From Wikipedia, the free encyclopedia

LARES
LARES satellite
Mission type Laser ranging satellite
Tests of general relativity [1] [2]
Operator Italian Space Agency (ASI)
COSPAR ID 2012-006A Edit this at Wikidata
SATCAT no.38077
Website http://www.lares-mission.com/
Mission durationLARES 1: 12 years, 2 months and 13 days (elapsed)
LARES 2: 1 year, 9 months and 12 days (elasped)
Spacecraft properties
ManufacturerCarlo Gavazzi Space
Launch mass386.8 kg
Dimensions36.4 cm (diameter)
Start of mission
Launch date13 February 2012, 10:00:00 UTC 14 July 2022, 13:13:43 UTC
Rocket Vega VV01 Vega-C VV21
Launch site Kourou, ELA-1
Contractor Arianespace
Orbital parameters
Reference system Geocentric orbit [3]
Regime Low Earth orbit
Perigee altitude1437 km
Apogee altitude1451 km
Inclination69.49°
Period114.75 minutes
 

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

Mission

LARES 1

LARES 1 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 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 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][ 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 2

A second satellite, LARES 2, was launched into orbit on 13 July 2022 at 13:13:43 UTC on a Vega-C. [14] It was originally due to launch in mid-2021. [15] [16] The launch was delayed to mid-2022 due to continuing impacts from the COVID-19 pandemic. [17] [18]

LARES 2 may improve the accuracy of the frame-dragging effect measurement to 0.2%. [19] Concerns about the actual possibility of reaching this goal were raised. [20] LARES 2 is made of a nickel alloy instead of a tungsten alloy. [21]

See also

References

  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. Public Domain 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.; 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. hdl: 11573/442872.
  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. S2CID  14946573.
  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. S2CID  118945777.
  13. ^ Paolozzi, A.; Ciufolini, I. (2013). "LARES successfully launched in orbit: Satellite and mission description". Acta Astronautica. 91: 313–321. arXiv: 1305.6823. Bibcode: 2013AcAau..91..313P. doi: 10.1016/j.actaastro.2013.05.011. S2CID  111380211.
  14. ^ European Space Agency, ed. (13 July 2022). "Vega-C successfully completes inaugural flight". www.esa.int. Retrieved 14 July 2022.
  15. ^ Henry, Caleb (14 September 2020). "Vega C debut slips to mid-2021". SpaceNews. Retrieved 14 September 2020.
  16. ^ "Launch Schedule – Spaceflight Now". 15 September 2020. Archived from the original on 15 September 2020. Retrieved 22 November 2021.
  17. ^ Kanayama, Lee (29 October 2021). "Ariane 6 undergoing preparations for its 2022 debut". NASASpaceFlight.com. Retrieved 22 November 2021.
  18. ^ "Launch Schedule – Spaceflight Now". Retrieved 22 November 2021.
  19. ^ A new laser-ranged satellite for General Relativity and space geodesy: I. An introduction to the LARES2 space experiment arXiv: 1910.13818
  20. ^ Iorio, L. (2023). "Limitations in Testing the Lense–Thirring Effect with LAGEOS and the Newly Launched Geodetic Satellite LARES 2". Universe. 9 (5): 211. arXiv: 2304.14649. Bibcode: 2023Univ....9..211I. doi: 10.3390/universe9050211.
  21. ^ "Mission Lares 2". Retrieved 13 July 2022.

External links

Retrieved from " https://en.wikipedia.org/?title=LARES_(satellite)&oldid=1188665872"