ESA’s Celeste target launch date confirmed

Celeste will play a pioneering role in elevating the future of Europe’s satellite navigation capabilities. As Europe’s first initiative for satellite navigation in low Earth orbit (LEO), the mission will be testing next-generation technologies and add new frequency bands for satellite navigation.

Celeste will demonstrate how a complementary layer flying closer to Earth can enhance Europe’s current Galileo system in medium Earth orbit (MEO), boosting the overall resilience, enhancing its performance and opening opportunities for new service capabilities directly from LEO.

The first two satellites successfully completed their test and qualification campaign and were formally declared ready for flight.

The satellites are currently being shipped to Rocket Lab’s launch complex in New Zealand, where they will undergo final testing and integration in the Electron rocket ahead of their launch no earlier than 24 March.

Celeste flies with first two satellites

Similarly to the early stages of the Galileo programme, Celeste will begin with two demonstrator satellites to secure the assigned frequency filings and to test representative navigation signals until the end of the year.

The two satellites consist of two large CubeSats (12U and 16U respectively), both developed by two consortia composed of a wide set of European players, one led by GMV (Spain) and the other led by Thales Alenia Space (France).

Together, they will enable in-orbit testing of next-generation technologies, including autonomous precise orbit determination without reliance on ground infrastructure, as well as stronger and faster radionavigation signals in L- and S-band from low Earth orbit.

Over the past months, both satellites successfully completed payload integration, radio-frequency compatibility tests, and environmental qualification, including thermal vacuum, mechanical and electromagnetic compatibility testing.

More satellites to follow

Eight larger satellites with additional capabilities are under development, with GMV and Thales Alenia Space each responsible for four of them. Design and development are progressing steadily, with an opportunity for subsequent launches from 2027 onwards.

The eight satellites will build on the work of the first two satellites and demonstrate radionavigation with additional novel signals and new frequency bands:

• S-band two-way navigation signals, for advanced positioning capabilities using 5G satellite waveforms.
• C-band signals, for additional resilience against jamming and interference.
• UHF-band signals, for enhanced penetration and in-door positioning.

“On top of the eight satellites, an additional one will include a payload to test miniaturised atomic clocks on board, along with other technologies,” says Roberto Prieto-Cerdeira, ESA’s Celeste project manager.

Once fully completed at an orbit between 500 and 560 km, the demonstrator mission will offer an ideal in-orbit testbench for a broad variety of downstream applications, such as autonomous vehicles, maritime navigation, critical infrastructure, polar and arctic operations, wireless networks, emergency services, asset tracking and Internet-of-Things applications.

“By carrying out these experimentation and demonstration activities in orbit, we are opening a platform where ESA can work hand-in-hand with end-user communities and stakeholders to demonstrate innovative technologies in satellite navigation, push boundaries and demonstrate services in conditions that mirror the real world,” adds Roberto.

ESA is offering interested third parties from ESA Participating States the opportunity to participate in the experimentation phase of the Celeste in-orbit demonstrator. More information is available on ESA’s Open Space Innovation Platform.

Following Celeste’s in-orbit demonstration, Celeste’s in-orbit preparatory phase, approved at ESA’s Ministerial Council in November 2025 (CM25), will focus on technology development, industrialisation and in-orbit validation, preparing for a potential operational system as part of the European Union GNSS infrastructure together with Galileo and EGNOS, also supporting potential commercial initiatives.

About Celeste

The Celeste mission is ESA’s initiative for LEO-PNT (Low Earth Orbit Positioning Navigation and Timing) and is currently in its in-orbit demonstration phase. This first phase features a demonstration constellation of 11 satellites that will fly in low Earth orbit to test innovative signals across various frequency bands. Its goal is to advance satellite navigation concepts for resilient positioning and timing services.

The Celeste in-orbit demonstration phase was approved at ESA’s Council at Ministerial Level of 2022. The fleet is being developed through two parallel contracts respectively led by GMV in Spain with OHB in Germany as core partner, and by Thales Alenia France as prime and Thales Alenia Italy as space segment responsible, and involving over 50 entities from more than 14 countries.

Celeste was further supported in ESA’s Council at Ministerial Level of 2025 (CM25), towards the implementation of the next phase: the LEO-PNT In-Orbit Preparatory phase.

Celeste also contributes to one of the three core pillars of ESA’s new European Resilience from Space (ERS) initiative, endorsed at CM25. ERS addresses critical security and resilience needs for Member States while laying the groundwork for future European strategic space capabilities.

For more information, visit www.esa.int/Celeste/.