Day: December 2, 2025

• Kelluu, a Finnish startup, is developing low-cost hydrogen airships that can fly for up to 12 hours.
• They’ve recently attracted attention from NATO, securing a deal with a member for trials.
• The airships are built near Russia and designed to withstand jamming and icy conditions.

In less than 10 seconds, Kelluu’s silver airships can soar from the ground to high above eastern Finland’s treelines, their motors puttering and their noses pointed skyward.

Gas blimps were first invented in the 19th century, but the Scandinavian startup is betting on a modern version of the old concept to help the West guard its territory.

Kelluu, a Finnish company located about 50 miles from the Russian border, is launching small, propeller-driven airships filled with hydrogen, which it believes can fill a gap in battlefield and border surveillance.

The startup is already finding success with NATO, being the first to secure a deal with a Western nation through a new innovators’ program run by the alliance.

Militaries or law enforcement agencies could equip a fleet of such remotely piloted airships with cameras and sensors, rotating them to monitor regions around the clock. Kelluu said its airships can be automated, meaning a human operator only has to set a target destination.

Airships won’t be easily survivable on an immediate frontline, but can surveil rear areas or combat zones near the fighting for long periods.

Small drones, meanwhile, typically can only fly for a few hours, while spy planes are often expensive, scarce, and need an onboard crew. Satellites have to wait to pass over a specific region to gather intelligence.

Niko Kuikka, the startup’s head of engineering, told Business Insider at Kelluu’s workshop in Finland that its airships can fly for half a day.

“Our customers don’t care so much what we are flying with, but they pay us to stay up in the air for 12 hours. That’s our specialty,” said Kuikka.

About as long as a city bus and six-and-a-half feet wide, Kelluu’s airships are tiny compared to the Zeppelins of World War I. The ship carries fuel, a propeller, and an onboard computer, and can be configured to transport an additional payload of up to 11 pounds for other gear such as sensors. Altitude can allow high-definition cameras or radar to survey a wider area.

Kuikka said a smaller size can be an advantage for Kelluu’s airships, which are designed to fly at top speeds of 33 mph.

They’re cheaper and easier to mass-manufacture, so a customer wouldn’t have to worry that losing a few airships might disable an entire fleet, he said.

Kelluu declined to disclose its pricing, but said its airships are meant to be low-cost.

“Having a kind of sitting duck in the air that costs a vast amount of money isn’t going to make sense,” Kuikka said.

‘Free interference’ from Russia

At Kelluu’s workshop, employees perform the final assembly of the airship and fill it with hydrogen, a lighter-than-air gas that serves to both lift its frame and power its propeller. In the upstairs attic, a team of about 10 computer engineers finetunes in-house software and a user interface for monitoring the airships.

The main team is based in Joensuu, a small city of 78,000 people just west of Russian Karelia.

That location is a key advantage for the airship company, Kuikka said.

Because Joensuu is so close to the border, it has to deal with frequent jamming from both Russia and Finland, or as Kuikka and his team call it: “free interference.”

While other firms may have to pay for tests, Kelluu’s airships must be resistant to electronic warfare to work in the first place, he said.

“We get all sorts of jamming and spoofing from the other side of the border, and also from this side of the border, so we have been proven to be pretty resilient against this sort of GSS denial,” he said.

Kelluu is also about 340 miles south of the Arctic Circle, so its team had to build its airships to withstand icy winds and temperatures that dropped in January to -15°F.

As such, the startup is positioning its airship as a particularly useful means of monitoring future Arctic bases or territories. The theory goes that the longer its fleet can stay aloft in rough conditions, the fewer people are needed on the ground to maintain and operate the airships.

“We are hoping to soon have an asset that can run multi-day missions, so you need even fewer persons working out there,” Kuikka said.

Catching NATO’s eye

Joensuu once heavily relied on Russian tourism, an income flow sapped dry in 2022 after the full-scale invasion of Ukraine prompted Finland to stop issuing tourist visas to Russians. The following year, Finnish authorities closed the country’s 833-mile land border with Russia.

Helsinki, like much of European NATO, is now grappling with the question of how to guard its eastern borders. The Finnish government is already raising concerns about illegal immigration, which it says Moscow is intentionally orchestrating as a gray warfare tactic.

Kelluu was founded in 2018, well before these issues drew public concern. It began by building airships for civilian use, such as monitoring power lines.

Now, the war is turning it into a rising star in Europe’s defense industry.

Kelluu was one of 14 firms picked by NATO’s Defence Innovation Accelerator for the North Atlantic, or DIANA, to enter the second phase of the alliance’s 2025 program.

The accelerator program is trying to connect allies with startups and defense contractors, pushing governments to adopt new tech into their militaries within two years. Roughly 2,600 companies or parties initially submitted proposals to DIANA this year.

After several showcases, Kelluu was the program’s first company to land a deal with an allied country under a new “Rapid Adoption Service” to conduct national trials, a program spokesperson told Business Insider.

Neither NATO nor Kelluu named the member state, but Fabrizio Berizzi, challenge manager at DIANA, praised Kelluu’s airships as “strongly versatile in terms of maneuvering and endurance” and useful for 24/7 surveillance.

“The airship solution proposed by Kelluu fills the gaps on aerial platforms operating in altitudes in between the typical UAS and aircraft airspaces,” he told Business Insider in a statement, referring to uncrewed aerial systems.

Berizzi highlighted the airships’ jamming-resistant capabilities, saying that they can operate in “electromagnetic contested and congested environments.”

Each airship is also “difficult to detect from radar due to its low radar cross section, or radar reflectivity,” he said.

Building thousands of airships

The material of the airship’s metallic, mirror-like skin is a company secret, the firm said. When asked if it helps avoid radar detection, the company declined to answer.

But Kuikka said the core feature of Kelluu airships is that their structure allows them to be filled safely with hydrogen, which is flammable and more dangerous than helium but provides better lift; it is also lower cost than helium.

These airships are built with a semi-rigid frame, meaning they have some structural integrity but primarily derive their shape from the gas within. Zeppelins, by contrast, had fully rigid frames, while other airships like the $21 million Goodyear blimp would collapse if they were deflated.

Janne Hietala, Kelluu’s CEO, said that lighter-than-air technology is often overlooked in the defense industry, especially with disaster stories like the Hindenburg marring its history.

NATO evaluators were surprised, he said, when they assessed the company’s airships during trials, which included naval showcases in the Atlantic.

“Nobody kind of believed us,” Hietala said. “When they looked at the specs, they were like: ‘Well, the wind is going to blow it away.’ But when we actually deploy, they’re like: ‘Oh, it actually works and makes sense.'”

Kelluu now maintains a small active fleet of just under 20 airships, but Hietala said it’s focused in the near future on scaling up mass production capacity.

Some of its airships are already being deployed in other countries, such as Latvia, for testing or client use. Kelluu now manages and operates the fleet for its clients, but is discussing the possibility that some militaries may want to operate their own airships.

“Our intention in Europe is to manufacture more than 500 for the Western world, and we expect to eventually have 3,500,” Hietala said.