LARES (satellite)

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

LARES
LARESball public.JPG
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
 

MissionEdit

LaunchEdit

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]

CompositionEdit

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 a nearly circular orbit near 1,451 kilometres (902 mi) and an inclination of 69.49 degrees. The satellite is tracked by the International Laser Ranging Service stations.[8]

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

Scientific goalsEdit

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][clarification needed]

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 2Edit

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 alsoEdit

ReferencesEdit

  1. ^ a b c "The LAser RElativity Satellite". The LARES Team. Archived from the original on 31 December 2012. 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.
  5. ^
  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.
  8. ^
  9. ^
    • 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.; 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.
  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

External linksEdit