List of objects at Lagrange points

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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

Sun–Earth L₁

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

Past probes

• 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

• The Solar and Heliospheric Observatory (SOHO) in a halo orbit around L1
  • Mission: Investigation of the outer layer of the Sun, making observations of solar wind and associated phenomena in the vicinity of L1, probing the interior structure of the Sun.
  • Launched: 2 December 1995
  • Arrival: Operational orbit in May 1996
  • Institution: ESA
• The Advanced Composition Explorer (ACE) in a Lissajous orbit
• WIND (At L₁ since 2004)

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

• Interstellar Mapping and Acceleration Probe slated for launch in late 2025
• NEO Surveyor
• SWFO-L1
• Vigil (ESA). One spacecraft in L1 and one in L5.

Sun–Earth L₂

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

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.
• The CNSA Chang'e 6 orbiter
• 2013 – 2025: The ESA Gaia mission’s thrusters moved the spacecraft away from L2 on 27 March 2025 and into a stable retirement orbit around the Sun that will minimise the chance that it comes within 10 million km Earth for at least the next century.

Present probes

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

• The joint Russian-German high-energy astrophysics observatory Spektr-RG
• The joint NASA, ESA and CSA James Webb Space Telescope (JWST)
• The ESA Euclid mission

Planned probes

• The NASA Nancy Grace Roman Space Telescope (WFIRST)
• The ESA PLATO mission, which will find and characterize rocky exoplanets.
• The JAXA LiteBIRD mission.
• The ESA Advanced Telescope for High ENergy Astrophysics (ATHENA)
• The ESA ARIEL mission, which will observe the atmospheres of exoplanets.
• The joint ESA-JAXA Comet Interceptor
• The NASA Large Ultraviolet Optical Infrared Surveyor (LUVOIR) which would replace the Hubble Space Telescope.

Cancelled probes

• The ESA Eddington mission
• The NASA Terrestrial Planet Finder mission (may be placed in an Earth-trailing orbit instead)

Sun–Earth L₃

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.

• There are no known objects in this orbital location. ^{[citation needed]}

Sun–Earth L₄

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

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

• Vigil (ESA). One spacecraft in L5.

Earth–Moon Lagrange points

Earth–Moon L2

• THEMIS
• Chang'e 5-T1
• Queqiao relay satellite
• EQUULEUS nanosat.

Earth–Moon L4 and L5

• Kordylewski clouds^[16]
• Future location of TDRS-style communication satellites to support L₂ satellite and further regions on the Moon.^[17][18]

Past probes

• 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

• Exploration Gateway Platform
• In his 1976 book The High Frontier: Human Colonies in Space Dr. Gerard O'Neill proposed the establishment of gigantic Space Islands in L₅. The inhabitants of the L5 Society should convert lunar material to huge solar power satellites. Many works of fiction, most notably the Gundam series, involve colonies at these locations.

Sun–Venus Lagrange points

L4

• 2013 ND15

Sun–Mars Lagrange points

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.

L4

• (121514) 1999 UJ7

L5

• 5261 Eureka
• (101429) 1998 VF31
• (311999) 2007 NS2
• (385250) 2001 DH47, 2001 FG24, (461377) 2001 FR127 (not confirmed as true Lagrangian asteroids)

Source: Minor Planet Center

Sun–Ceres Lagrange points

• 1372 Haremari
• (76146) 2000 EU16
• (185105) 2006 SV23

Sun–Jupiter Lagrange points

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

L4

• Trojan asteroids, Greek camp

L5

• Trojan asteroids, Trojan camp

L4 and L5

• Lucy (spacecraft), L4 in 2027, L5 in 2033

Saturn–Tethys Lagrange points

L4

• Telesto

L5

• Calypso

Saturn–Dione Lagrange points

L4

• Helene

L5

• Polydeuces, follows a "tadpole" orbit around L₅

Sun–Uranus Lagrange points

L3

• 83982 Crantor, follows a horseshoe orbit around L₃

L4

• (687170) 2011 QF99^[20]
• (636872) 2014 YX49

Sun–Neptune Lagrange points

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

L4

• 385571 Otrera
• 385695 Clete
• (612243) 2001 QR322
• 2005 TN53
• (613490) 2006 RJ103
• (527604) 2007 VL305

