Kelluu, (Kelluu is Finnish for Floating) a Finnish startup based in Joensuu, claims to operate “the world’s largest airship fleet” to deliver persistent, high accuracy aerial data for defence, infrastructure and environmental monitoring, with single flight endurance of ~12 hours and operations down to −30 °C. At first pass, much of this sounds like lighter than air déjà vu. But the novel combination here is small, hydrogen powered autonomous airships (for propulsion) that float using lifting gas, configured as a data as a service stack (sensors + autonomy + ground stations + processing) designed for BVLOS operations in harsh Nordic conditions.
Three pillars stand out:
- Operational endurance and persistence below clouds, at high spatial resolution
Kelluu positions itself as the “layer” between satellites (persistent but coarse) and drones/helicopters (accurate but short endurance/expensive). It advertises 12 hour missions with centimetre scale mapping, claims that are partly evidenced by customer deployments (e.g., Terrafame’s 60 km² digital twin operations) and NATO experimentation campaigns in 2025. While multirotor enterprise drones such as DJI M350 or Skydio X10 typically max out at 45 minutes to ~40 minutes, and even long endurance hybrids like Skyfront quote 5–13 hours under specific configurations, Kelluu’s promise is long duration + high overlap mapping without expending energy to stay aloft—thanks to buoyancy. - Arctic/BVLOS oriented autonomy and comms
Kelluu emphasises functioning in sub zero temperatures, GNSS denied environments, and integrating 5G/SATCOM backhaul, features demonstrated in NATO/DIANA pathways and the Task Force X (EFDL) technical event in Finland, where evaluators highlighted persistent autonomy and a “digital backbone” with NATO grade interoperability. For Nordic regulators and operators, that matters: BVLOS in Europe sits under EASA’s ‘specific’ category/SORA, with stringent detect and avoid, C2 link reliability, and safety cases; Kelluu’s push toward a Light UAS Operator Certificate (LUC) suggests a roadmap to recurring BVLOS approvals rather than ad hoc waivers. - Vertical integration around environmental intelligence
The platform’s integration of multispectral/thermal/LiDAR sensors and on board processing has been applied to Nordic forestry (early bark beetle detection, single tree analytics), power line and industrial monitoring, areas where endurance and low noise operations enable time series change detection at scale. This is not just a vehicle story; it’s a service and analytics play aligned with Nordic priorities: forestry health, biodiversity, grid reliability, and heavy industry stewardship.
What’s defensible vs. competitors?
Multirotor incumbents (DJI, Skydio) dominate with autonomy and mature payload ecosystems, but they can’t match 12 hour persistence without tethering or hybrid engines. Hybrid multicopters like Skyfront do challenge Kelluu’s endurance and payload flexibility, reaching 5–13 hours, but still expend power to hover and tend to be noisier and fuel dependent, trade offs in environmental missions and over sensitive assets.
Fixed wing/VTOL survey craft (Wingtra, Quantum Systems) deliver efficient coverage and survey grade photogrammetry, yet typical sorties remain sub 2 hours. In that context, Kelluu’s “satellite constellation under the clouds” proposition, continuous, low altitude coverage with high overlap, has merit.
Evidence of traction vs. hype?
The Terrafame deployment provides a concrete industrial use case; the DIANA Phase 2 selection and participation in REPMUS/Task Force X point to defence validation under winter conditions. External trade and energy outlets also reported emissions claims (−99.5% vs. conventional aerial monitoring) and >12 hour sorties, though these remain vendor origin statements amplified by media, so independent LCA or peer reviewed endurance data would strengthen credibility. Funding signals are modest (seed + DIANA accelerator support; ERDF €930k for Arctic authority integration), consistent with a capital efficient, small airship strategy rather than a moon shot.
Risks and unanswered questions.
Regulatory throughput: Achieving LUC is non trivial; Nordic BVLOS authorisations still hinge on each CONOPS, detect and avoid stack, continuity of C2, and airspace deconfliction.
Weather and wind envelopes: Airships are efficient but sail area sensitive; consistent operations in gusty coastal Nordics or mountainous Norway need published wind/icing envelopes beyond anecdotal “−30 °C capable.
”Lifting gas supply chain: The site highlights hydrogen power, but does not detail the lifting gas used for buoyancy and its logistics; helium scarcity/price volatility vs. hydrogen safety envelopes are material operational risks that need transparent documentation. (Kelluu’s public pages don’t specify the lift gas; third party coverage often focuses on hydrogen power, not the envelope gas.)
