The European Space Agency (ESA) has successfully launched its Gaia spacecraft. Its mission is to study and capture images of 1 per cent of the Milky Way's estimated 100 billion stars, in order to create the "most detailed 3D map" of the galaxy ever made."Gaia promises to build on the legacy of ESA's first star-mapping mission, Hipparcos, launched in 1989, to reveal the history of the galaxy in which we live," ESA director-general Jean-Jacques Dordain said in a statement.
"It is down to the expertise of Europe's space industry and scientific community that this next-generation mission is now well and truly on its way to making ground-breaking discoveries about our Milky Way."
Gaia lifted off in the early morning on 19 December atop a Soyuz rocket from Europe's spaceport in Kourou, French Guiana, the ESA said. After shedding all three rocket stages about 10 minutes into its flight, the unmanned spacecraft reached its temporary parking orbit nearly 110 miles above Earth.
As of Monday 23 December, flight controllers have activated Gaia's systems and the spacecraft is en route to "a gravitationally stable virtual point in space called L2" where it will be positioned in orbit nearly one million miles from Earth. Gaia will begin its five-year science mission at the conclusion of a four-month commissioning phase, "during which all of the systems and instruments will be turned on, checked, and calibrated" by controllers at the ESA's operations center in Darmstadt, Germany, the space agency said.
Gaia, designed and built by Astrium for the ESA, sports a pair of mirror telescopes that act in stereoscopic concert to capture 3D images. The spacecraft's e2v-built image sensors are sensitive to the tune of a billion-plus pixels and will record the star imagery captured by the telescopes, the ESA said.
Over its five-year mission, Gaia will focus in on about 1 per cent of the stars in our home galaxy, observing each of them an average of 70 times apiece to "measure the position and key physical properties of each star, including its brightness, temperature, and chemical composition," according to the space agency.
Gaia will also be measuring the distances from Earth of those stars. Scientists will use all of the data generated by the mission to "rewind" the history of the Milky Way to try to determine how it "was assembled over billions of years from the merging of smaller galaxies" and then "fast forward" to the future with models that try to determine its eventual fate, the ESA said.
"Gaia represents a dream of astronomers throughout history, right back to the pioneering observations of the ancient Greek astronomer Hipparchus, who catalogued the relative positions of around a thousand stars with only naked-eye observations and simple geometry," said Alvaro Giménez, the ESA's director of Science and Robotic Exploration. "Over 2,000 years later, Gaia will not only produce an unrivalled stellar census, but along the way has the potential to uncover new asteroids, planets, and dying stars."
Image: Flickr (TierraLady)