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GAIA
G
aia is a space astrometry mission designed to help tackle one of the most arduous challenges in
astronomy: to create an extraordinarily precise three-dimensional map of 1 billion stars throughout
our galaxy and beyond. It will measure position and velocity of all objects down to magnitude 20 and
achieve an unprecedented accuracy of 24 micro arcseconds at magnitude 15. In the process, it will map their
three-dimensional motions, which encode the origin and subsequent evolution of the galaxy.
Through comprehensive photometric and spectroscopic classification, it will provide the detailed physical
properties of each star observed: characterising their luminosity, temperature, gravity, and elemental
composition. This massive stellar census will provide the basic observational data to tackle an enormous range
of important problems related to the origin, structure, and evolutionary history of our galaxy.
GAIA structure
Gaia will continue the work done by the Hipparcos satellite, built by Astrium and launched in 1989. This
European mission was the first satellite to chart the positions of stars and catalogued over 2 million stars. The
data is now widely used by the entire community of professional astronomers.
All the space you need
Customer
European Space Agency
Mission
Astrometry. Precise 3D map of 1 billion stars up to magnitude 20.
Photometric and spectroscopic classification.
Orbit
L2 Lagrangian point of the Sun-Earth system
Spacecraft
The Gaia spacecraft configuration is driven by the required very high
thermo-mechanical stability of the entire spacecraft. A low disturbance
cold gas micro-propulsion is used for fine attitude control. The astrometric
instrument is used for precise rate sensing in fine pointing operating mode.
Payload
The payload consists of three instruments sharing the same telescope,
optical bench and focal plane:
• The astrometric instrument will measure the angular position of stars
• The photometric instrument will provide continuous star spectra in
the band 330 nm to 1000 nm
• The spectrometric instrument will provide radial velocity and high
resolution spectra data in a narrow spectral band around 860 nm
The payload is complemented with a laser interferometer and a Wave Front
Sensor for internal metrology purposes and with a rubidium atomic clock
for accurate time measurement and focal plane sequencing.
Features
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1 Gpixel focal plane @ 170 K
3 million stars/deg
Spectrum 320 - 1000 nm.
Radial velocity 847-874 nm (up to magnitude 17)
Power: 2000 W
GAIA Silicon Carbide Torus
Astrium as prime contractor for the spacecraft,
the Payload Module, the Service Module and
the central software, leads an industrial team
of 50 European companies.
INDUSTRIAL TEAM
AAE, Siemens
AMOS, CSL
Apco, Oerlikon, Syderal
Astrium, Zeiss
Launch Mass
2100 kg
Dimensions
Height = 3.5 m, deployed diameter = 10 m
Launch Date
2012
Mission Duration
5 years
Status
Implementation started March 2006
Astrium Responsibilities
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Rovsing, Terma
Astrium, TAS-E (Espacio),
Crisa, Rymsa, Sener
Prime Contractor
Payload Module development
Service Module development
Software
Assembly, Integration and Tests
Astrium, Boostec,
Intespace, Latelec, Sagem
Patria, SSF
TAS-I, Galileo Avionica
Key Features:
The astrometric accuracy relies on the very high stability of the telescopes thanks to the full silicon carbide
optical bench and optics. The large focal length enables the telescope to operate in dense sky areas up to
3 million stars /deg.
The data handling system controls the detection of stars, discrimination from cosmic events, constitution of
stars packets and data compression.
Cold gas micro-propulsion is used for the spacecraft fine attitude control.
McGinley
Kongsberg
Dutch Space, SSBV, TNO
7463tl sep © 2010 Astrium, images © 2010 Astrium, © 2010 ESA
Deimos, Ineti, Lusospace,
Skysoft
For more information please contact:
Elizabeth Seward, Marketing Manager
Earth Observation & Science Division
Astrium satellites
Gunnels Wood Road
Stevenage
Hertfordshire
SG1 2AS
United Kingdom
Phone: +44 (0) 1438 778060
FAX: +44 (0) 1438 778910
EMAIL: [email protected]
RUAG Aerospace
Astrium, ABSL, e2v, MSSL,
Vega
Arde
www.astrium.eads.net