The European aerospace firm EADS Astrium has won a contract to build a $403 million satellite that the European Space Agency will use to map more than a billion stars.
EADS said on its Web site on Thursday that it would develop and build the satellite for the Global Astrometric Interferometer for Astrophysics mission, also known as Gaia. The spacecraft is due for launch in 2011.
Gaia's primary mission is to create a three-dimensional rendering of our Milky Way galaxy, mapping more than 1 billion stars. The satellite also should be able to identify as many as 10,000 planets around other stars, and discover several tens of thousands of comets and asteroids in our own solar system.
The agreement with EADS Astrium was signed Thursday during a ceremony in Toulouse, France, ESA said.
“Gaia is our next grand challenge to understand our galactic home, the Milky Way,” ESA science director David Southwood said in an agency statement. “It is a great privilege to meet the team in EADS Astrium and to wish them well in working with us in this great project.”
Gaia will be the most accurate optical astronomy satellite ever built. It will scan the sky continuously for at least five years from a point in space known as the second Lagrangian point, or L2, located about 1 million miles (1.6 million kilometers) from Earth in the direction opposite to the sun. ESA said this position in space would offer a stable thermal environment, low radiation environment and high observing efficiency, since the sun, Earth and the moon would all be behind the instrument's field of view.
The accuracy of Gaia measurements will be extremely high: If an equivalent interferometer were on the moon, it could measure the thumbnail of a person on Earth, ESA said.
The spacecraft will use the global astronomy concept demonstrated on its predecessor — ESA’s mission Hipparcos, which was also built by EADS Astrium and mapped more than 100,000 stars in the late 1980s.
Gaia will be equipped with a deployable sun shield, covering an area of 1,075 square feet (100 square meters), to minimize temperature fluctuations on the highly sensitive optics. It will also have a new micropropulsion system to reduce disturbances to the optics during sky scanning.
This report includes information from Reuters and the European Space Agency.