Today at 10:14 a.m. German time, the first two satellites for ESA’s new Celeste navigation mission were successfully launched into space aboard an Electron rocket from the Māhia Launch Complex in New Zealand. The two satellites (IOD-1 and IOD-2, where IOD stands for In-Orbit Demonstrator) are microsatellites weighing 20 and 30 kilograms, respectively, designed to test new navigation technologies in low Earth orbit (LEO-PNT = Low Earth Orbit – Positioning-Navigation-Timing). This is expected to enable new applications such as indoor navigation or autonomous driving in the medium term.
The currently active European satellite navigation system, Galileo, consists of 30 satellites orbiting at an altitude of 23,222 kilometers in medium Earth orbit (MEO). At this altitude, just a few satellites are sufficient to ensure global coverage with navigation signals. However, in dense urban areas, tunnels, or inside buildings, Galileo and all other current navigation systems reach their limits. Due to the great distance between the satellites and Earth, the transmitted signals are comparatively weak and cannot always penetrate obstacles. Additionally, they are susceptible to interference such as jamming or spoofing.
In the future, therefore, a different approach is expected to prevail: navigation satellites will be placed in various orbits and will work in conjunction with ground-based systems to improve the accuracy and reliability of European navigation.
Navigation constellation in low Earth orbit
ESA's Celeste mission is designed to demonstrate the functionality of a navigation constellation in low Earth orbit. By placing the satellites closer to Earth, their signals can be received on the ground more quickly and with greater strength.
The demonstration mission will be implemented in phases. The successful launch of the first two satellites marks the first milestone in this process. These satellites are intended to secure frequencies and validate the basic system concept.
The next step is to expand the constellation with eight additional, significantly larger demonstrators. These are satellites weighing approximately 90 kilograms, which will be used starting in 2027 to test additional system functionalities—including signal transmission on frequencies not previously used. This will enable navigation signals to be received indoors in the future while also providing better protection against tampering.
The development of the demonstration satellites for Celeste was awarded by the ESA to two consortia led by the Spanish technology company GMV and Thales Alenia Space in France. Within the consortium led by GMV, OHB is a key partner responsible for the development of four of the larger demonstration satellites, including their payloads—which are currently in production in Bremen. OHB is involved in the IOD-1 microsatellite, launched today and managed by GMV, through the development of two key payload components.
“Reliable positioning, navigation, and timing information from space is an indispensable foundation for Europe’s industry and critical infrastructure,” says Marco Fuchs, CEO of OHB. “In this context, Celeste LEO-PNT makes an important contribution to strategic independence. The successful launch of the first satellites is a major milestone on the path to a fully operational constellation, and we are proud that our work contributes to European resilience and sovereignty.”
