Beyond the Horizon: Securing European Strategic Autonomy through Sovereign LEO Data Links

As NATO and Western military planners predicted in the late 1990s, air warfare has steadily shifted from platform-centric to Network-Centric Warfare (NCW) (Cebrowski and Garstka, 1998). Driven by the evolution of anti-air weaponry and radar, the decisive factor of victory has changed from the individual capabilities of platforms to the ability to effectively share information across a “Kill Web” of all actors (Alberts, Garstka and Stein, 1999). Air forces have adapted by adopting Tactical Data Links (TDL), real-time data communication systems (ANMB, 2016). They offer a Common Operational Picture (COP) of friendly and enemy positions, allowing enhanced decision-making for planners, frontline pilots, and ground-based anti-air crews reacting under time pressure in combat. NATO’s main contemporary TDL is Link 16. Adopted in 1998 by the ratification of STANAG 5516, it uses UHF radio waves to communicate between platforms in a jam-resistant fashion (NATO, n.d.).

However, the reliance on these radio signals limits Link 16 to Line-Of-Sight (LOS) communications, capping its range at 300 nautical miles (CJCSM 6520.01B, 2020). While any aircraft can serve as a relay node, it remains problematic in dense terrain such as mountainous areas (Data Link Solutions, 2024).

 

European air forces depend upon Link 16 for interoperability. However, this system depends on agreements with the United States and is vulnerable to a potential cut-off in case of a breakdown in transatlantic relations (Posen, 2020). MIDS terminals are subject to US ITAR rules and rely on US proprietary software and encryption updates (RAND Corporation, 2005). Considering the ongoing weakening of transatlantic relations, this dependence leaves European states vulnerable. If European states want full sovereignty over their air assets, they must resolve this issue.

 

How can European air forces resolve the weaknesses in their TDL system? 

 

This paper argues that by integrating TDL capabilities into the European IRIS² Low Earth Orbit (LEO) satellite constellation, European air forces can solve the LOS problem of their TDL while ensuring a sovereign capability to conduct NCW in the air, even if US-managed Link 16 goes down.

To demonstrate how this capability would come into existence, this paper first examines the institutional and technical architecture of the needed orbital capability, then analyses the industrial and operational logistics of such a European endeavour and finally studies the implementation of such a system into European air forces.

 

I- Institutional and technical architecture of the orbital capability

 

To understand how this solution would function, and the advantages it presents, we must understand LEO and current European capabilities. Low Earth Orbit is an area of Earth orbit ranging between 160 km and 2000 km above Earth’s surface. It is easier and cheaper to reach than farther orbits and offers lower signal latency (EBSCO, 2024).

 

IRIS² is one of the EU’s three flagship space programs and is set to enter full service in 2030. Following Copernicus for Earth observation and Galileo for navigation, it is intended to ensure sovereign and secure EU communications (ESA, 2025). It is composed of 290 satellites spread over Low and Medium Earth Orbit, the majority of which are in LEO. The program is overseen by the European Commission, while the European Space Agency (ESA) acts as the technical architect responsible for procurement and implementation. Operational management is conducted by the European Union Agency for the Space Programme (EUSPA), notably through the Security Accreditation Board (SAB), ensuring the safety of government data. Ownership of the satellites is shared through a Public-Private Partnership between the EU and the SpaceRISE consortium, although the EU retains full ownership and sovereignty over security-related components (Latvia Space, 2026) as part of a “government grade” tier reserved for sensitive information (ESA, 2025).

 

IRIS² is therefore an ideal framework for integrating a secure and sovereign satellite communication component for military TDL use, as it leverages existing EU institutions and expertise in large satellite constellation programs. Additionally, LEO offers comparatively cheap launch costs and the low latency required for real-time data exchange (EBSCO, 2024).

 

Achieving this requires an extension of the mandate of IRIS², which is currently intended for governmental and civilian communications. The adequate EU body to fund and manage such an extension is the European Defence Fund (EDF), which would be responsible for the defence-specific satellites.

 

These satellites would need military transponders capable of receiving the J-series message packets used by Link 16, encrypting them using European encryption keys, and broadcasting them back to combat platforms. In this way, the satellites become jam-resistant, resilient, encrypted Link 16 relays that bridge the LOS problem by offering Beyond-Line-Of-Sight (BLOS) capability.

