Aalto’s Zephyr returns after stratospheric flight over Kenya

One of the company’s Zephyr solar-powered stratospheric aircraft made a 13-day flight from the company’s so-called Aaltoport in Laikipia County, Kenya, during January.

The flight was the highest and longest unrefueled flight over Africa yet and allowed the company to begin using its Elvis powered vehicle to launch the aircraft, a process that has traditionally been done by hand. 

According to Aalto, the aircraft flew more than 13 days over 60,000 ft. in Kenyan airspace, testing what the company calls a direct-to-device payload allowing devices such cell phones the ability to receive 4G/5G connectivity when in remote areas away from static masts. 

Companies increasingly see Zephyr as a flying cell tower enabling the expansion of mobile network coverage in remote areas where building traditional cell phone masts would be prohibitively expensive. Aalto claims Zephyr can deliver low-latency, high-bandwidth cell phone communications directly to handsets, obviating the need for and cost of building and renting land for dozens or even hundreds of expensive cell towers, depending on the terrain, augmenting existing cell phone networks. 

The flight not only allowed Aalto to test the payload and characterise the performance of the connectivity system, but the company also validated improvements to Zephyr’s flight envelope to provide more stability and better performance.

“Zephyr’s return to stratospheric testing and operations is an important step in its commercial roadmap,” said Aalto CEO Hughes Boulnois. 

“For many years, we have worked with strategic partners on promoting technological innovation and opportunities across connectivity and Earth-observation markets," Boulnois said. "Now, thanks to the strategic vision of Kenyan regulators, we are one step closer to commercialising the stratosphere."

The site in Kenya is the first of a planned five to six locations around the world where Aalto hopes to operate its Aaltoports. The ports— where the Zephyrs can be assembled, launched and recovered—must be situated in areas where weather conditions are generally calm and favourable. 

Having multiple Aaltoports would mean the company could have access to the stratosphere on any given day, so if the weather were to be poor at one site, Zephyrs could be launched and ferried to another.