Chapter 12 - Materials safety

Abstract

All flight hardware is fabricated from materials, and safe and reliable materials and materials processes are essential to safety in space. Materials safety covers a very wide range of material and process technical issues. Materials used in the fabrication and processing of flight hardware need to be selected by considering the worst-case operational requirements for the particular application and the design engineering properties of the candidate materials. For example, the operational requirements include, but are not limited to, operational temperature limits, loads, contamination, life expectancy, moisture or other fluid media exposure, and vehicle related induced and natural space environments. Other properties that need to be considered in material selection include mechanical properties, fracture toughness, corrosion, thermal and mechanical fatigue properties, glass transition temperature, coefficient of thermal expansion mismatch, vacuum offgassing, fluids compatibility, microbial resistance, moisture resistance, fretting, galling, susceptibility to electrostatic discharge, and contamination. Conditions that could contribute to deterioration of hardware while in service need to receive special consideration.