On the day before the first two Celeste satellites were launched from Rocket Lab Complex 1 in New Zealand, Pietro Giordano, LEO-PNT System Manager at ESA/ESTEC, was at the 2026 Munich Space Summit, explaining the significance of Europe’s LEO-PNT system.
“Celeste is a program that started not even two years ago, and we are already aiming to launch our first two satellites, what we call the IOD-1 and the IOD-2,” Giordano said. The satellites, now in orbit, are CubeSats flying at around 510 kilometers altitude.
“The objective of the mission is to demonstrate technology,” Giordano said. “This IOD [in-orbit demonstrator] phase is fundamental for us to master the technology, the techniques that we want to apply for future systems.” The satellites are designed to validate new positioning signals, multi-frequency capabilities, and integration with next-generation networks.
Giordano highlighted the wider scope of the Celeste program. “The two companies in charge of development are GMV and Thales Alenia Space France. They’re not just building the satellites. They’re also responsible for the ground segment and system-level development, including the very important specification phase, which will start as soon as the satellites are flying.”
Starting now
Celeste will operate across multiple frequency bands, Giordano said, “moving from UHF to other bands and potentially targeting indoor applications. Of course, L-band is a fundamental and master band we all need to provide. S-band has two phases: there is the S-band allocated to RNSS [radionavigation satellite services], used by GNSS systems today. But we may explore potentially usable MSS (mobile satellite service) bands, and will leverage 5G and terrestrial networks. “We also have C-band, one of the more appealing bands for resilience,” Giordano said, emphasizing the versatility and future-proofing of the system.
The IOD phase lays the groundwork for an operational LEO-PNT network. “At Ministerial ’25,” Giordano said, “ESA proposed the in-orbit preparation phase [IOP] that will follow.” First IOP satellites could be launched in the 2027-2028 timeframe. “When it comes to 5G and the current IOD satellites, we’re only testing the very basics, the physical layer,” Giordano said. “We will go beyond that in the IOP phase, where we plan to implement the full-scale 5G network capabilities.”
Looking ahead, Celeste is open to adding additional small constellations and experiments, offering opportunities for European industry and third-party participation. Giordano said, “We have a very strong ambition to bring into space operational services at European level in 2032, and we cannot do it with just demonstration satellites.”
With IOD-1 and IOD-2 now in orbit, ESA has taken its first tangible step toward a resilient, multi-band European LEO-PNT system, promising enhanced positioning, navigation, and timing services for the decades ahead.
