The H-IIA rocket is used to launch satellites developed by the National Space Development Agency of Japan (NASDA) and was the first to be developed primarily with Japanese technology. YKK® fasteners are used to connect sections of the rocket known as the thermal curtains.
Thermal curtains, which were originally connected using cords, are used to protect vital equipment from the extreme heat emitted by the rocket.
However, the use of fasteners was considered as an alternative because cords were difficult to open and close during diagnostics and repairs.
As a result, special fireproof fasteners were adopted to connect these thermal curtains. The use of fasteners in rockets is what brought them into space.