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Eagle-1 QKD Satellite Launch Date: Why It Slipped to 2027–28

Eagle-1 QKD Satellite Launch Date: Why It Slipped to 2027–28 — Hadamard

Eagle-1, Europe’s first quantum key distribution (QKD) satellite, is now expected to launch at the end of 2027 or the beginning of 2028. That is the latest guidance from SES Techcom, and it puts the Eagle-1 QKD satellite launch date more than three years after the “as early as Q4 2024” target set when the launch contract was signed in 2022.

This article covers the history of the delays, who is building the satellite, what its QKD payload will test, and how the new optical ground station in Noordwijk is coming along. It also looks at the argument the mission’s backers make about post-quantum cryptography (PQC).

Eagle-1 launch date: the short answer

Alan Kurešević, managing director of SES Techcom, spoke at the EU Space Days conference in late May 2026. He said the satellite is in advanced production but the payload still faces technology challenges, and that launch is now expected at the end of 2027 or the beginning of 2028, according to Space Intel Report. European Spaceflight similarly reported that the launch had slipped to “no earlier than late 2027.”

One thing to watch for if you search this yourself: ESA’s Eagle-1 mission page still gives a launch in late 2026 or early 2027. That date is out of date. The operator’s newer statement supersedes it.

Eagle-1 delay to 2027: a history of slipping dates

Eagle-1 has slipped several times. Read in order, the public record looks like this:

  1. November 2022: SES selects Arianespace to launch Eagle-1 on a Vega C, with the flight expected “as early as Q4 2024.”
  2. May 2023: SES and TESAT announce the QKD payload contract.
  3. May 2025: A technical status paper on arXiv describes a launch planned for 2026 on Vega C.
  4. ESA mission page (still live): launch in late 2026 or early 2027.
  5. Late May 2026: SES Techcom says the end of 2027 or the beginning of 2028.

Two causes have been named publicly. The first is the availability of the Vega-C launcher. The second is technology challenges with the payload itself, Space Intel Report notes. SES has not said what those payload problems are, so any more detailed explanation is speculation.

What is Eagle-1, and who is building it?

ESA calls Eagle-1 Europe’s first space-based QKD system. Its job is to validate QKD from low Earth orbit down to the ground. It will also supply data for EuroQCI, the European Quantum Communication Infrastructure. After launch, ESA plans a three-year in-orbit validation campaign supported by the European Commission, according to the ESA mission page.

The industrial team is large. Based on the ESA infographic from October 2022 and the payload announcements:

  • SES, through SES Techcom in Luxembourg, leads a consortium of more than 20 European companies.
  • SITAEL (Italy) builds the satellite platform.
  • TESAT (Germany) builds the QKD payload, under a contract announced with SES in May 2023.
  • The Max Planck Institute for the Science of Light and the University of Erlangen-Nuremberg (FAU) lead the protocol work, per the arXiv status paper.

How Eagle-1’s QKD works: decoy-state BB84 from low Earth orbit

The fullest technical description is the arXiv paper “The European Satellite-Based QKD System EAGLE-1” by Hiemstra et al., submitted May 27, 2025. It describes Eagle-1 as a prepare-and-measure, satellite-to-ground QKD mission. The system has three parts: a satellite in sun-synchronous low Earth orbit, two optical ground stations, and an operations control center.

The protocol

Eagle-1 uses a decoy-state variant of BB84. The satellite prepares four phase-encoded qubit states on weak coherent double pulses, with a mean photon number below 1, and transmits in the telecom C-band. In plain terms, the satellite sends very faint laser pulses, each carrying one of four quantum states. A ground station measures them, and the two sides then distill a shared secret key from the results.

Decoy states deal with a known weakness of weak laser pulses: a pulse sometimes holds more than one photon, which opens the door to photon-number-splitting attacks. Mixing pulses of different intensities lets the receiver estimate how much an eavesdropper could have learned. If you want the underlying mechanics, including basis choice, sifting and the protocol’s real-world failure modes, see our BB84 protocol explainer.

The optical link

TESAT is supplying an adapted version of its SCOT80 laser terminal for the space segment. On the ground, the terminals include an upgraded DLR (German Aerospace Center) station and a new terminal developed in the Netherlands, according to ESA. DLR’s role is described in more detail in a December 2024 arXiv paper.

