Eye of Gaia: billion-pixel camera to map Milky Way

Last Updated: Thu, Jul 07, 2011 18:10 hrs

London, July 7 (IANS) The largest digital camera ever built for a space mission has been painstakingly mosaicked together from 106 separate electronic detectors.

The resulting 'billion-pixel array' will serve as the super-sensitive 'eye' of European Space Agency's (ESA) Galaxy-mapping Gaia mission.

While the naked human eye can see several thousand stars on a clear night, Gaia will map a billion stars within our own Milky Way Galaxy and its neighbours.

Gaia will be on a five-year mission from 2013, charting the galazies' brightness and spectral characteristics along with their 3D positions and motions, according to an ESA statement.

In order to detect distant stars up to a million times fainter than the eye can see, Gaia will carry 106 charge coupled devices (CCDs), advanced versions of chips within standard digital cameras.

Developed for the mission by e2v Technologies of Chelmsford, Britain, these rectangular detectors are a little smaller than a credit card, each one measuring 4.7x6 cm but thinner than a human hair.

The 0.5x1.0 m mosaic has been assembled at the Toulouse facility of Gaia prime contractor Astrium France.

Technicians spent much of May carefully fitting together each CCD package on the support structure, leaving only a one mm gap between them. Working in double shifts in strict cleanroom conditions, they added an average four CCDs per day, finally completing their task on 1 June.

'The mounting and precise alignment of the 106 CCDs is a key step in the assembly of the flight model focal plane assembly,' said Philippe Gare, ESA's Gaia payload manager.

--Indo-Asian News service


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