Kelluu is a Finnish deeptech company that designs, manufactures, and operates the world's largest fleet of autonomous, hydrogen-powered airships from its factory in Joensuu — just 60 km from the Finnish-Russian border. The company's lighter-than-air platforms fly for up to 12 hours on a single mission, deliver centimetre-level aerial imagery and sensor data across vast areas, and operate reliably in Arctic conditions down to -33°C and in GNSS-denied, heavily jammed environments. Kelluu fills the gap between satellites (which lack resolution) and drones (which lack endurance), offering persistent intelligence, surveillance, and reconnaissance (ISR) as a service across defence, border security, critical infrastructure, and environmental monitoring verticals.

The airships are hydrogen-powered — giving them five times the energy efficiency of battery drones — and can carry up to 6 kg of modular sensor payloads including EO/IR cameras, LiDAR, hyperspectral scanners, synthetic aperture radar (SAR), and communications relay systems. A small fleet of five airships can monitor approximately 30,000 km², an area comparable to Belgium. Kelluu converts this raw data into digital twins, live monitoring feeds, change-detection analyses, and geospatial AI models through its Kelluu AI Labs initiative.

On the defence side, Kelluu was selected for NATO's DIANA programme in 2024 from over 2,600 applicants and has completed two phases, making it one of the most operationally validated defence startups from Northern Europe. The company has participated in NATO exercises including REPMUS, Atlantic Trident, Dynamic Messenger, and Steadfast Dart, and was awarded the top mission-assurance capability by NATO LANDCOM at the Eastern Flank Deterrence Line demonstration in 2025. Its Generation 2 airship — offering 36 hours of endurance — is in development and expected to be operational in 2027. The company has grown from ~25 to ~80 employees within a year and is building a new factory in Joensuu to triple production capacity to 100 airships per year.