Thales Alenia Space is to take a “minority stake” in Airstar Aerospace, a company with know-how in balloon envelopes, in a bid to advance its Stratobus telecommunications airship project.

Grenoble, France-based Airstar in 2015 acquired a division of Zodiac Marine and has thus benefited from decades of experience in those stratospheric balloons that are used as probes for high-atmosphere research. It therefore has expertise in how materials behave at such altitudes and how to manage internal gas, says Thales Alenia Space. It will provide Thales Alenia Space with “paper-sheet-thin fabric that is able to carry more than 10 metric tons [22,00 lb.],” Airstar Aerospace CEO Romain Chabert adds.

Thales Alenia Space, otherwise a satellite manufacturer, believes airships have a sweet spot for some applications that they can effectively address at lower cost. A payload on a Stratobus flying at 12.4-mi. (20-km) altitude could thus provide broadband internet over a small-surface area. It could be well suited to upcoming 5G mobile communications, as a lower-altitude—compared to a geostationary satellite’s 19,900 mi.—provides shorter latency. Another mission could be surveillance over a given location, such as a war theater. A satellite could relay images to a government in a distant capital city.

The Stratobus is designed to be unmanned and would be controlled from a ground station or a satellite. The main challenge is for the airship to remain geostationary, to have powerful motors against the wind. The Stratobus’ first version will gather power via photovoltaic cells featuring a 21% efficiency thanks to ongoing progress in the technology. During daytime, electric current will simultaneously be used by electric motors and a water electrolysis process. The hydrogen and oxygen it will generate will feed a fuel cell. In turn, the fuel cell will supply electric power at night.

Thanks to its electric motors, the Stratobus will be able to remain immobile, relative to the ground, against a 50-kt. wind. Depending on actual wind speed, 5-8 kW will be available for the payload. Winds are stronger than 50 kt. only a few days per year between the tropics, and the area would thus be the most suitable to Stratobus operations, says Jean-Philippe Chessel, Stratobus product line manager. He foresees a market of a dozen Stratobuses per year for observation and surveillance. For telecommunications, sales could amount to hundreds per year, he asserts.

A critical design review is scheduled for late next year. A prototype is slated to fly late in late 2020 or early 2021, at least one year later than planned when the project was unveiled in 2014. A future version will feature solar concentrators to collect solar energy more efficiently.