The Ariane 5 rolled out of its final assembly building this morning at 8:30 a.m., and was greeted by skies that were especially sunny for the month of May in French Guiana.  After its transfer, the vehicle was secured in place on the ELA-3 launch zone at Europe’s Spaceport.

This wide-angle image provides an unusual perspective of the Spaceport’s Final Assembly Building, which has its main doors open in preparation for the Ariane 5’s rollout this morning with its Herschel and Planck payloads.

This clears the way for final pre-launch preparations and the countdown to a rare morning liftoff tomorrow at 10:12 a.m. (local time in French Guiana).

The unusual mission timing is due to Ariane 5’s deployment of its Herschel and Planck passengers on a trajectory that will take them to the Sun-Earth system’s second Lagrange point (L2), where they are to carry out their scientific missions.

Ariane 5 will deliver the spacecraft on an injection orbit with an apogee of nearly 1.2 million kilometers.  At this distance, Herschel and Planck will make their own maneuvers for the continuation to the L2 point, which is 1.5 million kilometers from Earth.

For this second Ariane 5 mission of 2009, the launcher’s payload lift performance will be 6,000 kg. – of which approximately 5,320 kg. is the combined weight of the two payloads.  The other mass includes the payload integration hardware and Ariane 5’s SYLDA dual-payload dispenser system.

Herschel will be the largest space telescope ever launched, and was conceived to provide astronomers with their best views of the universe at far-infrared and sub-millimeter wavelengths.  With a liftoff weight of 3,400 kg., Herschel carries a 3.5-meter-diameter mirror that will collect data for studies on the formation of stars and galaxies.

The 1,920-kg. Planck observatory is designed to scan the sky in nine wavelength bands, and is equipped with a telescope that has an effective aperture of 1.5 meters.  Data provided by this spacecraft will help determine the universe’s fundamental characteristics – including the overall geometry of space, the density of normal matter and the rate at which the universe is expanding.

Planck and Herschel were developed in the framework of the European Space Agency’s space science program.  Both spacecraft were built by Thales Alenia Space-led industry teams.