Is the stratosphere up for a gold rush?

When a Chinese balloon was shot down over the United States on February 4, a global diplomatic scandal ensued.

The US accused China of using the stratosphere – the area above 7 to 20 km altitude, depending on latitude – as a way to spy on the US. China responded with threats of its own, claiming the balloon was civilian and for meteorological purposes.

For Neal Unitt-Jones, however, thinking about stratospheric objects like the Chinese balloon is just an ordinary day at the office. “It was no surprise at all,” he said. “This technology has been around for a while. It’s just another utility in the stratosphere.”

In recent years, the space around the Earth has become increasingly crowded with satellites. Yet the higher regions of Earth’s atmosphere remain surprisingly untouched. However, a new generation of companies wants to change that. With large, unmanned aircraft, they want to broadcast 5G signals and monitor the Earth.

Unitt-Jones’ company, Cambridge-based Stratospheric Platforms, is one such company and plans to add another aircraft to the stratosphere — called a High-Altitude Pseudo Satellite, or HAPS.

If the vision of companies like Stratospheric Platforms becomes a reality, by the end of the decade the stratosphere may not only be filled with the occasional stray balloon, but also with unmanned, powered aircraft flying above regular air traffic. who can stay there for weeks or even months at a time.

Stratospheric Platforms has so far managed to raise more than $85 million in capital from German telecommunications company Deutsche Telekom and is in a fundraising round hoping to raise another $160 million. The idea is to use HAPS to provide telecommunications services from the stratosphere.

Aerospace giant Airbus has also been building a HAPS for years and plans to commercially launch its craft next year. Other major investors and aerospace players, such as SoftBank, BAE Systems and Boeing, are all testing HAPS designs or have made proposals.

“We see very interesting opportunities in this market,” said Hussain Bokhari, a senior analyst at research firm Northern Sky Research, which has conducted market studies for HAPS. It concluded in 2020 that by 2029, the market for stratospheric aircraft, including HAPS and balloons using high altitudes for services such as weather forecasting, would reach $4 billion in cumulative revenue.

It also predicted annual revenue growth of 13 percent over that period. “It will be exciting to see how the field develops,” said Bokhari.

Pseudo satellites

The company with the most advanced HAPS design is Airbus with its Zephyr. The aircraft has a wingspan of 25 meters (82 ft) and is powered by solar energy. During the day, solar panels charge the batteries that keep the plane flying at night.

In 2022, one of Airbus’ planes flew for 64 days in a row, after which it was lost. The Zephyr is currently going through the certification needed to make its commercial debut, which is expected to happen in late 2024.

“HAPS are like cell towers in the sky,” said Samer Halawi, CEO of AALTO HAPS, the Airbus spin-off dedicated to commercializing the Zephyr. “Signals broadcast from it can connect directly to your smartphone, which you can’t do from a satellite.”

HAPS will primarily be used in a manner similar to satellites. They can connect people and households on the ground, especially in poorly connected areas, or they can do Earth observation and gather information on things like economic flows or weather patterns. Military and national security applications are also being considered, such as espionage or border surveillance.

HAPS has been around for a long time, but so far most companies have failed to make the technology work in a commercially viable way. This is something Halawi knows very well. “When I first joined this company, someone gave me a picture of a 1945 HAPS design,” he said. “The idea is very old.”

However, according to Halawi, the technology has since changed and is approaching commercial readiness. Aircraft materials have become lighter, solar panels have been introduced and batteries are improving rapidly. “We are at the dawn of a completely new HAPS industry,” he said.

Whether HAPS will find real markets, however, remains to be seen. “HAPS needs to show real value,” Bokhari said. “The technology still needs to become more concrete and must show how it compares to existing options, such as satellites or ground infrastructure.”

However, according to proponents, HAPS has what it takes.

“Satellites fly higher, so cover larger areas. But that in turn entails downsides,” says Halawi. “Connections are better from the stratosphere. And we can take more detailed pictures when we fly lower. Moreover, we do not have to launch our HAPS into space, which saves costs.”

In addition, HAPS can operate alongside space, in some cases acting as an intermediate layer between satellites and ground links.

The hard networks

The provision of telecommunication services could be an important market for HAPS. For Stratospheric Platforms, the design could serve as the missing link for telecom networks in rural and remote areas where operators are reluctant to build expensive infrastructure for relatively small numbers of customers.

“The easy parts of terrestrial networks are now largely built,” says Unitt-Jones. “However, the hard parts can never be done.”

Stratospheric Platforms’ HAPS design is still in the concept stage and has not yet flown, unlike the Zephyr. The company hopes to fly its aircraft in the first half of 2025, with full commissioning in 2026.

The design also differs from that of the Zephyr. Stratospheric Platforms wants to power its vessels with hydrogen, not solar energy. This would mean less flight time, but could also allow for heavier equipment on the craft. The design would also be larger, with a wingspan of 60 meters (197 ft).

Regardless of the design, it remains to be seen whether the technology can actually achieve commercial success.

“This field has not had any significant investment yet,” said Bokhari. “There remains an element of insecurity. Investors are unsure whether to invest in space or HAPS. But at the same time, companies that think about space generally also think about HAPS. It really could be a booming new field.”

It is too early to say whether in a few years there will be hundreds or even thousands of unmanned aerial vehicles flying above us in the stratosphere, transmitting 5G signals. In any case, proponents are working hard to realize that.

“This is an opportunity,” said Unitt-Jones. “We don’t use the stratosphere as much as we could. And it is inevitable that someone will eventually.”