Test of filament wound CFRP prototype for cryogenic propellant tank of space plane

National Space Development Agency of Japan (NASDA) is conducting a feasibility study of applying CFRP to the cryogenic propellant tank of a reusable vehicle system. As a part of the feasibility study, we are now conducting tests of small filament winding (FW) tanks with 300mm diameter to study the possibility of the filament winding method for manufacturing. The first phase test of a FW tank was conducted in 1999. We analyzed the weak points of the first FW tank and conducted the second phase tank test under the collaboration works with Italian Aerospace Research Centre (CIRA). The design and manufacturing processes of the second phase test were improved, and the first tank was completed with half surface of the cylinder good (healthy surface) and another half no good with large wrinkles produced in the curing process. Leakage occurred in the first pressurization test at 0.3MPa at room temperature along a large wrinkle. After the leak points were repaired, the tank was used for waterproof testing at 1.0MPa and 1.5MPa and the strain data was obtained. Finally, we conducted a pressurization test at liquid nitrogen (LN2) temperature at 1.5MPa, 1.9MPa, and 2.0MPa. The healthy surface of the tank cylinder remained healthy even at 1.9MPa and there were no leaks occurred. The first leak occurred at 2.0MPa in the healthy area at LN2 temperature. This is a promising result for the next series for realizing a perfect tank.