{mprestriction ids="1,2"}All satellites are functioning nominally and have begun the testing and validation process, the company said.

“Similar to the first three launches, our team at the Satellite Network Operations Center immediately began running initial diagnostics as soon as the newly deployed satellites were captured by our network, just minutes after they were deployed,” said Scott Smith, chief operating officer at Iridium.

“This testing process has been running smoothly and will continue for several weeks, after which nine of the new satellites will begin their individual ascents to an operational orbit, replacing original vehicles. We’ll also be sending the tenth satellite to an adjacent orbital plane where it will go into service by summer 2018.”

Iridium NEXT will comprise a total of 66 satellites in the active constellation, of which 40 have now been launched. This most recent launch marks the midway point of the Iridium NEXT launch programme, and was the first Iridium launch to re-use a SpaceX rocket from a previous flight, with the first stage booster for Iridium-4 having previously been used for Iridium-2.

“It was an amazing sight to see the Iridium-2 booster back in flight today, carrying Iridium-4 into space. We are excited to be taking part in SpaceX’s rocket reusability initiative and make history as the first company to reuse the same booster,” said Matt Desch, chief executive officer, Iridium.

“With over half of the new constellation now in orbit, momentum around the testing of our new broadband service, Iridium Certus, will continue to progress quickly. I know our customers are very excited about our expanding capabilities.”

All of the Iridium NEXT launches will use SpaceX’s west coast launch facility in California. Four additional launches are planned for the first half of 2018, including a unique rideshare that will carry five Iridium NEXT satellites, and the twin satellites for the NASA/German Research Center for Geosciences (GFZ) Gravity Recovery and Climate Experiment Follow-On mission.

The $3 billion global satellite network is scheduled for completion by the end of 2018.{/mprestriction}