The Thales Alenia Space joint venture has completed the assembly and testing of first two of Iridium NEXT satellites at Orbital ATK facility in Gilbert, Arizona, US.

Built for satellite-based mobile voice and data communications provider Iridium Communications, the satellites are now being prepared for delivery to the launch site at Vandenberg Air Force Base in the US.

After being delivered to the launch site, the first two completed Iridium NEXT satellites will undergo processing by Iridium’s launch partner SpaceX, which will conduct a series of seven launches for Iridium.

Ten Iridium NEXT satellites will be deployed at a time, with first launch scheduled for September.

The entire Iridium NEXT satellites constellation is expected to be launched by late next year, with plan to enable Aireon’s satellite-based system to provide real-time global aircraft surveillance from 2018.

"This programme replaces the largest commercial satellite constellation in space with state-of-the-art technology and new capabilities."

Iridium Communications chief executive officer Matt Desch said: "After more than seven years of effort, the first of our next-generation satellites are finally ready for space.

"This programme replaces the largest commercial satellite constellation in space with state-of-the-art technology and new capabilities, allowing Iridium to support the connectivity needs of today, as well as those yet to be imagined."

According to a contract with Iridium, Thales Alenia Space and its subcontractor Orbital ATK will deliver a total of 81 Next satellites, with 66 serving as the operational satellites to replace the current Iridium network and the remainder serving as ground and on-orbit spares.

After assembly and integration, the first Next satellites underwent a series of tests, some of which included vibration and acoustic testing, thermal vacuum tests and others.

These tests were conducted to ensure the satellites ability to survive the launch and operate successfully when deployed.

Following the completion of the test, Orbital ATK is planning to add another 30 engineers to its team in order to increases production by more than five satellites a month.