List of objects at Lagrange points

This is a list of known objects which occupy, have occupied, or are planned to occupy any of the five Lagrange points of two-body systems in space.

A diagram showing the five Lagrange points in a two-body system

Sun–Earth Lagrange points

edit

Sun–Earth L1

edit

L1 is the Lagrange point located approximately 1.5 million kilometers from Earth towards the Sun.

Past probes

edit
  • International Cometary Explorer, formerly the International Sun–Earth Explorer 3 (ISEE-3), diverted out of L1 in 1983 for a comet rendezvous mission. Currently in heliocentric orbit. The Sun–Earth L1 is also the point to which the Reboot ISEE-3 mission was attempting to return the craft as the first phase of a recovery mission (as of September 25, 2014 all efforts have failed and contact was lost).[1]
  • NASA's Genesis probe collected solar wind samples at L1 from December 3, 2001, to April 1, 2004, when it returned the sample capsule to Earth. It returned briefly in late 2004 before being pushed into heliocentric orbit in early 2005.
  • LISA Pathfinder (LPF) was launched on 3 December 2015, and arrived at L1 on 22 January 2016, where, among other experiments, it tested the technology needed by (e)LISA to detect gravitational waves. LISA Pathfinder used an instrument consisting of two small gold alloy cubes.
  • The Chang'e 5 orbiter[2] (during extended mission. After ferrying lunar samples back to Earth in 2020, the transport module was sent to L1 where it is permanently stationed to conduct limited Earth-Sun observations.)

Present probes

edit
 
Animation of Deep Space Climate Observatory's trajectory from 11 February 2015 to 3 January 2017
  DSCOVR ·   Earth ·   Moon
  • The Deep Space Climate Observatory (DSCOVR), designed to image the sunlit Earth in 10 wavelengths (EPIC) and monitor total reflected radiation (NISTAR). Launched on 11 February 2015, began orbiting L1 on 8 June 2015 to study the solar wind and its effects on Earth.[3] DSCOVR is unofficially known as GORESAT, because it carries a camera always oriented to Earth and capturing full-frame photos of the planet similar to the Blue Marble. This concept was proposed by then-Vice President of the United States Al Gore in 1998[4] and was a centerpiece in his 2006 film An Inconvenient Truth.[5]
  • Aditya-L1 was successfully launched on 2 September 2023 and entered the halo orbit around the lagrange point on 6 January 2024.[6] It's a Solar observation mission by ISRO. It will study solar atmosphere, solar magnetic storms, and their impact on the environment around the Earth.[7]

Planned probes

edit

Sun–Earth L2

edit

L2 is the Lagrange point located approximately 1.5 million kilometers from Earth in the direction opposite the Sun. Spacecraft at the Sun–Earth L2 point are in a Lissajous orbit until decommissioned, when they are sent into a heliocentric graveyard orbit.[citation needed]

Past probes

edit
 
Animation of Wilkinson Microwave Anisotropy Probe's trajectory from 1 July 2001 to 7 April 2009
  WMAP ·   Earth
  • 2001 – 2010: NASA's Wilkinson Microwave Anisotropy Probe (WMAP)[8] observed the cosmic microwave background. It was moved to a heliocentric orbit to avoid posing a hazard to future missions.
  • 2003 – 2004: NASA's WIND. The spacecraft then went to Earth orbit, before heading to L1.[9]
  • 2009 – 2013:[10] The ESA Herschel Space Observatory exhausted its supply of liquid helium and was moved from the Lagrangian point in June 2013.
  • 2009 – 2013: At the end of its mission ESA's Planck spacecraft was put into a heliocentric orbit and passivated to prevent it from endangering any future missions.
  • 2011 – 2012: CNSA's Chang'e 2.[11][12] Chang'e 2 was then placed onto a heliocentric orbit that took it past the near-Earth asteroid 4179 Toutatis.

Present probes

edit
 
Gaia and James Webb Space Telescope orbit around Sun-Earth L2

Planned probes

edit

Cancelled probes

edit

Sun–Earth L3

edit

L3 is the Sun–Earth Lagrange point located on the side of the Sun opposite Earth, slightly outside the Earth's orbit. Direct communication with spacecraft in this position is blocked by the Sun.

Sun–Earth L4

edit

L4 is the Sun–Earth Lagrange point located close to the Earth's orbit 60° ahead of Earth.

