LARES (satellite)

LARES (Laser Relativity Satellite) is a passive satellite of the Italian Space Agency.[4]

LARES
LARES satellite
Mission typeLaser ranging satellite
Tests of general relativity[1][2]
OperatorItalian Space Agency (ASI)
COSPAR ID2012-006A
SATCAT no.38077
Websitehttp://www.lares-mission.com/
Spacecraft properties
Launch mass386.8 kg
Dimensions36.4 cm (diameter)
Start of mission
Launch date13 February 2012, 10:00:00 UTC
RocketVega VV01
Launch siteKourou, ELA-1
Orbital parameters
Reference systemGeocentric orbit[3]
RegimeLow Earth orbit
Perigee altitude1437 km
Apogee altitude1451 km
Inclination69.49°
Period114.75 minutes
 

Mission

Launch

LARES was launched into orbit on 13 February 2012 at 10:00:00 UTC. It was launched on the first Vega rocket from the ESA Centre Spatial Guyanais in Kourou, French Guiana.[5]

Composition

The satellite is made of THA-18N, a tungsten alloy,[6] and houses 92 cube-corner retroreflectors, which are used to track the satellite via laser from stations on Earth. LARES's body has a diameter of about 36.4 centimetres (14.3 in) and a mass of about 387 kilograms (853 lb).[1][7] LARES was inserted in an orbit with 1,451 kilometres (902 mi) of apogee, an inclination of 69.49°, and reduced eccentricity. The satellite is tracked by the International Laser Ranging Service stations.[8]

The LARES satellite is the densest object known orbiting the sun.[1] The high density helps reduce disturbances from environmental factors such as solar radiation pressure.

Scientific goals

The main scientific target of the LARES mission is the measurement of the Lense–Thirring effect with an accuracy of about 1%, according to principal investigator Ignazio Ciufolini and the LARES scientific team,[9] but the reliability of that estimate is contested.[10]

In contrast, a recent analysis of 3.5 years of laser-ranging data reported a claimed accuracy of about 4%.[11] Critical remarks appeared later in the literature.[12]

Beyond the project's key mission, the LARES satellite may be used for other tests of general relativity as well as measurements in the fields of geodynamics and satellite geodesy.[13]

LARES 2

A second satellite, LARES 2, is due to launch on a Vega-C in mid-2021.[14][15]

LARES 2 may improve the accuracy of the frame-dragging effect measurement to 0.2%. LARES 2's material is unknown, but it may use a copper alloy instead of a tungsten alloy.[16]

See also

References
  1. "The LAser RElativity Satellite". The LARES Team. Archived from the original on 31 December 2019. Retrieved 28 February 2013.
  2. "LARES". International Laser Ranging Service. Retrieved 28 February 2013. This article incorporates text from this source, which is in the public domain.
  3. Peat, Chris (29 July 2013). "LARES - Orbit". Heavens-Above. Retrieved 29 July 2013.
  4. "LARES: Satellite per misure relativistiche" (in Italian). Agenzia Spaziale Italiana. Archived from the original on 15 October 2009. Retrieved 12 March 2009.
  6. Proceedings of "9th YSESM "Youth Symposium on Experimental Solid Mechanics". Gruppo Italiano Frattura. p. 97. ISBN 9788895940304.
  7. Peroni, I.; et al. (2007). "The Design of LARES: A satellite for testing General Relativity". Proceedings of the 58th International Astronautical Congress. IAC-07-B4.2.07.
    • Ciufolini, I.; E. Pavlis; A. Paolozzi; J. Ries; R. Koenig; R. Matzner; G. Sindoni; H. Neumayer (2012). "Phenomenology of the Lense-Thirring effect in the solar system: Measurement of frame-dragging with laser ranged satellites". New Astronomy. 17 (3): 341–346. Bibcode:2012NewA...17..341C. doi:10.1016/j.newast.2011.08.003.
    • Ciufolini, I.; Paolozzi A.; Pavlis E. C.; Ries J. C.; Koenig R.; Matzner R. A.; Sindoni G. & Neumayer H. (2010). "Gravitomagnetism and Its Measurement with Laser Ranging to the LAGEOS Satellites and GRACE Earth Gravity Models". General Relativity and John Archibald Wheeler. Astrophysics and Space Science Library. 367. SpringerLink. pp. 371–434. doi:10.1007/978-90-481-3735-0_17. ISBN 978-90-481-3734-3.
    • Ciufolini, I.; Paolozzi A.; Pavlis E. C.; Ries J.; Koenig R.; Sindoni G.; Neumeyer H. (2011). "Testing Gravitational Physics with Satellite Laser Ranging". European Physical Journal Plus. 126 (8): 72. Bibcode:2011EPJP..126...72C. doi:10.1140/epjp/i2011-11072-2.
    • Ciufolini, I.; Pavlis E. C.; Paolozzi A.; Ries J.; Koenig R.; Matzner R.; Sindoni G.; Neumayer K.H. (3 August 2011). "Phenomenology of the Lense-Thirring effect in the Solar System: Measurement of frame-dragging with laser ranged satellites". New Astronomy. 17 (3): 341–346. Bibcode:2012NewA...17..341C. doi:10.1016/j.newast.2011.08.003.
    • Ciufolini, I.; V. G. Gurzadyan; R. Penrose; A. Paolozzi (2012). Geodesic motion in general relativity: LARES in Earth's gravity. Low Dimensional Physics and Gauge Principles. pp. i–xv. doi:10.1142/9789814440349_fmatter. ISBN 978-981-4440-33-2.
  10. Iorio, L. (2009). "Towards a 1% measurement of the Lense-Thirring effect with LARES?". Advances in Space Research. 43 (7): 1148–1157. arXiv:0802.2031. Bibcode:2009AdSpR..43.1148I. doi:10.1016/j.asr.2008.10.016.
    • Lorenzo Iorio (2009). "Recent Attempts to Measure the General Relativistic Lense-Thirring Effect with Natural and Artificial Bodies in the Solar System". PoS ISFTG. 017: 17. arXiv:0905.0300. Bibcode:2009isft.confE..17I.
  11. Ciufolini, I.; A. Paolozzi; E. C. Pavlis; R. Koenig; J. Ries; V. Gurzadyan; R. Matzner; R. Penrose; G. Sindoni; C. Paris; H. Khachatryan; S. Mirzoyan (March 2016). "A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model. Measurement of Earth's dragging of inertial frames". The European Physical Journal C. 76 (3): 120. arXiv:1603.09674. Bibcode:2016EPJC...76..120C. doi:10.1140/epjc/s10052-016-3961-8. PMC 4946852. PMID 27471430.
  12. Iorio, L. (February 2017). "A comment on " A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model. Measurement of Earth's dragging of inertial frames", by I. Ciufolini et al". The European Physical Journal C. 77 (2): 73. arXiv:1701.06474. Bibcode:2017EPJC...77...73I. doi:10.1140/epjc/s10052-017-4607-1.
  13. Paolozzi, A.; Ciufolini, I. (2013). "LARES successfully launched in orbit: Satellite and mission description". Acta Astronautica. 91: 313–321. arXiv:1305.6823. doi:10.1016/j.actaastro.2013.05.011.
  14. Henry, Caleb (14 September 2020). "Vega C debut slips to mid-2021". SpaceNews. Retrieved 14 September 2020.
  15. Clark, Stephen (4 September 2020). "Launch Schedule". Spaceflight Now. Retrieved 14 September 2020.
  16. A new laser-ranged satellite for General Relativity and space geodesy: I. An introduction to the LARES2 space experiment arXiv:1910.13818
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