- Stratospheric internet uses HAPS platforms at almost 20 km altitude to provide low-latency connectivity directly to conventional mobile phones.
- Projects like Zephyr (Aalto HAPS) and Sceye's airships seek to overcome Loon's shortcomings with maneuverable aircraft and autonomy of weeks.
- These solutions aim to reduce the digital divide in remote areas and compete in cost and capacity with satellite constellations like Starlink.
The so-called stratospheric internet has ceased to be a futuristic concept and has become one of the hottest fields in the telecommunications industry. While the world is focused on satellite constellations like Starlink and OneWeb, a group of companies is making a strong push to bring connectivity to the upper atmosphere using aircraft and airships capable of hovering almost 20 kilometers above the ground.
This new technological wave has a very clear objective: to connect the 2.200 billion people who still have very limited or no internet access because they live in rural areas, remote islands, or regions where deploying fiber optic cables or cell towers is not cost-effective. And, in doing so, it aims to compete with satellite internet by offering a lower-latency, more flexible, and, on paper, cheaper-to-maintain alternative.
What exactly is stratospheric internet?
When we talk about stratospheric internet, we're referring to the use of high-altitude platforms (HAPS) , that is, unmanned aircraft, solar-powered drones, or airships that fly in the stratosphere, typically between 18 and 21 kilometers above the Earth's surface. From this position, they function like cell towers in the sky , covering vast areas with data and voice signals.
The main difference compared to satellites is that these platforms are much closer to Earth . This allows for reduced signal delay (latency), which is crucial for uses requiring a fast response, such as video calls, online gaming, or critical applications in emergencies. Furthermore, they can send the signal directly to standard mobile phones , without the need for satellite dishes or special equipment in each home.
According to the specialized magazine MIT Technology Review, the potential of these HAPS (High Altitude Platforms) is enormous for bringing connectivity to remote and sparsely populated regions where the population is so low that building terrestrial infrastructure is not cost-effective. We're talking about small islands, mountain villages, desert areas, or forests where erecting towers or laying fiber optic cable is a real logistical and economic headache.
All of this arises in a context where, despite the existence of nearly 10.000 active Starlink satellites and some 650 OneWeb satellites , robust coverage is still not guaranteed across large areas of the planet. In other words, the promise of global satellite internet still has significant gaps, and that's where stratospheric internet aims to make a strong impact.
The precedent of Loon, Google's balloon project
Before this new generation of platforms, one of the best-known attempts was Loon, Google X's project . Launched in 2011, its idea was to create a network of high-altitude balloons in the stratosphere to act as a floating telecommunications network. The balloons were positioned at high altitudes and were theoretically meant to remain over specific areas to provide internet service.
On paper it sounded great, but in practice they ran into a basic physics problem: the balloons were completely dependent on wind currents . Although the system could change altitude to take advantage of winds from different directions, it was very difficult to keep a balloon exactly where it was needed for long periods of time.
This unpredictability necessitated a massive fleet of balloons in the air to ensure that at least some were within the service area, which drove up costs. As the project progressed, it became clear that the model was economically unviable . After years of testing, Google finally shut down Loon in 2021.
Despite that setback, the idea of harnessing the stratosphere to provide connectivity didn't die. Meanwhile, other companies had been working for some time on more controllable HAPS (High Altitude Platforms), with designs very different from balloons: maneuverable airships and fixed-wing drones powered by solar energy or hydrogen. The key was to create a platform that could remain almost stationary over a point, without relying on the wind.
Today, companies like Aalto HAPS or Sceye claim to have solved precisely that weak point that sank Loon, combining more efficient aerodynamics , intelligent avionics and propulsion systems capable of "pointing against the wind" to compensate for gusts and anchoring themselves, in practice, over a specific service area.
The key selling point of this new wave of projects is their ability to remain airborne for weeks or even months , operating as true floating antennas. We're no longer talking about simple prototypes: some platforms have broken significant records, demonstrating that the technology is maturing.
One of the most talked-about names is Aalto HAPS , a spin-off company from the European aerospace giant Airbus. Its flagship project is Zephyr , an ultralight, solar-powered drone with a wingspan of about 25 meters . This vehicle has been accumulating increasingly longer test flights, reaching a remarkable milestone: 67 consecutive days in the air in April 2025, a record within the HAPS sector.