  • Asteroid (706765) 2010 TK7 is the first discovered tadpole orbit companion to Earth, orbiting L4; like Earth, its mean distance to the Sun is about one astronomical unit.
  • Asteroid (614689) 2020 XL5 is the second Earth trojan, confirmed in November 2021, oscillating around L4 in a tadpole orbit and expected to remain there for at least 4000 years, until destabilized by Venus.[13]
  • STEREO A (Solar TErrestrial RElations Observatory – Ahead) made its closest pass to L4 in September 2009, on its orbit around the Sun, slightly faster than Earth.[14]
  • OSIRIS-REx passed near the L4 point and performed a survey for asteroids between 9 and 20 February 2017.

Sun–Earth L5

edit

L5, or Earth-trailing orbit, is the Sun–Earth Lagrange point located close to the Earth's orbit 60° behind Earth.

  • Asteroid (419624) 2010 SO16, in a horseshoe companion orbit with Earth, is currently proximal to L5 but at a high inclination.
  • STEREO B (Solar TErrestrial RElations Observatory – Behind) made its closest pass to L5 in October 2009, on its orbit around the Sun, slightly slower than Earth.[14]
  • The Spitzer Space Telescope is in an Earth-trailing heliocentric orbit drifting away c. 0.1 AU per year. In c. 2013–15 it has passed L5 in its orbit.
  • Hayabusa2 passed near L5 during the spring of 2017, and imaged the surrounding area to search for Earth trojans on 18 April 2018.[15]

Proposed

edit
  • Vigil (ESA). One spacecraft in L5.

Earth–Moon Lagrange points

edit

Earth–Moon L2

edit

Earth–Moon L4 and L5

edit

Past probes

edit
  • Hiten was the first spacecraft to demonstrate a low energy trajectory, passing by L4 and L5 to achieve lunar orbit at a very low fuel expense, compared to usual orbital techniques. Hiten did not find any conclusive increase in dust density at Lagrange points.[19]

Proposed objects

edit

Sun–Venus Lagrange points

edit

Sun–Mars Lagrange points

edit

Asteroids in the L4 and L5 Sun–Mars Lagrangian points are sometimes called Mars trojans, with a lower-case t, as "Trojan asteroid" was originally defined as a term for Lagrangian asteroids of Jupiter. They may also be called Mars Lagrangian asteroids.

Source: Minor Planet Center [1]

Sun–Ceres Lagrange points

edit

Sun–Jupiter Lagrange points

edit

Asteroids in the L4 and L5 Sun–Jupiter Lagrangian points are known as Jupiter Trojan asteroids or simply Trojan asteroids.

L4 and L5

edit

Saturn–Tethys Lagrange points

edit

Saturn–Dione Lagrange points

edit

Sun–Uranus Lagrange points

edit

Sun–Neptune Lagrange points

edit

Minor planets in the L4 and L5 Sun–Neptune Lagrangian points are called Neptune trojans, with a lower-case t, as "Trojan asteroid" was originally defined as a term for Lagrangian asteroids of Jupiter.

Data from: Minor Planet Center [2]

Tables of missions

edit

Color key:
  Unflown or planned mission   Mission en route or in progress (including mission extensions)   Mission at Lagrangian point completed successfully (or partially successfully)

