TRACKER GUIDE & MISSION EXPLAINER
Iridium NEXT Satellite Tracker: Polar Constellation and Crosslinks
Iridium NEXT is the second-generation spacecraft network supporting Iridium's global mobile communications system. The directory above lets you select one Iridium spacecraft and see its calculated low Earth orbit, current ground position and observer geometry.
Iridium states that the operational constellation uses 66 crosslinked satellites arranged as six near-polar planes with 11 satellites in each plane, supported by spares. The near-polar geometry is central to coverage at high latitudes.
Why Iridium's orbit is distinctive
The spacecraft operate at roughly 780 kilometres altitude. Their inclined, near-polar paths converge in geographic terms toward the polar regions, while inter-satellite links pass communications through the moving network. This differs from a geostationary system that depends on a small number of very distant, nearly fixed spacecraft.
The NEXT replacement campaign used multiple launches and completed deployment of the upgraded network in 2019. Catalogs can also contain spares or spacecraft at nonstandard positions, so one object should not be assumed to represent the entire constellation.
Using the tracker
- Search an Iridium name or NORAD catalog number.
- Open Track and follow the selected near-polar ground path.
- Set an observer location to calculate local azimuth and elevation.
- Compare another plane or spare spacecraft from the directory.
- Treat pass geometry separately from communications availability.
What the calculation can and cannot show
SGP4 propagation turns the selected element set into an estimated current position. The map does not show active voice or data links, inter-satellite routing, user traffic or operator status. It also does not predict historical Iridium flares; the antenna geometry of NEXT spacecraft differs from the first-generation satellites associated with famous bright flashes.
Orbital data remains useful for learning about planes, spacing, coverage and constellation resilience. Predictions can shift after manoeuvres or when a spare changes position.
Educational value
Iridium is a strong comparison with Starlink, OneWeb and GPS. All are constellations, but they use different altitudes, inclinations, purposes and network architectures. Mapping one satellite from each system reveals how mission requirements shape orbit design.
Crosslinks and global reach
Iridium spacecraft relay traffic between neighbouring satellites as well as to ground gateways. Crosslinks allow a call or message to travel through the orbital network before returning to Earth, reducing dependence on a gateway directly beneath every user. The moving geometry is easiest to appreciate by comparing satellites in adjacent planes. The tracker cannot show the link routing, but it supplies the orbital context that makes a pole-to-pole network possible.
Frequently asked questions
How many satellites are in the operational Iridium constellation?
Iridium describes 66 operational satellites in six planes, with additional spares supporting resilience.
How high do Iridium satellites fly?
Iridium gives an approximate low Earth orbit altitude of 780 kilometres.
Does the tracker show phone or data connections?
No. It shows calculated orbit geometry and is not connected to Iridium network operations.
Will Iridium NEXT satellites produce the old famous flares?
The predictable bright flares were associated mainly with first-generation spacecraft antenna geometry. This tracker does not predict brightness events.
Sources and further reading
Educational-use note: SpaceTracker.live is an independent educational website and is not an official mission-control service. Positions, paths, distances and pass predictions are computed from third-party orbital elements or ephemerides. They may be delayed or approximate and must not be used for navigation, collision avoidance or safety-critical decisions.
Last reviewed: August 21, 2026