Gaia (spacecraft)

Gaia
3D image of Gaia spacraft
Artist's impression of the Gaia spacecraft
Mission typeAstrometric observatory
OperatorESA
COSPAR ID2013-074A Edit this at Wikidata
SATCAT no.39479
Websitewww.esa.int/Science_Exploration/Space_Science/Gaia
Mission duration10 years, 11 months and 8 days
(in progress)
Spacecraft properties
Manufacturer
Launch mass2,029 kg (4,473 lb)[1]
Dry mass1,392 kg (3,069 lb)
Payload mass710 kg (1,570 lb)[2]
Dimensions4.6 m × 2.3 m (15.1 ft × 7.5 ft)
Power1,910 watts
Start of mission
Launch date19 December 2013, 09:12:14 UTC (2013-12-19UTC09:12:14Z)[3]
RocketSoyuz ST-B/Fregat-MT
Launch siteKourou ELS
ContractorArianespace
End of mission
Deactivated2025 (planned)
Orbital parameters
Reference systemSun–Earth L2
RegimeLissajous orbit
Periapsis altitude263,000 km (163,000 mi)[4]
Apoapsis altitude707,000 km (439,000 mi)[4]
Period180 days
Epoch2014
Main telescope
TypeThree-mirror anastigmat[1]
Diameter1.45 m × 0.5 m (4 ft 9 in × 1 ft 8 in)
Collecting area0.7 m2
Transponders
Band
Bandwidth
  • a few kbit/s down & up (S Band)
  • 3–8 Mbit/s download (X Band)
Instruments
  • ASTRO: Astrometric instrument
  • BP/RP: Photometric instrument
  • RVS: Radial velocity spectrometer
Gaia mission insignia
ESA insignia for Gaia

Gaia is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until 2025. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented precision,[5][6] and the positions of exoplanets by measuring attributes about the stars they orbit such as their apparent magnitude and color.[7] The mission aims to construct by far the largest and most precise 3D space catalog ever made, totalling approximately 1 billion astronomical objects, mainly stars, but also planets, comets, asteroids and quasars, among others.[8]

To study the precise position and motion of its target objects, the spacecraft monitored each of them about 70 times[9] over the five years of the nominal mission (2014–2019), and about as many during its extension.[10][11] Due to its detectors not degrading as fast as initially expected, the mission was given an extension.[12] As of March 2023, the spacecraft has enough micro-propulsion fuel to operate until the second quarter of 2025.[13] Gaia targets objects brighter than magnitude 20 in a broad photometric band that covers the extended visual range between near-UV and near infrared;[14] such objects represent approximately 1% of the Milky Way population.[9] Additionally, Gaia is expected to detect thousands to tens of thousands of Jupiter-sized exoplanets beyond the Solar System by using the astrometry method,[15][16] 500,000 quasars outside this galaxy and tens of thousands of known and new asteroids and comets within the Solar System.[17][18][19]

The Gaia mission continues to create a precise three-dimensional map of astronomical objects throughout the Milky Way and map their motions, which encode the origin and subsequent evolution of the Milky Way. The spectrophotometric measurements provide detailed physical properties of all stars observed, characterizing their luminosity, effective temperature, gravity and elemental composition. This massive stellar census is providing the basic observational data to analyze a wide range of important questions related to the origin, structure and evolutionary history of the Milky Way galaxy.

The successor to the Hipparcos mission (operational 1989–1993), Gaia is part of ESA's Horizon 2000+ long-term scientific program. Gaia was launched on 19 December 2013 by Arianespace using a Soyuz ST-B/Fregat-MT rocket flying from Kourou in French Guiana.[20][21] The spacecraft currently operates in a Lissajous orbit around the Sun–Earth L2 Lagrangian point.

  1. ^ a b "GAIA (Global Astrometric Interferometer for Astrophysics) Mission". ESA eoPortal. Retrieved 28 March 2014.
  2. ^ "Frequently Asked Questions about Gaia". ESA. 14 November 2013.
  3. ^ "Gaia Liftoff". ESA. 19 December 2013.
  4. ^ a b Cite error: The named reference esaenter was invoked but never defined (see the help page).
  5. ^ "ESA Gaia home". ESA. Retrieved 23 October 2013.
  6. ^ Spie (2014). "Timo Prusti plenary: Gaia: Scientific In-orbit Performance". SPIE Newsroom. doi:10.1117/2.3201407.13.
  7. ^ Bohan, Elise; Dinwiddie, Robert; Challoner, Jack; Stuart, Colin; Harvey, Derek; Wragg-Sykes, Rebecca; Chrisp, Peter; Hubbard, Ben; Parker, Phillip; et al. (Writers) (February 2016). Big History. Foreword by David Christian (1st American ed.). New York: DK. p. 77. ISBN 978-1-4654-5443-0. OCLC 940282526.
  8. ^ Cite error: The named reference NYT-20180501 was invoked but never defined (see the help page).
  9. ^ a b "ESA Gaia spacecraft summary". ESA. 20 May 2011.
  10. ^ "A billion pixels for a billion stars". BBC Science and Environment. BBC. 10 October 2011.
  11. ^ "We have already installed the eye of 'Gaia' with a billion pixels to study the Milky Way". Science Knowledge. 14 July 2011. Archived from the original on 6 April 2016.
  12. ^ "Gaia: fact sheet". ESA. 24 June 2013.
  13. ^ Cite error: The named reference esa-20230307 was invoked but never defined (see the help page).
  14. ^ "Expected Nominal Mission Science Performance". European Space Agency. Retrieved 20 November 2019.
  15. ^ Wenz, John (10 October 2019). "Lessons from scorching hot weirdo-planets". Knowable Magazine. Annual Reviews. doi:10.1146/knowable-101019-2. Retrieved 4 April 2022.
  16. ^ "Gaia Science Objectives". European Space Agency. 14 June 2013.
  17. ^ "Gaia's mission: solving the celestial puzzle". University of Cambridge. 21 October 2013.
  18. ^ "ESA's Gaia... Launches With A Billion Pixel Camera". Satnews.com. 19 December 2013.
  19. ^ "Gaia space telescope to detect killer asteroids". thehindubusinessline.com. 19 December 2013. Archived from the original on 3 June 2014.
  20. ^ "Announcement of Opportunity for the Gaia Data Processing Archive Access Co-Ordination Unit". ESA. 19 November 2012.
  21. ^ "Arianespace to launch Gaia; ESA mission will observe a billion stars in our galaxy". Press releases. Arianespace. 16 December 2009. Archived from the original on 18 September 2010.