Future and proposed missions

edit

See also

edit

Footnotes

edit
  1. ^ "ISEE-3 is in Safe Mode". Space College. 25 September 2014. "The ground stations listening to ISEE-3 have not been able to obtain a signal since Tuesday the 16th"
  2. ^ a b "Chang'e 5 Test Mission Updates". Spaceflight 101. Retrieved 14 December 2014.
  3. ^ US Department of Commerce, NOAA Satellites and Information Service. "NOAA's Satellite and Information Service (NESDIS)". Archived from the original on 2015-06-08.
  4. ^ "At long last: Al Gore's satellite dream blasts off". USA TODAY. 7 February 2015.
  5. ^ Mellow, Craig (August 2014). "Al Gore's Satellite". Air & Space/Smithsonian. Retrieved December 12, 2014.
  6. ^ Kumar, Chethan (6 January 2024). "Aditya reaches halo orbit around L1 point, Sun study to begin soon". The Times of India. Retrieved 6 January 2024.
  7. ^ "Aditya L1 Mission: Aditya L1 Launch LIVE Updates: Aditya L1 spacecraft successfully separated from PSLV rocket, now en route to Sun-Earth L1 point. ISRO says mission accomplished". The Economic Times. 2 September 2023. Archived from the original on 3 September 2023. Retrieved 2 September 2023.
  8. ^ "Mission Complete! WMAP Fires Its Thrusters For The Last Time". Archived from the original on 2012-07-14. Retrieved 2022-01-11.
  9. ^ "WIND Solar-Terrestrial Mission". ESA Earth Observation Portal. Retrieved December 31, 2021.
  10. ^ Toobin, Adam (2013-06-19). "Herschel Space Telescope Shut Down For Good, ESA Announces". Huffington Post.
  11. ^ "China's Moon orbiter Chang'e-2 travels 1.5 km into outer space". The Economic Times. 2011-08-30. Archived from the original on May 23, 2012. Retrieved 2011-08-31.
  12. ^ a b Lakdawalla, Emily (15 June 2012). "Update on yesterday's post about Chang'e 2 going to Toutatis". Planetary Society. Retrieved 26 June 2012.
  13. ^ Hui, Man-To; Wiegert, Paul A.; Tholen, David J.; Föhring, Dora (November 2021). "The Second Earth Trojan 2020 XL5". The Astrophysical Journal Letters. 922 (2): L25. arXiv:2111.05058. Bibcode:2021ApJ...922L..25H. doi:10.3847/2041-8213/ac37bf. S2CID 243860678.
  14. ^ a b NASA - Join STEREO and Explore Gravitational "Parking Lots" That May Hold Secret of Moon's Origin
  15. ^ "太陽−地球系のL5点付近の観測の結果について" (in Japanese). JAXA. 23 August 2017. Retrieved 2018-06-22.
  16. ^ Slíz-Balogh, Judith; Barta, András; Horváth, Gábor (11 November 2018). "Celestial mechanics and polarization optics of the Kordylewski dust cloud in the Earth–Moon Lagrange point L5 – I. Three-dimensional celestial mechanical modelling of dust cloud formation". Monthly Notices of the Royal Astronomical Society. 480 (4): 5550–5559. arXiv:1910.07466. Bibcode:2018MNRAS.480.5550S. doi:10.1093/mnras/sty2049.
  17. ^ Hornig, Andreas (2022-05-01). "TYCHO: Supporting Permanently Crewed Lunar Exploration with High-Speed Optical Communication from Everywhere". ESA.
  18. ^ Hornig, Andreas (2013-10-06). "TYCHO mission to Earth-Moon libration point EML-4 @ IAC 2013". IAC2013.
  19. ^ "Hiten", NSSDC.GSFC.NASA.gov.
  20. ^ Alexandersen, Mike; Gladman, Brett; Greenstreet, Sarah; Kavelaars, J. J.; Petit, Jean-Marc; Gwyn, Stephen (2013). "A Uranian Trojan and the Frequency of Temporary Giant-Planet Co-Orbitals". Science. 341 (6149): 994–997. arXiv:1303.5774. Bibcode:2013Sci...341..994A. doi:10.1126/science.1238072. PMID 23990557.
  21. ^ "Solar System Exploration: ISEE-3/ICE". NASA. Archived from the original on 2011-06-14. Retrieved 2010-09-28.
  22. ^ Lakdawalla, Emily (October 3, 2008). "It's Alive!". The Planetary Science Weblog. Archived from the original on February 20, 2012. Retrieved January 11, 2022.
  23. ^ Chang, Kenneth (August 8, 2014). "Rudderless Craft to Get Glimpse of Home Before Sinking Into Space's Depths". The New York Times.
  24. ^ "ACE MAG Spectrograms: 1 day starting 2019/3/15 (2019 074)". www.srl.caltech.edu. Retrieved 2020-02-12.
  25. ^ "LISA Pathfinder factsheet". ESA. 11 June 2012. Retrieved 26 June 2012.
