The Pleiades 1B payload for Arianespace's fourth Soyuz mission from French Guiana is now undergoing its pre-launch checkout at the Spaceport, readying this Earth observation satellite for a late-night liftoff on November 30.

Built by Astrium for the French CNES space agency, Pleiades 1B is being put through its paces inside the Spaceport's S1B payload preparation facility - where the dual-use, very-high-resolution satellite was transported following its arrival in French Guiana this week aboard a Boeing 747 cargo aircraft.

During the pre-launch preparations at the Spaceport, Pleiades 1B was removed from its shipping container in clean room conditions, and then raised to a vertical position for the startup of processing.

Pleiades 1B is designed to provide optical observation coverage with 50-centimeter resolution for the French and Spanish defense ministries, civil institutions and private users.

After being deployed by Soyuz, it will join the twin Pleiades 1A satellite - which was launched by an Arianespace Soyuz mission in December 2011 - for operation from a 695-km. quasi-polar heliosynchronous orbit.

This upcoming Arianespace flight is designated VS04 in the company's mission numbering system, denoting the fourth Soyuz liftoff from French Guiana since the medium-lift vehicle's October 2011 service entry.

It also is the second Soyuz mission for launch from the Spaceport in 2012, following Arianespace's October 12 success that orbited two European Galileo navigation satellites.