Overview
Iridium operates the only satellite constellation that provides truly global coverage — every square metre of the Earth's surface, including the poles, oceans, and airways. The Iridium NEXT constellation, completed in 2019, comprises 66 operational satellites in 6 orbital planes at approximately 780 km altitude, plus 9 in-orbit spares. Unlike Starlink and OneWeb, Iridium provides voice and narrowband data rather than broadband — but its unique cross-linked architecture means it works everywhere, with no gaps in coverage.
History: From Bankruptcy to Dominance
The original Iridium constellation was conceived at Motorola in the late 1980s — named after the element with 77 protons, reflecting the originally planned 77-satellite design (later reduced to 66). The system launched between 1997 and 1998 at a cost of $5 billion, making it the largest private satellite project in history. The company famously filed for bankruptcy in 1999 after failing to attract enough subscribers to cover costs. A group of investors acquired the entire constellation for just $25 million and relaunched the service, finding profitable niches in maritime, aviation, military, and emergency communications where terrestrial and GEO coverage cannot reach. The original satellites produced spectacular Iridium Flares — predictable bright glints visible from Earth — that became a beloved phenomenon for skywatchers.
Iridium NEXT
Between 2017 and 2019, SpaceX launched all 75 Iridium NEXT satellites across 8 Falcon 9 missions — one of the earliest large-scale constellation deployment campaigns. The new satellites feature Ka-band cross-links between every satellite in the constellation, enabling data to hop across the network without touching the ground — a capability that Starlink later adopted with laser inter-satellite links. Each Iridium NEXT satellite weighs approximately 860 kg and has a design life of 15+ years.
Services
Iridium Certus is the broadband service, offering speeds up to 704 kbps (midband) and 352 kbps over L-band terminals. While far slower than Starlink, Certus provides coverage everywhere, including polar regions where inclined-orbit LEO constellations have gaps. Iridium Push-to-Talk provides satellite-based group communications for field operations. Iridium Short Burst Data (SBD) powers IoT/M2M applications, with over 1.5 million active IoT devices on the network. Iridium GO! provides smartphone connectivity via a portable hotspot device. GMDSS: Iridium was approved as a Global Maritime Distress and Safety System provider in 2020 — mandatory safety communications for ships worldwide.
Key Markets & Direct-to-Device
Maritime is Iridium's largest market, with satellite communications mandatory under GMDSS. Aviation is the fastest-growing segment, with cockpit safety communications and, through partners like Gogo, inflight broadband. Military users (primarily the US Department of Defense under the EMSS contract) represent a stable, high-margin segment. Apple's Emergency SOS via Satellite uses the Globalstar network, but Iridium has partnered with Qualcomm to enable direct-to-device satellite messaging on Android devices — potentially expanding Iridium's reach to billions of smartphones.