  26. ^ "LISA Pathfinder Will Concludee Trailblazing Mission". ESA Science and Technology. ESA. 20 June 2017. Retrieved 17 August 2017.
  27. ^ "The Very Latest SOHO Images". sohowww.nascom.nasa.gov. Retrieved 2020-02-12.
  28. ^ Tran, Lina (2019-10-31). "25 Years of Science in the Solar Wind". NASA. Retrieved 2020-02-12.
  29. ^ "WMAP Facts". NASA. Retrieved 2013-03-18.
  30. ^ http://map.gsfc.nasa.gov/news/events.html WMAP Ceases Communications
  31. ^ "Herschel Factsheet". European Space Agency. 17 April 2009. Retrieved 2009-05-12.
  32. ^ "Herschel space telescope finishes mission". BBC News. 29 April 2013.
  33. ^ "Last command sent to ESA's Planck space telescope". European Space Agency. October 23, 2013. Retrieved October 23, 2013.
  34. ^ Fox, Karen C. (25 March 2015). "First ARTEMIS Spacecraft Successfully Enters Lunar Orbit". The Sun-Earth Connection: Heliophysics. NASA.
  35. ^ Hendrix, Susan (25 March 2015). "Second ARTEMIS Spacecraft Successfully Enters Lunar Orbit". The Sun-Earth Connection: Heliophysics. NASA.
  36. ^ "Worldwide launch schedule". Spaceflight Now. 27 November 2013. Archived from the original on 30 May 2010.
  37. ^ "ESA Science & Technology - Fact Sheet". sci.esa.int. Retrieved 2020-02-12.
  38. ^ Jones, Andrew (21 May 2018). "China launches Queqiao relay satellite to support Chang'e 4 lunar far side landing mission". GBTimes. Archived from the original on 22 May 2018. Retrieved 22 May 2018.
  39. ^ Xu, Luyuan (15 June 2018). "How China's lunar relay satellite arrived in its final orbit". The Planetary Society. Archived from the original on 17 October 2018.
  40. ^ "Illustration of the Spektr-RG spacecraft". 24 June 2020. Retrieved 25 December 2021.
  41. ^ "James Webb Space Telescope lifts off on historic mission". BBC News. 25 December 2021. Retrieved 2021-12-25.
  42. ^ "Follow Euclid's first months in space". ESA. 25 August 2023. Retrieved 2 September 2023.
  43. ^ Graham, William (2 September 2023). "India launches first solar research mission, Aditya-L1, aboard PSLV". NASASpaceFlight. Retrieved 2 September 2023.
  44. ^ "Halo-Orbit Insertion of Aditya-L1 Successfully Accomplished". www.isro.gov.in. Retrieved 2024-01-06.
  45. ^ Schmid, P.E. (July 28, 1967). "Lunar far-side communication satellites". NASA Goddard Space Flight Center. Retrieved 2020-09-14.
  46. ^ O'Neill, Gerard K. (September 1974). "The Colonization of Space". Physics Today. 27 (9): 32–40. Bibcode:1974PhT....27i..32O. doi:10.1063/1.3128863.
  47. ^ "Extended Tisserand graph and multiple lunar swing-by design with Sun perturbation" (PDF). JAXA. 3 March 2016. Retrieved 2016-06-07.
  48. ^ "DESTINYについて " (in Japanese). Archived from the original on 2015-10-07. Retrieved 2015-10-23.
  49. ^ "NASA teams evaluating ISS-built Exploration Platform roadmap". June 15, 2012.
  50. ^ Bergin, Chris (December 2011). "Exploration Gateway Platform hosting Reusable Lunar Lander proposed". NASA Spaceflight.com. Retrieved 2011-12-05.
  51. ^ "The Nancy Grace Roman Space Telescope". JPL. NASA. Retrieved 21 August 2021.
  52. ^ Masahashi, Hazumi (1 September 2015). "LiteBIRD" (PDF). indico.cern. Retrieved 2015-10-23.
  53. ^ "The origin of the Universe will be unveiled by the LiteBIRD cryogenic satellite". Grenoble Alpes University. 3 July 2023. Retrieved 26 December 2023.
  54. ^ Montier, L. (10 July 2019). "LiteBIRD Overview" (PDF). IN2P3. Retrieved 21 August 2021.
  55. ^ "ESA selects planet-hunting PLATO mission". ESA. 19 February 2014. Retrieved 25 April 2016.
  56. ^ Shibai, Hiroshi (2014-12-31), SPICA (PDF), retrieved 2015-02-24
  57. ^ "ESA Science & Technology: Athena to study the hot and energetic Universe". ESA. 27 June 2014. Retrieved 23 August 2014.
  58. ^ "Sun Chaser - A Mission to the Earth-Sun Lagrangian Point 4". NASA. 7 September 2022. Retrieved 20 October 2023.
  59. ^ "В РАН рассказали, когда состоится запуск космического телескопа "Спектр-М"". РИА Новости. 2019-06-29. Retrieved 2019-07-13.