The New Age of Tiny Airships

The smallest blimps can do the jobs that conventional drones can’t. 

Two silver radio-controlled blimps race around a figure-eight course inside a hangar in southwest Germany. Held annually in the city of Friedrichshafen—the birthplace of the Zeppelin—the Airship Regatta attracts competitors from around the world, all eager to showcase their technical prowess in designing and piloting small, helium-filled blimps.

Friedrichshafen is also a place to do business.

Andreas Burkart is a scientist and serial entrepreneur who likes to work in niche applications. Three years ago, he was racing (and winning) at the regatta when he was approached by a scientist from the European Organization for Nuclear Research, which operates the world’s largest and most powerful particle accelerator, the Large Hadron Collider in Switzerland. The collider, he explained to Burkart, was facing a conundrum: Its sensors sit inside large underground caverns awash with high levels of radiation. If the sensors malfunction during a critical moment of an experiment, it’s too dangerous to send in a human to investigate. 

Initially, a remotely piloted vehicle seemed the ideal solution, but the collider’s scientists didn’t like the idea of a multirotor drone swooping through the confined underground chambers, where a single crash could cause millions of dollars’ worth of damage to the scientific equipment. 

But what if the drone was a balloon?

“This is why they were so interested in airships,” says Burkart, who was able to build a collider-compatible prototype within six weeks. “Now they’ve successfully flown the airship drone in the caverns, completely remotely on autopilot, and we are working on a bigger project with them.”

Burkart increasingly finds himself at the forefront of developments in the field of small lighter-than-air drones—colloquially known as “tiny blimps.” He has monetized his expertise by co-founding Windreiter, a company that pledges: “From fully integrated autonomous inspection systems to title-winning racing airships, we do it all!”

The broader public is starting to take notice of these often-ethereal lighter-than-air platforms. In 2023, footage of a shimmering silver mini-airship—built by Finnish startup Kelluu—flying over Helsinki caused a brief internet sensation, with users on Reddit doing their best to identify the floating object. “It’s really, really cool,” says Kelluu co-founder and CEO Janne Hietala. “But this is why our flights cause reports of UFO sightings.” 

Kelluu was founded in 2018 with the goal of revolutionizing aerial monitoring by using small, autonomous, hydrogen-fuel-cell-powered airships with long loiter time to gather high-resolution data for border security, environmental monitoring, and even urban planning. 

“Our first R&D center was a shed,” laughs Hietala. Nine years later, Kelluu flies the largest airship fleet in the world, and its drones can stay in the air for up to 12 hours. Last year, Kelluu was one of 75 companies chosen to join NATO’s Defence Innovation Accelerator for the North Atlantic program, an initiative to foster dual-use innovation across the alliance by focusing on advanced science, engineering, and design.

“Initially, everybody thought we were these village idiots,” says Hietala. “Now we have started to operate a lot, fly between cities, fly in the Finnish Arctic, and people have started to think, well, they might actually do it.”

That’s because small lighter-than-air drones offer several advantages over their heavier-than-air counterparts. Their small size enables them to navigate narrow and restricted areas inaccessible to larger drones. The small airships can pass through doors, hover over stairwells, and inspect machinery up close. By using buoyant gases, tiny blimps require very little power to stay airborne, extending their flight time significantly compared to conventional propeller-driven drones with the same payload and battery capacity. And, unlike conventional drones, blimps have smaller propulsion systems that produce less turbulence—crucial for applications that require minimal disruption to the surrounding air, such as gas-source detection and localization. The petite airships are also much quieter, making them well-suited for covert surveillance and wildlife monitoring. 

On top of that, the soft envelope and low-mass design of tiny blimps pose a significantly lower risk of injury or damage in the event of a collision compared to heavier-than-air drones with fast-spinning, exposed propellers. For instance, Hybrid Airplane Technologies GmbH—a German manufacturer of a lighter-than-air drone named H-Aero—found a novel indoor use of its product when it conducted 3D scans of a 14th century Polish church for future restoration efforts.

Small wonder then that tiny blimp startups are popping up in countries from the United States to France to South Africa—all of whom want to secure a market share of the rapidly growing $73 billion global drone industry and to use their small airships for, variously, advertising, broadcasting, environmental monitoring, search and rescue, and, of course, surveillance. 

“Ultimately, the development of the multirotor drone may have reached its limits,” says Burkart. “Conventional drones are super-advanced, with very nice cameras, good flight handling and so on, but they cannot cross the safety limits you need to operate over people, and they cannot cross the barrier of energy density for longer flight times because the technology is not there for better batteries. So, you need another type of drone in order to reach very safe flight or very long flight, and I think this is the niche where the airships are jumping in.”

