Bus-Sized Uncrewed Airship Being Tested By NATO As Maritime Surveillance Platform
September 18th, 2025A 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
Via: The War Zone:
An uncrewed hydrogen-powered autonomous surveillance airship the size of a small bus has been floating over Portuguese waters, collecting imagery of ships and other objects. The goal of these test flights is to see if this airship can provide NATO with situational awareness of the maritime domain.
The flights are part of the alliance’s annual demonstration seeking new robotic technology to boost its defenses. The airship is one of several systems that NATO is evaluating during this exercise, which is called Robotic Experimentation and Prototyping using Maritime Unmanned Systems (REPMUS) 25 and Dynamic Messenger (DYMS) 25. NATO is also trialing unmanned surface and underwater vehicles, as well as other aerial ones, as part of the exercise.
The airship being tested is made by the Finnish Kelluu company, which also operates the aircraft. It is one of about 10 that are providing imagery and other sensing capabilities for commercial and scientific purposes. With NATO already conducting maritime security missions, the company sees a potential military role for its airships to provide persistent, low-level surveillance.