From a technical standpoint, Zephyr is designed to fly in the stratosphere and act as a mobile phone tower suspended high above the ground. According to Pierre-Antoine Aubourg, Chief Technology Officer of Aalto HAPS, the idea is to integrate it into commercial mobile operator networks so that it becomes, for all intents and purposes, another cell within the network, only floating at an altitude of almost 20 kilometers.
The first significant commercial trials of Zephyr will take place in southern Japan , in collaboration with mobile operator NTT DOCOMO and satellite telecommunications company Space Compass. Japan's geography has made it an ideal testing ground: it has some 430 inhabited islands , many of them mountainous, remote, and with relatively small populations, which greatly complicates the deployment of traditional infrastructure.
In these Japanese trials, Zephyr will broadcast high-speed 5G connectivity directly to standard smartphones, without requiring any special installation from the user. The frequency and the way it's integrated into the network will make the transition from a ground cell to the stratospheric platform virtually imperceptible to someone on the ground.
Stratospheric airships and new HAPS designs
Besides fixed-wing drones like Zephyr, another area of significant interest in this sector is stratospheric airships . This is where Sceye comes in, a company based in New Mexico (USA) that has developed a large aerostat, approximately 65 meters long, pressurized and powered by solar energy and helium.
Sceye founder and CEO Mikkel Frandsen maintains that his company has achieved what Loon could not, thanks to a combination of the airship's controllable shape , advanced avionics, and next-generation batteries. These batteries power an electric fan that allows the airship to "steer upwind," meaning it can counteract the wind currents and maintain its position over the desired area.
This design offers an added advantage: the airship's large surface area allows for the integration of solar panels and high-capacity batteries , as well as a payload capacity of over 250 kilograms. This enables the platform to maintain the necessary energy throughout day-night cycles and remain stable in both altitude and position, crucial for continuous service.
Sceye also has its sights set on Japan for its first pre-commercial trials of stratospheric connectivity. The company has partnered with SoftBank, one of Japan's telecommunications giants, which sees HAPS as a way to take its networks "to the next level" and cover rural or island areas that currently remain in the digital limbo.
Meanwhile, other major players are making moves. London-based World Mobile has acquired Stratospheric Platforms and is working on a hydrogen-powered stratospheric UAV equipped with a phased-array antenna capable, according to its plans, of delivering up to 200 Mbps to some 500.000 simultaneous users over an area of about 15.000 km², roughly equivalent to the coverage of more than 500 traditional cell phone towers.
Advantages over satellite internet and terrestrial infrastructure
The interest in stratospheric internet isn't just about the spectacle of seeing airships and drones high in the sky. The main motivation is economic and operational: to make connectivity profitable in areas where it isn't currently and to complement existing networks more flexibly.
One of the common criticisms of satellite internet, even advanced systems like Starlink, is that bandwidth is diluted when many users are concentrated in the same area. Because the satellites are in low Earth orbit, their "coverage cone" is very wide, like the beam of a flashlight: great for areas with dispersed users, but problematic when customer density increases.
There are very clear examples: in conflict zones, such as the battlefront in Ukraine, Starlink performance has been reported to drop from peak speeds of 220 Mbps to as low as 10 Mbps when usage spikes , for example, with many drones and ground robots connected simultaneously. In Indonesia, an island nation with a geography similar in some ways to Japan, some users have also reported a loss of speed as their subscriptions increased.
Frandsen goes so far as to say that Starlink's optimal performance begins to suffer when the density exceeds approximately one user per square kilometer , something that can happen even in island communities which, while not enormous, concentrate hundreds or thousands of people in a small area. This limitation leads operators to seek alternatives for certain regions.
HAPS, on the other hand, can hover over a specific region and adjust the number of platforms according to actual demand, without needing to deploy entire constellations for a single country or area. As Aubourg summarizes, if coverage is needed in a specific area, a single stratospheric aircraft is sufficient; if more capacity is required, more aircraft are added, but in a much more granular way.
Costs, business models and market potential
A key point in this story is how much this type of connectivity will actually cost compared to the alternatives. Currently, satellite internet remains prohibitively expensive for many users in developing countries. Starlink's rates start at around $10 a month in some parts of Africa, but millions of people in those countries live on barely $2 a day, so the service simply isn't cost-effective for them.
Companies like Aalto HAPS and Sceye argue that their platforms can reduce deployment costs per user compared to satellites and ground-based infrastructure in remote areas. By covering large regions with fewer aircraft and without the need to install thousands of towers, both initial investment and maintenance costs are reduced, which, in theory, should translate into lower prices for the end user.
