ESA launched the first satellites of the Celeste mission: Europe opens a new chapter in satellite navigation from low Earth orbit
On March 28, the European Space Agency made an important step forward in developing a more resilient and technologically advanced satellite navigation system, after the first two satellites of the Celeste mission were successfully launched from the Māhia Peninsula in New Zealand aboard an Electron rocket operated by the US-New Zealand company Rocket Lab. This is the first operational step in ESA’s LEO-PNT programme, that is, the development of positioning, navigation and precise timing services from low Earth orbit, which in the future should complement the existing European Galileo system and the regional EGNOS system.
The launch took place at 10:14 Central European Time, and the satellites separated from the launcher approximately one hour later, marking the start of the mission’s early operational phase. In this phase, flight control checks the operation of the subsystems, establishes stable communication with the spacecraft and prepares them for in-orbit testing. ESA states that these first two satellites have a dual task: technological and regulatory. In addition to confirming the key concepts of future European navigation from low orbit, they will in practice also activate the frequency resources in the L- and S-bands required for the further phases of the project, in accordance with the rules of the International Telecommunication Union.
Why Celeste is important for Europe
At the heart of the project is not the replacement of Galileo, but its upgrade. Today’s global navigation systems, including Galileo, GPS, GLONASS and BeiDou, rely mainly on satellites in medium Earth orbit. Such an architecture has been the foundation of civil and commercial navigation for decades, but the development of new technologies and society’s growing dependence on precise timing and positioning raise the question of additional system resilience. Through Celeste, ESA is therefore examining whether, alongside the existing medium-orbit layer, a complementary layer of satellites in low orbit, closer to Earth, can be introduced, one that would provide a stronger signal, greater availability in challenging environments and new types of services.
ESA Director General Josef Aschbacher assessed that the mission opens a new frontier in satellite navigation and shows how a low-orbit constellation can complement Europe’s Galileo. According to ESA’s interpretation, Celeste is among the first agency projects to adopt a development approach inspired by the so-called New Space model, with an emphasis on faster development, modularity and more flexible introduction of technical solutions. ESA believes that this very approach should enable Europe to remain competitive in a rapidly changing field in which not only traditional space agencies compete, but also agile private companies.
Francisco-Javier Benedicto Ruiz, Director of ESA’s Directorate of Navigation, said that over the past two decades Galileo and EGNOS have become an integral part of European infrastructure, with economic and security effects that go beyond the space industry itself. Within that framework, Celeste is seen as the next step: not as an experiment without immediate practical value, but as a platform that should show whether Europe can further strengthen its autonomy and resilience in the field of positioning, navigation and precise timing.
What navigation from low orbit brings
The main advantage of satellites in low Earth orbit is that they fly significantly closer to the planet’s surface than traditional navigation satellites. For the first phase of Celeste, ESA states a quasi-polar orbit between 500 and 600 kilometres in altitude. Because of the shorter distance, the signal reaching users can be more robust, and in combination with new frequency bands this opens the way to testing advanced services that are more difficult to achieve in current systems or more difficult to make sufficiently reliable in all conditions.
This primarily refers to environments in which today’s navigation signals are weakened or often blocked. ESA specifically highlights urban canyons, that is, densely built urban areas, then remote polar and Arctic regions, but also applications in transport, from autonomous vehicles and railways to maritime and aviation. In crisis situations, an additional satellite layer could also help improve the availability of positioning and message exchange with emergency services. In a broader technological sense, Celeste also serves as a test platform for tracking connected devices, Internet of Things applications and the development of navigation solutions in indoor spaces, which has for years been one of the most difficult areas of satellite navigation.
It is important to emphasise that ESA is not promising an immediate commercial revolution here. This is a demonstration mission whose goal is to verify technologies under real operating conditions in orbit. But such missions are precisely the bridge between laboratory development and future operational systems. If the results confirm expectations, Europe would gain the technological basis for a decision on establishing a permanent operational navigation layer in low orbit, linked to Galileo and EGNOS.
The first two satellites are only the beginning of a wider constellation
In its current demonstration phase, Celeste is not conceived as a project of only two satellites. ESA states that the full in-orbit demonstration configuration will consist of 11 satellites, with one spare spacecraft. Additional launches are planned from 2027 onward, and the goal is to create a diverse constellation that will enable a wide range of experiments across different frequency bands, user environments and application types.
The first two spacecraft are also a demonstration of the industrial model on which Celeste was built. IOD-1 is a 12U CubeSat with a mass of about 20 kilograms developed by Spain’s GMV, while IOD-2 is a 16U CubeSat with a mass of about 30 kilograms under the leadership of Thales Alenia Space. ESA points out that the entire project is being developed through two parallel industrial contracts: one led by GMV with Germany’s OHB as a key partner, and the other by Thales Alenia Space of France, with Thales Alenia Space in Italy responsible for the space segment. More than 50 entities from more than 14 European countries are involved in these two industrial consortia, which gives the project a strong political and industrial dimension as well.
