ESA Launches First Two CELESTE LEO-PNT Satellites on Electron Rocket

On March 28, 2026, at 10:14 AM CET, the first two demonstrator satellites of ESA's CELESTE constellation lifted off from New Zealand aboard a Rocket Lab Electron vehicle, part of the "Daughter of the Stars" mission. The satellites, named IOD-1 and IOD-2 (In Orbit Demonstration), were successfully deployed into a near-polar orbit less than an hour after launch.

These satellites represent the initial phase of the CELESTE LEO-PNT program, an ESA initiative designed to test a novel approach to providing satellite navigation services from Low Earth Orbit. The goal is to complement existing systems like Galileo with closer-to-Earth satellites, transforming previously theoretical technologies into practical applications.

IOD-1 and IOD-2 were constructed by GMV and Thales Alenia Space, who served as prime contractors and are also responsible for operations and the ground segment. With this launch, the program now enters its crucial in-orbit testing phase.

Six Months of In-Orbit Testing

The two satellites are expected to operate for approximately six months. During this period, they will test technologies destined for the future CELESTE constellation. They will provide L-band links, already common in navigation systems, but more importantly, they will trial the use of S-band, an innovative step for ESA in this domain.

The primary objective is to evaluate how a Low Earth Orbit constellation can support Galileo, thereby enhancing the resilience of navigation services. Utilizing diverse orbits and multiple frequency bands aims to mitigate risks associated with interference, spoofing, or potential attacks on satellites. CELESTE is a key component of ESA's European Resilience from Space (ERS) program, pre-approved during the last ESA Ministerial meeting in Bremen.

Meanwhile, Thales Alenia Space has confirmed ongoing work on the next four satellites, slated for launch in 2027. Potential future applications for CELESTE include Direct-to-Device communication services for emergencies.