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Galactic surveyor Gaia moves en route to launch pad

Elizabeth Howell, News Writer
Aug 26, 2013, 7:00 UTC

Sen—The Gaia satellite only has one more roadtrip to complete before arriving at its launch pad in French Guiana.

The satellite's successful flight from Toulouse, France on Friday represents a major logistical milestone for the team that has spent years testing and constructing Gaia, which will observe a billion stars to high precision when it begins operations.

From the airport in Cayenne -- French Guiana's capital -- Gaia will then take a 64-kilometre journey by truck to its launch site in Kourou. The blastoff will take place later in 2013.

"This is a very exciting day for the Gaia mission and all the teams involved, who have worked for years to get to where we are today," stated Giuseppe Sarri, ESA’s Gaia project manager. "Arriving in Kourou and starting the launch campaign is a great achievement."

Gaia -- a galactic surveyor backed by the European Space Agency -- aims to map millions of stars to high precision to construct a 3-D map of the Milky Way, which is the galaxy in which Earth resides.

The map would not only mark the positions of the stars, but would also take note of their respective motions. Stars will also be catalogued by parameters such as composition, luminosity and composition.

A billion stars is a vast number, but still only represents about 1% of the stars in the Milky Way. Still, researchers said the survey would be a good representation of the stellar companions in our galaxy and provide more clues on the universe's current state, its past and its future.

"Gaia will also uncover tens of thousands of previously unseen objects, including asteroids in our solar system, planets around nearby stars, and exploding stars – supernovas – in other galaxies," the European Space Agency stated.

A cutaway of the Gaia spaceprobe showing its instruments. Credit: ESA

Another major matter that Gaia will tackle is how dark matter is distributed in the universe. Astronomers believe that most of the mass and energy of the universe -- 96% -- is in a form that can't be sensed with traditional telescope technology. 

Dark matter and dark energy can be seen through their effects, such as how they bend light from a distant background galaxy due to their immense masses. They also affect the movement of stars, which is one of the areas that Gaia will specialize in. 

Other parts of Gaia are also en route. On Wednesday, its sunshield and the majority of the equipment required for ground support will also be shipped to Cayenne.

After Gaia launches, it will head to a point of stable gravitational influence between the Earth and Sun, called a Lagrangian point. This will allow it to keep its two telescopes trained on the universe without undue interference from Earth's planetary mass (which could block some observations) or gravity.

The spacecraft has a five-year prime mission that will also feature the largest digital camera ever lofted from the planet. The camera has a billion pixels of resolution.