Iridium NEXT Constellation, Built by Thales Alenia Space, Now Completely Deployed in Orbit

The Iridium NEXT constellation of satellites, developed and built by Thales Alenia Space, the joint company between Thales (67%) and Leonardo (33%), leading an industrial consortium, is now fully operational. Following eight successful launches* between January 2017 and January 2019, a total of 75 Iridium NEXT satellites are now fully deployed in low Earth orbit (LEO). More specifically, the constellation operates with 66 satellites at an altitude of about 780 kilometers, distributed in six orbital planes of 11 satellites each, backed by nine in-orbit replacement satellites and six ground spares.

Iridium NEXT: a large-scale program and a human achievement
Iridium NEXT is not only an impressive technical achievement, based on a highly innovative, even novel concept, but above all an industrial and human achievement, for which all of Thales Alenia Space’s European facilities teamed up to meet an inspiring challenge.

Thales Alenia Space is prime contractor for the Iridium NEXT program, responsible for engineering, production, procurement and integration operations, along with the ground and in-orbit testing of the constellation’s overall performance.

The satellite design was refined and tested on two initial models at Thales Alenia Space’s plants in Toulouse and Cannes. Volume production took place at a subcontractor’s premises, the Northrop Grumman Corporation facility in Gilbert, Arizona (formerly Orbital ATK). Satellite integration was performed on site under the direction of a Thales Alenia Space team, specially detached for the purpose. Satellite orbital positioning and in-orbit tests were prepared and executed by Thales Alenia Space teams at Iridium’s Satellite Network Operation Center (SNOC) in Leesburg, Virginia.

A feat of technological prowess, carried off with panache by Thales Alenia Space in partnership with subcontractors and the customer, Iridium Communications

• Deliver a series of 81 satellites.
• Deploy a complete and complex turnkey system from end to end.
• Ensure compatibility between the old and new generations of Iridium satellites without any interruption in user service (Slot Swap**).
• Lead an international industrial consortium.
• Ensure the in-orbit routing of telecommunications signals.***

Iridium NEXT, the world’s highest performance, most flexible and most sophisticated constellation
The major challenge for Thales Alenia Space was to deploy a complete and complex turnkey system from end to end, while also ensuring compatibility between the old and new generations of Iridium satellites. This is the first time that an operator and a manufacturer have worked hand-in-hand to replace an entire constellation of 66 satellites, one by one, without any interruption in user service**.

The Iridium NEXT constellation represents the state of the art in terms of technology and flexibility. It features global coverage, plus independence from local ground infrastructure due to each satellite being linked to the four closest satellites, in front, behind, to the right and left. No matter where the user is located on land, at sea or in the air, Iridium provides coverage, enabling them to communicate. This type of direct satellite access, whether for transmission or reception, means that reliable communications are available, even in the case of natural disasters or conflicts, in isolated areas, or to provide secure communications with protection against intrusion and piracy***.

Denis Allard, Vice President for Constellation Projects at Thales Alenia Space, said, “Thales Alenia Space is especially proud of having built the Iridium NEXT constellation. We have delivered all 81 satellites in this system, now operational, right on schedule, rising to a challenge that our people met with panache. The success of this complex program further confirms Thales Alenia Space’s global leadership in the constellation market, and also consolidates our unrivaled expertise as prime contractor for complex end-to-end and turnkey communications systems.”

*75 satellites orbited in 8 launches; 66 now operational in orbit

• 8th launch - January 11, 2019 – 10 satellites
• 7th launch – July 25, 2018 – 10 satellites
• 6th launch – May 23, 2018 - 5 satellites
• 5th launch – March 30, 2018 – 10 satellites
• 4th launch – December 23, 2017 – 10 satellites
• 3rd launch – October 9, 2017 – 10 satellites
• 2nd launch – June 26, 2017 – 10 satellites
• 1st launch – January 14, 2017 – 10 satellites
• Iridium NEXT – Setting the standards in constellations - September 10, 2018
• First Iridium NEXT Satellites Declared Ready for Shipment and Launch Date Announced - June 15, 2016
• Thales Alenia Space announces that Iridium NEXT contract is now in full effect / Iridium Contract for $ 2.2 billion (€ 1.7 billion) covers Design and Build of 81 satellites - October 26, 2010

**Slot Swap

• Because these satellites are in low Earth orbit, the Thales Alenia Space teams in Leesburg, Virginia who manage orbital injection and positioning have only 10 minutes of visibility from their ground stations to send commands to the satellites.
• Satellite control is then transferred to Iridium teams for Slot Swap operations. This entails ensuring the compatibility between the old and new generations of Iridium satellites without interrupting user service – a daunting feat, especially given how close the old and new satellites are to each other.
• Each Iridium NEXT satellite is fitted with a star sensor from Leonardo, used to accurately determine and control its orbit.

***Routing signals in orbit

• Each satellite is linked to the four closest satellites, in front/behind/left/right, which makes the service totally independent from the need for any local ground infrastructure.
• This in-orbit routing capability, all software managed, is handled by an onboard processor (OBP) and a platform computer (PFC), along with associated software – the most complex software used on constellation satellites to date.
• All of this software can be uploaded from the ground, meaning that updates can be loaded whenever needed, as well as higher-performance versions that will enable Iridium to enhance its customer service offering.