LARES (satellite)

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

LARES

LARES satellite
Mission type	Laser ranging satellite Tests of general relativity[1][2]
Operator	Italian Space Agency (ASI)
COSPAR ID	2012-006A
SATCAT no.	38077
Website	http://www.lares-mission.com/
Mission duration	LARES 1: 12 years, 8 months and 30 days (elapsed) LARES 2: 2 years, 3 months and 29 days (elasped)
Spacecraft properties
Manufacturer	Carlo Gavazzi Space
Launch mass	386.8 kg
Dimensions	36.4 cm (diameter)
Start of mission
Launch date	13 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 altitude	1437 km
Apogee altitude	1451 km
Inclination	69.49°
Period	114.75 minutes

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

• Spaceflight portal

• LAGEOS similar satellites launched in 1976
• List of laser ranging satellites
• List of passive satellites
• PAGEOS
• Project Echo
• Vega flight VV01

References

1. "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. • "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". This article incorporates text from this source, which is in the public domain.
   • "LARES page on the ILRS Site". This article incorporates text from this source, which is in the public domain.
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. S2CID 120442993.

   • 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. hdl:11573/442872.

   • 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. Vol. 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. S2CID 122205903.

   • 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.

   • 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. 93–97. arXiv:1302.5163. doi:10.1142/9789814440349_0008. ISBN 978-981-4440-33-2. S2CID 119023319.
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.

    • 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. S2CID 6079748.

    • 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. S2CID 15698399.

    • 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. doi:10.22323/1.081.0017. S2CID 15033615.

    • Iorio, L. (2010). "On the impact of the atmospheric drag on the LARES mission" (PDF). Acta Physica Polonica B. 41 (4): 753–765. arXiv:0809.3564. Bibcode:2010AcPPB..41.4753I. 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. S2CID 119206212.

    • 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. S2CID 120442993.

    • 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. 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

• 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.