3. New structural technologies

3.1 The return of steel

Steel is making a remarkable comeback in the New Space sector, thanks to its intrinsic characteristics, which once again make it a suitable material for large-scale space applications. Its high mechanical strength enables it to withstand the loads and stresses inherent in launches and the extreme conditions of space. For example, high-grade stainless steel, such as type 304L or 316L, is used in the manufacture of rocket fuel tanks, providing the corrosion resistance and sealing essential for propellant storage. The emblematic example is SpaceX's Starship. It should be noted that this is really a return to basics, as the Saturn and Ariane 1-4 first stages already made extensive use of high-performance steels, not to mention solid rocket boosters.

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