AALTO plans to launch several additional test flights of its ultra-long-endurance Zephyr from a new facility in Kenya this year, following a successful first sortie which spanned more than 13 days.
During the flight, which was launched from the facility in Kenya’s Laikipia County on 20 January, the aircraft demonstrated its utility as a high-altitude pseudo satellite (HAPS) while carrying a company-developed direct-to-device 4G/5G connectivity payload.
Work to prepare the remote site and secure required airworthiness approvals from the Kenyan authorities was completed last year, as the Airbus-owned company also performed a technology and industrial transfer activity, AALTO chief executive Hughes Boulnois tells FlightGlobal.
“Now we have this operating base which enables us to fly much more often, and at times of the year when nobody else in the HAPS community can fly,” he says. “That is really a critical differentiator for us.”
During the recent flight, the aircraft operated in the stratosphere to a maximum altitude of 74,000ft, but was intentionally brought down to 55,000-60,000ft several times to assess its manoeuvring characteristics.
“Last year we did a lot of tests in improving the stability and performance of the aircraft – the 13-day flight was really to confirm that all the improvements we have made on the platform and the system overall are working,” Boulnois says.
“We have also improved the flight envelope of the aircraft, which makes it much more resistant to turbulence.”
Also tested last year from Yuma, Arizona, the improvements include a new flight-control system, stabilisation mechanism and recovery mode.
“Now we have an aircraft that is extremely stable, even during take-off and landing,” he says. Its deployment has also been aided by a new launch vehicle named ELVIS. Required for operations from the high-altitude site in Kenya, AALTO says it results in a more reliable and robust process.
Boulnois – who took the lead role at AALTO last October, succeeding Samer Halawi – describes 2025 as to be a “transition phase” for the company, involving operational demonstrations.
“We are not flying for world records – it’s to demonstrate the full end-to-end capability for the benefit of the customers,” he says. “We will have a series of flights this year that will demonstrate that for commercial customers, and [connectivity provider] HAPS Japan in particular, but also for governmental customers.”
A next flight is expected to be launched from its Kenyan base “very soon”, with this to use a second aircraft.
“We are already hiring a local, Kenyan maintenance team, who are very highly skilled,” he adds. “In the second half of this year we have less people travelling there [from the UK] – we will be operating from Kenya with Kenyans.”
AALTO is required to have a pilot at the Kenyan site to monitor take-off, operations and landing, but Boulnois says that for flights when Zephyr exits Kenyan airspace control will be passed to its UK strategic operations centre in Farnborough, Hampshire.
AALTO will launch commercial services next year with the HAPS Japan venture, which also involves NTT Docomo and Space Compass.
“We will do a gradual entry into service, but we will also in 2026 start a first operational capability probably with some governmental customers,” he reveals.
“We are looking at customers who are daring and taking a risk and testing technologies to advance faster: governmental and military. The geopolitical aspect of the world we are living in is really pushing us to accelerate that path, because they see the value of Zephyr.
“The persistence of the aircraft in the stratosphere is really a game-changer compared to satellite-based imaging, or a classic UAV [unmanned air vehicle] that can do 24 hours of flight. We are really breaking that way of operating things,” he claims.
“We are currently having discussions with several customers, and they are very interested,” he says, while declining to provide further details.
Potential applications could include flying in support of national efforts to improve the early detection of forest fires, he says as an example.
While the longest stratospheric Zephyr flight to date lasted 64 days, Boulnois says the platform has a technical envelope which will enable it to remain airborne for 90 days. “Our target is 200 days of on-station capability,” he adds.
Coinciding with the recent test flight, a cyclone hit the Indian Ocean territory of Mayotte, prompting authorities to make use of SpaceX Starlink satellites to restore connectivity on the ground.
“We could have taken off from Kenya and been there in a few days, and delivered a very important service to the population [with Zephyr],” he says.
Meanwhile, Brigadier Hillary Kipkosgey, acting chief executive of the Kenya Space Agency, says the body is “committed to promoting adoption and use of enabling technologies that are innovative, secure and impactful”.
“HAPS is a unique capability with potential use cases that Kenya recognises as critical to many stakeholders,” Kipkosgey adds. “Through our support to AALTO, we are pleased to demonstrate Kenya’s global leadership in creating a new hub for near-space technology.”
Separately, AALTO also is continuing to conduct meteorological site surveys ahead of establishing future other launch and recovery sites to enhance its global presence, with Boulnois saying two locations are currently being assessed.
