Europe’s investment in HydRON, a multi-orbit optical data relay network, signals a pivotal shift in how data is moved across Earth and beyond.
The program aims to transform satellite connectivity, bridging the gap between low Earth orbit (LEO), geostationary orbit (GEO) and terrestrial networks with blazing-fast laser links.
According to the European Space Agency, it would not only deliver a technological leap forward for optical communications, but also reshape the space economy and future-proof Europe’s role in an increasingly competitive global market.
As spacefaring nations and companies race to develop faster, more resilient connectivity, the question isn’t whether optical relays will become the new standard — it’s how quickly and at what scale.
Using lasers capable of delivering up to 100 gigabits per second (Gb/s) and potentially beyond, HydRON would enable real-time data transfer to overcome the typical delays of LEO satellites, which can take up to 90 minutes to pass over approved ground stations for communication.
The stakes are high. Operators relying on legacy systems face growing pressure to integrate with next-generation networks. Real-time connectivity will be critical for everything from Earth observation and defense to deep-space exploration and direct-to-device services.
But with cutting-edge technology comes new challenges: cybersecurity risks, regulatory hurdles and cost barriers that could slow adoption.
Time to demonstrate
Europe recently awarded funding needed to deploy core space infrastructure in three years as a way to demonstrate HydRON, or High Throughput Optical Network, part of ESA’s ScyLight optical and quantum communications program.
The demonstration initiative is divided into three sections: Elements #1 and #2 covering its space-based foundations, and Element #3, which would support new entrants developing their own products and services for the network.
Element #1 envisages a ring of nine interconnected LEO satellites, plus one spare, equipped with optical terminals that would transfer data to and from terrestrial nodes and other LEO satellites when ground stations are not in view.
Canadian small satellite operator Kepler Communications secured a 36-million euro ($38 million) contract Oct. 16 from ESA to lead Element #1 development.
ESA awarded a contract for an undisclosed amount Feb. 14 to European aerospace giant Thales Alenia Space to lead Element #2, comprising a LEO node and a node in GEO.
The Element #2 LEO spacecraft is designed to interface with ground stations and other LEO satellites, as well as to connect with higher GEO to showcase HydRON’s multi-orbit extension.
Both elements cover the full process from design and deployment to in-orbit validation, with follow-on contracts expected for a two-year validation phase to test the system.
ScyLight manager Harald Hauschildt said ESA plans to award multiple Element #3 contracts so market entrants can test the interoperability of their space, ground and airborne terminals with the orbital infrastructure.
This will serve as a way to validate their systems and business cases.
ESA is “already working closely with industry on a set of specifications to take optical connectivity up and beyond the 100Gb/s margin,” he said via email, “and having various contracts under [the third element] would allow [us] to validate and demonstrate some of the ideas that industry is currently exploring.”
New capabilities, new markets
Kepler, which currently provides low-data-rate connectivity for devices beyond the reach of terrestrial networks after deploying 21 sun-synchronous satellites, also has plans for its own data relay network to chase increasing demand for real-time connectivity.
Last year, the operator said it successfully tested optical inter-satellite links between a pair of prototypes in LEO.
Kepler plans to build and deploy 10 data relay satellites by the end of 2025 as part of the first tranche of its relay network. Upgraded payloads would be introduced in a subsequent tranche to support Kepler and HydRON’s mission.
Meanwhile, NASA is also betting on the private sector to develop advanced space relay systems after decades of relying on its own Tracking and Data Relay Satellite (TDRS) constellation.
In 2022, NASA awarded $278.5 million in funded Space Act Agreements to six companies eager to show services that could eventually replace TDRS and address the agency’s future needs: SES Government Solutions, Inmarsat Government, Kuiper Government Services, Telesat U.S. Services, SpaceX and Viasat. Demonstrations are slated to kick off this year.
Kepler’s U.S. division also partnered with NASA last year to exchange information and explore data relay demonstration opportunities.
NASA and ESA demonstrations will serve as a bellwether for an emerging data relay industry.
If their partners can prove the viability of high-speed optical relays, it could accelerate global adoption. On the other hand, delays or cost overruns could cede the advantage to private firms building their own independent relay constellations.
This article first appeared in the March 2025 issue of SpaceNews Magazine.