The ground segment: SES’s Eagle-1 optical ground station in Noordwijk

The Dutch terminal now has a site. On July 15, 2026, SES and Airbus Netherlands signed a ground lease with the Municipality of Noordwijk for a plot on the NL Space Campus, next to ESA’s ESTEC technical center, according to the SES press release and SatNews coverage.

Item Detail
Prime contractor TNO
Builder Airbus Netherlands
Facilities Control room, telescope dome, adaptive optics to correct for atmospheric turbulence
Civil construction Through late 2026
Assembly Starting 2027
Target operation Early 2028

Adaptive optics matter here because turbulence in the atmosphere distorts the incoming beam, and a QKD downlink depends on collecting as many of the faint photons as possible. Note also the timing: the station’s early-2028 operating target falls inside the satellite’s new launch window. If either slips further, the start of the in-orbit validation campaign probably moves too.

How does Eagle-1 compare with China’s Micius?

Eagle-1 is not the first QKD satellite. China’s Micius launched from Jiuquan on August 16, 2016. In 2017 it distributed entangled photon pairs to two ground stations, Delingha and Lijiang, 1,203 km apart. It recorded a Bell-inequality violation of 2.37 ± 0.09, published as “Satellite-based entanglement distribution over 1200 kilometers” in Science 356, 1140 (2017).

Micius (China) Eagle-1 (Europe)
Launch August 16, 2016 Expected end 2027 or early 2028
Result / approach cited here Entanglement distribution to two stations 1,203 km apart Prepare-and-measure, decoy-state BB84 variant
Orbit Low Earth orbit Sun-synchronous low Earth orbit
Main goal Scientific demonstration Validation and data for EuroQCI

If Eagle-1 launches on the current schedule, it will follow Micius by more than a decade. The two approaches also differ. In a prepare-and-measure scheme, the satellite holds key material during the exchange, so it has to be a trusted node. Entanglement-based schemes, like the one Micius used for its Bell test, are a different design. For how quantum links might eventually scale beyond single satellite passes, see our quantum internet explainer on repeaters and teleportation.

Satellite QKD vs post-quantum cryptography: does Europe still need Eagle-1?

This is the question behind much of the coverage. Kurešević argued that PQC cannot replace QKD for sensitive communications. His reasoning, as reported by Space Intel Report, is that sending photons over land at extremely low power is not feasible beyond about 150 km, which makes a satellite the most efficient way to cover longer distances.

This is the operator’s position, not a settled consensus. The distance argument is about how to deliver QKD over long ranges. It does not show that QKD is needed in the first place. Security agencies have raised practical objections: QKD needs dedicated hardware, it still relies on classical authentication, and real implementations open attack surfaces of their own. Our article on why the NSA still won’t back quantum key distribution sets out that counter-position in detail.

In practice, the two approaches may end up doing different jobs. PQC is software and can be deployed across existing networks and devices. Satellite QKD is a physical-layer experiment aimed at a narrow set of high-assurance links. Hadamard, which publishes this blog, takes the software route with BB84, an Ethereum Layer 2 rollup whose accounts rely on hash commitments instead of ECDSA keys. Despite the shared name, it uses no quantum hardware.

What to watch next for Eagle-1

  • Payload updates: any disclosure of what the payload challenges are and whether they have been fixed.
  • Launch vehicle confirmation: Vega-C availability was one cause of the delay, so watch for a firm launch slot.
  • Noordwijk milestones: civil works finishing in late 2026 and assembly starting in 2027.
  • ESA’s page: whether ESA updates its late-2026/early-2027 date to match the operator’s guidance.
  • EuroQCI planning: how results from the three-year validation campaign feed into Europe’s wider quantum communication infrastructure.

FAQ

When will Eagle-1 launch?

SES Techcom said in late May 2026 that launch is expected at the end of 2027 or the beginning of 2028. ESA’s mission page still says late 2026 or early 2027, but that date is outdated.

Why has Eagle-1 been delayed so many times?

Two causes have been named: Vega-C launcher availability and technology challenges with the QKD payload. SES has not said publicly what the payload problems are.

What QKD protocol does Eagle-1 use?

A decoy-state BB84 variant. It uses four phase-encoded qubit states on weak coherent double pulses with a mean photon number below 1, transmitted in the C-band from a sun-synchronous low Earth orbit.

Does Europe still need satellite QKD if post-quantum cryptography exists?

SES argues that it does. Its view is that PQC cannot replace QKD for sensitive communications, and that ground-based photon links aren’t feasible beyond about 150 km. Critics, including the NSA, disagree, and that debate is not settled.

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