Sceye and SoftBank Complete Trans-Pacific Stratospheric HAPS Flight to Japan

Trans-Pacific Stratospheric Flight Achievement

In a landmark development for non-terrestrial telecommunications, aerospace and materials science company Sceye, together with Japanese telecommunications operator SoftBank Corp., has completed the first trans-Pacific flight of its Service Test Program ^[1][7]. The mission, designated as Service Test 1 (ST1), saw a High-Altitude Platform System (HAPS) travel over 15,000 kilometers across the Pacific Ocean from New Mexico to Japan ^[1][7]. Operating within the stratosphere, the mission validated mobile broadband connectivity to unmodified standard devices, backhauled traffic directly into SoftBank Corp.'s core network, and demonstrated integrated edge computing alongside aerial communications with drones ^[1][7].

The accomplishment represents Sceye's first flight to Asia and marks a significant milestone toward the commercial deployment and operational adoption of HAPS as stratospheric infrastructure ^[1][7]. By proving that a stratospheric platform can navigate intercontinental distances and maintain station over target territories, Sceye and SoftBank Corp. aim to establish an enduring layer of connectivity between ground-level infrastructure and space-based satellites ^[1][7].

Flight Profile and Technical Execution of ST1

The ST1 mission commenced on August 9, 2026, launching at 7:00 AM MDT from New Mexico ^[1][7]. Over the course of a 13-day trans-Pacific transit, the stratospheric platform covered more than 15,000 kilometers before successfully entering Japanese managed airspace ^[1][7]. Once stationed over Japan, the vehicle maintained continuous flight operations within Japanese airspace for more than seven days ^[1][7].

Station-keeping is a vital technical parameter for stratospheric telecommunications platforms, which must stay positioned over specific geographic footprints to deliver stable service ^[1][7]. During its extended period in Japanese airspace, ST1 demonstrated navigational stability, achieving a station-seeking radius as low as 5 kilometers while operating at stratospheric altitudes ^[1][7]. This precision confirmed the platform's ability to maintain a persistent operational area over target locations across consecutive day and night cycles ^[1][7].

Direct-to-Device Broadband and the SceyeCELL Payload

A primary payload aboard the ST1 mission was the SceyeCELL, an advanced stratospheric communications system designed to act as a cell tower in the sky ^[1][7]. The SceyeCELL payload was developed to deliver wide-area mobile broadband connectivity directly to standard, unmodified consumer devices without requiring specialized user terminals or satellite ground dishes ^[1][7].

During the operational demonstration over Japan, Sceye and SoftBank Corp. validated a comprehensive suite of telecommunications services routed through SoftBank's core network ^[1][7]. The system successfully delivered text messaging, real-time voice calls, standard internet access, and continuous video streaming directly to commercial smartphones ^[1][7]. In addition to standard commercial consumer applications, the test program validated mission-critical emergency services, successfully executing emergency calls and transmitting alerts via an emergency messaging system structured for large-scale disasters ^[1][7].

Furthermore, the ST1 platform carried out edge computing workloads and verified communications links with aerial drones, proving the feasibility of high-altitude systems coordinating seamlessly with other airborne vehicles ^[1][7]. When deployed at full commercial scale, a single Sceye HAPS unit is designed to cover an area equivalent to approximately 500 ground-based terrestrial cell towers, offering an expansive communications umbrella from a single aerial node ^[1][7].

Advantages of Stratospheric Architecture

The operational success of ST1 underscores the strategic advantages of the stratosphere as an infrastructure domain for next-generation networks ^[1][7]. Operating in the stratosphere allows platforms to occupy an optimal vantage point that bridges the physical gap between terrestrial masts and orbital spacecraft ^[1][7]. The altitude is sufficiently high to provide wide-area coverage spanning extensive regions, yet close enough to Earth to maintain low-latency, high-capacity broadband links directly with standard consumer hardware ^[1][7].

Sceye's platforms are engineered to maintain their altitude and designated operating area through consecutive day and night cycles, effectively functioning similarly to geostationary satellites ^[1][7]. However, because they operate in the stratosphere, they fly roughly 1,800 times closer to the Earth's surface than geostationary satellites while avoiding the significant launch expenses and orbital complexities of space missions ^[1][7]. This proximity and persistence offer space-like vantage capabilities at a fraction of the cost ^[1][7].

Strategic Partnership, Investment, and Future 6G Networks

The demonstration in Japan builds directly upon a strategic investment made by SoftBank Corp. in Sceye in 2025 ^[1][7]. SoftBank Corp., a leading operator of telecommunications and IT businesses in Japan and globally, invested in Sceye's HAPS-based infrastructure to build scalable non-terrestrial solutions that complement traditional terrestrial base stations and satellite constellations ^[1][7].

According to Mikkel Vestergaard Frandsen, Founder and Chief Executive Officer of Sceye, the trans-Pacific flight represents a defining moment for the commercialization of HAPS ^[1][7]. He highlighted that flying more than 15,000 kilometers from the United States to Japan demonstrates the platform performance necessary to establish the stratosphere as a viable infrastructure tier for artificial intelligence, edge computing, and emerging 6G standards ^[1][7].

Together, Sceye and SoftBank Corp. are progressing beyond isolated technology demonstrations toward real-world commercial network integration ^[1][7]. Both entities share an overarching roadmap for Non-Terrestrial Networks (NTN), viewing HAPS as transformative infrastructure capable of expanding digital coverage, delivering resilient emergency backup during catastrophic natural disasters, and expanding network architectures into unified three-dimensional communication fabrics encompassing ground, air, and space ^[1][7].

Sources

1. Sceye and SoftBank Corp. Complete Stratospheric Connectivity Demonstration in Japan, Advancing Towards HAPS Commercialization www.prnewswire.co.uk
2. Sceye and SoftBank Corp. Complete Stratospheric Connectivity Demonstration in Japan, Advancing Towar www.ad-hoc-news.de