Scale and economics: Claiming the “world’s largest airship fleet” is eye catching; quantifying fleet size, utilisation, and cost per mapped km² against helicopter contracts and drone programmes would test the economic moat.
Competition’s catch up: Hybrid multicopters are pushing 5–13h endurance with higher payloads, and tethered drones can achieve persistence for fixed sites, nibbling at segments Kelluu targets.
For Nordic defence, grid and forestry stakeholders, Kelluu’s blend of long endurance, low altitude, high resolution monitoring, validated in live industrial and NATO contexts, amounts to a real, if narrow, innovation: not a radical airframe breakthrough, but a coherent system that exploits buoyancy physics, Arctic hardening, and BVLOS workflows to deliver persistent data with lower environmental impact. The burden of proof now lies in scaling authorisations (LUC), publishing independent endurance/availability metrics, and disclosing lift gas logistics to answer operational risks.
Fact box — Kelluu at a glance
• What it is: Small, autonomous hydrogen powered airships (for propulsion) that float via lifting gas; 12 hour sorties; centimetre level mapping; service model spanning sensors to analytics.
• Use cases in Nordics: Digital twins and safety monitoring at Terrafame (Finland); forestry single tree analytics in Sundsvall pilots (Sweden); defence ISR experiments (Finland/DIANA).
• Key tech claims: Arctic operation (to −30 °C), GNSS denied resilience, 5G/SATCOM backbone, multi sensor payloads (e.g., AgEagle RedEdge P), time series change detection.
• Regulatory trajectory: ERDF funded push toward EASA LUC; BVLOS under ‘specific’ category/SORA.
• Comparative edge: Persistence vs. drones/helicopters; resolution vs. satellites; low noise and lower emissions.
• Open questions: Lift gas type/logistics, wind/icing performance envelopes, fleet size/utilisation economics.
References
AgEagle / Environmental Press Finland. (2023, August 23). Kelluu unmanned airships equipped with AgEagle’s RedEdge P multispectral sensors… [environmen…inland.com]
Aerospace Global News. (2025). Kelluu airships offer “satellite constellation under the clouds”. [aerospaceg…alnews.com]
Business Insider. (2025, December 2). Airship maker for NATO in Finland says Russia is helping by jamming. [businessinsider.com]
Daily Scandinavian. (2025, February 12). The world’s largest airship fleet – in Finland. [dailyscand…navian.com]
Defence Blog. (2025, September 1). Finnish hydrogen airship joins NATO exercise. [defence-blog.com]
EASA. (2020). NPA 2020 07: UAS beyond visual line of sight in the “specific” category. [easa.europa.eu]
Energy Reporters. (2025, September 13). “12 hours airborne using hydrogen power”: Finnish Kelluu airship… [energy-reporters.com]
EU CAP Network. (n.d.). Kelluu – an airship that collects extensive accurate information about forests… [eu-cap-net….europa.eu]
European Regional Development Fund / Kelluu. (2025, October 7). EU funds Kelluu’s project to strengthen Arctic security… [kelluu.com]
Kelluu. (2022, October 10). A new breeze to lift airship manufacturing. [kelluu.com]
Kelluu. (2023, October 10). Terrafame initiates operation of Kelluu’s autonomous airships… [kelluu.com]
Kelluu. (2024, June 6). Kelluu begins operations in Sweden! [kelluu.com]
Kelluu. (2025, December 12). Kelluu’s persistent autonomy awarded by NATO LANDCOM. [kelluu.com]
Kelluu. (n.d.). Home; Company; Platform overview (FAQ/claims). [kelluu.com], [kelluu.com]
NATO DIANA. (2025, November 20). Kelluu: Hydrogen powered airships delivering security and infrastructure intelligence. [diana.nato.int]
SingleTree (EU project). (2025, November 19). Kelluu advances single tree monitoring in Sundsvall, Sweden. [singletree.eu]
Skyfront. (n.d.). Leaders in long endurance hybrid drones (Perimeter series specs). [skyfront.com]
Tracxn / CB Insights / PitchBook. (2024–2026). Kelluu company and funding profiles. [tracxn.com], [cbinsights.com], [pitchbook.com]
Traficom event deck (Kelluu). (n.d.). Net zero persistent aerial inspection and surveillance. [traficom.fi]
Photo: Kelluu’s Persistent Autonomy awarded by NATO LANDCOM
