Tokyo – September 07, 2026 -- Sceye's high-altitude platform system flew more than 15,000 km through the stratosphere from New Mexico to Japan in 13 days, marking the company's first flight to Asia and a milestone toward commercial deployment of stratospheric telecom infrastructure.
The Service Test 1 (ST1) mission launched August 9, 2026 at 7:00 a.m. Mountain Daylight Time from New Mexico and spent over seven days operating in airspace controlled by Japan, executed in partnership with SoftBank Corp. (Tokyo: 9434).
Platform delivers mobile broadband to unmodified devices via SoftBank's core network
Upon reaching Japanese airspace, ST1 demonstrated mobile broadband connectivity to standard devices through SoftBank's core network, including text messaging, voice calls, internet access and video streaming. The tests also covered emergency alert broadcasting for large-scale disaster scenarios and drone communications.
Onboard SceyeCELL module functions as a stratospheric cell tower
The mission carried the SceyeCELL module, described as a first-of-its-kind "cell tower in the sky" designed to deliver broadband mobile access directly to standard devices across wide areas. A single fully deployed Sceye HAPS platform is designed to cover territory equivalent to roughly 500 ground-based cell towers.
Onboard edge processing cuts data latency by more than 40%
Using a server installed on the HAPS platform, Sceye and SoftBank processed data directly onboard, achieving an average two-way data response time of 68 milliseconds -- more than a 40% latency reduction compared with cloud processing over the internet. The companies said it was the first successful global test in which a mobile core network and processing web server were installed on a HAPS platform, with request processing performed entirely onboard before results were relayed to smartphones.
Platform held position within a 5 km radius at 16.5 km altitude
The platform operated at approximately 16.5 km altitude, maintaining position within a 5 km radius over an extended period while simultaneously running telecom, drone and emergency communication tasks. Sceye said the platform confirmed connectivity performance comparable to ground networks while reducing radio interference for terrestrial base stations. As of publication, ST1 continued its return flight over the Pacific toward the United States.
SoftBank backed Sceye's HAPS infrastructure with 2025 investment
SoftBank Corp. invested in Sceye's stratospheric HAPS infrastructure in 2025, betting on the technology as a scalable complement to ground towers and satellite constellations. Sceye CEO Mikkel Vestergaard Frandsen said the New Mexico-to-Japan flight demonstrates the operational performance needed to turn the stratosphere into a full infrastructure layer for AI, edge computing and 6G.
SoftBank Corp. President and CEO Junichi Miyakawa said the mission marked Japan's first experimental stratospheric communication service in national airspace and a step toward commercializing HAPS as part of a three-dimensional network linking ground, sky and space.
Mission follows earlier 10,000km endurance flight to Brazil
ST1 builds on Sceye's Endurance Program completed earlier in 2026, in which the SE2 HAPS platform flew more than 10,000 km from New Mexico to the Brazilian coast and held position over a target zone for several days to test long-duration operations ahead of the Service Test Program.