How could Celeste IOD-1 change satellite navigation?

Satellite navigation is part of our daily lives. From mobile applications and connected vehicles to power grids, telecommunications, and emergency services, much of modern infrastructure relies on positioning, navigation, and timing (PNT) signals.

For decades, global systems such as Galileo and GPS, based mainly on satellites in Medium Earth Orbit (MEO), have provided increasingly accurate and reliable services. However, technology needs to continue evolving. The emergence of autonomous vehicles, hyper-connected critical infrastructures, and applications requiring high resilience against interference is driving a new generation of navigation systems.

That’s where Celeste comes in. This European demonstration mission, led by the European Space Agency (ESA), seeks to demonstrate the potential of incorporating satellites into low orbits to complement the current capabilities of Galileo and EGNOS.

Why take navigation to low Earth orbits?

Current satellite navigation systems operate mainly from orbits located at an altitude of about 20,000 kilometers. This architecture has proven to be extremely reliable, but also has inherent limitations due to the distance at which the signals are generated.

Signals arriving from medium Earth orbits are extremely weak, making them vulnerable to interference, jamming, or attacks. Furthermore, certain emerging applications demand greater robustness and more dynamic response times.

This is where the LEO-PNT (Low Earth Orbit - Positioning, Navigation, and Timing) constellations come into play. By operating at altitudes of approximately 500 and 1,200 kilometers, the satellites can transmit more powerful signals and use different frequency bands that are harder to jam, improving resilience and expanding existing navigation capabilities.

The vision for the future is not to replace Galileo, but to complement it through a multi-orbit architecture capable of combining the advantages of different orbital altitudes. Indeed, ultimately,  this is Celeste’s strategic goal.

Celeste: a new European navigation layer

Celeste is one of the most innovative European projects in the field of satellite navigation. The program, led by the European Space Agency and developed by the European space industry, seeks to demonstrate how LEO constellations can be integrated into the European navigation ecosystem to provide more robust, precise, and resilient services.

Beyond its technological component, the program also has a strong strategic dimension. Europe is seeking to strengthen its technological autonomy and prepare the next generation of PNT services in an increasingly demanding and competitive global landscape.

The program’s name has special significance. “Celeste” pays tribute to Galileo Galilei’s daughter Maria Celeste Galilei, symbolizing scientific curiosity and the history of human knowledge and exploration of the heavens.

Celeste IOD-1: from concept to reality

The program’s is currently in its Celeste In-Orbit Demonstrator (IOD) phase, with a demonstration mission that will validate key navigation technologies in flight from low orbits.

The IOD constellation will consist of up to eleven satellites developed by two European consortia working in parallel. The GMV-led consortium is in charge of developing six of these satellites, including the mission’s first demonstrator satellite: Celeste IOD-1.

This first satellite was developed by GMV together with Alén Space on a 12U CubeSat platform, a compact format that nonetheless offers cutting-edge capabilities for validating critical navigation technologies.

The highlights of the Celeste program include not only its technological ambition, but also the speed at which it is being developed. The project officially kicked off in March 2024 and just two years later, on 28 March 2026, the mission’s first satellites, Celeste IOD-1 and Celeste IOD-2, were successfully launched from New Zealand aboard a Rocket Lab Electron launcher.

In a satellite navigation mission, these timeframes are extraordinarily fast, even for a demonstration mission. Celeste clearly reflects a new way of developing space missions under the New Space paradigm: more agile iterations, highly integrated teams, and great adaptability.

This pace has also posed a major challenge for all the teams involved. For GMV, leading a mission of this nature within such tight timelines has meant facing a very high level of technical and operational demand. But the effort is paying off.

One of the most special moments of the program came on the morning of 8 April. ESA and GMV teams met at ESTEC to receive the first navigation signal transmitted by Celeste IOD-1.

This was a historic milestone for Europe: the signal sent by GMV’s satellite became the first European dual-band (L and S) navigation transmission from a LEO-PNT mission.

Beyond the demonstrator: the future of European navigation

Celeste IOD is only the first step in a much more ambitious roadmap. Following the demonstration phase, the program plans to move on to further stages of industrialization and in-orbit validation to develop more advanced satellites and mature the technologies required for a potential future operational constellation.

The long-term vision is to build a European multi-orbit system that will be fully integrated with Galileo and EGNOS and capable of delivering more precise, robust, and reliable services for critical applications such as autonomous driving, 5G/6G services, and critical infrastructure protection.

At a time when dependence on PNT services is growing, initiatives such as Celeste show how Europe is already preparing today the capabilities that will define the navigation systems of tomorrow.

Author: Andrés Juez