Global mobile satellite communications firm Iridium has announced on Friday (28 July) that SpaceX will launch 10 more Iridium Next satellites from the Vandenberg Air Force Base in California on 30 September. The launch will bring the total number of satellites deployed for Iridium's modernised constellation of low-Earth orbit telecommunications satellites to 30.

SpaceX delivered the first 10 Iridium Next satellites to low-Earth orbit in January in its first successful launch since the massive and expensive Falcon 9 explosion in September 2016. The second batch of satellites was launched on 25 June during SpaceX's milestone "weekend doubleheader" when the Elon Musk-owned company launched back-to-back Falcon 9 rocket launches and landings in 48 hours.

The third launch, scheduled for 6.30pm PST comes as part of SpaceX's seven-flight contract with Iridium to launch a total of 75 Next satellites to orbit on newly manufactured Falcon 9 rockets, 10 satellites at a time.

"Unlike previous launches where some Iridium NEXT satellites were sent drifting to an orbital plane different from where they were launched, all 10 satellites for this launch are currently planned to provide service in orbital plane four", Iridium said in a statement. "The Iridium constellation's unique architecture is designed with six polar orbiting planes consisting of 11 interconnected satellites per plane, with in-orbit spares, creating a true web of connectivity around the planet."

The fourth Iridium Next launch is scheduled for November.

Iridium's $3bn (£2.28bn) next-generation global satellite network is expected to be completed by mid-2018 and will replace its current fleet of satellites in "one of the largest technology upgrades ever completed in space", the firm said.

In case of inclement weather, a backup launch date for the third Iridium Next launch is set for 1 October.

SpaceX's third Iridium Next satellite launch is set for 30 September SpaceX