World Mobile, for its part, has put very specific figures on the table. According to Richard Deakin, head of its stratospheric division, nine Stratomast platforms would be enough to provide high-speed service to Scotland's 5,5 million inhabitants at a total cost of approximately 40 million pounds per year. In everyday terms, that would be equivalent to about 60 pence per person per month , well below current Starlink subscription fees in the UK, which are around 75 pounds per month.
Even so, industry analysts maintain a cautious stance. Studies such as those by Analysis Mason project that the HAPS market could reach around $1.900 billion by 2033, a modest figure compared to estimates for the satellite internet industry, which could reach around $33.440 billion by 2030. In other words, the satellite market will foreseeably be much larger, but HAPS aims to capture very specific and strategic niches.
It's worth remembering that HAPS technology isn't new in concept . It has been researched since the 1990s, almost in parallel with the development of mega-constellations of satellites. However, the drop in the cost of space launches and the massive investments of companies like SpaceX meant that stratospheric solutions were relegated to the back burner for a time. Now they are making a strong comeback thanks to improvements in materials, batteries, solar panels, and control systems.
Regulation, security, and applications beyond internet access
For stratospheric internet to become commonplace, having the technology ready isn't enough; regulators need to deem it viable and safe. In this regard, the U.S. Federal Aviation Administration (FAA) has begun to take action, publishing a roughly 50-page document that explores how to integrate a significant number of HAPS platforms into U.S. airspace.
This regulatory interest is not accidental. In the United States, there are still about 8 million unconnected households , around 4,5% of the population, according to data from the American Community Survey by the Census Bureau. For proponents of High-Speed Mobile Platforms (HAPS), these platforms can offer a cheaper and more flexible solution than deploying new fiber networks or continuing to expand traditional mobile infrastructure.
In addition to internet access, stratospheric platforms have a range of other very promising applications . Governments and security forces can use them for border surveillance, maritime or air traffic control, reconnaissance missions, and emergency communications in natural disasters or armed conflicts, where ground-based infrastructure may be destroyed or rendered unusable.
In the field of civil protection and the environment, HAPS serve as observation and remote sensing platforms : early detection of forest fires, weather monitoring, emissions monitoring, and control of pollutant spills. Their ability to remain over the same region for extended periods makes them an ideal tool for these types of prolonged tasks.
They are also beginning to explore more exotic commercial possibilities, such as stratospheric tourist airships to take passengers to the "edge of space" and offer high-altitude flight experiences. These same platforms could transport scientific or technological payloads and serve as testbeds for new sensors, cameras, or communication systems.
NASSAT and connectivity solutions for HAPS
Alongside the development of aircraft and airships, specific communications solutions are being created to allow these platforms to integrate seamlessly with satellite and terrestrial networks. One example is NASSAT, which is working on advanced connectivity systems designed to operate along the Satellite/Stratosphere/Earth axis and provide robust links at high altitudes.
NASSAT's solutions include flat electronic antennas with no moving parts , featuring electronic beam steering, automatic signal acquisition, and dynamic polarization switching. These antennas are designed to support rapid switching between different HTS and VHTS satellites, maintaining latency of less than approximately 35 milliseconds, even under demanding conditions.
In the stratospheric to ground-level segment, these proposals combine technologies such as massive MIMO and 3D beamforming , with the option to operate in bands like the S-band to improve robustness against interference and adverse atmospheric conditions. All of this relies on advanced materials such as aerogel, Kapton, Teflon, and carbon fiber, as well as thermal control systems capable of maintaining internal temperatures around 25 °C when external temperatures reach -70 °C.
Beyond the purely technical aspects, NASSAT emphasizes that many HAPS projects still lack comprehensive communications solutions and that there is a significant opportunity for companies that can offer complete packages, from the antenna to integration with operator networks and public agencies. For this reason, it collaborates with both government entities and private companies and aerospace consortia.
If all these pieces fall into place, stratospheric internet is well-positioned to become a true complement to satellite and terrestrial networks , especially in rural, island, or disaster-stricken areas where deploying traditional antennas is slow, expensive, or impractical. What happens in the coming years in Japan, Indonesia, Scotland, or parts of Africa will be crucial in determining the extent to which these platforms can deliver on their promise of truly bridging the digital divide and competing head-to-head with giants like Starlink.