This is how European NATO members can leverage EU institutions to build a sovereign European satellite communications layer enabling BLOS TDL capabilities.

 

II- Industrial and operational logistics of launch

 

We have seen how the technical and institutional architecture of this capability would function; it is now important to understand the logistics of deploying it. Europe must retain sovereignty over satellite production and launch.

 

There are three needed capabilities for placing satellites in orbit: the ability to design and produce satellites, launchers capable of placing payloads into orbit, and adequate launch sites.

Firstly, Europe possesses a strong industrial base capable of manufacturing LEO satellites. The SpaceRISE consortium tasked with deploying IRIS² concentrates much of this expertise. It includes the Luxembourg-based SES SA, the Spanish Hispasat S.A, and the French Eutelsat SA, alongside major European aerospace and defence actors such as Airbus Defence and Space and Thales Alenia Space (European Commission, 2024). Their combined expertise in multinational operations, LEO satellite manufacturing, and defence communications ensures autonomous European production of the satellites needed for a TDL constellation.

 

Regarding launchers, Europe possesses two launcher options, both designed and produced in the EU. Ariane 6 is Europe’s heavy-lift option, capable of deploying high-volume payloads and delivering many TDL satellites into LEO at once. For a more flexible and cheaper solution, Europe can rely on the Vega-C rocket, adapted for lighter payloads and more suitable for the replacement of individual satellites or precise orbiting of specific nodes (ESA, 2025).

 

In terms of sovereign launch sites, Europe has fewer options, primarily relying on the Guiana Space Centre in Kourou, French Guiana, the only European spaceport currently capable of Ariane 6 and Vega-C launches (CNES, 2026). While this offers a sovereign launch capability, it stretches supply lines. The Norwegian Andøya and Swedish Esrange spaceports offer future alternatives. Though not yet capable of launching Europe’s current launchers, they could eventually support small launch vehicles from European startups such as Germany’s Isar Aerospace and its Spectrum launch vehicle, capable of carrying 1000 kg to LEO (Isar Aerospace, 2026).

 

Europe thus possesses the industrial and technological resources necessary for sovereign LEO launches without relying on outside partners, ensuring the rollout of a European TDL satellite constellation.

 

III- Integration and standardization: retrofitting the fleet for sovereignty

 

Now that we have established the orbital architecture of this solution, it is necessary to understand how this new TDL capability would integrate within European air forces.

 

The goal of integrating a LEO satellite-based TDL solution is not to replace US systems outright, but to ensure sovereignty while maintaining interoperability. Rather than replacing existing Link 16 architecture, this European solution should be additive, ensuring interoperability with NATO partners while preserving sovereign capability in times of strategic divergence.

 

To achieve this, the European satellite TDL must adhere to STANAG 5516 by continuing to use J-series messages. European aircraft using the system would still communicate in the same language as US and NATO partner assets. Sovereignty lies not in the language of communication, but in the transport and encryption of the data. If US encryption becomes unavailable, the European TDL solution would rely on sovereign encryption managed by EUSPA’s SAB, ensuring secure communications through IRIS² satellites.

 

However, integrating this technology across Europe’s diverse fleet, from legacy F-16s to Eurofighters, remains a challenge. Aircraft would need updates to their avionics suites, including emitters capable of sending J-series messages to LEO satellites and sovereign decryption modules for incoming messages. Fighter jets could also require upward-facing antennas for direct satellite communication.

 

Such an upgrade effort should rely on existing institutions to establish standards and avoid fragmentation. The European Defence Agency (EDA) would oversee standardization across different airframes, ensuring uniformity among participating air forces. Managing the retrofits themselves would remain the responsibility of member states, although the Organisation for Joint Armament Cooperation (OCCAR) could support procurement and contract management for multinational programs.

 

Ultimately, the rollout of this solution requires retrofits to existing airframes. By relying on centralized standards through the EDA and cooperative procurement through OCCAR, Europe can integrate this satellite-based TDL into the “kill web” of its air assets.

 

Conclusion

 

Europe is faced with the reality of its armed forces’ reliance on the United States. In the air domain, the inability of European actors to conduct NCW independently of US technology remains a dangerous Achilles’ heel. However, through the procurement and rollout of a satellite-based TDL, Europe can not only bridge the gap that a potential US cut-off or NATO withdrawal would leave but also solve the problem of LOS-limited communications by establishing a sovereign BLOS communications network.

 

References: 

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