The Channel Islands-based company has transported the satellites from the Thales Alenia Space facility in Rome to the launch site of Le Centre Spatial Guyanais in French Guiana.
The first four satellites were launched in 2013 and Telecom Cook Islands was the first customer to benefit when the service went live in mid-March, after months of testing.
According to Space Newsfeed, fuelling of the next four satellites will be completed in separate processes.
Once launched, they will be positioned at a medium-orbit altitude of 8062 km.
O3b Networks’ vision is to create a space-based constellation capable of providing high-speed internet to people in the developing world - “the other three billion people”.
Having four more satellites in orbit will provide a more robust internet service.
Telecom has transmitters which track one satellite at a time - from horizon to horizon - switching to the next satellite every 90 minutes.
When eight satellites are in orbit, the handover will take place faster, every 45 minutes.
Telecom has said it will be keeping its existing geostationary satellite service in place, in case of any future problems.
Rarotonga was the first to benefit from 03b and Telecom is hoping to extend the service to the entire Southern Group by the end of this year.