Japanese space startup AstroX (based in Fukushima Prefecture) announced at a Tokyo press event on May 26 that it plans to launch a balloon roughly 100 meters in diameter to an altitude of 20–25 kilometers in the stratosphere as early as December this year. From this balloon, the company intends to fire its domestically developed “FOX2” rocket into space, aiming to reach the 100-kilometer altitude mark where outer space begins. According to CEO Shota Oda, success would make AstroX the world’s first private enterprise to successfully launch a rocket using a balloon as a launch platform.
Approximately 5 meters long, the FOX2 rocket uses solid synthetic resin fuel, which ensures relatively high safety standards. For its inaugural flight, it will carry infrasound detection sensors developed by Kochi Institute of Technology; these sensors detect low-frequency sound waves imperceptible to human ears. Prior to the main launch, AstroX plans to conduct preliminary tests involving balloon launches and combustion experiments in the stratosphere before December.
Compared to ground-based launches, balloon-assisted launches eliminate the need to build dedicated launch facilities, thereby significantly cutting down research, development, and operational costs. AstroX estimates that if it manages to conduct 50 launches annually, each launch would cost roughly 500 million yen (about $3.4 million). The company aims to place small satellites into orbit by fiscal year 2029 and expects to begin commercial operations thereafter. While teams such as US-based JP Aerospace have previously explored similar balloon-launch methods, no commercial implementation has yet been achieved. Consequently, whether AstroX succeeds in completing these crucial verification steps by year-end remains a key point of interest for industry observers.