The thermal signature lingers for nearly an hour after a Russian submarine glides away from its Arctic berth—invisible to the naked eye and most satellite cameras, but glowing like a beacon in the longwave infrared spectrum. It's exactly the kind of intelligence European defense officials want to capture without relying on American providers.
That proposition helped Constellr, a Freiburg-based space startup, close one of the largest Series A rounds in European space tech: €37 million, announced February 10. Alpine Space Ventures led the investment, with Lakestar co-leading, pushing the company's total capital raised to €75 million since launching in 2020.
The round caps a remarkable pivot. Constellr started life measuring crop water stress for farmers. Now it's selling what it calls "defence-grade thermal intelligence" to governments anxious about gaps in their sovereign surveillance capabilities.
A Constellation With Political Overtones
Two satellites are already up. Sky-Bee-1 lifted off aboard a SpaceX Falcon 9 in January 2025, followed by a second in June. Both circle Earth in sun-synchronous orbit at 510 kilometers, their cryocooled infrared cameras—built in partnership with German aerospace contractor OHB System AG—capturing thermal imagery at 30-meter native resolution. Post-processing sharpens that to roughly 10 meters, with temperature accuracy within 1-2 Kelvin.
In March, the company released first-light imagery: Tokyo at night, buildings radiating stored heat in ghostly gradations. It was a proof of concept. The real customers, though, aren't urban planners tracking heat islands.
They're defense ministries.
Constellr plans to scale to around 30 satellites by 2030, creating what CEO Max Gulde has termed a "real-time thermal intelligence atlas." The next generation of platforms will push resolution below five meters—fine enough to distinguish individual vehicles or infrastructure components, even in total darkness.
Maritime surveillance has become the clearest use case. Ships leave thermal trails long after they've disappeared over the horizon, betraying their presence near sensitive naval installations. Optical satellites go blind after sunset. Thermal sensors don't blink.
The Sovereignty Pitch
The strategic shift didn't happen in a vacuum. European governments, rattled by geopolitical turbulence and increasingly wary of data dependencies, have been hunting for homegrown intelligence capabilities. Thermal imaging from orbit is a particularly acute gap—most providers operate out of the United States or Israel.
Constellr has positioned itself as the answer to that problem, perhaps more aggressively than its founders initially anticipated. The company already holds a multi-year contract as a Copernicus Contributing Mission, feeding data into the European Commission and European Space Agency's earth observation programs. Last December, it signed a data access agreement with Germany's DLR space agency.
Alpine Space Ventures, the Munich fund that led the round, is itself a product of this new European assertiveness. Its €170 million vehicle counts the European Investment Fund and NATO Innovation Fund among its backers—an unusual constellation of public and alliance capital aimed at closing strategic technology gaps.
Lakestar, better known for backing consumer internet companies like Skype and Spotify, has recently pivoted toward defense resilience. The firm's co-lead on this round signals how quickly the investment thesis around "dual-use" technology has evolved.
Also joining: Semapa Next, Bayern Kapital, Cardumen Capital, Cooperative Ventures, and Kineo Finance. Existing backers Vsquared, CosmiCapital, Fraunhofer's tech transfer fund, and the EIC Fund all returned.
A Market Heating Up
Constellr isn't alone in chasing thermal intelligence from space. California-based Hydrosat raised $60 million just a month earlier, in January, with its own agricultural-roots-to-defense story. OroraTech, another German startup, closed a €37 million Series B last year focused on wildfire detection and monitoring—though its sensor resolution runs coarser.
The comparison to Hydrosat is particularly apt. Both companies started with similar mandates—precision agriculture, water management, climate monitoring. Both realized that governments would pay more, and faster, than agricultural cooperatives.
The wildfire angle, which OroraTech has leaned into, offers a more palatable commercial narrative. Monitoring submarine bases carries different optics.
Constellr is threading that needle by also pursuing commercial distribution. In February, it signed a partnership with Japan's SKY Perfect JSAT to distribute thermal data for domestic buyers—use cases that presumably skew more toward urban planning, energy auditing, and disaster response than military surveillance.
Still, the company's public messaging has grown unmistakably martial. Terms like "sovereign control" and "allied customers" now dominate its pitch decks. There's little mention of irrigation optimization.
What Comes Next
The Series A will fund satellite manufacturing, ground infrastructure, and the development of what Constellr calls "next-generation defense-grade systems." Translation: higher resolution, faster revisit times, and secure data pipelines that keep information within European and allied networks.
Whether the market can support three or four thermal imaging constellations—each racing to 20 or 30 satellites—remains an open question. Launch costs have plummeted, but the capital intensity of space infrastructure hasn't. And defense contracts, while lucrative, come with bureaucratic timelines that can test even well-funded startups.
For now, Constellr is betting that Europe's appetite for strategic autonomy will outweigh those risks. Two satellites are operational. Twenty-eight more are on the drawing board. And somewhere over the Barents Sea, a thermal trail is fading—but not before the cameras catch it.