L5

• 2008 LC18
• 2004 KV18
• 2011 HM102

Tables of missions

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

Lagrangian point missions

Mission	Lagrangian point	Agency	Description
International Sun–Earth Explorer 3 (ISEE-3)	Sun–Earth L1	NASA	Launched in 1978, it was the first spacecraft to be put into orbit around a libration point, where it operated for four years in a halo orbit about the L1 Sun–Earth point. After the original mission ended, it was commanded to leave L1 in September 1982 in order to investigate comets and the Sun.[21] Now in a heliocentric orbit, an unsuccessful attempt to return to halo orbit was made in 2014 when it made a flyby of the Earth–Moon system.[22][23]
Advanced Composition Explorer (ACE)	Sun–Earth L1	NASA	Launched 1997. Has fuel to orbit near L1 until 2024. Operational as of 2019[update].[24]
Deep Space Climate Observatory (DSCOVR)	Sun–Earth L1	NASA	Launched on 11 February 2015. Planned successor of the Advanced Composition Explorer (ACE) satellite.
LISA Pathfinder (LPF)	Sun–Earth L1	ESA, NASA	Launched one day behind revised schedule (planned for the 100th anniversary of the publication of Einstein's General Theory of Relativity), on 3 December 2015. Arrived at L1 on 22 January 2016.[25] LISA Pathfinder was deactivated on 30 June 2017.[26]
Solar and Heliospheric Observatory (SOHO)	Sun–Earth L1	ESA, NASA	Orbiting near L1 since 1996. Operational as of 2020[update].[27]
WIND	Sun–Earth L1	NASA	Arrived at L1 in 2004 with fuel for 60 years. Operational as of 2019[update].[28]
Wilkinson Microwave Anisotropy Probe (WMAP)	Sun–Earth L2	NASA	Arrived at L2 in 2001. Mission ended 2010,[29] then sent to solar orbit outside L2.[30]
Herschel Space Telescope	Sun–Earth L2	ESA	Arrived at L2 July 2009. Ceased operation on 29 April 2013; will be moved to a heliocentric orbit.[31][32]
Planck Space Observatory	Sun–Earth L2	ESA	Arrived at L2 July 2009. Mission ended on 23 October 2013; Planck has been moved to a heliocentric parking orbit.[33]
Chang'e 2	Sun–Earth L2	CNSA	Arrived in August 2011 after completing a lunar mission before departing en route to asteroid 4179 Toutatis in April 2012.[12]
ARTEMIS mission extension of THEMIS	Earth–Moon L1 and L2	NASA	Mission consists of two spacecraft, which were the first spacecraft to reach Earth–Moon Lagrangian points. Both moved through Earth–Moon Lagrangian points, and are now in lunar orbit.[34][35]
WIND	Sun–Earth L2	NASA	Arrived at L2 in November 2003 and departed April 2004.
Gaia Space Observatory	Sun–Earth L2	ESA	Launched 19 December 2013.[36] Operational as of 2020[update].[37]
Chang'e 5-T1 Service Module	Earth–Moon L2	CNSA	Launched on 23 October 2014, arrived at L2 halo orbit on 13 January 2015.[2]
Queqiao	Earth–Moon L2	CNSA	Launched on 21 May 2018, arrived at L2 halo orbit on June 14 for Chang'e 4 mission.[38] Queqiao is the first ever communication relay and radio astronomy satellite at operating its location.[39]
Spektr-RG	Sun–Earth L2	IKI RAN DLR	Launched 13 July 2019. Roentgen and Gamma space observatory. Operational as of June 2020.[40]
Chang'e 5 Service Module	Sun–Earth L1	CNSA	Launched on 23 November 2020, arrived at L1 halo orbit on 15 March 2021.
James Webb Space Telescope (JWST)	Sun–Earth L2	NASA, ESA, CSA	Launched on 25 December 2021, arrived at L2 point on 24 January 2022. Operational as of 2022.[41]
Euclid	Sun–Earth L2	ESA, NASA	Launched on 1 July 2023, arrived at L2 point on 28 July 2023. Currently in testing phase as of September 2023.[42]
Aditya-L1	Sun–Earth L1	ISRO	Launched on 2 September 2023[43] and was successfully inserted into an orbit about Sun-Earth L1 point on 6 January 2024.[44]
Chang'e 6 Service Module	Sun–Earth L2	CNSA	Launched on 3 May 2024, arrived at L2 halo orbit on 9 September 2024.

Future and proposed missions

Future and proposed missions to Lagrangian points

Mission	Lagrangian point	Agency	Description
"Lunar Far-Side Communication Satellites"	Earth–Moon L2	NASA	Proposed in 1968 for communications on the far side of the Moon during the Apollo program, mainly to enable an Apollo landing on the far side—neither the satellites nor the landing were ever realized.[45]
Space colonization and manufacturing	Earth–Moon L4 or L5	—	First proposed in 1974 by Gerard K. O'Neill[46] and subsequently advocated by the L5 Society.
EQUULEUS	Earth–Moon L2	University of Tokyo, JAXA	6U CubeSat, launch planned in 2021 as a secondary payload onboard SLS Artemis 1.[47]
DESTINY+	Earth–Moon L2	JAXA	JAXA "Medium-Sized Focused Mission"; launch planned for 2025.[48]
Exploration Gateway Platform	Earth–Moon L2[49]	NASA	Proposed in 2011.[50]
Nancy Grace Roman Space Telescope (WFIRST)	Sun–Earth L2	NASA, USDOE	Launch planned for 2026.[51]
LiteBIRD	Sun–Earth L2[52]	JAXA, NASA	JAXA's next "Strategic Large Mission"; launch planned for 2032.[53][54]
Interstellar Mapping and Acceleration Probe (IMAP)	Sun–Earth L1	NASA	Planned for launch in early 2025.
Space Weather Follow On - Lagrange 1 (SWFO-L1)	Sun–Earth L1	NOAA	Planned for launch in early 2025 as a rideshare to IMAP.
Planetary Transits and Oscillations of stars (PLATO)	Sun–Earth L2	ESA	Planned for launch in 2026 for an initial six-year mission.[55]
Space Infrared Telescope for Cosmology and Astrophysics (SPICA)	Sun–Earth L2	JAXA, ESA, SRON	As of 2015[update], awaiting approval from both Japanese and European side, launch proposed for 2032.[56]
Advanced Telescope for High Energy Astrophysics (ATHENA)	Sun–Earth L2	ESA	Launch planned for 2035.[57]
ESA Vigil	Sun–Earth L5	ESA	Observatory for early warning of increased solar activity. Launch planned for 2029.
Sun Chaser[58]	Sun–Earth L4	—	Observatory for early warning of solar particle events. Early proposal phase.
Spektr-M	Sun–Earth L2	Roscosmos	Possible launch after 2030.[59]

See also

• Trojan (celestial body)
• Co-orbital configuration