Small wonders

The designers of lighter-than-air drones have faced considerable technical challenges in shrinking an airship by a factor of 10 or more—this is due to the laws of physics, particularly the square-cube law. As an airship’s size decreases, its volume (and thus its lift) drops much faster than its surface area (which determines drag), requiring a disproportionately higher thrust-to-weight ratio to achieve a reasonable speed. 

“This is why early airships have always been so large,” says Burkart. “We are working against the room by trying to make them as small as possible, and this causes a lot of problems, especially regarding weight.” 

The last giant rigid airship built in Friedrichshafen, in 1939, was a staggering 735 feet in length. The first large rigid airship to be built since then, LTA Research’s Pathfinder One, is still a whopping 408-feet-long, whereas the new airship drones range from nine feet for a racing drone to around 40 feet for a small airship and down to two feet for a nano-drone.

“It becomes a mass equation problem,” says Hietala. “How much energy storage and energy output can you have? How much drag? Smaller is better for that, but then how much payload can you have and how light do your structures need to be to have an operational equation for the airship? That’s a really difficult engineering challenge that we basically had to solve.”

“The large rigid airships of the early 1900s did find limited success, especially in the role of long-distance transportation,” says curator Thomas Paone, who oversees the lighter-than-air collection at the National Air and Space Museum. “But they faced two major obstacles that led to them falling out of favor. First, they were always susceptible to weather, as three of the four U.S. Navy-operated large rigid airships were lost due to heavy storms. Second, the use of hydrogen as a lifting gas, although inexpensive and more plentiful than helium, led to the very public destruction of the Hindenburg, which led to the public abandoning the technology.”

But somewhat ironically, observes Hietala, the use of hydrogen for fuel cells and as a lifting gas has become a key enabler for the success of small airships. Hydrogen fuel cells have a significantly higher energy-density by weight compared to conventional batteries, and hydrogen generates more lift than helium. 

“There is a real stigma to airships and hydrogen,” says Hietala. “But the concept of unmanned allows the use of hydrogen as a lifting gas. It comes from not one single innovation, but hundreds of small innovations needed to make this work.

“We created a new kind of pressurizer combined with a semi-rigid structure that removed the traditional ballonet,” adds Hietala, referring to the air-filled bag, or compartment, within an airship that controls buoyancy and maintains the shape of the envelope by adjusting the amount of contained air. “We simplified the design and made it lighter. It allowed the use of hydrogen as a lifting gas—safely. Combining this with lightweight PEM (proton exchange membrane) hydrogen fuel cells that were just maturing post-2020, and there you go.”

The high energy-density of hydrogen is what enables lighter-than-air drones to operate for hours—or even days. “The propulsion on an airship is not used to counter gravity, but you do need it to go against the wind, and its ability to do this will determine the availability of your platform, and even where you want to operate,” says Hietala. “In the past, airship drones have often been underpowered and have had limited availability because you can only fly them in nice weather. So, we wanted to get it right this time, and from early on, we tested different propulsion systems in high winds, strong gusts, turbulence, and even in the Finnish Arctic.”

What has made the small airship truly feasible, though, is the cornucopia of technology and materials that have emerged in other fields. “The 1990s and early 2000s were not in favor of lighter-than-air technology for the simple reason that everything was too heavy, robust,  and bulky,” says Alexander Mijatovic, who founded a Serbian lighter-than-air company, Aero Drum Limited, in 1999. “The main difference, that I painfully remember, was the information gathering process. Where and whom to ask about the materials for the envelope, how to develop the object into parts that can be joined together to get the desired shape, what electronics to use and where to get them. Without the internet, the data collection process was extremely slow and very often dead-end.”

And, back then, drones still used analog cameras—complicated systems that required servo focusing and servo film winding. “With the advent of digital cameras, the lighter-than-air technology started to transform and get rid of unnecessary kilos,” says Mijatovic.

The borrowed technology has also helped make airship drones more weather-resistant than their colossal predecessors, as well as their heaver-than-air counterparts. Unlike conventional drones that rely on visual and optical sensors, lighter-than-air drones can accommodate more robust sensor payloads, making them superior in seeing through poor conditions caused by precipitation and fog. 

“All this tech is helping to make airships smaller and more efficient,” says Hietala. “People were saying an outdoor airship that is smaller than 12 meters [39 feet] is impossible, but we have been flying successfully with a three-meter airship.”

