Fueling of Soyuz is now underway 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.

Today’s Arianespace flight – designated VS10 in the company’s launcher family numbering system – is set for liftoff at 3:37 p.m., local time in French Guiana. The first two O3b Networks spacecraft will be released at just over 2 hours after liftoff, followed by deployment of the remaining two passengers nearly 22 minutes later – completing the mission.

Payload lift performance for this flight is approximately 3,180 kg., including about 2,800 kg. for the four Ka-band satellites, which were produced by Thales Alenia Space for O3b Networks.