Such a model is not accidental. Through Celeste, Europe is not only testing technology in orbit, but also its own ability to quickly organise a complex cross-border industrial undertaking in a field that is becoming strategically sensitive. At a time when space infrastructure is increasingly openly linked with economic security, transport, energy, telecommunications and crisis management, the question of who controls navigation capabilities also becomes a question of political autonomy.
From demonstration to a possible operational European network
According to ESA’s plans, the demonstration activities will be followed by the so-called in-orbit preparatory phase, which was additionally supported at ESA’s ministerial council in 2025, known as CM25. In that stage, with strong reliance on European industry, technologies would be validated in orbit and the pre-operational infrastructure needed for the next step would be built. In other words, the current mission is not an isolated technological experiment, but part of a broader path towards a possible European decision to establish an operational LEO-PNT system.
ESA openly links Celeste to the new European Resilience from Space initiative, also confirmed at CM25. In that strategy, the combination of navigation, connectivity and Earth observation is described as one of the pillars of strengthening Europe’s resilience in crises and security-sensitive circumstances. Such a framework shows that Celeste is more than a specialist space project. It is part of a broader political response to a changed geopolitical environment, growing demands for independent infrastructure and the need for Europe not to leave critical services exclusively to external actors.
Although the final decision on a full operational system still has to be made by the European Union, the demonstration phase has a clear purpose: to prepare the industry, the regulatory framework and the technical evidence for that political choice. This means that Celeste’s success will not be measured only by how precise individual experiments in orbit are, but also by how convincingly it will show that Europe can build a reliable, interoperable and economically justified additional navigation layer.
A new generation of services and markets
Satellite navigation has long since ceased to be limited to driving a car or displaying a location on a mobile phone. Precise timing and positioning systems are embedded in telecommunications networks, financial systems, energy grids, logistics, rail transport, civil aviation, maritime surveillance and a wide range of industrial processes. Every advance in resilience and precision therefore also has a direct economic effect. ESA emphasises in its publications that Galileo and EGNOS are already today a European success story that creates economic value while at the same time strengthening independence and security.
If it succeeds in confirming the expected advantages of the LEO layer, Celeste could open the door to services that are today limited by technical compromises. In urban environments, that can mean a more stable signal among tall buildings. In transport, it could help automated control systems that require availability and reliability above the level of ordinary consumer navigation. In remote areas, including polar and Arctic zones, an additional layer could increase service availability where that is currently more challenging. For the Internet of Things sector, the possibility of tracking a large number of connected devices with a new combination of frequencies and signals is important.
The experimental function of the constellation itself is equally important. ESA states that later satellites, in addition to the L-band, will also include demonstrations in the S-band associated with 5G satellite waveforms, the C-band for precise and resilient PNT testing, and UHF for better penetration and applications focused on indoor spaces. This shows that Celeste is not conceived merely as a “lower version” of the existing navigation system, but as a platform on which the future convergence of satellite navigation, communications and new digital services will be tested.
Europe is accelerating space projects in new circumstances
The project gains additional weight from the fact that, according to ESA data, the transition from concept to first launch was achieved in less than two years, which is an exceptionally fast pace for a navigation demonstration mission. In the European space context, this is interpreted as a sign of a change in approach: fewer slow and rigid development cycles, and more iterative testing and early learning from flight demonstrations. Such a change is becoming ever more important as the global space race accelerates and development decisions increasingly have direct security and economic consequences.
That is precisely why Celeste should be viewed on two levels. The first is engineering: can Europe prove that satellites in low orbit can indeed provide measurable additional value for positioning, navigation and precise timing. The second is strategic: can the European institutional and industrial system turn such evidence into operational capabilities quickly enough. In that sense, the March 28 launch is not only a successful Electron rocket flight, but also a test of Europe’s ability to develop in real time the technologies that will be key in the next decade.
For now, the mission has entered its most sensitive, but also most interesting period. The early phase of operations in orbit will show whether the systems on the two spacecraft are ready for the series of technical demonstrations that follow. If those checks proceed according to plan, Celeste could become one of the more important European technological projects at the intersection of the space industry, digital infrastructure and strategic autonomy, with consequences that go far beyond the space sector itself.
Sources:- ESA – official announcement on the launch of the first satellites of the Celeste mission and the start of the early operational phase (link)- ESA – official Celeste mission page with a description of the project’s goals, its relationship to Galileo and the planned constellation of 11 satellites (link)- ESA – “Celeste in-orbit demonstration constellation”, overview of the demonstration architecture, the New Space approach and further launches from 2027 (link)- ESA – “Celeste IOD - Facts and figures”, technical data on the orbit, size and mass of the first satellites and the frequency bands (link)- ESA – “Watch live: First Celeste launch”, confirmation of the March 28, 2026 launch time and basic data on the first phase of the mission (link)- ESA – CM25 and European Resilience from Space, the context of support for the Celeste project within the broader framework of European resilience from space (link)
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