Researcher Marco Pellegrino and his colleagues at the Technology Innovation Institute in the United Arab Emirates discovered the difficulties of designing a small airship drone—in his case, a nano-drone blimp—for the first time during a project undertaken when he was pursuing a master’s degree. One major drawback of nano-drones is their limited flight time. Batteries are usually heavy, and if designers add more batteries to a drone, it now requires more power for lift. The most efficient battery Pellegrino’s team could find had a flight duration of 12 minutes. Other batteries last far less.

“Our idea of the blimp was to have a platform that was to fly around people indoors, and that most of the power would be used for moving it, and not maintaining it at a certain altitude,” says Pellegrino. “In this way, it should achieve a much longer flight time.”

The first challenge for Pellegrino and his colleagues was the number of sensors they wanted to put on the device. The more they wanted to shrink the blimp, the less weight they could add, meaning they couldn’t include all the sensors they thought would be useful for making a reliable flight, such as a positioning system.

“The second [challenge] is the computational power,” says Pellegrino. “On a drone, you must run a lot of algorithms that calculate the position and calculate the stabilization. These are all very computer intensive, and the more refined you want this algorithm to be, the more power you need. If you shrink the drone too much, the battery won’t be big enough to power this.”

Their solution was to modify existing semi-commercial components for nano-drones—such as the circuit—and work through five iterations of the material for the envelope, so it was strong enough, but not too heavy that it added excess weight. They used open-source software to lower costs.

“Our idea was to have a device that was able to fly in all directions, while still being a blimp, and we managed it within its own limitations,” says Pellegrino. “It was a balloon—60 centimeters across.” This size is large compared to a heavier-than-air nano-drone, which is around 10 centimeters across, but 60 centimeters is still small enough to have all the features a conventional drone can have. The result was that Pellegrino’s blimp can fly reliably a lot longer, up to 30 minutes.

“One of the greatest things that we did was to run an AI on board the drone, which was able to avoid obstacles using a very, very, very small camera, and considering the limited power that we have on this platform, this is already a very good result,” says Pellegrino.

Reinventing the past

All airships face a common existential challenge that has hindered their development. Whereas conventional aircraft have been constantly improved since the Wright brothers took flight at Kitty Hawk in 1903, there was an extended break in the development of airships following the demise of the Hindenburg in 1937.

“A great deal of knowledge is now on a theoretical level,” says Burkart. “Today engineers may know the formulas, and know how to calculate them, but the people that worked with their hands to manufacture them, they don’t exist anymore. So we must recreate all the techniques or borrow them from other fields, and this is a big and very steep learning curve.”

But the small size of Kelluu’s and its rivals’ machines might explain why these airship drones appear to be succeeding while their much larger cousins are struggling to get airborne. It took around two years for LTA Research’s Pathfinder One rigid airship to go from its public rollout to its first flight (“Leviathans of the Air,” Fall 2023).

Hietala visited LTA Research at Moffett airfield in California a few months ago. “We met with the engineering team, and I think the unique thing we realized is that they need to develop basically all the same systems that we now have,” he says. “We’ve gone through everything in miniature size, but we’ve moved so much faster because we can do a small, easy to manufacture approach, and have had to solve a lot of problems with airships that they haven’t even found out yet because we operate in the real world, and they haven’t really done a great deal of flight training.”

Lighter-than-air drones have another advantage: Regulators like them. They fly slowly, float down like a balloon if their engines fail, and hit the ground softly because the envelope acts as a parachute. In fact, research suggests that small airship drones have 90 percent less risk of causing damage or injury compared to heavier-than-air drone rivals carrying similar payloads. 

As such, tiny airships fit within existing UAV regulations, and their safety profile explains why the European Union Aviation Safety Agency permits them to operate in all different airspaces and risk categories. The small blimps are even exempt from restrictions that forbid other types of drones from flying over urban areas. “We can operate on top of Munich if we want,” says Hietala

He envisions a not-so-distant future that sees 500 tiny blimps hovering in the skies above Europe, later expanding to a fleet of 3,500 flying over the entire Western world. Says Hietala: “Having a persistent autonomous flying infrastructure preventing disasters, optimizing the way we produce food, and generally improving our ability to sustain habitation here on Earth starts to make sense —and it’s very much doable.” 

Mark Piesing is an award-winning aviation journalist. He is the author of N-4 Down: The Hunt for the Arctic Airship Italia (Mariner Books, 2021).

This article, originally titled "Tiny Blimps, Big Ambitions," is from the Winter 2026 issue of Air & Space Quarterly, the National Air and Space Museum's signature magazine that explores topics in aviation and space, from the earliest moments of flight to today. Explore the full issue.

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