On Space Flight Pressure Vessel Fracture Control
SourcePressure vessels (PVs) are classified as fracture critical items in most space systems including the space shuttle, launch vehicles, and spacecraft. Fracture control requirements specified in MIL-STD-1522A are being implemented to the metallic PVs used in most of the space programs. However, requirements in “-1522A” are not applicable to composite overwrapped pressure vessels (COPVs), which are widely used in current space programs. A research, development, test, and evaluation (RDT&E) program is being conducted to generate database needed for establishing fracture control requirements for the COPVs. This paper provides an overview of the fracture control of the metallic PVs and reports important findings obtained from this RDT&E program. The important COPV findings include fatigue and fracture analysis methods used for the metallic liners, nondestructive evaluation techniques, and impact damage effects on the composite overwraps.