June 22, 2022

SoftBank ST Flex400x275SoftBank’s mobile carrier division has announced completion of the initial testing of Altaeros’ ST-Flex, an autonomous aerostat (tethered blimp). Operational and telecommunications tests were performed at Japan’s Hokkaido Spaceport in Taiki Town.

The two companies first launched the ST-Flex on May 2, and performed evaluation tests through May. ST-Flex carried SoftBank’s base station system, which included a proprietary cylindrical antenna that realizes communication area footprint fixation, to a height of 816 feet (249 meters). It was then connected to ground equipment via optical fiber and power conductors embedded in the tethers. The purpose of the test was to determine the autonomous technology to support a High Altitude Platform Station (HAPS) system.

“The newly developed high-altitude tethered aerostat base station was operable at higher altitudes and carried heavier communication payloads, and it also achieved wider area network coverage with greater communication stability during the trial,” SoftBank said.

The Aerostat Autopilot autonomous control system eliminates on-site crew for daily operations, the company said. During the test program, the ST-Flex operated in highly variable weather conditions, including gale-force wind. Three tether autonomous controls create stability in the aerostat and control pitch, roll and yaw to keep the aerostat steady, even in variable weather conditions. 

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“We are incredibly excited to have completed the first international launch of the ST-Flex,” said Ben Glass, CEO of Altaeros. “Successful testing of SoftBank’s Footprint Fixation Technology on the ST-Flex is a huge milestone, which will further the development and effectiveness of many aerial telecommunications platforms to help bring critical services around the world.”

Based on the results of the field trial, SoftBank said it will study ways to utilize the knowledge and data and apply it to telecommunication network disaster preparedness scenarios and the construction of HAPS-based telecommunication platforms.

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