NATO joins global race to utilise airships for reconnaissance VIDEO

An uncrewed, hydrogen-powered autonomous surveillance airship about the size of a small bus has been hovering over Portuguese waters, gathering imagery of ships and other objects. The purpose of these test flights is to determine whether the airship can enhance NATO’s situational awareness in the maritime domain.

The flights are part of NATO’s annual exercise showcasing new robotic technologies designed to strengthen defence capabilities. The airship is one of many systems under evaluation during the Robotic Experimentation and Prototyping using Maritime Unmanned Systems (REPMUS) 25 and Dynamic Messenger (DYMS) 25 exercises, according to reporting by The War Zone (TWZ). Alongside the airship, NATO is also trialling unmanned surface, underwater, and aerial vehicles.

Built and operated by the Finnish company Kelluu, the airship is one of about 10 currently providing imagery and sensing capabilities for commercial and scientific uses. Given NATO’s ongoing maritime security missions, Kelluu sees a military role for its craft in delivering persistent, low-level surveillance.

At about 12 meters long, the Kelluu LTA is relatively compact for an airship. According to the company, it can fly for roughly 12 hours at low altitudes and carry various sensors, including electro-optical/infrared cameras and passive systems capable of detecting electromagnetic emissions. Designed to operate from austere locations without runways, these airships fly “very quietly and without emissions, providing real-time connectivity without being limited by radio-link ranges [BRLOS],” said company CEO Janne Hietala.

A Finnish hydrogen-fueled dirigible called “Kelluu” is participating in NATO's annual REPMUS exercise.
The long-range reconnaissance airship covers an area up to 300 km in diameter.
And the promotional video is beautiful. pic.twitter.com/TZYsZaqE4K

— Roy🇨🇦 (@GrandpaRoy2) September 17, 2025

While NATO officials declined to discuss specific systems participating in REPMUS25, they stressed the importance of experimentation. “All of these systems require experimentation and integration into the operational environment,” Cmdr. Arlo Abrahamson, spokesperson for NATO’s Allied Maritime Command, told TWZ. “We want to place these systems in the hands of our operators and ensure those systems meet the operational requirements of Allied forces.”

The demonstration comes after NATO launched Operation Baltic Sentry earlier this year, following several cases of suspected underwater cable sabotage attributed to Russia. In one instance, Finnish authorities reported that the Russian-linked vessel Eagle S deliberately dragged its anchor across the seabed to sever cables; investigators later found the ship loaded with spy gear.

Airship use is expanding beyond NATO as well. In March 2024, Caliber.Az cited the Russian opposition outlet Meduza that hackers exposed correspondence between Russian and Iranian defence companies, revealing Iran’s interest in acquiring “spy balloons” from Russia.

According to TWZ, China is also heavily investing in lighter-than-air technologies. A massive hangar in a remote northwestern region is tied to its development of high-altitude airships that could be used for intelligence gathering, long-range communications, missile defence early warning, or even as launch platforms for drones and other payloads.

By Nazrin Sadigova