During its journey, Sceye's ST1 traveled nearly 30,000 km and re-entered continental U.S. on September 4, 2026. ST1 reached airspace near Sceye's headquarters in Moriarty, New Mexico on September 5, 2026, where Sceye completed additional vehicle testing and a planned termination and descent.
"Groundbreaking and historic only begin to describe our ST1 flight," says Mikkel Vestergaard Frandsen, Founder and CEO of Sceye. "This mission proved not only that our technology, vehicle systems, payload, and operational infrastructure are ready for connectivity services, but also that the stratosphere is where the future non-terrestrial infrastructure lies. The stratosphere is what will enable the always-on future – including the promised land of 6G. Together ground, stratosphere, and space – each operating at their optimal strengths, will change the course of humanity."
Conducted in partnership with SoftBank Corp. (TOKYO: 9434, "SoftBank"), a leading operator of telecommunications and IT businesses in Japan and globally, ST1 marks Sceye's first flight to Asia and a groundbreaking milestone toward the commercial deployment of HAPS as stratospheric infrastructure. ST1 carried SceyeCELL, a first-of-its-kind "cell tower in the sky" designed to deliver wide-area mobile broadband directly to standard devices from the stratosphere. When deployed at full scale, one Sceye HAPS is designed to cover the equivalent area of approximately 500 terrestrial towers.
The stratosphere offers the optimal vantage point: It is close enough to Earth for high-capacity connectivity and observation, yet the altitude is high enough for wide-area reach. Importantly, the stratosphere offers space-like conditions without the cost of being in space and the disadvantages of being in orbit. Sceye's HAPS maintain altitude and their area of operation in the stratosphere through consecutive day and night cycles, operating like geostationary satellites, only 1,800 times closer to Earth and at a fraction of the cost.
Sceye's ST1 mission successfully:
- Traveled nearly 30,000 km from New Mexico to Japan and back to New Mexico over a month-long journey
- Operated within Japanese-managed airspace for over 7 days
- Remained continuously within its target location on the coast of Japan for an extended period, achieving a station-seeking radius as low as 5 km
- Operated between 16.5 and 17 km altitude while completing telecommunications, drone, and emergency communications
- Demonstrated mobile broadband from the stratosphere, including text messaging, voice calls, internet access, and video streaming
- Tested emergency calls, using an emergency alert messaging system designed for large-scale disasters, as well as communications with drones
- Confirmed communications performance equivalent to that of terrestrial networks while reducing radio interference with ground-based base stations
- Through a server installed on the HAPS, Sceye and SoftBank conducted data processing directly on the platform, demonstrating an average round-trip processing response time of 68 milliseconds, reducing communications latency by over 40% compared with internet-based cloud processing. This marks the world's first successful test in which a mobile core network and a web server for processing were installed on a HAPS, enabling response processing to be performed entirely onboard the HAPS and the results to be relayed back to smartphones.
ST1 is the first flight of Sceye's Service Test Program.
About Sceye
Founded in 2014, Sceye (pronounced "sky") is an aerospace company dedicated to advancing stratospheric infrastructure to connect people and protect the planet. Sceye leads the High-Altitude Platform Systems (HAPS) industry, focusing on universal connectivity, climate monitoring, natural resource management, and disaster prevention.
Contact: press@sceye.com
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