Europe's Gaia "star-mapper" has arrived in French Guiana for an Arianespace Soyuz launch later this year on a mission to chart the locations and motions of a billion stars, while also opening opportunities in discovering new celestial objects in the hundreds of thousands.

Gaia was delivered aboard a chartered Antonov An-124 cargo jetliner at Felix Eboue International Airport near the capital city of Cayenne - clearing the way for its transfer via road to the Spaceport.

With a liftoff mass of 2,030 kg. - which includes the spacecraft's two optical telescopes, three science instruments, as well as a 10-meter deployable "skirt" as a sunshield and a power generator - Gaia will observe one billion stars approximately 70 times each over five years.

A truly impressive space charting mission

Many aspects of this mission - organized by the European Space Agency - are impressive. The spacecraft carries one of the largest digital cameras to be placed in space (with nearly one billion pixels), and is designed to detect celestial objects that are a million times fainter than the unaided human eye can see.

Built by Astrium at its Toulouse, France facility, Gaia will be operated by the European Space Agency to provide a representative sample from which the properties of the entire galaxy can be measured, ultimately allowing astronomers to determine its origin and evolution.

Gaia's two optical telescopes will determine star locations and velocities, splitting their light into a spectrum for analysis. The spacecraft will operate from an orbit around the Sun, at the L2 Lagrangian point located some 1.5 million kilometers beyond Earth's orbit.

Discoveries numbering in the hundreds of thousands also anticipated

During its operation, Gaia also is expected to find hundreds of thousands of new celestial objects - including asteroids, comets, extra-solar planets, brown dwarf "failed stars," supernovae and quasars.

When completed, the mission's data archive should exceed 1 petabyte (1 million gigabytes), which is equivalent to about 200,000 DVDs worth of data.

Gaia arrived at French Guiana with a portion of its ground support equipment. A second air cargo flight later this month is to bring Gaia's sunshield and the remaining ground support equipment.

A mission follow-up to Hipparcos, also launched by Arianespace

The star-mapper has its roots in the European Space Agency's Hipparcos space astrometry platform, lofted by Arianespace on an Ariane-series vehicle in 1989. The Soyuz mission with Gaia is designated VS07 in Arianespace's launcher family numbering system, representing this medium-lift workhorse's seventh flight from French Guiana.

It will follow two other Arianespace launches currently in preparation at the Spaceport: Flight VA215, scheduled for August 29 with an Ariane 5 to orbit the EUTELSAT 25B/Es'hail 1 and GSAT-7 relay satellites; and VS06, targeted in late September with a Soyuz to deploy four connectivity spacecraft for O3b Networks.