The Soyuz mission with a very-high-resolution imaging satellite has entered its final countdown for tonight's launch from the Spaceport in French Guiana - the fourth such flight performed by Arianespace.
Fueling of the Soyuz' main stages has now begun on the launch pad, with the vehicle protected by a 53-meter-tall mobile gantry. The gantry will be rolled back to its parked position one hour before liftoff, revealing the completed launcher for the first time.
In the countdown's final phase, a drop-off command for the upper composite's umbilical connection will be given at 2 min. 25 sec. before liftoff, followed by retraction of the umbilical mast for Soyuz' lower stages occurring at 20 sec. prior to liftoff.
Tonight's Arianespace mission - designated VS04 in the company's launcher family numbering system - is set for liftoff at exactly 11:02:50 p.m. local time in French Guiana. Its Pleiades 1B passenger will be released 55 minutes later, following two burns of Soyuz' Fregat upper stage.
Payload performance for the flight is an estimated 1,070 kg., which includes approximately 970 kg. for Pleiades 1B.
As a dual-use satellite, Pleiades 1B will provide optical imaging coverage for French and European defense ministries, institutions and civil users. It is to join the similar Pleiades 1A satellite, launched last December by Arianespace on Soyuz' second mission from the Spaceport.