2020 |volume=24 |issue=2 |pages=54 |doi=10.1007/s10291-020-0965-5|doi-access=free |bibcode=2020GPSS...24...54S }}</ref> [[QZSS]],<ref>{{cite journal |last1=Sośnica |first1=K. |last2=Bury |first2=G. |last3=Zajdel |first3=R. |last4=Strugarek |first4=D. |last5=Drożdżewski |first5=M. |last6=Kazmierski |first6=K. |title=Estimating global geodetic parameters using SLR observations to Galileo, GLONASS, BeiDou, GPS, and QZSS |journal=Earth, Planets and Space |date=December 2019 |volume=71 |issue=1 |pages=20 |doi=10.1186/s40623-019-1000-3|bibcode=2019EP&S...71...20S |doi-access=free }}</ref> and two [[GPS satellites]]<ref>{{cite journal |last1=Sośnica |first1=Krzysztof |last2=Thaller |first2=Daniela |last3=Dach |first3=Rolf |last4=Steigenberger |first4=Peter |last5=Beutler |first5=Gerhard |last6=Arnold |first6=Daniel |last7=Jäggi |first7=Adrian |title=Satellite laser ranging to GPS and GLONASS |journal=Journal of Geodesy |date=July 2015 |volume=89 |issue=7 |pages=725–743 |doi=10.1007/s00190-015-0810-8|bibcode=2015JGeod..89..725S |doi-access=free }}</ref>) as well as in [[satellite gravimetry]] ([[GOCE]]<ref>{{cite journal |last1=Strugarek |first1=Dariusz |last2=Sośnica |first2=Krzysztof |last3=Jäggi |first3=Adrian |title=Characteristics of GOCE orbits based on Satellite Laser Ranging |journal=Advances in Space Research |date=January 2019 |volume=63 |issue=1 |pages=417–431 |doi=10.1016/j.asr.2018.08.033|bibcode=2019AdSpR..63..417S |s2cid=125791718 }}</ref>) [[satellite altimetry]] (e.g., [[TOPEX/Poseidon]], [[Sentinel-3]]<ref>{{cite journal |last1=Strugarek |first1=Dariusz |last2=Sośnica |first2=Krzysztof |last3=Arnold |first3=Daniel |last4=Jäggi |first4=Adrian |last5=Zajdel |first5=Radosław |last6=Bury |first6=Grzegorz |last7=Drożdżewski |first7=Mateusz |title=Determination of Global Geodetic Parameters Using Satellite Laser Ranging Measurements to Sentinel-3 Satellites |journal=Remote Sensing |date=30 September 2019 |volume=11 |issue=19 |pages=2282 |doi=10.3390/rs11192282|bibcode=2019RemS...11.2282S |doi-access=free }}</ref>).
Retroreflectors can also be used for inter-satellite laser ranging instead of ground-tracking (e.g., [[GRACE-FO]]).<ref>{{cite web |last=Schwarz |first=Oliver |date=2016-01-21 |title=GRACE FO Laser Ranging Interferometer |url=http://spacetech-i.com/products/optical-instruments/grace-fo-laser-ranging-interferometer |url-status=dead |archive-url=https://web.archive.org/web/20191206085105/https://spacetech-i.com/products/optical-instruments/grace-fo-laser-ranging-interferometer |archive-date=2019-12-06 |access-date=2018-04-06 |website=SpaceTech GmbH |language=en}}</ref>

The [[BLITS|BLITS (Ball Lens In The Space) spherical retroreflector satellite]] was placed into orbit as part of a September 2009 Soyuz launch<ref>{{Cite web |last1=Zak |first1=Anatoly |last2=Günes |first2=S. |date=2007-04-25 |title=Space exploration in 2009 |url=http://www.russianspaceweb.com/2009.html |url-status=live |archive-url=https://web.archive.org/web/20240115053452/https://www.russianspaceweb.com/2009.html |archive-date=2024-01-15 |access-date=2024-01-15 |website=RussianSpaceWeb.com |language=en}}</ref> by the [[Federal Space Agency of the Russian Federation|Federal Space Agency of Russia]] with the assistance of the [[International Laser Ranging Service]], an independent body originally organized by the [[International Association of Geodesy]], the [[International Astronomical Union]], and international committees.<ref>{{cite web |last=Tyahla |first=Lori J. |date=2013-02-20 |title=ILRS Missions: BLITS |url=http://ilrs.gsfc.nasa.gov/missions/satellite_missions/current_missions/blit_general.html |url-status=dead |archive-url=https://web.archive.org/web/20130220215607/http://ilrs.gsfc.nasa.gov/missions/satellite_missions/current_missions/blit_general.html |archive-date=2013-02-20 |access-date=2013-02-20 |website=International Laser Ranging Service |language=en}}</ref> The ILRS central bureau is located at the United States' [[Goddard Space Flight Center]].
The reflector, a type of [[Luneburg lens]], was developed and manufactured by the Institute for Precision Instrument Engineering (IPIE) in Moscow. The mission was interrupted in 2013 after a collision with [[space debris]].<ref name="EOportal">{{cite web|title=BLITS (Ball Lens In The Space)
 |url=https://directory.eoportal.org/web/eoportal/satellite-missions/b/blits
 |publisher=[[ESA]], Earth Observation portal}}</ref><ref>{{cite web |last=Blau |first=Patrick |date=2013-03-09 |title=Russian BLITS Satellite hit by Space Debris |url=http://www.spaceflight101.net/blits-satellite-collision-january-2013.html |url-status=usurped |archive-url=https://archive.today/20161005043844/http://www.spaceflight101.net/blits-satellite-collision-january-2013.html |archive-date=2016-10-05 |access-date=2020-04-16 |website=Spaceflight101: Space News and Beyond |language=en}}</ref>{{cbignore|bot=InternetArchiveBot}}