To determine the cause of failure of the GIGA IV flight one of the items we never knew for sure was tested. A casing was machined from the same batch of aluminium tube as flown in the GIGA IV flight. Two forward closures were installed and the casing was filled with water. A hydraulic hand pump was used to increase the pressure and the casing was tested to destruction.

Finally we do not only have a calculated maximum casing pressure but also a real life test:

• Calculated design burst pressure: 162bar.
• Real life burst pressure: 173bar or 2500psi.

Conclusion: the design of the retaining bolts has been validated and proved not to be the weakest point. In fact, the casing itself by material choice and wall thickness proved to be the weakest point. However, this test proved the casing design is meeting or exceeding all its design criteria.