Part 6/10:
As SpaceX strived to enhance the Raptor engine, they encountered significant challenges, chiefly the issues surrounding high temperatures and pressures. Raptor operates at a staggering pressure of around 300 bar (4,351 psi) in its combustion chamber and can reach even higher temperatures in its pre-burners. This necessitated the use of advanced materials, developed by SpaceX's metallurgy experts, to withstand the extreme conditions without melting.
In designing the Raptor, SpaceX had to innovate not just with materials but also with cooling techniques. They likely incorporated multiple methods, including active cooling using cryogenic liquids to keep the engine components at manageable temperatures and film cooling, which creates a protective barrier around critical areas of the engine.