AstroX, a Fukushima-based space startup, has completed the second close of its Series A funding round, bringing the total amount raised to 2.32 billion yen ($15.6 million). The fresh capital will be deployed to accelerate the development of its high-altitude balloon launch system and to bolster its engineering workforce, with the aim of reaching outer space by the end of 2026.

Funding Details and Backers

The second close was executed through a third-party allocation of shares. New investors include One Capital and Inclusion Japan, alongside several angel investors. They join a roster of backers visible in the company’s disclosures, which includes ANRI (Alpha), Deepcore, Daiwa Corporate Investment, and major financial institutions such as SMBC and Mizuho Bank.

Shinji Asada, Co-Founder and CEO of One Capital, cited AstroX’s blend of strategic design and technical capability as a key driver for the investment. “The Rockoon method represents an extremely rational approach to linking technology with commercial viability in the shortest possible distance,” Asada stated.

The “Rockoon” Strategy

Founded in May 2022 by CEO Sho Oda, AstroX is attempting to revive “Japan as No. 1” in the space sector by solving a critical bottleneck: the lack of domestic launch capacity. While the global space industry is projected to exceed 160 trillion yen by 2040, nearly 100% of Japan’s small satellites are currently launched via foreign rockets.

AstroX utilizes the “Rockoon” method—a hybrid system where a rocket is lifted by a balloon to a high altitude before ignition. This approach aims to drastically reduce costs and enable high-frequency, responsive launches. The company targets a launch cost of under 500 million yen ($3.3 million) per flight, significantly lower than the current market average of 1.5 billion yen for small rockets.

Operational Milestones

The funding announcement follows a technical breakthrough in December 2025, when AstroX successfully tested its launcher mechanism. The experiment involved the aerial separation of a dummy rocket from the balloon platform’s launcher, a critical step in validating the flight hardware.

With the Series A financing secured, the company is now shifting focus to the practical application of the technology, specifically aiming for stratospheric launch and space domain entry within the year.

Japan Startup Observer

AstroX Closes Series A at ¥2.32 Billion to…