A spacecraft designed for a five-year mission to map precisely the stars of the Milky Way has arrived in French Guiana for launch this year, officials said.

The European Space Agency's billion-star surveyor spacecraft dubbed Gaia left France Thursday aboard a Russian Antonov transport plane and arrived in French Guiana early Friday.

"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," Giuseppe Sarri, Gaia project manager, said in a release from ESA headquarters in Paris. "Arriving in Kourou and starting the launch campaign is a great achievement."

When launched from the Kourou spaceport, Gaia will make observations of a billion stars to determine their precise positions in space and their motions through it, with the goal of creating a highly accurate 3-D model of the Milky Way galaxy.

Although a billion stars is only around 1 percent of all the stars spread across the Milky Way, they will provide a representative sample from which the properties of the whole galaxy can be measured, officials said.

Measuring the temperature, luminosity and composition of that census of stars will allow astronomers to determine the origin and the evolution of our galaxy, they said.

"We are now looking forward to the coming weeks of final preparation, which we will undertake with the same care and determination that the teams have shown so far when building the spacecraft," Sarri said.