An European Space Agency Perspective On Advanced Metallic Materials and Manufacturing Processes

The majority of materials used in spacecraft structure and mechanical devices, propulsion systems and launchers manufacture are normally selected from known and well proven aircraft applications. However, the advancement in space technology has been made possible by many specific breakthroughs in metallurgy and metallurgical processing, facilitating the development of highly sophisticated space systems. In the present paper a detail review of current research and development programme performed at the European Space Agency (ESA) in the field of metallic materials, coating systems and manufacturing processes is presented. It covers application ranging from large launchers primary structures, spacecraft elements as well as materials for electronic applications. In particular, the use of Friction Stir Welding (FSW) for manufacturing launcher metallic stages and cryogenic tanks is presented. Space hardware developments performed within the last decade have highlighted the significant potentialities of Additive Manufacturing (AM) including the reduction of the of space missions environmental impact. Mass saving by more than 50 % is often obtained, and up to 95% has been possible for one selected part. Additive Manufacturing (AM) technologies are extensively exploited on conventional and non-conventional metals, polymers, ceramics and geopolymers (lunar regolith), ranging from few grams up to few tons of material: applications on satellites and launchers structures, radio frequency harness and components, mechanisms, propulsion and thermal management applications are addressed. Materials for near Sun missions heat-shields as well as black/white coatings for heat shielding applications as well as crushable materials for probes are presented. Finally, restrictions imposed by environmental regulations in Europe have as an immediate implication for space programme the possible disruption of qualified materials and processes. In order to satisfy stringent environmental International Regulation, ESA has taken the lead in exploring and qualifying for space use Hexavalent chromium free corrosion protection coatings as well as lead free electronic assemblies materials.