US aerospace company Sceye completed testing of its HAPS platform — a High-Altitude Platform Station that doubles as a giant cell tower and an airborne data center. The aircraft covered nearly 30,000 km during the mission, flying from New Mexico to Japan and back. Throughout the trip, it provided mobile connectivity for Japanese carrier SoftBank’s network.
The mission, called Service Test 1 (ST1), launched on August 9, 2026. Just 13 days later, the platform reached Japan, where it ran a series of connectivity tests with SoftBank. On September 4, HAPS returned to US airspace, landing near Sceye’s headquarters in New Mexico the following day after final checks. It was the platform’s second test round — in the spring, a Sceye airship spent 12 days in the stratosphere with a base station on board.
The mission’s main goal was to test SceyeCELL, a full mobile base station. From the stratosphere, the platform delivered broadband connectivity directly to ordinary smartphones on SoftBank’s network, with no special equipment required. Sceye estimates a single platform could eventually replace roughly 500 ground-based cell towers.
The test marked another step in Sceye’s partnership with SoftBank, which invested in the stratospheric internet project last year.
Follow Mediasat on Google News: the latest in TV, telecom and tech
During the flight, engineers also tested emergency calls, a mass public alert system, and drone communications. Sceye sees such platforms as part of a future three-tier telecom network spanning ground stations, stratospheric platforms, and satellites. SoftBank has experimented with elevated base stations before — last year, the carrier tested 5G equipment mounted on an aircraft flying at three kilometers.
Another feature of the project was an onboard data center. The platform carried a server and mobile-network core components, processing some data directly in the stratosphere instead of sending it to remote cloud centers.
Average signal latency in this setup was 68 milliseconds. Moving the computing onto the platform itself cut response times by more than 40% compared with traditional cloud processing, according to Sceye and SoftBank. The companies call it the first successful experiment of its kind, with a mobile network core and web server running entirely on board a stratospheric platform.
Sceye views HAPS as a middle layer between cell towers and satellite constellations. Operating in the stratosphere puts the platform much closer to Earth than satellites, which lowers latency while covering a far larger area than a traditional ground base station.
