LARES (satellite)

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

LARES

LARES satellite
Mission type	Laser ranging satellite Test of GR[1][2]
Operator	Italian Space Agency (ASI)
COSPAR ID	2012-006A
SATCAT no.	38077
Website	http://www.lares-mission.com/
Spacecraft properties
Launch mass	386.8 kg
Dimensions	364 mm (diameter)
Start of mission
Launch date	13 February 2012, 22:45:00 UTC
Rocket	Vega VV01
Launch site	Kourou, ELA-1
Orbital parameters
Reference system	Geocentric[3]
Regime	Low Earth
Perigee altitude	1437 km
Apogee altitude	1451 km
Inclination	69.49°
Period	114.75 minutes
Epoch	13 February 2012

Mission

Launch

LARES was launched into orbit on 13 February 2012. It was launched on a 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 1,450 kilometres (900 mi) of perigee, an inclination of 69.5°, 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 December 2020.[14]

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.[15]

See also

• LAGEOS similar satellites launched in 1976
• List of laser ranging satellites
• List of passive satellites
• PAGEOS
• Project Echo

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.
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. • "Vega Launch Vehicle". European Space Agency.
   • "Vega overview". Archived from the original on 30 March 2009.
   • "Prepping satellite to test Albert Einstein".
   • "Overview of ESA activities in 2012 of interest to media".
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. • "International Laser Ranging Service".
   • "LARES page on the ILRS Site".
9. • Ciufolini, I.; Paolozzi A.; Pavlis E. C.; Ries J. C.; Koenig R.; Matzner R. A.; Sindoni G. & Neumayer H. (2009). "Towards a One Percent Measurement of Frame Dragging by Spin with Satellite Laser Ranging to LAGEOS, LAGEOS 2 and LARES and GRACE Gravity Models". Space Science Reviews. 148 (1–4): 71–104. Bibcode:2009SSRv..148...71C. doi:10.1007/s11214-009-9585-7.
   • 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.
   • Paolozzi, A.; Ciufolini I.; Vendittozzi C. (2011). "Engineering and scientific aspects of LARES satellite". Acta Astronautica. 69 (3–4): 127–134. Bibcode:2011AcAau..69..127P. doi:10.1016/j.actaastro.2011.03.005. ISSN 0094-5765.
   • 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.; A. Paolozzi; C. Paris (2012). "Overview of the LARES mission: orbit, error analysis and technological aspects". Journal of Physics. Conference Series. 354 (1): 012002. Bibcode:2012JPhCS.354a2002C. doi:10.1088/1742-6596/354/1/012002.
   • 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.
    • Iorio, L. (2009). "Will the recently approved LARES mission be able to measure the Lense–Thirring effect at 1%?". General Relativity and Gravitation. 41 (8): 1717–1724. arXiv:0803.3278. Bibcode:2009GReGr..41.1717I. doi:10.1007/s10714-008-0742-1.
    • Iorio, L. (2009). "An Assessment of the Systematic Uncertainty in Present and Future Tests of the Lense-Thirring Effect with Satellite Laser Ranging". Space Science Reviews. 148 (1–4): 363. arXiv:0809.1373. Bibcode:2009SSRv..148..363I. doi:10.1007/s11214-008-9478-1.
    • 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.
    • Iorio, L. (2010). "On the impact of the atmospheric drag on the LARES mission" (PDF). Acta Physica Polonica B. 41 (4): 753–765. Archived from the original (PDF) on 1 March 2012. Retrieved 21 May 2010.
    • Iorio, L.; Lichtenegger, H.I.M.; Ruggiero, M.L.; Corda, C. (2011). "Phenomenology of the Lense-Thirring effect in the solar system". Astrophysics and Space Science. 331 (2): 351. arXiv:1009.3225. Bibcode:2011Ap&SS.331..351I. doi:10.1007/s10509-010-0489-5.
    • Renzetti, G. (2012). "Are higher degree even zonals really harmful for the LARES/LAGEOS frame-dragging experiment?". Canadian Journal of Physics. 90 (9): 883–888. Bibcode:2012CaJPh..90..883R. doi:10.1139/p2012-081.
    • Renzetti, G. (October 2013). "First results from LARES: An analysis". New Astronomy. 23-24: 63–66. Bibcode:2013NewA...23...63R. doi:10.1016/j.newast.2013.03.001.
    • Ciufolini, I.; A. Paolozzi; E. C. Pavlis; J. C. Ries; R. Koenig; R. A. Matzner; G. Sindoni; H. Neumayer (2009). "Towards a One Percent Measurement of Frame Dragging by Spin with Satellite Laser Ranging to LAGEOS, LAGEOS 2 and LARES and GRACE Gravity Models". Space Science Reviews. 148 (1–4): 71–104. Bibcode:2009SSRv..148...71C. doi:10.1007/s11214-009-9585-7.
    • Renzetti, G. (May 2015). "On Monte Carlo simulations of the LAser RElativity Satellite experiment". Acta Astronautica. 113: 164–168. Bibcode:2015AcAau.113..164R. doi:10.1016/j.actaastro.2015.04.009.
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. "Launch Schedule". spaceflightnow.com. SFN. 18 May 2020. Retrieved 18 May 2020.
15. A new laser-ranged satellite for General Relativity and space geodesy: I. An introduction to the LARES2 space experiment arXiv:1910.13818

External links

• LARES Mission: official Web Site of LARES Mission.
• LARES - Testing of General Relativity on ASI's page
• LARES - Pronto al via! article with images of LARES on ASI's site (in Italian)
• LARES Satellite Information LARES page on the ILRS Web Site.